51
|
Ozawa Y, Ohno Y, Nagata H, Tamokami K, Nishikimi K, Oshima Y, Hamabuchi N, Matsuyama T, Ueda T, Toyama H. Advances for Pulmonary Functional Imaging: Dual-Energy Computed Tomography for Pulmonary Functional Imaging. Diagnostics (Basel) 2023; 13:2295. [PMID: 37443688 DOI: 10.3390/diagnostics13132295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/01/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
Dual-energy computed tomography (DECT) can improve the differentiation of material by using two different X-ray energy spectra, and may provide new imaging techniques to diagnostic radiology to overcome the limitations of conventional CT in characterizing tissue. Some techniques have used dual-energy imaging, which mainly includes dual-sourced, rapid kVp switching, dual-layer detectors, and split-filter imaging. In iodine images, images of the lung's perfused blood volume (PBV) based on DECT have been applied in patients with pulmonary embolism to obtain both images of the PE occluding the pulmonary artery and the consequent perfusion defects in the lung's parenchyma. PBV images of the lung also have the potential to indicate the severity of PE, including chronic thromboembolic pulmonary hypertension. Virtual monochromatic imaging can improve the accuracy of diagnosing pulmonary vascular diseases by optimizing kiloelectronvolt settings for various purposes. Iodine images also could provide a new approach in the area of thoracic oncology, for example, for the characterization of pulmonary nodules and mediastinal lymph nodes. DECT-based lung ventilation imaging is also available with noble gases with high atomic numbers, such as xenon, which is similar to iodine. A ventilation map of the lung can be used to image various pulmonary diseases such as chronic obstructive pulmonary disease.
Collapse
Affiliation(s)
- Yoshiyuki Ozawa
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Yoshiharu Ohno
- Department of Diagnostic Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Hiroyuki Nagata
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Keigo Tamokami
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Keitaro Nishikimi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Yuka Oshima
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Nayu Hamabuchi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Takahiro Matsuyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| |
Collapse
|
52
|
Alizadeh LS, Vogl TJ, Waldeck SS, Overhoff D, D'Angelo T, Martin SS, Yel I, Gruenewald LD, Koch V, Fulisch F, Booz C. Dual-Energy CT in Cardiothoracic Imaging: Current Developments. Diagnostics (Basel) 2023; 13:2116. [PMID: 37371011 DOI: 10.3390/diagnostics13122116] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/31/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
This article describes the technical principles and clinical applications of dual-energy computed tomography (DECT) in the context of cardiothoracic imaging with a focus on current developments and techniques. Since the introduction of DECT, different vendors developed distinct hard and software approaches for generating multi-energy datasets and multiple DECT applications that were developed and clinically investigated for different fields of interest. Benefits for various clinical settings, such as oncology, trauma and emergency radiology, as well as musculoskeletal and cardiovascular imaging, were recently reported in the literature. State-of-the-art applications, such as virtual monoenergetic imaging (VMI), material decomposition, perfused blood volume imaging, virtual non-contrast imaging (VNC), plaque removal, and virtual non-calcium (VNCa) imaging, can significantly improve cardiothoracic CT image workflows and have a high potential for improvement of diagnostic accuracy and patient safety.
Collapse
Affiliation(s)
- Leona S Alizadeh
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Department of Diagnostic and Interventional Radiology, Bundeswehrzentralkrankenhaus Koblenz, 56072 Koblenz, Germany
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
| | - Stephan S Waldeck
- Department of Diagnostic and Interventional Radiology, Bundeswehrzentralkrankenhaus Koblenz, 56072 Koblenz, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital Mainz, 55131 Mainz, Germany
| | - Daniel Overhoff
- Department of Diagnostic and Interventional Radiology, Bundeswehrzentralkrankenhaus Koblenz, 56072 Koblenz, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital Mannheim, 68167 Mannheim, Germany
| | - Tommaso D'Angelo
- Diagnostic and Interventional Radiology Unit, Department of Biomedical Sciences and Morphological and Functional Imaging, "G. Martino" University Hospital Messina, 98124 Messina, Italy
| | - Simon S Martin
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
| | - Ibrahim Yel
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
| | - Leon D Gruenewald
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
| | - Vitali Koch
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
| | - Florian Fulisch
- Department of Diagnostic and Interventional Radiology, Bundeswehrzentralkrankenhaus Koblenz, 56072 Koblenz, Germany
| | - Christian Booz
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, 60590 Frankfurt, Germany
| |
Collapse
|
53
|
Arico' FM, Trimarchi R, Portaluri A, Barilla' C, Migliaccio N, Bucolo GM, Cicero G, Sofia C, Booz C, Vogl TJ, Marino MA, Ascenti V, D'Angelo T, Mazziotti S, Ascenti G. Virtual monoenergetic dual-layer dual-energy CT images in colorectal cancer: CT diagnosis could be improved? LA RADIOLOGIA MEDICA 2023:10.1007/s11547-023-01663-0. [PMID: 37310558 DOI: 10.1007/s11547-023-01663-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/05/2023] [Indexed: 06/14/2023]
Abstract
PURPOSE To compare conventional CT images and virtual monoenergetic images (VMI) at dual-layer dual-energy CT (dlDECT) in patients with colorectal cancer (CRC) through quantitative analysis and to investigate the added value of VMI. MATERIAL AND METHODS Sixty-six consecutive patients with histologically documented CRC and available VMI reconstructions were retrospectively investigated. Subsequently, forty-two patients, without any colonic disease at colonoscopy, were selected as control group. Conventional CT images and VMI reconstructions at energy levels ranging from 40 (VMI40) to 100 keV (VMI100) in 10 keV increments, were obtained from the late arterial phase. First, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were obtained to select the best VMI reconstruction. Finally, the diagnostic accuracy of conventional CT and VMI40 in late arterial phase was evaluated. RESULTS On quantitative analysis, SNR and CNR were higher for VMI40 (19.5 ± 7.7 and 11.8 ± 6.2, respectively) with statistically significant differences compared to conventional CT (P < 0.05) and all the other VMI reconstructions (P < 0.05), except for VMI50 (P > 0.05). The addition of VMI40 to conventional CT images significantly improved the area under the curve (AUC) for the diagnosis of CRC, increasing it from 0.875 to 0.943 for reader 1 (P < 0.05) and from 0.916 to 0.954 for reader 2 (P < 0.05). The improvement was greater in the less experienced radiologist (0.068) compared to the more experienced one (0.037). CONCLUSION VMI40 has showed the highest quantitative image parameters. Furthermore, the use of VMI40 can lead to a significant improvement in the diagnostic performance for detecting CRC.
Collapse
Affiliation(s)
- Francesco Marcello Arico'
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Renato Trimarchi
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy.
| | - Antonio Portaluri
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Claudia Barilla'
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Nicola Migliaccio
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Giuseppe Mauro Bucolo
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Giuseppe Cicero
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Carmelo Sofia
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Christian Booz
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Thomas J Vogl
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Maria Adele Marino
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Velio Ascenti
- Postgraduate School of Radiodiagnostics, Policlinico Universitario, University of Milan, Milan, Italy
| | - Tommaso D'Angelo
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Silvio Mazziotti
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| | - Giorgio Ascenti
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico Universitario G.Martino, University of Messina, Via Consolare Valeria 1, 98123, Messina, Italy
| |
Collapse
|
54
|
Guerrini S, Bagnacci G, Perrella A, Meglio ND, Sica C, Mazzei MA. Dual Energy CT in Oncology: Benefits for Both Patients and Radiologists From an Emerging Quantitative and Functional Diagnostic Technique. Semin Ultrasound CT MR 2023; 44:205-213. [PMID: 37245885 DOI: 10.1053/j.sult.2023.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Dual-energy CT (DECT) imaging makes it possible to identify the characteristics of materials that cannot be recognized with conventional single-energy CT (SECT). In the postprocessing study phase, virtual monochromatic images and virtual-non-contrast (VNC) images, also permits reduction of dose exposure by eliminating the precontrast acquisition scan. Moreover, in virtual monochromatic images, the iodine contrast increases when the energy level decreases resulting in better visualization of hypervascular lesions and in a better tissue contrast between hypovascular lesions and the surrounding parenchyma; thus, allowing for reduction of required iodinate contrast material, especially important in patients with renal impairment. All these advantages are particularly important in oncology, providing the possibility of overcoming many SECT imaging limits and making CT examinations safer and more feasible in critical patients. This review explores the basis of DECT imaging and its utility in routine oncologic clinical practice, with particular attention to the benefits of this technique for both the patients and the radiologists.
Collapse
Affiliation(s)
- Susanna Guerrini
- Unit of Diagnostic Imaging, Department of Medical Sciences, University of Siena, Azienda Ospedaliero-Universitaria Senese, Siena, Italy.
| | - Giulio Bagnacci
- Diagnostic Imaging Unit, Department of Diagnostic Imaging, Azienda USL-Toscana Sud-Est, Poggibonsi, Valdelsa, Italy
| | - Armando Perrella
- Diagnostic Imaging Unit, Department of Diagnostic Imaging, Azienda USL-Toscana Sud-Est, Grosseto, Italy
| | - Nunzia Di Meglio
- Unit of Diagnostic Imaging, Department of Medical Sciences, University of Siena, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Cristian Sica
- Unit of Diagnostic Imaging, Department of Medical, Surgical and Neuro Sciences and of Medical Sciences, University of Siena, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Maria Antonietta Mazzei
- Unit of Diagnostic Imaging, Department of Medical, Surgical and Neuro Sciences and of Medical Sciences, University of Siena, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| |
Collapse
|
55
|
Madhavan AA, Yu L, Brinjikji W, Cutsforth-Gregory JK, Schwartz FR, Mark IT, Benson JC, Amrhein TJ. Utility of Photon-Counting Detector CT Myelography for the Detection of CSF-Venous Fistulas. AJNR Am J Neuroradiol 2023; 44:740-744. [PMID: 37202116 PMCID: PMC10249691 DOI: 10.3174/ajnr.a7887] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/26/2023] [Indexed: 05/20/2023]
Abstract
CSF-venous fistulas are an increasingly recognized type of CSF leak that can be particularly challenging to detect, even with recently improved imaging techniques. Currently, most institutions use decubitus digital subtraction myelography or dynamic CT myelography to localize CSF-venous fistulas. Photon-counting detector CT is a relatively recent advancement that has many theoretical benefits, including excellent spatial resolution, high temporal resolution, and spectral imaging capabilities. We describe 6 cases of CSF-venous fistulas detected on decubitus photon-counting detector CT myelography. In 5 of these cases, the CSF-venous fistula was previously occult on decubitus digital subtraction myelography or decubitus dynamic CT myelography using an energy-integrating detector system. All 6 cases exemplify the potential benefits of photon-counting detector CT myelography in identifying CSF-venous fistulas. We suggest that further implementation of this imaging technique will likely be valuable to improve the detection of fistulas that might otherwise be missed with currently used techniques.
Collapse
Affiliation(s)
- A A Madhavan
- From the Division of Neuroradiology (A.A.M., L.Y., W.B., I.T.M., J.C.B.)
| | - L Yu
- From the Division of Neuroradiology (A.A.M., L.Y., W.B., I.T.M., J.C.B.)
| | - W Brinjikji
- From the Division of Neuroradiology (A.A.M., L.Y., W.B., I.T.M., J.C.B.)
| | - J K Cutsforth-Gregory
- Department of Radiology and Department of Neurology (J.K.C.-G.), Mayo Clinic, Rochester, Minnesota
| | - F R Schwartz
- Division of Neuroradiology (F.R.S., T.J.A.), Department of Radiology, Duke University Medical Center, Durham, North Carolina
| | - I T Mark
- From the Division of Neuroradiology (A.A.M., L.Y., W.B., I.T.M., J.C.B.)
| | - J C Benson
- From the Division of Neuroradiology (A.A.M., L.Y., W.B., I.T.M., J.C.B.)
| | - T J Amrhein
- Division of Neuroradiology (F.R.S., T.J.A.), Department of Radiology, Duke University Medical Center, Durham, North Carolina
| |
Collapse
|
56
|
Zhong J, Pan Z, Chen Y, Wang L, Xia Y, Wang L, Li J, Lu W, Shi X, Feng J, Yan F, Zhang H, Yao W. Robustness of radiomics features of virtual unenhanced and virtual monoenergetic images in dual-energy CT among different imaging platforms and potential role of CT number variability. Insights Imaging 2023; 14:79. [PMID: 37166511 PMCID: PMC10175529 DOI: 10.1186/s13244-023-01426-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 04/05/2023] [Indexed: 05/12/2023] Open
Abstract
OBJECTIVES To evaluate robustness of dual-energy CT (DECT) radiomics features of virtual unenhanced (VUE) image and virtual monoenergetic image (VMI) among different imaging platforms. METHODS A phantom with sixteen clinical-relevant densities was scanned on ten DECT platforms with comparable scan parameters. Ninety-four radiomic features were extracted via Pyradiomics from VUE images and VMIs at energy level of 70 keV (VMI70keV). Test-retest repeatability was assessed by Bland-Altman analysis. Inter-platform reproducibility of VUE images and VMI70keV was evaluated by coefficient of variation (CV) and quartile coefficient of dispersion (QCD) among platforms, and by intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC) between platform pairs. The correlation between variability of CT number radiomics reproducibility was estimated. RESULTS 92.02% and 92.87% of features were repeatable between scan-rescans for VUE images and VMI70keV, respectively. Among platforms, 11.30% and 28.39% features of VUE images, and 15.16% and 28.99% features of VMI70keV were with CV < 10% and QCD < 10%. The average percentages of radiomics features with ICC > 0.90 and CCC > 0.90 between platform pairs were 10.00% and 9.86% in VUE images and 11.23% and 11.23% in VMI70keV. The CT number inter-platform reproducibility using CV and QCD showed negative correlations with percentage of the first-order radiomics features with CV < 10% and QCD < 10%, in both VUE images and VMI70keV (r2 0.3870-0.6178, all p < 0.001). CONCLUSIONS The majority of DECT radiomics features were non-reproducible. The differences in CT number were considered as an indicator of inter-platform DECT radiomics variation. Critical relevance statement: The majority of radiomics features extracted from the VUE images and the VMI70keV were non-reproducible among platforms, while synchronizing energy levels of VMI to reduce the CT number value variability may be a potential way to mitigate radiomics instability.
Collapse
Affiliation(s)
- Jingyu Zhong
- Department of Imaging, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Zilai Pan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yong Chen
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Lingyun Wang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yihan Xia
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Lan Wang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jianying Li
- Computed Tomography Research Center, GE Healthcare, Beijing, 100176, China
| | - Wei Lu
- Computed Tomography Research Center, GE Healthcare, Shanghai, 201203, China
| | - Xiaomeng Shi
- Department of Materials, Imperial College London, London, SW7 2AZ, UK
| | - Jianxing Feng
- Haohua Technology Co., Ltd., Shanghai, 201100, China
| | - Fuhua Yan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Huan Zhang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Weiwu Yao
- Department of Imaging, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China.
| |
Collapse
|
57
|
Dabli D, Durand Q, Frandon J, de Oliveira F, Pastor M, Beregi J, Greffier J. Impact of the automatic tube current modulation (ATCM) system on virtual monoenergetic image quality for dual-source CT: A phantom study. Phys Med 2023; 109:102574. [PMID: 37004360 DOI: 10.1016/j.ejmp.2023.102574] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/23/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
PURPOSE To assess the impact of the automatic tube current modulation (ATCM) on virtual monoenergetic images (VMIs) quality in dual-source CT(DSCT). MATERIALS AND METHODS Acquisitions were performed on DSCT using the Mercury phantom. The acquisition parameters for an abdomen-pelvic examination with single-energy CT(SECT) and dual-energy CT(DECT) imaging were used. Acquisitions were performed for each imaging mode using fixed mAs and ATCM. The mAs value was set to obtain a volume CT dose index of 11 mGy in fixed mAs acquisitions. This value was used as the reference mAs in ATCM acquisitions. The noise power spectrum and task-based transfer function at 40,50,60 and 70 keV levels were computed on VMIs and SECT images. The detectability index (d') was calculated for a lesion with an iodine concentration of 10 mg/mL. RESULTS The noise magnitude on VMIs was higher with the ATCM system than with fixed mAs for all energy levels and section diameters of 21,26 and 31 cm. The noise texture and spatial resolution were similar between the fixed mAs and ATCM acquisitions for both imaging modes. The d' values were lower for all energy levels with ATCM than with fixed mAs acquisitions for 21 and 26 cm diameters by -39.82 ± 9.32%, similar at 31 cm diameter -4.13 ± 0.24% and higher at 36 cm diameter 10.40 ± 6.69%. It was higher on VMIs at all energy levels compared to SECT images. CONCLUSIONS The ATCM system could be used with DECT imaging to optimize patient exposure without changing the noise texture and spatial resolution of VMIs compared to fixed mAs and SECT.
Collapse
|
58
|
Dillinger D, Overhoff D, Booz C, Kaatsch HL, Piechotka J, Hagen A, Froelich MF, Vogl TJ, Waldeck S. Impact of CT Photon-Counting Virtual Monoenergetic Imaging on Visualization of Abdominal Arterial Vessels. Diagnostics (Basel) 2023; 13:diagnostics13050938. [PMID: 36900082 PMCID: PMC10000913 DOI: 10.3390/diagnostics13050938] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
PURPOSE The novel photon-counting detector (PCD) technique acquires spectral data for virtual monoenergetic imaging (VMI) in every examination. The aim of this study was the evaluation of the impact of VMI of abdominal arterial vessels on quantitative and qualitative subjective image parameters. METHODS A total of 20 patients that underwent an arterial phase computed tomography (CT) scan of the abdomen with a novel PCD CT (Siemens NAEOTOM alpha) were analyzed regarding attenuation at different energy levels in virtual monoenergetic imaging. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated and compared between the different virtual monoenergetic (VME) levels with correlation to vessel diameter. In addition, subjective image parameters (overall subjective image quality, subjective image noise and vessel contrast) were evaluated. RESULTS Our research showed decreasing attenuation levels with increasing energy levels in virtual monoenergetic imaging regardless of vessel diameter. CNR showed best overall results at 60 keV, and SNR at 70 keV with no significant difference to 60 keV (p = 0.294). Subjective image quality was rated best at 70 keV for overall image quality, vessel contrast and noise. CONCLUSIONS Our data suggest that VMI at 60-70 keV provides the best objective and subjective image quality concerning vessel contrast irrespective of vessel size.
Collapse
Affiliation(s)
- Daniel Dillinger
- Department of Vascular Surgery and Endovascular Surgery, Bundeswehr Central Hospital, Rübenacher Straße 170, 56072 Koblenz, Germany
- Correspondence:
| | - Daniel Overhoff
- Department of Radiology and Neuroradiology, Bundeswehr Central Hospital, Rübenacher Straße 170, 56072 Koblenz, Germany
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Christian Booz
- Institute for Diagnostic and Interventional Radiology, Goethe-University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
| | - Hanns L. Kaatsch
- Department of Radiology and Neuroradiology, Bundeswehr Central Hospital, Rübenacher Straße 170, 56072 Koblenz, Germany
| | - Joel Piechotka
- Department of Radiology and Neuroradiology, Bundeswehr Central Hospital, Rübenacher Straße 170, 56072 Koblenz, Germany
| | - Achim Hagen
- Department of Vascular Surgery and Endovascular Surgery, Bundeswehr Central Hospital, Rübenacher Straße 170, 56072 Koblenz, Germany
| | - Matthias F. Froelich
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Thomas J. Vogl
- Institute for Diagnostic and Interventional Radiology, Goethe-University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
| | - Stephan Waldeck
- Department of Radiology and Neuroradiology, Bundeswehr Central Hospital, Rübenacher Straße 170, 56072 Koblenz, Germany
- Department of Neuroradiology, University Medical Center Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| |
Collapse
|
59
|
Xu JJ, Ulriksen PS, Bjerrum CW, Achiam MP, Resch TA, Lönn L, Lindskov Hansen K. Characterizing incidental mass lesions in abdominal dual-energy CT compared to conventional contrast-enhanced CT. Acta Radiol 2023; 64:945-950. [PMID: 35918808 DOI: 10.1177/02841851221116306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Incidental findings are common in abdominal computed tomography (CT) and often warrant further investigations with economic implications as well as implications for patients. PURPOSE To evaluate the potential of dual-energy CT (DECT) in the identification and/or characterization of abdominal incidental mass lesions compared to conventional contrast-enhanced CT. MATERIAL AND METHODS This retrospective study from a major tertiary hospital included 96 patients, who underwent contrast-enhanced abdominal DECT. Incidental lesions in adrenals, kidneys, liver, and pancreas were evaluated by two board-certified abdominal radiologists. Observer 1 only had access to standard CT reconstructions, while observer 2 had access to standard CT as well as DECT reconstructions. Disagreements were resolved by consensus review and used as a reference for observers using McNemar's test. RESULTS Observers 1 and 2 identified a total of 40 and 34 findings, respectively. Furthermore, observer 1 registered 13 lesions requiring follow-up, of which seven (two renal and five adrenal lesions) were resolved following consensus review using DECT (P = 0.008). The inter-observer agreement was near perfect (κ = 0.82). CONCLUSION DECT has the potential to improve the immediate characterization of incidental findings when compared to conventional CT for abdominal imaging.
Collapse
Affiliation(s)
- Jack Junchi Xu
- Department of Diagnostic Radiology, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Peter Sommer Ulriksen
- Department of Diagnostic Radiology, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
| | - Camilla Wium Bjerrum
- Department of Diagnostic Radiology, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
| | - Michael Patrick Achiam
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- Department of Surgical Gastroenterology, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
| | - Timothy Andrew Resch
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- Department of Vascular Surgery, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
| | - Lars Lönn
- Department of Diagnostic Radiology, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, 53146Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
60
|
Wiesmueller M, Meixner CR, Weber M, Kesting M, Nagel AM, Wuest W, May MS, Roemer FW, Uder M, Heiss R. Time-of-Flight Angiography in Ultra-High-Field 7 T MRI for the Evaluation of Peroneal Perforator Arteries Before Osseomyocutaneous Flap Surgery. Invest Radiol 2023; 58:216-222. [PMID: 36165876 PMCID: PMC9914154 DOI: 10.1097/rli.0000000000000926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/11/2022] [Indexed: 10/14/2022]
Abstract
OBJECTIVES Presurgical identification and morphologic characterization of the peroneal perforator arteries (PPAs) are essential for osseomyocutaneous flap surgery. The aim of this study was to evaluate PPAs using time-of-flight (TOF) angiography in 7 T magnetic resonance imaging in comparison with dual-energy computed tomographic angiography (CTA). MATERIALS AND METHODS In this prospective study, TOF angiography and CTA of both lower legs were acquired before flap surgery from 07/2019 to 02/2020. Magnetic resonance imaging was performed using a dedicated 28-channel knee coil with an acquisition time of 9:55 minutes (voxel size: 0.4 × 0.4 × 0.8 mm). Computed tomographic angiography was acquired with a third-generation dual-source computed tomography on the same day. Virtual monoenergetic reconstructions at 40 keV photon energy served as the standard of reference for PPA identification and subtyping. Two independent readers assessed the image quality, quantity, length assessment, and classification according to surgical considerations of PPAs for TOF angiography and CTA. Both TOF angiography and CTA were used for presurgical flap design and were evaluated by an orofacial surgeon. RESULTS Ten patients (mean age, 59.9 ± 14.9 years; 7 men) were included. Time-of-flight angiography and CTA identified 53 and 51 PPAs in total, respectively. Time-of-flight angiography showed superior image quality (both readers, P < 0.05). Time-of-flight angiography enabled specific classification of PPA subtypes more often (53 vs 39; P < 0.05), and both readers reported higher diagnostic confidence for TOF angiography than CTA in all patients (interrater agreement κ = 0.8; P < 0.05). Regarding length assessment, PPAs were significantly more conspicuous with TOF angiography (TOF mean , 50 ± 11 mm; CTA mean , 40 ± 9 mm; P = 0.001). In comparison with CTA, TOF angiography prospectively changed the orofacial surgeon's final decision on the presurgical selected PPAs in 60% of cases. CONCLUSIONS Presurgical assessment of PPAs is feasible using TOF in 7 T magnetic resonance imaging. Moreover, TOF angiography was superior to CTA for classifying and identifying PPAs, which may facilitate the planning of reconstructive surgery.
Collapse
Affiliation(s)
| | | | - Manuel Weber
- Department of Oral and Maxillofacial Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Marco Kesting
- Department of Oral and Maxillofacial Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Armin M. Nagel
- From the Institute of Radiology, University Hospital Erlangen
- Division of Medical Physics in Radiology, German Cancer Research Centre (DKFZ), Heidelberg, Germany
| | - Wolfgang Wuest
- From the Institute of Radiology, University Hospital Erlangen
| | - Matthias S. May
- From the Institute of Radiology, University Hospital Erlangen
| | - Frank W. Roemer
- From the Institute of Radiology, University Hospital Erlangen
- Quantitative Imaging Center (QIC), Department of Radiology, Boston University School of Medicine, Massachusetts
| | - Michael Uder
- From the Institute of Radiology, University Hospital Erlangen
| | - Rafael Heiss
- From the Institute of Radiology, University Hospital Erlangen
| |
Collapse
|
61
|
Wang Y, Chen X, Lu G, Su Y, Yang L, Shi G, Zhang F, Zhuo J, Duan X, Hu H. Improving the Visualization of the Adrenal Veins Using Virtual Monoenergetic Images from Dual-Energy Computed Tomography before Adrenal Venous Sampling. Tomography 2023; 9:485-496. [PMID: 36960999 PMCID: PMC10037600 DOI: 10.3390/tomography9020040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/15/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
(1) Background: This study explored the optimal energy level in advanced virtual monoenergetic images (VMI+) from dual-energy computed tomography angiography (DE-CTA) for adrenal veins visualization before adrenal venous sampling (AVS). (2) Methods: Thirty-nine patients were included in this prospective single-center study. The CT value, noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured in both adrenal veins and abdominal solid organs and were then compared between VMI+ within the range of 40-80 kiloelectron volt (keV). The visualization rate of the adrenal veins and the overall image quality of solid organs were subjectively compared among different keV VMI+. The AVS success rate was recorded for 20 patients. (3) Results: For the adrenal veins, 40 keV VMI+ had the peak CT value, noise and CNR (p < 0.05). Subjectively, the visualization rate was the highest at 40 keV (100% for the right adrenal vein, and 97.4% for the left adrenal vein) (p < 0.05). For solid organs, the CT value, noise and CNR at 50 keV were lower than those at 40 keV (p < 0.05), but the SNR was similar between 40 keV and 50 keV. The overall subjective image quality of solid organs at 50 keV was the best (p < 0.05). The AVS success rate was 95%. (4) Conclusions: For VMI+, 40 keV was the preferential energy level to obtain a high visualization rate of the adrenal veins and a high success rate of AVS, while 50 keV was the favorable energy level for the depiction of abdominal organs.
Collapse
Affiliation(s)
- Yu Wang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| | - Xiaohong Chen
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| | - Guoxiong Lu
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| | - Yun Su
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| | - Lingjie Yang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| | - Guangzi Shi
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Fang Zhang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Jiayi Zhuo
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| | - Xiaohui Duan
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Huijun Hu
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, No. 107 Yanjiang Road West, Guangzhou 510120, China
| |
Collapse
|
62
|
Xu JJ, Lönn L, Budtz-Jørgensen E, Jawad S, Ulriksen PS, Hansen KL. Evaluation of thin-slice abdominal DECT using deep-learning image reconstruction in 74 keV virtual monoenergetic images: an image quality comparison. Abdom Radiol (NY) 2023; 48:1536-1544. [PMID: 36810705 DOI: 10.1007/s00261-023-03845-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/23/2023]
Abstract
PURPOSE To compare noise, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and image quality using deep-learning image reconstruction (DLIR) vs. adaptive statistical iterative reconstruction (ASIR-V) in 0.625 and 2.5 mm slice thickness gray scale 74 keV virtual monoenergetic (VM) abdominal dual-energy CT (DECT). METHODS This retrospective study was approved by the institutional review board and regional ethics committee. We analysed 30 portal-venous phase abdominal fast kV-switching DECT (80/140kVp) scans. Data were reconstructed to ASIR-V 60% and DLIR-High at 74 keV in 0.625 and 2.5 mm slice thickness. Quantitative HU and noise assessment were measured within liver, aorta, adipose tissue and muscle. Two board-certified radiologists evaluated image noise, sharpness, texture and overall quality based on a five-point Likert scale. RESULTS DLIR significantly reduced image noise and increased CNR as well as SNR compared to ASIR-V, when slice thickness was maintained (p < 0.001). Slightly higher noise of 5.5-16.2% was measured (p < 0.01) in liver, aorta and muscle tissue at 0.625 mm DLIR compared to 2.5 mm ASIR-V, while noise in adipose tissue was 4.3% lower with 0.625 mm DLIR compared to 2.5 mm ASIR-V (p = 0.08). Qualitative assessments demonstrated significantly improved image quality for DLIR particularly in 0.625 mm images. CONCLUSIONS DLIR significantly reduced image noise, increased CNR and SNR and improved image quality in 0.625 mm slice images, when compared to ASIR-V. DLIR may facilitate thinner image slice reconstructions for routine contrast-enhanced abdominal DECT.
Collapse
Affiliation(s)
- Jack J Xu
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100, Copenhagen, Denmark. .,Department of Clinical Medicine, University of Copenhagen, 2100, Copenhagen, Denmark.
| | - Lars Lönn
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Esben Budtz-Jørgensen
- Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Samir Jawad
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100, Copenhagen, Denmark
| | - Peter S Ulriksen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100, Copenhagen, Denmark
| | - Kristoffer L Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, 2100, Copenhagen, Denmark
| |
Collapse
|
63
|
Thor D, Titternes R, Poludniowski G. Spatial resolution, noise properties, and detectability index of a deep learning reconstruction algorithm for dual-energy CT of the abdomen. Med Phys 2023; 50:2775-2786. [PMID: 36774193 DOI: 10.1002/mp.16300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/18/2022] [Accepted: 01/17/2023] [Indexed: 02/13/2023] Open
Abstract
BACKGROUND Iterative reconstruction (IR) has increasingly replaced traditional reconstruction methods in computed tomography (CT). The next paradigm shift in image reconstruction is likely to come from artificial intelligence, with deep learning reconstruction (DLR) solutions already entering the clinic. An enduring disadvantage to IR has been a change in noise texture, which can affect diagnostic confidence. DLR has demonstrated the potential to overcome this issue and has recently become available for dual-energy CT. PURPOSE To evaluate the spatial resolution, noise properties, and detectability index of a commercially available DLR algorithm for dual-energy CT of the abdomen and compare it to single-energy (SE) CT. METHODS An oval 25 cm x 35 cm custom-made phantom was scanned on a GE Revolution CT scanner (GE Healthcare, Waukesha, WI) at two dose levels (13 and 5 mGy) and two iodine concentrations (8 and 2 mg/mL), using three typical abdominal scan protocols: dual-energy (DE), SE 80 kV (SE-80 kV) and SE 120 kV (SE-120 kV). Reconstructions were performed with three strengths of IR (ASiR-V: AR0%, AR50%, AR100%) and three strengths of DLR (TrueFidelity: low, medium, high). The DE acquisitions were reconstructed as mono-energetic images between 40 and 80 keV. The noise power spectrum (NPS), task transfer function (TTF), and detectability index (d') were determined for the reconstructions following the recommendations of AAPM Task Group 233. RESULTS Noise magnitude reductions (relative to AR0%) for the SE protocols were on average (-29%, -21%) for (AR50%, TF-M), while for DE-70 keV were (-28%, -43%). There was less reduction in mean frequency (fav ) for DLR than for IR, with similar results for SE and DE imaging. There was, however, a substantial change in the NPS shape when using DE with DLR, quantifiable by a marked reduction in the peak frequency (fpeak ) that was absent in SE mode. All protocols and reconstructions (including AR0%) exhibited slight to moderate shifts towards lower spatial frequencies at the lower dose (<12% in fav ). Spatial resolution was consistently superior for DLR compared to IR for SE but not for DE. All protocols and reconstructions (including AR0%) showed decreased resolution with reduced dose and iodine concentration, with less decrease for DLR compared to IR. DLR displayed a higher d' than IR. The effect of energy was large: d' increased with lower keV, and SE-80 kV had higher d' than SE-120 kV. Using DE with DLR could provide higher d' than SE-80 kV at the higher dose but not at lower dose. CONCLUSIONS DE imaging with DLR maintained spatial resolution and reduced noise magnitude while displaying less change in noise texture than IR. The d' was also higher with DLR than IR, suggesting superiority in detectability of iodinated contrast. Despite these trends being consistent with those previously established for SE imaging, there were some noteworthy differences. For DE imaging there was no improvement in resolution compared to IR and a change in noise texture. DE imaging with low keV and DLR had superior detectability to SE DLR at the high dose but was not better than SE-80 kV at low dose.
Collapse
Affiliation(s)
- Daniel Thor
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden.,Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Rebecca Titternes
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Gavin Poludniowski
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
64
|
Lim W, Sodemann EB, Büttner L, Jonczyk M, Lüdemann WM, Kahn J, Geisel D, Jann H, Aigner A, Böning G. Spectral Computed Tomography-Derived Iodine Content and Tumor Response in the Follow-Up of Neuroendocrine Tumors-A Single-Center Experience. Curr Oncol 2023; 30:1502-1515. [PMID: 36826076 PMCID: PMC9954990 DOI: 10.3390/curroncol30020115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/08/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023] Open
Abstract
Spectral computed tomography (SCT) allows iodine content (IC) calculation for characterization of hypervascularized neoplasms and thus might help in the staging of neuroendocrine tumors (NETs). This single-center prospective study analyzed the association between SCT-derived IC and tumor response in the follow-up of metastasized NETs. Twenty-six patients with a median age of 70 years (range 51-85) with histologically proven NETs and a total of 78 lesions underwent SCT for staging. Because NETS are rare, no primary NET types were excluded. Lesions and intralesional hotspots were measured in virtual images and iodine maps. Tumor response was classified as progressive or nonprogressive at study endpoint. Generalized estimating equations served to estimate associations between IC and tumor response, additionally stratified by lesion location. Most commonly affected sites were the lymph nodes, liver, pancreas, and bones. Median time between SCT and endpoint was 64 weeks (range 5-260). Despite statistical imprecision in the estimate, patients with higher IC in lymphonodular metastases had lower odds for disease progression (adjusted OR = 0.21, 95% CI: 0.02-2.02). Opposite tendencies were observed in hepatic and pancreatic metastases in unadjusted analyses, which vanished after adjusting for therapy and primary tumor grade.
Collapse
Affiliation(s)
- Winna Lim
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
- Correspondence:
| | - Elisa Birgit Sodemann
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Laura Büttner
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Martin Jonczyk
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Willie Magnus Lüdemann
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Johannes Kahn
- Institute of Neuroradiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Dominik Geisel
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Henning Jann
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Annette Aigner
- Institute of Biometry and Clinical Epidemiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Georg Böning
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| |
Collapse
|
65
|
Dabli D, Loisy M, Frandon J, de Oliveira F, Meerun AM, Guiu B, Beregi JP, Greffier J. Comparison of image quality of two versions of deep-learning image reconstruction algorithm on a rapid kV-switching CT: a phantom study. Eur Radiol Exp 2023; 7:1. [PMID: 36617620 PMCID: PMC9826773 DOI: 10.1186/s41747-022-00314-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 11/05/2022] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND To assess the impact of the new version of a deep learning (DL) spectral reconstruction on image quality of virtual monoenergetic images (VMIs) for contrast-enhanced abdominal computed tomography in the rapid kV-switching platform. METHODS Two phantoms were scanned with a rapid kV-switching CT using abdomen-pelvic CT examination parameters at dose of 12.6 mGy. Images were reconstructed using two versions of DL spectral reconstruction algorithms (DLSR V1 and V2) for three reconstruction levels. The noise power spectrum (NSP) and task-based transfer function at 50% (TTF50) were computed at 40/50/60/70 keV. A detectability index (d') was calculated for enhanced lesions at low iodine concentrations: 2, 1, and 0.5 mg/mL. RESULTS The noise magnitude was significantly lower with DLSR V2 compared to DLSR V1 for energy levels between 40 and 60 keV by -36.5% ± 1.4% (mean ± standard deviation) for the standard level. The average NPS frequencies increased significantly with DLSR V2 by 23.7% ± 4.2% for the standard level. The highest difference in TTF50 was observed at the mild level with a significant increase of 61.7% ± 11.8% over 40-60 keV energy with DLSR V2. The d' values were significantly higher for DLSR V2 versus DLSR V1. CONCLUSIONS The DLSR V2 improves image quality and detectability of low iodine concentrations in VMIs compared to DLSR V1. This suggests a great potential of DLSR V2 to reduce iodined contrast doses.
Collapse
Affiliation(s)
- Djamel Dabli
- Department of Medical Imaging, IMAGINE UR UM 103, Montpellier University, Nîmes University Hospital, Bd Prof Robert Debré, 30029, Nîmes Cedex 9, France.
| | - Maeliss Loisy
- Department of Medical Imaging, IMAGINE UR UM 103, Montpellier University, Nîmes University Hospital, Bd Prof Robert Debré, 30029 Nîmes Cedex 9, France
| | - Julien Frandon
- Department of Medical Imaging, IMAGINE UR UM 103, Montpellier University, Nîmes University Hospital, Bd Prof Robert Debré, 30029 Nîmes Cedex 9, France
| | - Fabien de Oliveira
- Department of Medical Imaging, IMAGINE UR UM 103, Montpellier University, Nîmes University Hospital, Bd Prof Robert Debré, 30029 Nîmes Cedex 9, France
| | - Azhar Mohamad Meerun
- grid.157868.50000 0000 9961 060XSaint-Eloi University Hospital, Montpellier, France
| | - Boris Guiu
- grid.157868.50000 0000 9961 060XSaint-Eloi University Hospital, Montpellier, France
| | - Jean-Paul Beregi
- Department of Medical Imaging, IMAGINE UR UM 103, Montpellier University, Nîmes University Hospital, Bd Prof Robert Debré, 30029 Nîmes Cedex 9, France
| | - Joël Greffier
- Department of Medical Imaging, IMAGINE UR UM 103, Montpellier University, Nîmes University Hospital, Bd Prof Robert Debré, 30029 Nîmes Cedex 9, France
| |
Collapse
|
66
|
Sauerbeck J, Adam G, Meyer M. Spectral CT in Oncology. ROFO-FORTSCHR RONTG 2023; 195:21-29. [PMID: 36167316 DOI: 10.1055/a-1902-9949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Spectral CT is gaining increasing clinical importance with multiple potential applications, including oncological imaging. Spectral CT-specific image data offers multiple advantages over conventional CT image data through various post-processing algorithms, which will be highlighted in the following review. METHODOLOGY The purpose of this review article is to provide an overview of potential useful oncologic applications of spectral CT and to highlight specific spectral CT pitfalls. The technical background, clinical advantages of primary and follow-up spectral CT exams in oncology, and the application of appropriate spectral tools will be highlighted. RESULTS/CONCLUSIONS Spectral CT imaging offers multiple advantages over conventional CT imaging, particularly in the field of oncology. The combination of virtual native and low monoenergetic images leads to improved detection and characterization of oncologic lesions. Iodine-map images may provide a potential imaging biomarker for assessing treatment response. KEY POINTS · The most important spectral CT reconstructions for oncology imaging are virtual unenhanced, iodine map, and virtual monochromatic reconstructions.. · The combination of virtual unenhanced and low monoenergetic reconstructions leads to better detection and characterization of the vascularization of solid tumors.. · Iodine maps can be a surrogate parameter for tumor perfusion and potentially used as a therapy monitoring parameter.. · For radiotherapy planning, the relative electron density and the effective atomic number of a tissue can be calculated.. CITATION FORMAT · Sauerbeck J, Adam G, Meyer M. Onkologische Bildgebung mittels Spektral-CT. Fortschr Röntgenstr 2023; 195: 21 - 29.
Collapse
Affiliation(s)
- Julia Sauerbeck
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, Hamburg, Germany
| | - Gerhard Adam
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, Hamburg, Germany
| | - Mathias Meyer
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, Hamburg, Germany
| |
Collapse
|
67
|
Advances in Bone Joint Imaging-Metal Artifact Reduction. Diagnostics (Basel) 2022; 12:diagnostics12123079. [PMID: 36553086 PMCID: PMC9776622 DOI: 10.3390/diagnostics12123079] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/01/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022] Open
Abstract
Numerous types of metal implants have been introduced in orthopedic surgery and are used in everyday practice. To precisely evaluate the postoperative condition of arthroplasty or trauma surgery, periprosthetic infection, and the loosening of implants, it is important to reduce artifacts induced by metal implants. In this review, we focused on technical advances in metal artifact reduction using digital tomosynthesis, computed tomography, and magnetic resonance imaging. We discussed new developments in diagnostic imaging methods and the continuous introduction of novel technologies to reduce metal artifacts; however, these innovations have not yet completely removed metal artifacts. Different algorithms need to be selected depending on the size, shape, material and implanted body parts of an implant. Future advances in metal artifact reduction algorithms and techniques and the development of new sequences may enable further reductions in metal artifacts even on original images taken previously. Moreover, the combination of different imaging modalities may contribute to further reductions in metal artifacts. Clinicians must constantly update their knowledge and work closely with radiologists to select the best diagnostic imaging method for each metal implant.
Collapse
|
68
|
Yalynska T, Polacin M, Frauenfelder T, Martini K. Impact of Photon Counting Detector CT Derived Virtual Monoenergetic Images on the Diagnosis of Pulmonary Embolism. Diagnostics (Basel) 2022; 12:diagnostics12112715. [PMID: 36359558 PMCID: PMC9689164 DOI: 10.3390/diagnostics12112715] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Purpose: To assess the impact of virtual-monoenergetic-image (VMI) energies on the diagnosis of pulmonary embolism (PE) in photon-counting-detector computed-tomography (PCD-CT). Methods: Eighty patients (median age 60.4 years) with suspected PE were retrospectively included. Scans were performed on PCD-CT in the multi-energy mode at 120 kV. VMIs from 40−70 keV in 10 keV intervals were reconstructed. CT-attenuation was measured in the pulmonary trunk and the main branches of the pulmonary artery. Signal-to-noise (SNR) ratio was calculated. Two radiologists evaluated subjective-image-quality (noise, vessel-attenuation and sharpness; five-point-Likert-scale, non-diagnostic−excellent), the presence of hardening artefacts and presence/visibility of PE. Results: Signal was highest at the lowest evaluated VMI (40 keV; 1053.50 HU); image noise was lowest at the highest VMI (70 keV; 15.60 HU). Highest SNR was achieved at the lowest VMI (p < 0.05). Inter-reader-agreement for subjective analysis was fair to excellent (k = 0.373−1.000; p < 0.001). Scores for vessel-attenuation and sharpness were highest at 40 keV (both:5, range 4/3−5; k = 1.000); scores for image-noise were highest at 70 keV (4, range 3−5). The highest number of hardening artifacts were reported at 40 keV (n = 22; 28%). PE-visualization was rated best at 50 keV (4.7; range 4−5) and decreased with increasing VMI-energy (r = −0.558; p < 0.001). Conclusions: While SNR was best at 40 keV, subjective PE visibility was rated highest at 50 keV, potentially owing to the lower image noise and hardening artefacts.
Collapse
|
69
|
Toshima F, Yoneda N, Terada K, Inoue D, Gabata T. DECT Numbers in Upper Abdominal Organs for Differential Diagnosis: A Feasibility Study. Tomography 2022; 8:2698-2708. [PMID: 36412684 PMCID: PMC9680450 DOI: 10.3390/tomography8060225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022] Open
Abstract
Evaluating the similarity between two entities such as primary and suspected metastatic lesions using quantitative dual-energy computed tomography (DECT) numbers may be useful. However, the criteria for the similarity between two entities based on DECT numbers remain unclear. We therefore considered the possibility that a similarity in DECT numbers within the same organ could provide suitable standards. Thus, we assumed that the variation in DECT numbers within a single organ is sufficiently minimal to be considered clinically equivalent. Therefore, the purpose of this preliminary study is to investigate the differences in DECT numbers within upper abdominal organs. This retrospective study included 30 patients with data from hepatic protocol DECT scans. DECT numbers of the following parameters were collected: (a, b) 70 and 40 keV CT values, (c) slope, (d) effective Z, and (e, f) iodine and water concentration. The agreement of DECT numbers obtained from two regions of interest in the same organ (liver, spleen, and kidney) were assessed using Bland-Altman analysis. The diagnostic ability of each DECT parameter to distinguish between the same or different organs was also assessed using receiver operating characteristic analysis. The 95% limits of agreement within the same organ exhibited the narrowest value range on delayed phase (DP) CT [(c) -11.2-8.3%, (d) -2.0-1.5%, (e) -11.3-8.4%, and (f) -0.59-0.62%]. The diagnostic ability was notably high when using differences in DECT numbers on portal venous (PVP) and DP images (the area under the curve of DP: 0.987-0.999 in (c)-(f)). Using the variability in DECT numbers in the same organ as a criterion for defining similarity may be helpful in making a differential diagnosis by comparing the DECT numbers of two entities.
Collapse
|
70
|
Mahmoudi S, Bernatz S, Althoff FC, Koch V, Grünewald LD, Scholtz JE, Walter D, Zeuzem S, Wild PJ, Vogl TJ, Kinzler MN. Dual-energy CT based material decomposition to differentiate intrahepatic cholangiocarcinoma from hepatocellular carcinoma. Eur J Radiol 2022; 156:110556. [PMID: 36270195 DOI: 10.1016/j.ejrad.2022.110556] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/29/2022] [Accepted: 10/07/2022] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess the potential of material decomposition in dual-energy CT (DECT) to differentiate intrahepatic cholangiocarcinoma (iCCA) from hepatocellular carcinoma (HCC). METHOD In this retrospective study, we included 94 patients (26 female (27.7 %), median age 64.5 (interquartile range 55.5-74.5) years) with either iCCA or HCC who underwent abdominal contrast-enhanced DECT in arterial phase. To test for differences between iCCA (n = 47) and HCC (n = 47), we evaluated mean attenuation and DECT material density values including iodine density (ID), normalized iodine uptake (NIU), fat fraction, and lesion-to-liver parenchyma ratio. Histopathology served as reference standard for all lesions. We used univariate logistic regression models for the outcome iCCA versus HCC. ROC curve analysis was applied to assess discriminative ability of the model. Model accuracy was evaluated by calculating the Brier score. Youden index was applied to establish thresholds to differentiate between iCCA and HCC. RESULTS Comparison of quantitative image parameters revealed significant differences between iCCA and HCC for ID (1.6 ± 0.5 mg/ml vs 2.8 ± 0.8 mg/ml, p < 0.001), NIU (14.5 ± 4.8 vs 24.8 ± 10.3, p < 0.001), attenuation (41.9 ± 10.1 HU vs 47.9 ± 8.9 HU, p = 0.003), and fat fraction (12.0 ± 7.8 % vs 9.0 ± 6.4 %, p = 0.045). ROC curve analysis revealed highest ability to differentiate iCCA from HCC for ID (AUC = 0.93, 95 % CI 0.89-0.98). For ID, an optimal threshold of 2.33 mg/dl was determined to discriminate between iCCA and HCC (sensitivity 89.4 %, specificity 76.6 %). CONCLUSIONS DECT-based iodine quantification can serve as a tool for the differentiation of iCCA and HCC in contrast-enhanced CT. ID yielded the highest diagnostic performance and may assist in clinical routine CT diagnostics.
Collapse
Affiliation(s)
- Scherwin Mahmoudi
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Simon Bernatz
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Friederike C Althoff
- Department of Internal Medicine II, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Vitali Koch
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Leon D Grünewald
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Jan-Erik Scholtz
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Dirk Walter
- Department of Internal Medicine I, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Stefan Zeuzem
- Department of Internal Medicine I, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Peter J Wild
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany; Wildlab, University Hospital Frankfurt MVZ GmbH, Frankfurt am Main, Germany.
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| | - Maximilian N Kinzler
- Department of Internal Medicine I, University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany.
| |
Collapse
|
71
|
Virtual monochromatic spectral attenuation curve analysis for evaluation of incidentally detected small renal lesions using rapid kilovoltage-switching dual-energy computed tomography. ABDOMINAL RADIOLOGY (NEW YORK) 2022; 47:3817-3827. [PMID: 35945346 DOI: 10.1007/s00261-022-03634-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 01/18/2023]
Abstract
PURPOSE To determine whether the spectral attenuation curve on a rapid kilovoltage-switching dual-energy computed tomography (DECT) scan can distinguish enhancing from nonenhancing incidental small (1-4 cm) renal lesions compared with conventional single-energy attenuation changes. METHODS This retrospective study enrolled 46 patients with 78 renal lesions (24 enhancing; 54 nonenhancing) who underwent DECT with DE mode performed during the portovenous or nephrographic phase. Final diagnosis of enhancing and nonenhancing masses was confirmed by pathology or imaging following the established criteria. Virtual monochromatic images (VMI) were reconstructed, and the slopes between the VMI dataset at 40-70 keV (Slope HU40-70), 40-100 keV (Slope HU40-100), and 40-140 keV (Slope HU40-140) were measured. Visual assessment of the curve pattern was recorded. Diagnostic accuracies were calculated with a cross-validated Mann-Whitney U test, and correlations of quantitative spectral parameters and intraclass correlation coefficient (ICC) were calculated using Spearman's rho correlation. RESULTS All quantitative and qualitative spectral analysis parameters significantly differentiated the enhancing and nonenhancing lesions (P < 0.001). The optimal slope thresholds calculated by cross-validation for Slope HU40-70, Slope HU40-100, and Slope HU40-140 were 3.0, 1.8 and 1.2, respectively for reader 1 and 3.0, 1.9 and 1.15, respectively for reader 2. Using a slope threshold at all datasets yielded a high diagnostic accuracy of 96 for reader 1 and 95 for reader 2. Using a ∆HU threshold of 20 HU yielded an accuracy of 100. Visual analysis of the curve pattern also yielded high accuracy of 94. CONCLUSIONS The spectral attenuation curve on rapid kilovoltage-switching DECT gives excellent diagnostic accuracy differentiating between incidental enhancing and nonenhancing renal lesions. This benefit of DECT will be most helpful when the true unenhanced phase is not performed.
Collapse
|
72
|
Graafen D, Müller L, Halfmann M, Düber C, Hahn F, Yang Y, Emrich T, Kloeckner R. Photon-counting detector CT improves quality of arterial phase abdominal scans: A head-to-head comparison with energy-integrating CT. Eur J Radiol 2022; 156:110514. [PMID: 36108479 DOI: 10.1016/j.ejrad.2022.110514] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/26/2022] [Accepted: 09/03/2022] [Indexed: 11/19/2022]
Abstract
PURPOSE Photon-counting detector (PCD)-CT is expected to have a substantial impact on oncologic abdominal imaging. We compared subjective and objective image quality between PCD-CT and conventional energy-integrating detector (EID-)CT arterial phase abdominal scans. METHODS This study included 84 patients undergoing both types of abdominal CT. EID-CT scans were acquired with a tube voltage of 100 kVp. With PCD-CT, acquired with 120-kVp, we reconstructed polychromatic T3D images and virtual monoenergetic images (VMIs) in 10-keV intervals from 40 to 90 keV. Quantitative image analysis included noise and contrast-to-noise ratio (CNR) of hepatic vessels, kidney cortex, and hypervascular liver lesions to liver parenchyma. Three raters used a 5-point Likert scale for qualitative image analysis of image noise and contrast, lesion conspicuity, and overall image quality. Radiation dose exposure (CT dose index) was compared between the two CT types. RESULTS Mean CT dose index and effective dose were respectively 18 % and 26 % lower with PCD-CT versus EID-CT. Compared with EID-CT, CNRs of kidney cortex and vessel to liver parenchyma were significantly higher in PCD-CT VMIs at energies ≤ 60 keV and in polychromatic T3D images (p < 0.004). Overall image quality of PCD-CT VMIs at 50 and 60 keV was rated as significantly better (p < 0.01) than the EID-CT images (inter-reader agreement alpha = 0.80). Lesion conspicuity was significantly better in low-keV VMIs (p < 0.03) and worse in > 70-keV VMIs. CONCLUSIONS With low-keV VMI, PCD-CT yields significantly improved objective and subjective quality of arterial phase oncological imaging compared with EID-CT. This advantage may translate into higher diagnostic confidence and lower radiation dose protocols.
Collapse
Affiliation(s)
- D Graafen
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - L Müller
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - M Halfmann
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany; German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
| | - C Düber
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - F Hahn
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Y Yang
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - T Emrich
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany; German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
| | - R Kloeckner
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| |
Collapse
|
73
|
Huls SJ, Shlapak DP, Kim DK, Leng S, Carr CM. Utility of Dual-Energy CT to Improve Diagnosis of CSF Leaks on CT Myelography following Lateral Decubitus Digital Subtraction Myelography with Negative Findings. AJNR Am J Neuroradiol 2022; 43:1539-1543. [PMID: 36574327 PMCID: PMC9575522 DOI: 10.3174/ajnr.a7628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/12/2022] [Indexed: 01/26/2023]
Abstract
CSF leaks, including CSF-venous fistulas, which cause spontaneous intracranial hypotension, remain difficult to diagnose, even on digital subtraction myelography and CT myelography. Dual-energy CT technology has been used to improve diagnostic utility within multiple organ systems. The capability of dual-energy CT to create virtual monoenergetic images can be leveraged to increase conspicuity of contrast in CSF-venous fistulas and direct epidural CSF leakage to improve the diagnostic utility of CT myelography. Six cases (in 5 patients) are shown in which virtual monoenergetic images demonstrate a leak location that was either occult or poorly visible on high- or low-kilovolt series. This clinical report describes the novel application of dual-energy CT for the detection of subtle CSF leaks including CSF-venous fistulas.
Collapse
Affiliation(s)
- S J Huls
- From the Department of Radiology, Mayo Clinic, Ringgold Standard Institution, Rochester, Minnesota
| | - D P Shlapak
- From the Department of Radiology, Mayo Clinic, Ringgold Standard Institution, Rochester, Minnesota
| | - D K Kim
- From the Department of Radiology, Mayo Clinic, Ringgold Standard Institution, Rochester, Minnesota
| | - S Leng
- From the Department of Radiology, Mayo Clinic, Ringgold Standard Institution, Rochester, Minnesota
| | - C M Carr
- From the Department of Radiology, Mayo Clinic, Ringgold Standard Institution, Rochester, Minnesota
| |
Collapse
|
74
|
Spectral imaging in the pediatric chest: past, present and future. Pediatr Radiol 2022; 52:1910-1920. [PMID: 35726069 DOI: 10.1007/s00247-022-05404-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/28/2022] [Accepted: 05/14/2022] [Indexed: 12/14/2022]
Abstract
Computed tomography technology continues to undergo evolution and improvement with each passing decade. From its inception in 1971, to the advent of commercially available dual-energy CT just over a decade ago, and now to the latest innovation, photon-counting detector CT, CT's utility for resolving and discriminating tissue types improves. In this review we discuss the impact of spectral imaging, including dual-energy CT and the recently available photon-counting detector CT, on the imaging of the pediatric chest. We describe the current capabilities and future directions of CT imaging, encompassing both the lungs and the surrounding tissues.
Collapse
|
75
|
Toia GV, Mileto A, Wang CL, Sahani DV. Quantitative dual-energy CT techniques in the abdomen. Abdom Radiol (NY) 2022; 47:3003-3018. [PMID: 34468796 DOI: 10.1007/s00261-021-03266-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023]
Abstract
Advances in dual-energy CT (DECT) technology and spectral techniques are catalyzing the widespread implementation of this technology across multiple radiology subspecialties. The inclusion of energy- and material-specific datasets has ushered overall improvements in CT image contrast and noise as well as artifacts reduction, leading to considerable progress in radiologists' ability to detect and characterize pathologies in the abdomen. The scope of this article is to provide an overview of various quantitative clinical DECT applications in the abdomen and pelvis. Several of the reviewed applications have not reached mainstream clinical use and are considered investigational. Nonetheless awareness of such applications is critical to having a fully comprehensive knowledge base to DECT and fostering future clinical implementation.
Collapse
Affiliation(s)
- Giuseppe V Toia
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Mailbox 3252, Madison, WI, 53792, USA.
| | - Achille Mileto
- Department of Radiology, Mayo Clinic, 200 First Street, SW, Rochester, MN, 55905, USA
| | - Carolyn L Wang
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Dushyant V Sahani
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| |
Collapse
|
76
|
Fernández-Pérez GC, Fraga Piñeiro C, Oñate Miranda M, Díez Blanco M, Mato Chaín J, Collazos Martínez MA. Dual-energy CT: Technical considerations and clinical applications. RADIOLOGIA 2022; 64:445-455. [PMID: 36243444 DOI: 10.1016/j.rxeng.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/20/2022] [Indexed: 06/16/2023]
Abstract
Although dual-energy CT was initially described by Hounsfield in 1973, it remains underused in clinical practice. It is therefore important to emphasize the clinical benefits and limitations of this technique. Iodine mapping makes it possible to quantify the uptake of iodine, which is very important in characterizing tumors, lung perfusion, pulmonary nodules, and the tumor response to new treatments. Dual-energy CT also makes it possible to obtain virtual single-energy images and virtual images without iodinated contrast or without calcium, as well as to separate materials such as uric acid or fat and to elaborate hepatic iron overload maps. In this article, we review some of the clinical benefits and technical limitations to improve understanding of dual-energy CT and expand its use in clinical practice.
Collapse
Affiliation(s)
- G C Fernández-Pérez
- Servicio de Radiodiagnóstico, Hospital Universitario Río Hortega, Grupo Recoletas, Valladolid, Spain.
| | - C Fraga Piñeiro
- Técnico Aplicaciones Siemens Healthineers, General Electric Company, Spain
| | - M Oñate Miranda
- Servicio de Radiodiagnóstico, Hospital Universitario Río Hortega, Valladolid, Spain
| | - M Díez Blanco
- Servicio de Radiodiagnóstico, Hospital Universitario Río Hortega, Valladolid, Spain
| | - J Mato Chaín
- Servicio de Radiodiagnóstico, Hospital Universitario Río Hortega, Valladolid, Spain
| | | |
Collapse
|
77
|
Fernández-Pérez G, Fraga Piñeiro C, Oñate Miranda M, Díez Blanco M, Mato Chaín J, Collazos Martínez M. Energía Dual en TC. Consideraciones técnicas y aplicaciones clínicas. RADIOLOGIA 2022. [DOI: 10.1016/j.rx.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
78
|
Automated Dual-energy Computed Tomography-based Extracellular Volume Estimation for Myocardial Characterization in Patients With Ischemic and Nonischemic Cardiomyopathy. J Thorac Imaging 2022; 37:307-314. [PMID: 35475983 DOI: 10.1097/rti.0000000000000656] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES We aimed to validate and test a prototype algorithm for automated dual-energy computed tomography (DECT)-based myocardial extracellular volume (ECV) assessment in patients with various cardiomyopathies. METHODS This retrospective study included healthy subjects (n=9; 61±10 y) and patients with cardiomyopathy (n=109, including a validation cohort n=60; 68±9 y; and a test cohort n=49; 69±11 y), who had previously undergone cardiac DECT. Myocardial ECV was calculated using a prototype-based fully automated algorithm and compared with manual assessment. Receiver-operating characteristic analysis was performed to test the algorithm's ability to distinguish healthy subjects and patients with cardiomyopathy. RESULTS The fully automated method led to a significant reduction of postprocessing time compared with manual assessment (2.2±0.4 min and 9.4±0.7 min, respectively, P <0.001). There was no significant difference in ECV between the automated and manual methods ( P =0.088). The automated method showed moderate correlation and agreement with the manual technique ( r =0.68, intraclass correlation coefficient=0.66). ECV was significantly higher in patients with cardiomyopathy compared with healthy subjects, regardless of the method used ( P <0.001). In the test cohort, the automated method yielded an area under the curve of 0.98 for identifying patients with cardiomyopathies. CONCLUSION Automated ECV estimation based on DECT showed moderate agreement with the manual method and matched with previously reported ECV values for healthy volunteers and patients with cardiomyopathy. The automatically derived ECV demonstrated an excellent diagnostic performance to discriminate between healthy and diseased myocardium, suggesting that it could be an effective initial screening tool while significantly reducing the time of assessment.
Collapse
|
79
|
Dual-source computed tomography protocols for the pediatric chest - scan optimization techniques. Pediatr Radiol 2022:10.1007/s00247-022-05468-7. [PMID: 35948645 PMCID: PMC9365683 DOI: 10.1007/s00247-022-05468-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/28/2022] [Accepted: 07/21/2022] [Indexed: 11/26/2022]
Abstract
The gold standard for pediatric chest imaging remains the CT scan. An ideal pediatric chest CT has the lowest radiation dose with the least motion degradation possible in a diagnostic scan. Because of the known inherent risks and costs of anesthesia, non-sedate options are preferred. Dual-source CTs are currently the fastest, lowest-dose CT scanners available, utilizing an ultra-high-pitch mode resulting in sub-second CTs. The dual-energy technique, available on dual-source CT scanners, gathers additional information such as pulmonary blood volume and includes relative contrast enhancement and metallic artifact reduction, features that are not available in high-pitch flash mode. In this article we discuss the benefits and tradeoffs of dual-source CT scan modes and tips on image optimization.
Collapse
|
80
|
Abdellatif W, Vasan V, Kay FU, Kohli A, Abbara S, Brewington C. Know your way around acute unenhanced CT during global iodinated contrast crisis: a refresher to ED radiologists. Emerg Radiol 2022; 29:1019-1031. [PMID: 35945464 PMCID: PMC9363271 DOI: 10.1007/s10140-022-02085-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 08/02/2022] [Indexed: 11/30/2022]
Abstract
Due to a contrast shortage crisis resulting from the decreased supply of iodinated contrast agents, the American College of Radiology (ACR) has issued a guidance statement followed by memoranda from various hospitals to preserve and prioritize the limited supply of contrast. The vast majority of iodinated contrast is used by CT, with a minority used by vascular and intervention radiology, fluoroscopy, and other services. A direct consequence is a paradigm shift to large volume unenhanced CT scans being utilized for acute and post traumatic patients in EDs, an uncharted territory for most radiologists and trainees. This article provides radiological diagnostic guidance and a pictorial example through systematic review of common unenhanced CT findings in the acute setting.
Collapse
Affiliation(s)
- Waleed Abdellatif
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA.
| | - Vasantha Vasan
- Abdominal Imaging Division, Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Fernando U Kay
- Cardiothoracic Imaging Division, Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Ajay Kohli
- Departments of Radiology and Orthopedic Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Suhny Abbara
- Cardiothoracic Imaging Division, Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Cecelia Brewington
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| |
Collapse
|
81
|
Godreau JP, Vulasala SSR, Gopireddy D, Rao D, Hernandez M, Lall C, Bhosale P, Virarkar MK. Introducing and Building a Dual-Energy CT Business. Semin Ultrasound CT MR 2022; 43:355-363. [PMID: 35738821 DOI: 10.1053/j.sult.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In recent years, there has been increased utilization of Dual-energy CT (DECT) in diagnostic imaging, mainly due to a reduction of effective radiation dose and lower intravenous contrast dose requirement in DECT imaging compared to conventional CT. A comprehensive imaging protocol and teamwork involving technologists and radiologists are needed to successfully implement DECT in clinical practice. At the same time, insight into the direct and indirect expenditures incurred is critical for rendering a cost-effective service to the patient and institution. This paper focuses on introducing the foundations of DECT to the readers and discusses the impediments encountered during the implementation of DECT in clinical practice. Potential solutions to these challenges are also proposed.
Collapse
Affiliation(s)
- Jean-Paul Godreau
- Department of Radiology, University of Florida College of Medicine, Jacksonville, FL
| | | | | | - Dinesh Rao
- Department of Radiology, University of Florida College of Medicine, Jacksonville, FL
| | - Mauricio Hernandez
- Department of Radiology, University of Florida College of Medicine, Jacksonville, FL
| | - Chandana Lall
- Department of Radiology, University of Florida College of Medicine, Jacksonville, FL
| | - Priya Bhosale
- Department of Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Mayur K Virarkar
- Department of Radiology, University of Florida College of Medicine, Jacksonville, FL.
| |
Collapse
|
82
|
Kaproth-Joslin K, Hobbs S, Rajiah P, Chaturvedi A, Chaturvedi A. Optimizing low contrast volume thoracic CT angiography: From the basics to the advanced. J Clin Imaging Sci 2022; 12:41. [PMID: 36128360 PMCID: PMC9479554 DOI: 10.25259/jcis_51_2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/30/2022] [Indexed: 11/04/2022] Open
Abstract
Contrast-enhanced CT angiography (CTA) is a widely used, noninvasive imaging technique for evaluating cardiovascular structures. Contrast-induced nephrotoxicity is a concern in renal disease; however, the true nephrotoxic potential of iodinated contrast media (CM) is unknown. If a renal impaired patient requires CTA, it is important to protect the kidneys from further harm by reducing total iodinated CM volume while still obtaining diagnostic quality imaging. These same reduced volume CM techniques can also be applied to nonrenal impaired patients in times of CM shortage. This educational review discusses several modifications to CTA that can be adapted to both conventional 64-slice and the newer generation CT scanners which enable subsecond acquisition with a reduced CM volume technique. Such modifications include hardware and software adjustments and changes to both the volume and flow rate of administered CM, with the goal to reduce the dose of CM without compromising diagnostic yield.
Collapse
Affiliation(s)
| | - Susan Hobbs
- Department of Imaging Sciences, University of Rochester, Rochester, New York, United States
| | - Prabhakar Rajiah
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, United States
| | - Apeksha Chaturvedi
- Department of Imaging Sciences, University of Rochester, Rochester, New York, United States
| | - Abhishek Chaturvedi
- Department of Imaging Sciences, University of Rochester, Rochester, New York, United States
| |
Collapse
|
83
|
Xu JJ, Lönn L, Budtz-Jørgensen E, Hansen KL, Ulriksen PS. Quantitative and qualitative assessments of deep learning image reconstruction in low-keV virtual monoenergetic dual-energy CT. Eur Radiol 2022; 32:7098-7107. [PMID: 35895120 DOI: 10.1007/s00330-022-09018-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/01/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To evaluate a novel deep learning image reconstruction (DLIR) technique for dual-energy CT (DECT) derived virtual monoenergetic (VM) images compared to adaptive statistical iterative reconstruction (ASIR-V) in low kiloelectron volt (keV) images. METHODS We analyzed 30 venous phase acute abdominal DECT (80/140 kVp) scans. Data were reconstructed to ASIR-V and DLIR-High at four different keV levels (40, 50, 74, and 100) with 1- and 3-mm slice thickness. Quantitative Hounsfield unit (HU) and noise assessment were measured within the liver, aorta, fat, and muscle. Subjective assessment of image noise, sharpness, texture, and overall quality was performed by two board-certified radiologists. RESULTS DLIR reduced image noise by 19.9-35.5% (p < 0.001) compared to ASIR-V in all reconstructions at identical keV levels. Contrast-to-noise ratio (CNR) increased by 49.2-53.2% (p < 0.001) in DLIR 40-keV images compared to ASIR-V 50 keV, while no significant difference in noise was identified except for 1 and 3 mm in aorta and for 1-mm liver measurements, where ASIR-V 50 keV showed 5.5-6.8% (p < 0.002) lower noise levels. Qualitative assessment demonstrated significant improvement particularly in 1-mm reconstructions (p < 0.001). Lastly, DLIR 40 keV demonstrated comparable or improved image quality ratings when compared to ASIR-V 50 keV (p < 0.001 to 0.22). CONCLUSION DLIR significantly reduced image noise compared to ASIR-V. Qualitative assessment showed that DLIR significantly improved image quality particularly in thin sliced images. DLIR may facilitate 40 keV as a new standard for routine low-keV VM reconstruction in contrast-enhanced abdominal DECT. KEY POINTS • DLIR enables 40 keV as the routine low-keV VM reconstruction. • DLIR significantly reduced image noise compared to ASIR-V, across a wide range of keV levels in VM DECT images. • In low-keV VM reconstructions, improvements in image quality using DLIR were most evident and consistent in 1-mm sliced images.
Collapse
Affiliation(s)
- Jack Junchi Xu
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark. .,Department of Clinical Medicine, University of Copenhagen, 2100, Copenhagen, Denmark.
| | - Lars Lönn
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Esben Budtz-Jørgensen
- Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer L Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Peter S Ulriksen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| |
Collapse
|
84
|
Wehrse E, Klein L, Rotkopf LT, Stiller W, Finke M, Echner G, Glowa C, Heinze S, Ziener CH, Schlemmer HP, Kachelrieß M, Sawall S. Ultrahigh resolution whole body photon counting computed tomography as a novel versatile tool for translational research from mouse to man. Z Med Phys 2022:S0939-3889(22)00066-6. [PMID: 35868888 DOI: 10.1016/j.zemedi.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/18/2022] [Accepted: 06/19/2022] [Indexed: 11/19/2022]
Abstract
X-ray computed tomography (CT) is a cardinal tool in clinical practice. It provides cross-sectional images within seconds. The recent introduction of clinical photon-counting CT allowed for an increase in spatial resolution by more than a factor of two resulting in a pixel size in the center of rotation of about 150 µm. This level of spatial resolution is in the order of dedicated preclinical micro-CT systems. However so far, the need for different dedicated clinical and preclinical systems often hinders the rapid translation of early research results to applications in men. This drawback might be overcome by ultra-high resolution (UHR) clinical photon-counting CT unifying preclinical and clinical research capabilities in a single machine. Herein, the prototype of a clinical UHR PCD CT (SOMATOM CounT, Siemens Healthineers, Forchheim, Germany) was used. The system comprises a conventional energy-integrating detector (EID) and a novel photon-counting detector (PCD). While the EID provides a pixel size of 0.6 mm in the centre of rotation, the PCD provides a pixel size of 0.25 mm. Additionally, it provides a quantification of photon energies by sorting them into up to four distinct energy bins. This acquisition of multi-energy data allows for a multitude of applications, e.g. pseudo-monochromatic imaging. In particular, we examine the relation between spatial resolution, image noise and administered radiation dose for a multitude of use-cases. These cases include ultra-high resolution and multi-energy acquisitions of mice administered with a prototype bismuth-based contrast agent (nanoPET Pharma, Berlin, Germany) as well as larger animals and actual patients. The clinical EID provides a spatial resolution of about 9 lp/cm (modulation transfer function at 10%, MTF10%) while UHR allows for the acquisition of images with up to 16 lp/cm allowing for the visualization of all relevant anatomical structures in preclinical and clinical specimen. The spectral capabilities of the system enable a variety of applications previously not available in preclinical research such as pseudo-monochromatic images. Clinical ultra-high resolution photon-counting CT has the potential to unify preclinical and clinical research on a single system enabling versatile imaging of specimens and individuals ranging from mice to man.
Collapse
Affiliation(s)
- E Wehrse
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - L Klein
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany; Division of X-ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - L T Rotkopf
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - W Stiller
- Diagnostic and Interventional Radiology (DIR), Heidelberg University Hospital, Heidelberg, Germany
| | - M Finke
- Diagnostic and Interventional Radiology (DIR), Heidelberg University Hospital, Heidelberg, Germany
| | - G Echner
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - C Glowa
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Radiation Oncology and Radiotherapy, University Hospital Heidelberg, Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - S Heinze
- Institute of Forensic and Traffic Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - C H Ziener
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - H-P Schlemmer
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - M Kachelrieß
- Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; Division of X-ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - S Sawall
- Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; Division of X-ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| |
Collapse
|
85
|
Jungblut L, Sartoretti T, Kronenberg D, Mergen V, Euler A, Schmidt B, Alkadhi H, Frauenfelder T, Martini K. Performance of virtual non-contrast images generated on clinical photon-counting detector CT for emphysema quantification: proof of concept. Br J Radiol 2022; 95:20211367. [PMID: 35357902 PMCID: PMC10996315 DOI: 10.1259/bjr.20211367] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/09/2022] [Accepted: 03/22/2022] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE To evaluate the performance of virtual non-contrast images (VNC) compared to true non-contrast (TNC) images in photon-counting detector computed tomography (PCD-CT) for the evaluation of lung parenchyma and emphysema quantification. METHODS 65 (mean age 73 years; 48 male) consecutive patients who underwent a three-phase (non-contrast, arterial and venous) chest/abdomen CT on a first-generation dual-source PCD-CT were retrospectively included. Scans were performed in the multienergy (QuantumPlus) mode at 120 kV with 70 ml intravenous contrast agent at an injection rate of 4 ml s-1. VNC were reconstructed from the arterial (VNCart) and venous phase (VNCven). TNC and VNC images of the lung were assessed quantitatively by calculating the global noise index (GNI) and qualitatively by two independent, blinded readers (overall image quality and emphysema assessment). Emphysema quantification was performed using a commercially available software tool at a threshold of -950 HU for all data sets. TNC images served as reference standard for emphysema quantification. Low attenuation values (LAV) were compared in a Bland-Altman plot. RESULTS GNI was similar in VNCart (103.0 ± 30.1) and VNCven (98.2 ± 22.2) as compared to TNC (100.9 ± 19.0, p = 0.546 and p = 0.272, respectively). Subjective image quality (emphysema assessment and overall image quality) was highest for TNC (p = 0.001), followed by VNCven and VNCart. Both, VNCart and VNCven showed no significant difference in emphysema quantification as compared to TNC (p = 0.409 vs. p = 0.093; respectively). CONCLUSION Emphysema evaluation is feasible using virtual non-contrast images from PCD-CT. ADVANCES IN KNOWLEDGE Emphysema quantification is feasible and accurate using VNC images in PCD-CT. Based on these findings, additional TNC scans for emphysema quantification could be omitted in the future.
Collapse
Affiliation(s)
- Lisa Jungblut
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Thomas Sartoretti
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Daniel Kronenberg
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Victor Mergen
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Andre Euler
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Bernhard Schmidt
- Siemens Healthcare GmbH, Computed Tomography,
Forchheim, Germany
| | - Hatem Alkadhi
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Thomas Frauenfelder
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| | - Katharina Martini
- Institute of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich,
Zurich, Switzerland
| |
Collapse
|
86
|
Lennartz S, Hokamp NG, Kambadakone A. Dual-Energy CT of the Abdomen: Radiology In Training. Radiology 2022; 305:19-27. [PMID: 35727149 DOI: 10.1148/radiol.212914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 61-year-old man with an esophageal cancer diagnosis underwent staging dual-energy CT of the chest and abdomen in the portal venous phase after contrast media administration. Aside from the primary tumor and suspicious local lymph nodes, CT revealed hypoattenuating ambiguous liver lesions, an incidental right adrenal nodule, and a right renal lesion with soft-tissue attenuation. In addition, advanced atherosclerosis of the abdominal aorta and its major branches was noted. This article provides a case-based review of dual-energy CT technologies and their applications in the abdomen. The clinical utility of virtual monoenergetic images, virtual unenhanced images, and iodine maps is discussed.
Collapse
Affiliation(s)
- Simon Lennartz
- From the Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany (S.L., N.G.H.); and Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Boston, Mass (A.K.)
| | - Nils Große Hokamp
- From the Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany (S.L., N.G.H.); and Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Boston, Mass (A.K.)
| | - Avinash Kambadakone
- From the Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne, Germany (S.L., N.G.H.); and Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Boston, Mass (A.K.)
| |
Collapse
|
87
|
Photon-Counting Detector CT Virtual Monoengergetic Images for Cochlear Implant Visualization—A Head to Head Comparison to Energy-Integrating Detector CT. Tomography 2022; 8:1642-1648. [PMID: 35894001 PMCID: PMC9326530 DOI: 10.3390/tomography8040136] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/07/2022] [Accepted: 06/18/2022] [Indexed: 11/24/2022] Open
Abstract
Cochlear implants (CIs) are the primary treatment method in patients with profound sensorineural hearing loss. Interpretation of postoperative imaging with conventional energy-integrating detector computed tomography (EID-CT) following CI surgery remains challenging due to metal artifacts. Still, the photon-counting detector (PCD-CT) is a new emerging technology with the potential to eliminate these problems. This study evaluated the performance of virtual monoenergetic (VME) EID-CT images versus PCD-CT in CI imaging. In this cadaveric study, two temporal bone specimens with implanted CIs were scanned with EID-CT and PCD-CT. The images were assessed according to the visibility of interelectrode wire, size of electrode contact, and diameter of halo artifacts. The visibility of interelectrode wire sections was significantly higher when reviewing PCD-CT images. The difference in diameter measurements for electrode contacts between the two CT scanner modalities showed that the PCD-CT technology generally led to significantly larger diameter readings. The larger measurements were closer to the manufacturer’s specifications for the CI electrode. The size of halo artifacts surrounding the electrode contacts did not differ significantly between the two imaging modalities. PCT-CT imaging is a promising technology for CI imaging with improved spatial resolution and better visibility of small structures than conventional EID-CT.
Collapse
|
88
|
Jacobsen MC, Beriwal S, Dyer BA, Klopp AH, Lee SI, McGinnis GJ, Robbins JB, Rauch GM, Sadowski EA, Simiele SJ, Stafford RJ, Taunk NK, Yashar CM, Venkatesan AM. Contemporary image-guided cervical cancer brachytherapy: Consensus imaging recommendations from the Society of Abdominal Radiology and the American Brachytherapy Society. Brachytherapy 2022; 21:369-388. [PMID: 35725550 DOI: 10.1016/j.brachy.2022.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/15/2022] [Accepted: 04/24/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE To present recommendations for the use of imaging for evaluation and procedural guidance of brachytherapy for cervical cancer patients. METHODS An expert panel comprised of members of the Society of Abdominal Radiology Uterine and Ovarian Cancer Disease Focused Panel and the American Brachytherapy Society jointly assessed the existing literature and provide data-driven guidance on imaging protocol development, interpretation, and reporting. RESULTS Image-guidance during applicator implantation reduces rates of uterine perforation by the tandem. Postimplant images may be acquired with radiography, computed tomography (CT), or magnetic resonance imaging (MRI), and CT or MRI are preferred due to a decrease in severe complications. Pre-brachytherapy T2-weighted MRI may be used as a reference for contouring the high-risk clinical target volume (HR-CTV) when CT is used for treatment planning. Reference CT and MRI protocols are provided for reference. CONCLUSIONS Image-guided brachytherapy in locally advanced cervical cancer is essential for optimal patient management. Various imaging modalities, including orthogonal radiographs, ultrasound, computed tomography, and magnetic resonance imaging, remain integral to the successful execution of image-guided brachytherapy.
Collapse
Affiliation(s)
- Megan C Jacobsen
- The University of Texas MD Anderson Cancer Center, Department of Imaging Physics, Houston, TX
| | - Sushil Beriwal
- Allegheny Health Network, Department of Radiation Oncology, Pittsburgh, PA; Varian Medical Systems, Palo Alto, CA
| | - Brandon A Dyer
- Legacy Health, Department of Radiation Oncology, Portland, OR
| | - Ann H Klopp
- The University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, TX
| | - Susanna I Lee
- Massachusetts General Hospital, Department of Radiology, Boston, MA
| | - Gwendolyn J McGinnis
- The University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, TX
| | | | - Gaiane M Rauch
- The University of Texas MD Anderson Cancer Center, Department of Abdominal Imaging, Houston, TX
| | | | - Samantha J Simiele
- The University of Texas MD Anderson Cancer Center, Department of Radiation Physics, Houston, TX
| | - R Jason Stafford
- The University of Texas MD Anderson Cancer Center, Department of Imaging Physics, Houston, TX
| | - Neil K Taunk
- University of Pennsylvania, Department of Radiation Oncology, Philadelphia, PA
| | - Catheryn M Yashar
- University of California San Diego, Department of Radiation Oncology, San Diego, CA
| | - Aradhana M Venkatesan
- The University of Texas MD Anderson Cancer Center, Department of Abdominal Imaging, Houston, TX.
| |
Collapse
|
89
|
Seo JY, Joo I, Yoon JH, Kang HJ, Kim S, Kim JH, Ahn C, Lee JM. Deep learning-based reconstruction of virtual monoenergetic images of kVp-switching dual energy CT for evaluation of hypervascular liver lesions: Comparison with standard reconstruction technique. Eur J Radiol 2022; 154:110390. [PMID: 35724579 DOI: 10.1016/j.ejrad.2022.110390] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 01/12/2022] [Accepted: 05/31/2022] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate clinical applicability of deep learning(DL)-based reconstruction of virtual monoenergetic images(VMIs) of arterial phase liver CT obtained by rapid kVp-switching dual-energy CT for evaluation of hypervascular liver lesions. MATERIALS AND METHODS We retrospectively included 109 patients who had available late arterial phase liver CT images of the liver obtained with a rapid switching kVp DECT scanner for suspicious intra-abdominal malignancies. Two VMIs of 70 keV and 40 keV were reconstructed using adaptive statistical iterative reconstruction (ASiR-V) for arterial phase scans. VMIs at 40 keV were additionally reconstructed with a vendor-agnostic DL-based reconstruction technique (ClariCT.AI, ClariPi, DL 40 keV). Qualitative, quantitative image quality and subjective diagnostic acceptability were compared according to reconstruction techniques. RESULTS In qualitative analysis, DL 40 keV images showed less image noise (4.55 vs 3.11 vs 3.95, p < 0.001), better image sharpness (4.75 vs 4.16 vs 4.3, p < 0.001), better image contrast (4.98 vs 4.72 vs 4.19, p < 0.017), better lesion conspicuity (4.61 vs 4.23 vs 3.4, p < 0.001) and diagnostic acceptability (4.59 vs 3.88 vs 4.09, p < 0.001) compared with ASiR-V 40 keV or 70 keV image sets. In quantitative analysis, DL 40 keV significantly reduced image noise relative to ASiR-V 40 keV images (49.9%, p < 0.001) and ASiR-V 70 keV images (85.2%, p = 0.012). DL 40 keV images showed significantly higher CNRlesion to the liver and SNRliver than ASiR-V 40 keV image and 70 keV images (p < 0.001). CONCLUSION DL-based reconstruction of 40 keV images using vendor-agnostic software showed greater noise reduction, better lesion conspicuity, image contrast, image sharpness, and higher overall image diagnostic acceptability than ASiR for 40 keV or 70 keV images in patients with hypervascular liver lesions.
Collapse
Affiliation(s)
- June Young Seo
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ijin Joo
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jeong Hee Yoon
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyo Jin Kang
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sewoo Kim
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jong Hyo Kim
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Republic of Korea; Center for Medical-IT Convergence Technology Research, Advanced Institutes of Convergence Technology, Suwon, Republic of Korea; Research Institute, ClariPi, Seoul, Republic of Korea
| | - Chulkyun Ahn
- Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Republic of Korea; Research Institute, ClariPi, Seoul, Republic of Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| |
Collapse
|
90
|
Initial Investigation of Clinical Value of Noise-Optimized Virtual Monoenergetic Images Derived From Dual-Energy Computed Tomography Angiography in Preoperative Perforator Planning of Anterolateral Thigh Flap Transplantation. J Comput Assist Tomogr 2022; 46:560-567. [PMID: 35405721 DOI: 10.1097/rct.0000000000001320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To objectively and subjectively assess the image characteristics of noise-optimized virtual monoenergetic images [MEI (+)] and polyenergetic images (PEIs) from dual-energy computed tomography angiography and then to explore the clinical value of the optimal MEI (+) in preoperative perforator planning of anterolateral thigh (ALT) flap transplantation. METHODS Sixteen patients (32 thighs) who underwent lower extremity run-off dual-energy computed tomography angiography for planning ALT flap transplantation were enrolled. One standard PEI and 5 MEI (+) in 10-keV intervals (range, 40-80 keV) were reconstructed. First, we compared the image quality subjectively (branch order, image quality, and vascular network continuity) and objectively (vascular attenuation, image noise, signal-to-noise ratio, and the contrast-to-noise ratio). Then, we compared the clinical value (number, type, source artery, pedicle length, caliber, and location of all sizable perforators) between the optimal MEI (+) and PEI groups. RESULTS The 40-keV MEI (+) was rated superior subjective and objective image quality metrics to PEI (all P < 0.001). Compared with PEI, 40 keV MEI (+) increased the number of visible perforators, the percentage of perforators with identifiable types, and the measurable length of perforator pedicle (all P < 0.001). CONCLUSIONS We recommend 40 keV MEI (+) for the visualization of perforators and their contribution to the selection and location of suitable perforators in preoperative planning for ALT flaps.
Collapse
|
91
|
Rajendran K, Petersilka M, Henning A, Shanblatt ER, Schmidt B, Flohr TG, Ferrero A, Baffour F, Diehn FE, Yu L, Rajiah P, Fletcher JG, Leng S, McCollough CH. First Clinical Photon-counting Detector CT System: Technical Evaluation. Radiology 2022; 303:130-138. [PMID: 34904876 PMCID: PMC8940675 DOI: 10.1148/radiol.212579] [Citation(s) in RCA: 235] [Impact Index Per Article: 117.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/20/2021] [Accepted: 12/21/2021] [Indexed: 11/11/2022]
Abstract
Background The first clinical CT system to use photon-counting detector (PCD) technology has become available for patient care. Purpose To assess the technical performance of the PCD CT system with use of phantoms and representative participant examinations. Materials and Methods Institutional review board approval and written informed consent from four participants were obtained. Technical performance of a dual-source PCD CT system was measured for standard and high-spatial-resolution (HR) collimations. Noise power spectrum, modulation transfer function, section sensitivity profile, iodine CT number accuracy in virtual monoenergetic images (VMIs), and iodine concentration accuracy were measured. Four participants were enrolled (between May 2021 and August 2021) in this prospective study and scanned using similar or lower radiation doses as their respective clinical examinations performed on the same day using energy-integrating detector (EID) CT. Image quality and findings from the participants' PCD CT and EID CT examinations were compared. Results All standard technical performance measures met accreditation and regulatory requirements. Relative to filtered back-projection reconstructions, images from iterative reconstruction had lower noise magnitude but preserved noise power spectrum shape and peak frequency. Maximum in-plane spatial resolutions of 125 and 208 µm were measured for HR and standard PCD CT scans, respectively. Minimum values for section sensitivity profile full width at half maximum measurements were 0.34 mm (0.2-mm nominal section thickness) and 0.64 mm (0.4-mm nominal section thickness) for HR and standard PCD CT scans, respectively. In a 120-kV standard PCD CT scan of a 40-cm phantom, VMI iodine CT numbers had a mean percentage error of 5.7%, and iodine concentration had root mean squared error of 0.5 mg/cm3, similar to previously reported values for EID CT. VMIs, iodine maps, and virtual noncontrast images were created for a coronary CT angiogram acquired with 66-msec temporal resolution. Participant PCD CT images showed up to 47% lower noise and/or improved spatial resolution compared with EID CT. Conclusion Technical performance of clinical photon-counting detector (PCD) CT is improved relative to that of a current state-of-the-art CT system. The dual-source PCD geometry facilitated 66-msec temporal resolution multienergy cardiac imaging. Study participant images illustrated the effect of the improved technical performance. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Willemink and Grist in this issue.
Collapse
Affiliation(s)
- Kishore Rajendran
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Martin Petersilka
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - André Henning
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Elisabeth R. Shanblatt
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Bernhard Schmidt
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Thomas G. Flohr
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Andrea Ferrero
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Francis Baffour
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Felix E. Diehn
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Lifeng Yu
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Prabhakar Rajiah
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Joel G. Fletcher
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Shuai Leng
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| | - Cynthia H. McCollough
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (K.R., A.F., F.B., F.E.D., L.Y., P.R., J.G.F., S.L., C.H.M.); Siemens Healthineers, Forchheim, Germany (M.P., A.H., B.S., T.G.F.); and Siemens Medical Solutions, Malvern, Pa (E.R.S.)
| |
Collapse
|
92
|
Zhou J, Chen J, Wang M, Chen F, Zhang K, Cong R, Fan X, Yang J, He B. A study on spinal level, length, and branch type of the inferior mesenteric artery and the position relationship between the inferior mesenteric artery, left colic artery, and inferior mesenteric vein. BMC Med Imaging 2022; 22:38. [PMID: 35260088 PMCID: PMC8903147 DOI: 10.1186/s12880-022-00764-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/22/2022] [Indexed: 11/17/2022] Open
Abstract
Background This study was aimed to explore the clinical application of dual-energy computed tomography (DECT) monoenergetic plus (mono+) imaging to evaluate anatomical variations in the inferior mesenteric artery (IMA). Methods The clinical and imaging data of 212 patients who had undergone total abdominal DECT were retrospectively analyzed. The post-processing mono+ technique was used to obtain 40-keV single-level images in the arterial phase. Three-dimensional reconstruction was performed to evaluate the relationship between the IMA root position and the spinal level, IMA length, and IMA branch type, as well as the position of the left colic artery (LCA) and inferior mesenteric vein (IMV) at the IMA root level. Results The IMA root was located at the L3 level in 78.3% of cases and at the L2/L3 level in 3.3%. The highest vertebral level of IMA origin was L2 (4.2%), and the lowest was L4 (7.1%). The distance from the IMA root to the level of the sacral promontory was 99.58 ± 13.07 mm, which increased with the elevation of the IMA root at the spinal level. Of the patients, 53.8% demonstrated Type I IMA, 23.1% Type II, 20.7% Type III, and 2.4% Type IV. The length of the IMA varied from 13.6 to 66.0 mm. 77.3% of the IMAs belonged to Type A, the adjacent type, and 22.7% to Type B, the distant type. Conclusion DECT mono+ can preoperatively evaluate the anatomical characteristics of the IMA and the positional relationship between the LCA and IMV at the IMA root level, which would help clinicians plan individualized surgery for patients. DECT mono+ optimal energy level can preoperatively determine the position of the IMA root. DECT mono+ can preoperatively evaluate the anatomical characteristics of the IMA. DECT mono+ can preoperatively determine the positional relationship between the LCA and IMV at the IMA root level.
Collapse
Affiliation(s)
- Jie Zhou
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China.,Department of Radiology, Changzhou Hospital of Traditional Chinese Medicine, Jiangsu, 213000, China
| | - Jinghao Chen
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China
| | - Meirong Wang
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China
| | - Feixiang Chen
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China
| | - Kun Zhang
- Department of Electrical Engineering, Nantong University, Jiangsu, 226001, China
| | - Ruochen Cong
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China
| | - Xiaole Fan
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China
| | - Jushun Yang
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China.
| | - Bosheng He
- Department of Radiology, Affiliated Hospital 2 of Nantong University, No. 6 Hai Er Xiang North Road, Nantong, 226001, Jiangsu, China. .,Clinical Medicine Research Center, Affiliated Hospital 2 of Nantong University, Jiangsu, 226001, China. .,Nantong Key Laboratory of Intelligent Medicine Innovation and Transformation, Jiangsu, 226001, China.
| |
Collapse
|
93
|
Odedra D, Narayanasamy S, Sabongui S, Priya S, Krishna S, Sheikh A. Dual Energy CT Physics-A Primer for the Emergency Radiologist. FRONTIERS IN RADIOLOGY 2022; 2:820430. [PMID: 37492677 PMCID: PMC10364985 DOI: 10.3389/fradi.2022.820430] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/17/2022] [Indexed: 07/27/2023]
Abstract
Dual energy CT (DECT) refers to the acquisition of CT images at two energy spectra and can provide information about tissue composition beyond that obtainable by conventional CT. The attenuation of a photon beam varies depends on the atomic number and density of the attenuating material and the energy of the incoming photon beam. This differential attenuation of the beam at varying energy levels forms the basis of DECT imaging and enables separation of materials with different atomic numbers but similar CT attenuation. DECT can be used to detect and quantify materials like iodine, calcium, or uric acid. Several post-processing techniques are available to generate virtual non-contrast images, iodine maps, virtual mono-chromatic images, Mixed or weighted images and material specific images. Although initially the concept of dual energy CT was introduced in 1970, it is only over the past two decades that it has been extensively used in clinical practice owing to advances in CT hardware and post-processing capabilities. There are numerous applications of DECT in Emergency radiology including stroke imaging to differentiate intracranial hemorrhage and contrast staining, diagnosis of pulmonary embolism, characterization of incidentally detected renal and adrenal lesions, to reduce beam and metal hardening artifacts, in identification of uric acid renal stones and in the diagnosis of gout. This review article aims to provide the emergency radiologist with an overview of the physics and basic principles of dual energy CT. In addition, we discuss the types of DECT acquisition and post processing techniques including newer advances such as photon-counting CT followed by a brief discussion on the applications of DECT in Emergency radiology.
Collapse
Affiliation(s)
- Devang Odedra
- Department of Radiology, University of Toronto, Toronto, ON, Canada
| | - Sabarish Narayanasamy
- Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
| | - Sandra Sabongui
- Keenan Research Centre for Biomedical Science, St Michael's Hospital, Toronto, ON, Canada
| | - Sarv Priya
- Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
| | - Satheesh Krishna
- Department of Medical Imaging, Mount Sinai Hospital, and Women's College Hospital, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Adnan Sheikh
- Department of Radiology, The University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
94
|
Pinilo J, Hutt A, Labreuche J, Faivre JB, Flohr T, Schmidt B, Duhamel A, Remy J, Remy-Jardin M. Evaluation Of a New Reconstruction Technique for Dual-Energy (DECT) Lung Perfusion: Preliminary Experience In 58 Patients. Acad Radiol 2022; 29 Suppl 2:S202-S214. [PMID: 34446359 DOI: 10.1016/j.acra.2021.07.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/16/2021] [Accepted: 07/24/2021] [Indexed: 01/01/2023]
Abstract
PURPOSE To compare dual-energy (DE) lung perfused blood volume generated by subtraction of virtual monoenergetic images (Lung Mono) with images obtained by three-compartment decomposition (Lung PBV). MATERIAL AND METHODS The study included 58 patients (28 patients with and 30 patients without PE) with reconstruction of Lung PBV images (i.e., the reference standard) and Lung Mono images. The inter-technique comparison was undertaken at a patient and segment level. RESULTS The distribution of scores of subjective image noise (patient level) significantly differed between the two reconstructions (p<0.0001), with mild noise in 58.6% (34/58) of Lung Mono images vs 25.9% (15/58) of Lung PBV images. Detection of perfusion defects (segment level) was concordant in 1104 segments (no defect: n=968; defects present: n=138) and discordant in 2 segments with a PE-related defect only depicted on Lung Mono images. Among the 28 PE patients, the distribution of gradient of attenuation between perfused areas and defects was significantly higher on Lung Mono images compared to Lung PBV (median= 73.5 HU (QI=65.0; Q3=86.0) vs 24.5 HU (22.0; 30.0); p<0.0001). In all patients, fissures were precisely identified in 77.6% of patients (45/58) on Lung Mono images while blurred (30/58; 51.7%) or not detectable (28/58; 48.3%) on Lung PBV images. CONCLUSION Lung Mono perfusion imaging allows significant improvement in the overall image quality and improved detectability of PE-type perfusion defects.
Collapse
|
95
|
Zhang X, Zhang G, Xu L, Bai X, Lu X, Yu S, Sun H, Jin Z. Utilisation of virtual non-contrast images and virtual mono-energetic images acquired from dual-layer spectral CT for renal cell carcinoma: image quality and radiation dose. Insights Imaging 2022; 13:12. [PMID: 35072807 PMCID: PMC8787008 DOI: 10.1186/s13244-021-01146-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/18/2021] [Indexed: 12/23/2022] Open
Abstract
Background Renal cell carcinoma (RCC) is the most common renal malignant tumour. We evaluated the potential value and dose reduction of virtual non-contrast (VNC) images and virtual monoenergetic images (VMIs) from dual-layer spectral CT (DL-CT) in the diagnosis of RCC. Results Sixty-two patients with pathologically confirmed RCC who underwent contrast-enhanced DL-CT were retrospectively analysed. For the comparison between true non-contrast (TNC) and VNC images of the excretory phase, the attenuation, image noise, signal-to-noise ratio (SNR) and subjective image quality of tumours and different abdominal organs and tissues were evaluated. To compare corticomedullary phase images and low keV VMIs (40 to 100 keV) from the nephrographic phase, the attenuation, image noise, SNR and subjective lesion visibility of the tumours and renal arteries were evaluated. For the tumours, significant differences were not observed in attenuation, noise or SNR between TNC and VNC images (p > 0.05). For the abdominal organs and tissues, except for fat, the difference in attenuation was 100% within 15 HU and 96.78% within 10 HU. The subjective image quality of TNC and VNC images was equivalent (p > 0.05). The attenuation of lesions in 40 keV VMIs and renal arteries in 60 keV VMIs were similar to those in the corticomedullary images (p > 0.05). The subjective lesion visibility in low keV VMIs is slightly lower than that in the corticomedullary images (p < 0.05). Using VNC and VMIs instead of TNC and corticomedullary phase images could decrease the radiation dose by 50.5%. Conclusion VNC images and VMIs acquired from DL-CT can maintain good image quality and decrease the radiation dose for diagnosis of RCC.
Collapse
|
96
|
Image-Quality Assessment of Polyenergetic and Virtual Monoenergetic Reconstructions of Unenhanced CT Scans of the Head: Initial Experiences with the First Photon-Counting CT Approved for Clinical Use. Diagnostics (Basel) 2022; 12:diagnostics12020265. [PMID: 35204356 PMCID: PMC8871064 DOI: 10.3390/diagnostics12020265] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/14/2022] [Accepted: 01/19/2022] [Indexed: 01/31/2023] Open
Abstract
In 2021, the first clinical photon-counting CT (PCCT) was introduced. The purpose of this study is to evaluate the image quality of polyenergetic and virtual monoenergetic reconstructions in unenhanced PCCTs of the head. A total of 49 consecutive patients with unenhanced PCCTs of the head were retrospectively included. The signals ± standard deviations of the gray and white matter were measured at three different locations in axial slices, and a measure of the artifacts below the cranial calvaria and in the posterior fossa between the petrous bones was also obtained. The signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for all reconstructions. In terms of the SNRs and CNRs, the polyenergetic reconstruction is superior to all virtual monoenergetic reconstructions (p < 0.001). In the MERs, the highest SNR is found in the 70 keV MER, and the highest CNR is in the 65 keV MER. In terms of artifacts below the cranial calvaria and in the posterior fossa, certain MERs are superior to polyenergetic reconstruction (p < 0.001). The PCCT provided excellent image contrast and low-noise profiles for the differentiation of the grey and white matter. Only the artifacts below the calvarium and in the posterior fossa still underperform, which is attributable to the lack of an artifact reduction algorithm in image postprocessing. It is conceivable that the usual improvements in image postprocessing, especially with regard to glaring artifacts, will lead to further improvements in image quality.
Collapse
|
97
|
Impact of Contrast Enhancement and Virtual Monoenergetic Image Energy Levels on Emphysema Quantification. Invest Radiol 2022; 57:359-365. [DOI: 10.1097/rli.0000000000000848] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
98
|
Image quality comparison of single-energy and dual-energy computed tomography for head and neck patients: a prospective randomized study. Eur Radiol 2022; 32:7700-7709. [PMID: 35441839 PMCID: PMC9668949 DOI: 10.1007/s00330-022-08689-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/15/2022] [Accepted: 02/22/2022] [Indexed: 01/03/2023]
Abstract
OBJECTIVES The aim of this study was to compare the quality of images obtained using single-energy computed tomography (SECT) performed with automated tube voltage adaptation (TVA) with dual-energy CT (DECT) weighted average images. METHODS Eighty patients were prospectively randomized to undergo either SECT with TVA (n = 40, ref. mAs 200) or radiation dose-matched DECT (n = 40, 80/Sn150 kV, ref. mAs tube A 91/tube B 61) on a dual-source CT scanner. Objective image quality was evaluated as dose-normalized contrast-to-noise ratio (CNRD) for the jugular veins relative to fatty tissue and muscle tissue and for muscle tissue relative to fatty issue. For subjective image quality, reproduction of anatomical structures, image artifacts, image noise, spatial resolution, and overall diagnostic acceptability were evaluated at sixteen anatomical substructures using Likert-type scales. RESULTS Effective radiation dose (ED) was comparable between SECT and DECT study groups (2.9 ± 0.6 mSv/3.1 ± 0.7 mSv, p = 0.5). All examinations were rated as excellent or good for clinical diagnosis. Compared to the CNRD in the SECT group, the CNRD in the DECT group was significantly higher for the jugular veins relative to fatty tissue (7.51/6.08, p < 0.001) and for muscle tissue relative to fatty tissue (4.18/2.90, p < 0.001). The CNRD for the jugular veins relative to muscle tissue (3.33/3.18, p = 0.51) was comparable between groups. Image artifacts were less pronounced and overall diagnostic acceptability was higher in the DECT group (all p = 0.01). CONCLUSIONS DECT weighted average images deliver higher objective and subjective image quality than SECT performed with TVA in head and neck imaging. KEY POINTS • Weighted average images derived from dual-energy CT deliver higher objective and subjective image quality than single-energy CT using automated tube voltage adaptation in head and neck imaging. • If available, dual-energy CT acquisition may be preferred over automated low tube voltage adopted single-energy CT for both malignant and non-malignant conditions.
Collapse
|
99
|
Yue W, Yang W, peng H, Zhong Feng N, Hong Jie H. Comparative study of the image quality of twin beam dual energy and single energy carotid CT angiography. Eur J Radiol 2022; 148:110160. [DOI: 10.1016/j.ejrad.2022.110160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/18/2021] [Accepted: 01/12/2022] [Indexed: 12/14/2022]
|
100
|
Euler A, Zadory M, Breiding PS, Sartoretti T, Ghafoor S, Froehlich JM, Donati OF. Realistic Kidney Tissue Surrogates for Multienergy Computed Tomography-Feasibility and Estimation of Energy-Dependent Attenuation Thresholds for Renal Lesion Enhancement in Low-kV and Virtual Monoenergetic Imaging. Invest Radiol 2021; 56:791-798. [PMID: 33899757 DOI: 10.1097/rli.0000000000000790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The aims of this study were to assess if kidney tissue surrogates (KTSs) are superior to distilled water-iodine solutions in the emulation of energy-dependent computed tomography (CT) attenuation characteristics of renal parenchyma and to estimate attenuation thresholds for definite lesion enhancement for low-kV single-energy and low-keV dual-energy virtual monoenergetic imaging. METHODS A water-filled phantom (diameter, 30 cm) with multiple vials was imaged on a dual-source dual-energy CT (DS-DE) and a single-source split-filter dual-energy CT (SF-DE), both in single-energy mode at 80, 100, 120, 140 kVp and in dual-energy mode at 80/Sn150, 90/Sn150, and 100/Sn150 kVp for DS-DE and AuSn120 kVp for SF-DE. Single-energy images, linear-blended dual-energy images, and virtual monoenergetic imaging at energy levels from 40 to 190 keV were reconstructed. First, attenuation characteristics of KTS in solid and liquid consistencies were compared. Second, solid KTSs were developed to match the CT attenuation of unenhanced renal parenchyma at 120 kVp as retrospectively measured in 100 patients. Third, CT attenuation of KTS-iodine and water-iodine solutions at 8 different iodine concentrations (0-10 mg I/mL) were compared as a function of tube voltage and of keV level using multiple linear regression models. Energy-dependent attenuation thresholds for definite lesion enhancement were calculated. RESULTS Unenhanced renal parenchyma at 120 kVp measured on average 30 HU on both scanners in the patient cohort. Solid KTS with a water content of 80% emulated the attenuation of unenhanced renal parenchyma (30 HU) more accurately compared with water-iodine solutions (0 HU). Attenuation difference between KTS-iodine and water-iodine solutions converged with increasing iodine concentration and decreasing x-ray energy due to beam-hardening effects. A slight attenuation difference of approximately 2 HU was found between the 2 CT scanners. Attenuation thresholds for definite lesion enhancement were dependent on tube voltage and keV level and ranged from 16.6 to 33.2 HU and 3.2 to 68.3 HU for single-energy and dual-energy CT scan modes for DS-DE and from 16.1 to 34.3 HU and 3.3 to 92.2 HU for SF-DE. CONCLUSIONS Kidney tissue surrogates more accurately emulate the energy-dependent CT attenuation characteristics of renal parenchyma for multienergy CT compared with conventional water-iodine approaches. Energy-dependent thresholds for definite lesion enhancement could facilitate lesion characterization when imaging at different energies than the traditional 120 kVp.
Collapse
Affiliation(s)
- André Euler
- From the Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, University of Zurich
| | | | - Philipe Sebastian Breiding
- From the Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, University of Zurich
| | | | - Soleen Ghafoor
- From the Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, University of Zurich
| | | | - Olivio Fabrizio Donati
- From the Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, University of Zurich
| |
Collapse
|