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Naimi S, Tetteh MA, Ashraf H, Johansen S. Evaluation of an in-use chest CT protocol in lung cancer screening - A single institutional study. Acta Radiol Open 2024; 13:20584601241256005. [PMID: 39044837 PMCID: PMC11265249 DOI: 10.1177/20584601241256005] [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: 11/26/2023] [Accepted: 05/02/2024] [Indexed: 07/25/2024] Open
Abstract
Background Lung cancer is the most common cause of cancer-related death worldwide and therefore there has been a growing demand for low-dose computed tomography (LDCT) protocols. Purpose To investigate and evaluate the dose and image quality of patients undergoing lung cancer screening (LCS) using LDCT in Norway. Materials and Methods Retrospective dosimetry data, volumetric CT dose index (CTDIvol) and dose-length product (DLP), from 70 average-size and 70 large-size patients who underwent LDCT scan for LCS were included in the survey. Effective dose and size-specific dose were calculated for each examination and were compared with the American Association of Physicists in Medicine (AAPM) requirement. For a quantitative image quality analysis, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were determined for different regions in the chest with two iterative reconstruction techniques, iDose and Iterative Model Reconstruction. Differences in dose and image quality between average-size and large-size patients were evaluated by Independent sample t test, and Wilcoxon signed rank test within the same patient group. Results The independent sample t test revealed significant differences (p < .05) in dose values between average-size and large-size patients. Mean CTDIvol and DLP for average-size patients were 2.8 mGy and 115 mGy.cm, respectively, with appropriate increment for the large-size patients. Image quality (image noise, SNR, and CNR) did not significantly differ between patient groups when images were reconstructed with a model based iterative reconstruction algorithm. Conclusion The screening protocol assessed in this study resulted in CTDIvol values that were compliant with AAPM recommendation. No significant differences in objective image quality were found between patient groups.
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Affiliation(s)
- Salma Naimi
- Health faculty, Oslo Metropolitan University, Oslo, Norway
| | - Mercy Afadzi Tetteh
- Department of Diagnostic Imaging, Akershus University Hospital, Lørenskog, Norway
| | - Haseem Ashraf
- Department of Diagnostic Imaging, Akershus University Hospital, Lørenskog, Norway
- Division of Medicine and Laboratory Sciences, University of Oslo, Oslo, Norway
| | - Safora Johansen
- Health faculty, Oslo Metropolitan University, Oslo, Norway
- Department of Cancer Treatment, Oslo University Hospital, Oslo, Norway
- Health and Social Sciences, Cluster, Singapore Institution of Technology, Singaporee
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Varghese BA, Cen SY, Jensen K, Levy J, Andersen HK, Schulz A, Lei X, Duddalwar VA, Goodenough DJ. Investigating the role of imaging factors in the variability of CT-based texture analysis metrics. J Appl Clin Med Phys 2024; 25:e14192. [PMID: 37962032 PMCID: PMC11005980 DOI: 10.1002/acm2.14192] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 08/02/2023] [Accepted: 10/12/2023] [Indexed: 11/15/2023] Open
Abstract
OBJECTIVE This study assesses the robustness of first-order radiomic texture features namely interquartile range (IQR), coefficient of variation (CV) and standard deviation (SD) derived from computed tomography (CT) images by varying dose, reconstruction algorithms and slice thickness using scans of a uniform water phantom, a commercial anthropomorphic liver phantom, and a human liver in-vivo. MATERIALS AND METHODS Scans were acquired on a 16 cm detector GE Revolution Apex Edition CT scanner with variations across three different nominal slice thicknesses: 0.625, 1.25, and 2.5 mm, three different dose levels: CTDIvol of 13.86 mGy for the standard dose, 40% reduced dose and 60% reduced dose and two different reconstruction algorithms: a deep learning image reconstruction (DLIR-high) algorithm and a hybrid iterative reconstruction (IR) algorithm ASiR-V50% (AV50) were explored, varying one at a time. To assess the effect of non-linear modifications of images by AV50 and DLIR-high, images of the water phantom were also reconstructed using filtered back projection (FBP). Quantitative measures of IQR, CV and SD were extracted from twelve pre-selected, circular (1 cm diameter) regions of interest (ROIs) capturing different texture patterns across all scans. RESULTS Across all scans, imaging, and reconstruction settings, CV, IQR and SD were observed to increase with reduction in dose and slice thickness. An exception to this observation was found when using FBP reconstruction. Lower values of CV, IQR and SD were observed in DLIR-high reconstructions compared to AV50 and FBP. The Poisson statistics were more stringently noted in FBP than DLIR-high and AV50, due to the non-linear nature of the latter two algorithms. CONCLUSION Variation in image noise due to dose reduction algorithms, tube current, and slice thickness show a consistent trend across phantom and patient scans. Prospective evaluation across multiple centers, scanners and imaging protocols is needed for establishing quality assurance standards of radiomics.
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Affiliation(s)
- Bino Abel Varghese
- Keck Medical CenterDepartment of RadiologyUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Steven Yong Cen
- Keck Medical CenterDepartment of RadiologyUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Kristin Jensen
- Department of Physics and Computational RadiologyOsloNorway
| | | | | | - Anselm Schulz
- Department of Radiology and Nuclear MedicineOslo University HospitalOsloNorway
| | - Xiaomeng Lei
- Keck Medical CenterDepartment of RadiologyUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Vinay Anant Duddalwar
- Keck Medical CenterDepartment of RadiologyUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - David John Goodenough
- Department of RadiologyGeorge Washington UniversityWashingtonDistrict of ColumbiaUSA
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Henning MK, Aaløkken TM, Martinsen AC, Johansen S. The impact of body compositions on contrast medium enhancement in chest CT: a randomised controlled trial. BJR Open 2023; 5:20230054. [PMID: 37942494 PMCID: PMC10630975 DOI: 10.1259/bjro.20230054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 11/10/2023] Open
Abstract
Objective To compare a fixed-volume contrast medium (CM) protocol with a combined total body weight (TBW) and body composition-tailored protocol in chest CT. Methods and materials Patients referred for routine contrast enhanced chest CT were prospectively categorised as normal, muscular or overweight. Patients were accordingly randomised into two groups; Group 1 received a fixed CM protocol. Group 2 received CM volume according to a body composition-tailored protocol. Objective image quality comparisons between protocols and body compositions were performed. Differences between groups and correlation were analysed using t-test and Pearson's r. Results A total of 179 patients were included: 87 in Group 1 (mean age, 51 ± 17 years); and 92 in Group 2 (mean age, 52 ± 17 years). Compared to Group 2, Group 1 showed lower vascular attenuation in muscular (mean 346 Hounsfield unit (HU) vs 396 HU; p = 0.004) and overweight categories (mean 342 HU vs 367 HU; p = 0.12), while normal category patients showed increased attenuation (385 vs 367; p = 0.61). In Group 1, strongest correlation was found between attenuation and TBW in muscular (r = -.49, p = 0.009) and waist circumference in overweight patients (r = -.50, p = 0.005). In Group 2, no significant correlations were found for the same body size parameters. In Group 1, 13% of the overweight patients was below 250 HU (p = 0.053). Conclusion A combined TBW and body composition-tailored CM protocol in chest CT resulted in more homogenous enhancement and fewer outliers compared to a fixed-volume protocol. Advances in knowledge This is, to our knowledge, the first study to investigate the impact of various body compositions on contrast medium enhancement in chest CT.
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Racine D, Mergen V, Viry A, Eberhard M, Becce F, Rotzinger DC, Alkadhi H, Euler A. Photon-Counting Detector CT With Quantum Iterative Reconstruction: Impact on Liver Lesion Detection and Radiation Dose Reduction. Invest Radiol 2023; 58:245-252. [PMID: 36094810 DOI: 10.1097/rli.0000000000000925] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To assess image noise, diagnostic performance, and potential for radiation dose reduction of photon-counting detector (PCD) computed tomography (CT) with quantum iterative reconstruction (QIR) in the detection of hypoattenuating and hyperattenuating focal liver lesions compared with energy-integrating detector (EID) CT. MATERIALS AND METHODS A medium-sized anthropomorphic abdominal phantom with liver parenchyma and lesions (diameter, 5-10 mm; hypoattenuating and hyperattenuating from -30 HU to +90 HU at 120 kVp) was used. The phantom was imaged on ( a ) a third-generation dual-source EID-CT (SOMATOM Force, Siemens Healthineers) in the dual-energy mode at 100 and 150 kVp with tin filtration and ( b ) a clinical dual-source PCD-CT at 120 kVp (NAEOTOM Alpha, Siemens). Scans were repeated 10 times for each of 3 different radiation doses of 5, 2.5, and 1.25 mGy. Datasets were reconstructed as virtual monoenergetic images (VMIs) at 60 keV for both scanners and as linear-blended images (LBIs) for EID-CT. For PCD-CT, VMIs were reconstructed with different strength levels of QIR (QIR 1-4) and without QIR (QIR-off). For EID-CT, VMIs and LBIs were reconstructed using advanced modeled iterative reconstruction at a strength level of 3. Noise power spectrum was measured to compare image noise magnitude and texture. A channelized Hotelling model observer was used to assess diagnostic accuracy for lesion detection. The potential for radiation dose reduction using PCD-CT was estimated for the QIR strength level with the highest area under the curve compared with EID-CT for each radiation dose. RESULTS Image noise decreased with increasing QIR level at all radiation doses. Using QIR-4, noise reduction was 41%, 45%, and 59% compared with EID-CT VMIs and 12%, 18%, and 33% compared with EID-CT LBIs at 5, 2.5, and 1.25 mGy, respectively. The peak spatial frequency shifted slightly to lower frequencies at higher QIR levels. Lesion detection accuracy increased at higher QIR levels and was higher for PCD-CT compared with EID-CT VMIs. The improvement in detection with PCD-CT was strongest at the lowest radiation dose, with an area under the receiver operating curve of 0.917 for QIR-4 versus 0.677 for EID-CT VMIs for hyperattenuating lesions, and 0.900 for QIR-4 versus 0.726 for EID-CT VMIs for hypoattenuating lesions. Compared with EID-CT LBIs, detection was higher for QIR 1-4 at 2.5 mGy and for QIR 2-4 at 1.25 mGy (eg, 0.900 for QIR-4 compared with 0.854 for EID-CT LBIs at 1.25 mGy). Radiation dose reduction potential of PCD-CT with QIR-4 was 54% at 5 mGy compared with VMIs and 39% at 2.5 mGy compared with LBIs. CONCLUSIONS Compared with EID-CT, PCD-CT with QIR substantially improved focal liver lesion detection, especially at low radiation dose. This enables substantial radiation dose reduction while maintaining diagnostic accuracy.
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Affiliation(s)
- Damien Racine
- From the Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne
| | - Victor Mergen
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich
| | - Anaïs Viry
- From the Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne
| | - Matthias Eberhard
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich
| | - Fabio Becce
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - David C Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Hatem Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich
| | - André Euler
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich
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Mokhtar A, Aabdelbary ZA, Sarhan A, Gad HM, Ahmed MT. Studies on the radiation dose, image quality and low contrast detectability from MSCT abdomen by using low tube voltage. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2021. [DOI: 10.1186/s43055-021-00613-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
To study radiation dose, image quality and low-contrast cylinder detectability from multislice CT (MSCT) abdomen by using low tube voltage using the American College of Radiology (ACR) phantom. The ACR phantom (low-contrast module) was scanned with 64 MSCT scanner (Brilliance, Philips Medical System, Eindhoven, Netherlands) with 80 and 120 KVP, utilizing different tube current time product (mAs) range from 50 to 380 mAs. The image noise (SD), signal to noise ratio, contrast-to-noise ratio (CNR), and scores of low contrast detectability were assessed for every image respectively.
Results
From images analyses, the noise essentially increased with the use of low tube voltage. The CNR was 0.94 ± 0.27 at 120 KVP, and CNR was 0.43 ± 0.22 at 80 KVP. However, with the same dose, there were no differences of statistical significance in scores of low-contrast detectability between 120 KVP at 300mAs and 80 KVP at (200–380) mAs (p > 0.05). At 300 mAs, the CTDIvol obtained at 80 KVP was about 29% of that at 120 KVP. The CTDIvol obtained at 80 KVP were decreased from 5% at 50 mAs, to 37% at 380 mAs.
Conclusions
There is a possibility to decrease exposure of radiation virtually by reducing KVP from 120 to 80 KVP in examination of abdominal CT when the high tube current is used, though increasing image noise at low tube voltage.
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Godt JC, Johansen CK, Martinsen ACT, Schulz A, Brøgger HM, Jensen K, Stray-Pedersen A, Dormagen JB. Iterative reconstruction improves image quality and reduces radiation dose in trauma protocols; A human cadaver study. Acta Radiol Open 2021; 10:20584601211055389. [PMID: 34840815 PMCID: PMC8619783 DOI: 10.1177/20584601211055389] [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: 04/19/2021] [Accepted: 10/07/2021] [Indexed: 12/02/2022] Open
Abstract
Background Radiation-related cancer risk is an object of concern in CT of trauma patients, as these represent a young population. Different radiation reducing methods, including iterative reconstruction (IR), and spilt bolus techniques have been introduced in the recent years in different large scale trauma centers. Purpose To compare image quality in human cadaver exposed to thoracoabdominal computed tomography using IR and standard filtered back-projection (FBP) at different dose levels. Material and methods Ten cadavers were scanned at full dose and a dose reduction in CTDIvol of 5 mGy (low dose 1) and 7.5 mGy (low dose 2) on a Siemens Definition Flash 128-slice computed tomography scanner. Low dose images were reconstructed with FBP and Sinogram affirmed iterative reconstruction (SAFIRE) level 2 and 4. Quantitative image quality was analyzed by comparison of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). Qualitative image quality was evaluated by use of visual grading regression (VGR) by four radiologists. Results Readers preferred SAFIRE reconstructed images over FBP at a dose reduction of 40% (low dose 1) and 56% (low dose 2), with significant difference in overall impression of image quality. CNR and SNR showed significant improvement for images reconstructed with SAFIRE 2 and 4 compared to FBP at both low dose levels. Conclusions Iterative image reconstruction, SAFIRE 2 and 4, resulted in equal or improved image quality at a dose reduction of up to 56% compared to full dose FBP and may be used a strong radiation reduction tool in the young trauma population.
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Affiliation(s)
- Johannes Clemens Godt
- Department of Radiology and Nuclear Medicine, Oslo University Hospital Ullevål, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Cathrine K Johansen
- Department of Radiology and Nuclear Medicine, Oslo University Hospital Ullevål, Oslo, Norway
| | - Anne Catrine T Martinsen
- The Research Department, Sunnaas Rehabilitation Hospital, Norway.,Faculty of Health Sciences, Oslo Metropolitan University, Oslo, Norway.,Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Anselm Schulz
- Department of Radiology and Nuclear Medicine, Oslo University Hospital Ullevål, Oslo, Norway.,Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Helga M Brøgger
- Department of Radiology and Nuclear Medicine, Oslo University Hospital Ullevål, Oslo, Norway
| | - Kristin Jensen
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Arne Stray-Pedersen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
| | - Johann Baptist Dormagen
- Department of Radiology and Nuclear Medicine, Oslo University Hospital Ullevål, Oslo, Norway
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7
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Cristofaro M, Busi Rizzi E, Piselli P, Pianura E, Petrone A, Fusco N, Di Stefano F, Schinina' V. Image quality and radiation dose reduction in chest CT in pulmonary infection. Radiol Med 2020; 125:451-460. [PMID: 32048157 DOI: 10.1007/s11547-020-01139-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 01/16/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan comparing two protocols. MATERIALS AND METHODS Fifty-nine patients were enrolled. The two CT protocols were applied using Iterative Reconstruction (ASIR™) 40% but different noise indexes, recording dose-length product (DLP) and volume computed tomography dose index (CTDIvol). The subjective IQ was rated based on the distinction of anatomic details using a 4-point Likert scale based on the European Guidelines on Quality Criteria for CT. For each patient, two single CTs, at enrollment (group 1) and at follow-up after lowering the dose (group 2), were evaluated by two radiologists evaluating, for each examination, five different lung regions (central zone-CZ; peripheral zone-PZ; sub-pleural region-SPR; centrilobular region-CLR; and apical zone-AZ). An inter-observer agreement was expressed by weighted Cohen's kappa statistics (k) and intra-individual differences of subjective image analysis through visual grading characteristic (VGC) analysis. RESULTS An average 50.4% reduction in CTDIvol and 51.5% reduction in DLP delivered were observed using the dose-reduced protocol. An agreement between observers evaluating group 1 CTs was perfect (100%) and moderate to good in group 2 examinations (k-Cohen ranging from 0.56 for PZ and AZ to 0.70 for SPR). In the VGC analysis, image quality ratings were significantly better for group 1 than group 2 scans for all regions (AUCVGC ranging from 0.56 for CZ to 0.62). However, disagreement was limited to a score 4 (excellent)-to-score 3 (good) IQ transition; apart from a single case in PZ, both the observers scored the IQ at follow-up as 2 (sufficient) starting from a score 4 (excellent). CONCLUSION Dose reduction achieved in the follow-up CT scans, although a lower IQ still allows a good diagnostic confidence.
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Affiliation(s)
- Massimo Cristofaro
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Elisa Busi Rizzi
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Pierluca Piselli
- Clinical Epidemiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy.
| | - Elisa Pianura
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Ada Petrone
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Nicoletta Fusco
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Federica Di Stefano
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Vincenzo Schinina'
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
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Jensen CT, Wagner-Bartak NA, Vu LN, Liu X, Raval B, Martinez D, Wei W, Cheng Y, Samei E, Gupta S. Detection of Colorectal Hepatic Metastases Is Superior at Standard Radiation Dose CT versus Reduced Dose CT. Radiology 2018; 290:400-409. [PMID: 30480489 PMCID: PMC6357984 DOI: 10.1148/radiol.2018181657] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Purpose To evaluate colorectal cancer hepatic metastasis detection and characterization between reduced radiation dose (RD) and standard dose (SD) contrast material-enhanced CT of the abdomen and to qualitatively compare between filtered back projection (FBP) and iterative reconstruction algorithms. Materials and Methods In this prospective study (from May 2017 through November 2017), 52 adults with biopsy-proven colorectal cancer and suspected hepatic metastases at baseline CT underwent two portal venous phase CT scans: SD and RD in the same breath hold. Three radiologists, blinded to examination details, performed detection and characterization of 2-15-mm lesions on the SD FBP and RD adaptive statistical iterative reconstruction (ASIR)-V 60% series images. Readers assessed overall image quality and lesions between SD FBP and seven different iterative reconstructions. Two nonblinded consensus reviewers established the reference standard using the picture archiving and communication system lesion marks of each reader, multiple comparison examinations, and clinical data. Results RD CT resulted in a mean dose reduction of 54% compared with SD. Of the 260 lesions (233 metastatic, 27 benign), 212 (82%; 95% confidence interval [CI]: 76%, 86%) were detected with RD CT, whereas 252 (97%; 95% CI: 94%, 99%) were detected with SD (P < .001); per-lesion sensitivity was 79% (95% CI: 74%, 84%) and 94% (95% CI: 90%, 96%) (P < .001), respectively. Mean qualitative scores ranked SD images as higher quality than RD series images, and ASIR-V ranked higher than ASIR and Veo 3.0. Conclusion CT evaluation of colorectal liver metastases is compromised with modest radiation dose reduction, and the use of iterative reconstructions could not maintain observer performance. © RSNA, 2018.
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Affiliation(s)
- Corey T Jensen
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Nicolaus A Wagner-Bartak
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Lan N Vu
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Xinming Liu
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Bharat Raval
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - David Martinez
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Wei Wei
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Yuan Cheng
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Ehsan Samei
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
| | - Shiva Gupta
- From the Departments of Diagnostic Radiology (C.T.J., N.A.W., L.N.V., B.R., D.M., S.G.), Biostatistics (W.W.), and Physics (X.L.), University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; and Duke University Medical Center, Durham, NC (Y.C., E.S.)
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Sugawara H, Suzuki S, Katada Y, Ishikawa T, Fukui R, Yamamoto Y, Abe O. Comparison of full-iodine conventional CT and half-iodine virtual monochromatic imaging: advantages and disadvantages. Eur Radiol 2018; 29:1400-1407. [PMID: 30209591 DOI: 10.1007/s00330-018-5724-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/05/2018] [Accepted: 08/16/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE To compare image quality of abdominal arteries between full-iodine-dose conventional CT and half-iodine-dose virtual monochromatic imaging (VMI). MATERIALS AND METHODS We retrospectively evaluated images of 21 patients (10 men, 11 women; mean age, 73.9 years) who underwent both full-iodine (600 mg/kg) conventional CT and half-iodine (300 mg/kg) VMI. For each patient, we measured and compared CT attenuation and the contrast-to-noise ratio (CNR) of the aorta, celiac artery, and superior mesenteric artery (SMA). We also compared CT dose index (CTDI). Two board-certified diagnostic radiologists evaluated visualisation of the main trunks and branches of the celiac artery and SMA in maximum-intensity-projection images. We evaluated spatial resolution of the two scans using an acrylic phantom. RESULTS The two scans demonstrated no significant difference in CT attenuation of the aorta, celiac artery, and SMA, but CNRs of the aorta and celiac artery were significantly higher in VMI (p = 0.011 and 0.030, respectively). CTDI was significantly higher in VMI (p = 0.024). There was no significant difference in visualisation of the main trunk of the celiac artery and SMA, but visualisation of the gastroduodenal artery, pancreatic arcade, branch of the SMA, marginal arteries, and vasa recta was significantly better in the conventional scan (p < 0.001). The calculated modular transfer function (MTF) suggested decreased spatial resolution of the half-iodine VMI. CONCLUSION Large-vessel depiction and CNRs were comparable between full-iodine conventional CT and half-iodine VMI images, but VMI did not permit clear visualisation of small arteries and required a larger radiation dose. KEY POINTS ・Reducing the dose of iodine contrast medium is essential for chronic kidney disease patients to prevent contrast-induced nephropathy. ・In virtual monochromatic images at low keV, contrast of relatively large vessels is maintained even with reduced iodine load, but visibility of small vessels is impaired with decreased spatial resolution. ・We should be aware about the advantages and disadvantages associated with virtual monochromatic imaging with reduced iodine dose.
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Affiliation(s)
- Haruto Sugawara
- Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan.,Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Shigeru Suzuki
- Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan.
| | - Yoshiaki Katada
- Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan
| | - Takuya Ishikawa
- Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan
| | - Rika Fukui
- Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan
| | - Yuzo Yamamoto
- Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan
| | - Osamu Abe
- Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
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