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Jarunnarumol N, Kamalian S, Lev MH, Gupta R. Neuroradiology Applications of Dual and Multi-energy Computed Tomography. Radiol Clin North Am 2023; 61:973-985. [PMID: 37758364 DOI: 10.1016/j.rcl.2023.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Computed tomography (CT) imaging has become an essential diagnostic tool for most emergent clinical conditions, owing to its speed, accuracy, cost, and few contraindications, compared with MR imaging cross-sectional imaging. Spectral CT, which includes dual, multienergy, and photon-counting CT, is superior to conventional single-energy CT (SECT) in many respects. Spectral information enables differentiation between materials with similar Hounsfield Unit attenuations on SECT; examples include but are not limited to "virtual noncontrast," "virtual noncalcium," and most notably for neuro applications, "hemorrhage versus iodine." This article expands on the many possible benefits of spectral CT in neuroimaging.
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Affiliation(s)
- Natthawut Jarunnarumol
- Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | - Shahmir Kamalian
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Michael H Lev
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Rajiv Gupta
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Baba A, Kurokawa R, Kurokawa M, Reifeiss S, Policeni BA, Ota Y, Srinivasan A. Advanced imaging of head and neck infections. J Neuroimaging 2023. [PMID: 36922159 DOI: 10.1111/jon.13099] [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: 12/29/2022] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/17/2023] Open
Abstract
When head and neck infection is suspected, appropriate imaging contributes to treatment decisions and prognosis. While contrast-enhanced CT is the standard imaging modality for evaluating head and neck infections, MRI can better characterize the skull base, intracranial involvement, and osteomyelitis, implying that these are complementary techniques for a comprehensive assessment. Both CT and MRI are useful in the evaluation of abscesses and thrombophlebitis, while MRI is especially useful in the evaluation of intracranial inflammatory spread/abscess formation, differentiation of abscess from other conditions, evaluation of the presence and activity of inflammation and osteomyelitis, evaluation of mastoid extension in middle ear cholesteatoma, and evaluation of facial neuritis and labyrinthitis. Apparent diffusion coefficient derived from diffusion-weighted imaging is useful for differential diagnosis and treatment response of head and neck infections in various anatomical sites. Dynamic contrast-enhanced MRI perfusion may be useful in assessing the activity of skull base osteomyelitis. MR bone imaging may be of additional value in evaluating bony structures of the skull base and jaw. Dual-energy CT is helpful in reducing metal artifacts, evaluating deep neck abscess, and detecting salivary stones. Subtraction CT techniques are used to detect progressive bone-destructive changes and to reduce dental amalgam artifacts. This article provides a region-based approach to the imaging evaluation of head and neck infections, using both conventional and advanced imaging techniques.
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Affiliation(s)
- Akira Baba
- Division of Neuroradiology, Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Ryo Kurokawa
- Division of Neuroradiology, Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mariko Kurokawa
- Division of Neuroradiology, Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Scott Reifeiss
- Department of Radiology, Roy Caver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Bruno A Policeni
- Department of Radiology, Roy Caver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Yoshiaki Ota
- Division of Neuroradiology, Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Ashok Srinivasan
- Division of Neuroradiology, Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
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Marshall EL, Ginat DT, Sammet S. Computed Tomography Imaging Artifacts in the Head and Neck Region. Neuroimaging Clin N Am 2022; 32:271-277. [DOI: 10.1016/j.nic.2022.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Gaddam DS, Dattwyler M, Fleiter TR, Bodanapally UK. Principles and Applications of Dual Energy Computed Tomography in Neuroradiology. Semin Ultrasound CT MR 2021; 42:418-433. [PMID: 34537112 DOI: 10.1053/j.sult.2021.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dual-energy computed tomography (DE CT) is a promising tool with many current and evolving applications. Available DE CT scanners usually consist of one or two tubes, or use layered detectors for spectral separation. Most DE CT scanners can be used in single energy or dual-energy mode, except for the layered detector scanners that always acquire data in dual-energy mode. However, the layered detector scanners can retrospectively integrate the data from two layers to obtain conventional single energy images. DE CT mode enables generation of virtual monochromatic images, blended images, iodine quantification, improving conspicuity of iodinated contrast enhancement, and material decomposition maps or more sophisticated quantitative analysis not possible with conventional SE CT acquisition with an acceptable or even lower dose than the SE CT. This article reviews the basic principles of dual-energy CT and highlights many of its clinical applications in the evaluation of neurological conditions.
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Affiliation(s)
- Durga Sivacharan Gaddam
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD
| | - Matthew Dattwyler
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD
| | - Thorsten R Fleiter
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD
| | - Uttam K Bodanapally
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD.
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Diekhoff T, Scheel M, Kress W, Hamm B, Jahnke P. Dual-energy computed tomography of the neck-optimizing tube current settings and radiation dose using a 3D-printed patient phantom. Quant Imaging Med Surg 2021; 11:1144-1155. [PMID: 33816156 DOI: 10.21037/qims-20-854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Dual-energy computed tomography (DECT) is increasingly used in studies and clinical practice. However, the best protocol is controversially discussed and whether it exhibits more radiation exposure compared to conventional protocols. Thus, the purpose of the study was to determine optimal tube current settings for DECT in a 3D-printed anthropomorphic phantom of the neck. Methods A 3D-printed iodinated ink based phantom of a contrast enhanced CT of the neck was imaged. Six dual-energy multi-detector computed tomography scans were performed with six different tube currents (80 kVp: 30-400 mAs; 135 kVp: 5-160 mAs). 120 virtual blended images (VBIs) and 66 virtual monochromatic images (VMIs) were reconstructed and 12 regions of interest (bilaterally: common carotid arteries, subcutaneous soft tissue, mandibular bone, sternocleidomastoid muscle, submandibular gland, and mid-image: vertebral body of C2 and pharyngeal space) in six consecutive slices resulting in 96 measurements per scan were performed. Hounsfield units and signal- and contrast-to-noise ratio were compared to single-energy computed tomography as standard of reference. Results VBIs overestimated the Hounsfield units (P<0.0001). Optimal dual-energy scanning parameters resulted in 120% (100 kVe: 51.2 vs. 61.7 and 65.2, for signal and contrast-to-noise ratio, respectively; 120 kVe: 60.8 vs. 72.1 vs. 128.3) of the radiation exposure with about 80% of the signal/contrast-to-noise ratio of the corresponding single-energy images. However, optimal weighting of tube currents for both voltages depended on the desired reconstruction. Conclusions Dual-energy protocols apply an estimated 120% of the single-energy radiation exposure and result in approximately 80% of the image quality. Tube current settings should be adapted to the desired information.
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Affiliation(s)
- Torsten Diekhoff
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany
| | - Michael Scheel
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany
| | - Wiebke Kress
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany
| | - Bernd Hamm
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany
| | - Paul Jahnke
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2, 10178 Berlin, Germany
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Blind Separation Model of Multi-voltage Projections for the Hardening Artifact Correction in Computed Tomography. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2020.102236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Farr JB, Moyers MF, Allgower CE, Bues M, Hsi WC, Jin H, Mihailidis DN, Lu HM, Newhauser WD, Sahoo N, Slopsema R, Yeung D, Zhu XR. Clinical commissioning of intensity-modulated proton therapy systems: Report of AAPM Task Group 185. Med Phys 2020; 48:e1-e30. [PMID: 33078858 DOI: 10.1002/mp.14546] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023] Open
Abstract
Proton therapy is an expanding radiotherapy modality in the United States and worldwide. With the number of proton therapy centers treating patients increasing, so does the need for consistent, high-quality clinical commissioning practices. Clinical commissioning encompasses the entire proton therapy system's multiple components, including the treatment delivery system, the patient positioning system, and the image-guided radiotherapy components. Also included in the commissioning process are the x-ray computed tomography scanner calibration for proton stopping power, the radiotherapy treatment planning system, and corresponding portions of the treatment management system. This commissioning report focuses exclusively on intensity-modulated scanning systems, presenting details of how to perform the commissioning of the proton therapy and ancillary systems, including the required proton beam measurements, treatment planning system dose modeling, and the equipment needed.
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Affiliation(s)
- Jonathan B Farr
- Department of Medical Physics, Applications of Detectors and Accelerators to Medicine, Meyrin, 1217, Switzerland
| | | | - Chris E Allgower
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, 46202, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ, 85259, USA
| | - Wen-Chien Hsi
- University of Florida Proton Therapy Institute, University of Florida, Jacksonville, FL, 32206, USA
| | - Hosang Jin
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Dimitris N Mihailidis
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hsiao-Ming Lu
- Department of Radiation Oncology, Hefei Ion Medical Center, 1700 Changning Avenue, Gaoxin District, Hefei, Anhui, 230088, China
| | - Wayne D Newhauser
- Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA.,Mary Bird Perkins Cancer Center, Baton Rouge, LA, 70809, USA
| | - Narayan Sahoo
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Roelf Slopsema
- Department of Radiation Oncology, Emory Proton Therapy Center, Emory University, Atlanta, GA, 30322, USA
| | - Daniel Yeung
- Saudi Proton Therapy Center, King Fahad Medical City, Riyadh, Riyadh Province, 11525, Saudi Arabia
| | - X Ronald Zhu
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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Wang S, Xing HX, Li J, Zhang YJ, Fan TY, Yuan SH, Hu XD, Xu M. Correlation of displacement of mediastinal metastatic lymph nodes with adjacent organs in non-small cell lung cancer on four-dimensional computed tomography. PRECISION RADIATION ONCOLOGY 2019. [DOI: 10.1002/pro6.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Suzhen Wang
- Shandong Cancer Hospital Affiliated to Shandong University; Department of Radiation Oncology; Shandong China
| | - Huai-Xin Xing
- Shandong Cancer Hospital & Institute; Department of Anesthesiology; Shandong China
| | - Jianbin Li
- Shandong Cancer Hospital Affiliated to Shandong University; Department of Radiation Oncology; Shandong Cancer Hospital & Institute; Shandong China
| | | | - Ting-Yong Fan
- Shandong Cancer Hospital & Institute; Shandong China
| | | | - Xu-Dong Hu
- Shandong Cancer Hospital & Institute; Shandong China
| | - Min Xu
- Shandong Cancer Hospital & Institute; Shandong China
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High-Pitch Wide-Coverage Fast-Kilovoltage-Switching Dual-Energy CT: Impact of Pitch on Noise, Spatial Resolution, and Iodine Quantification in a Phantom Study. AJR Am J Roentgenol 2019; 212:W64-W72. [PMID: 30645160 DOI: 10.2214/ajr.18.19851] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The purpose of this study was to assess the impact of high pitch values on image noise, spatial resolution, and iodine quantification in single-source wide-coverage fast-kilovoltage-switching dual-energy CT (DECT). MATERIALS AND METHODS Two phantom experiments were conducted. First, image noise and spatial resolution in the x-, y-, and z-directions were assessed. Second, the accuracy of iodine quantification was investigated with multiple-size phantoms with pure iodine and blood-iodine inserts. Both phantoms were scanned repeatedly with a third-generation fast-kilovoltage-switching DECT scanner with a collimation width of 80 mm at four different pitch values (0.5, 0.99, 1.375, 1.53) and three different gantry rotation times (0.6, 0.8, 1.0 second). Image noise, spatial resolution, and absolute error of iodine concentration (E) were measured. A linear mixed effects model was used to determine the effect of pitch, rotation time, and size on the error of iodine concentration. RESULTS Image noise and xy spatial resolution were comparable among the four pitch values. Spatial resolution in the z-direction was inferior and had higher variance at a low pitch of 0.5 compared with pitches of 0.99, 1.375, and 1.53. Error of iodine concentration was significantly affected by pitch and rotation time (p < 0.001). E decreased with increasing pitch and decreasing rotation time. In detail, mean E was 0.91 ± 0.47 mg I/mL for a pitch of 0.5, 0.52 ± 0.29 mg I/mL for 0.99, 0.44 ± 0.25 mg I/mL for 1.375, and 0.40 ± 0.25 mg I/mL for 1.53. CONCLUSION High-pitch wide-coverage fast-kilovoltage-switching DECT can be performed without impairing image quality or iodine quantification, and the results are superior to those of imaging at a low pitch of 0.5.
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How to Incorporate Dual-Energy Computed Tomography Into Your Neuroradiology Practice: Questions and Answers. J Comput Assist Tomogr 2018; 42:824-830. [PMID: 30371617 DOI: 10.1097/rct.0000000000000810] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dual-energy computed tomography (DECT) has many current and evolving applications in neuroradiology including material decomposition, improving conspicuity of iodinated contrast enhancement, and artifact reduction. However, there are multiple challenges in incorporating DECT into practice including hardware selection, postprocessing software requirements, technologist and physician training, and numerous workflow issues. This article reviews in a question-and-answer format common issues that arise when incorporating DECT into a busy neuroradiology practice.
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