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Rajiah PS, Weber N, Loewen J, Kasten H, Williamson E, Moore A, Leng S. Dynamic CT Angiography in Vascular Imaging: Principles and Applications. Radiographics 2022; 42:E224-E225. [PMID: 36178805 DOI: 10.1148/rg.210177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Prabhakar Shantha Rajiah
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
| | - Nikkole Weber
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
| | - Jennifer Loewen
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
| | - Holly Kasten
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
| | - Eric Williamson
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
| | - Alastair Moore
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
| | - Shuai Leng
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 559905 (P.S.R., N.W., J.L., H.K., E.W., S.L.); and Department of Radiology, Baylor University Medical Center, Dallas, Tex (A.M.)
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Kalarakis G, Brehmer K, Svensson A, Axelsson R, Brismar TB, Tzortzakakis A. Combining contrast-enhanced ultrasound, CT perfusion and 99mTc-Sestamibi SPECT/CT to guide diagnosis in a case of solid renal tumour. BJR Case Rep 2021; 7:20200115. [PMID: 33614118 PMCID: PMC7869121 DOI: 10.1259/bjrcr.20200115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 11/11/2022] Open
Abstract
Definitive, pre-operative differentiation of solid renal lesions by ultrasound, contrast-enhanced multiphasic CT or MRI examinations is often not possible. An increasing amount of literature indicates the added value of 99mTc-Sestamibi SPECT/CT, CT perfusion and contrast-enhanced ultrasound in the pre-operative characterisation of solid renal tumours. This case report presents the diagnostic approach of a solid renal tumour that turned out to be a hybrid oncocytic chromophobe tumour in a patient with Stage 3 renal failure by combining the three aforementioned modern examination techniques.
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Affiliation(s)
- Georgios Kalarakis
- Department of Radiology, Karolinska University Hospital, Huddinge, Stockholm, Sweden
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Abstract
Computed tomography angiography (CTA) has become a mainstay for the imaging of vascular diseases, because of high accuracy, availability, and rapid turnaround time. High-quality CTA images can now be routinely obtained with high isotropic spatial resolution and temporal resolution. Advances in CTA have focused on improving the image quality, increasing the acquisition speed, eliminating artifacts, and reducing the doses of radiation and iodinated contrast media. Dual-energy computed tomography provides material composition capabilities that can be used for characterizing lesions, optimizing contrast, decreasing artifact, and reducing radiation dose. Deep learning techniques can be used for classification, segmentation, quantification, and image enhancement.
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Affiliation(s)
- Prabhakar Rajiah
- Department of Radiology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55904, USA.
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Jiang K, Ferguson CM, Abumoawad A, Saad A, Textor SC, Lerman LO. A modified two-compartment model for measurement of renal function using dynamic contrast-enhanced computed tomography. PLoS One 2019; 14:e0219605. [PMID: 31291361 PMCID: PMC6619810 DOI: 10.1371/journal.pone.0219605] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/27/2019] [Indexed: 12/14/2022] Open
Abstract
Objectives To validate and adapt a modified two-compartment model, originally developed for magnetic resonance imaging, for measuring human single-kidney glomerular filtration rate (GFR) and perfusion using dynamic contrast-enhanced computed tomography (DCE-CT). Methods This prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Thirty-eight patients with essential hypertension (EH, n = 13) or atherosclerotic renal artery stenosis (ARAS, n = 25) underwent renal DCE-CT for GFR and perfusion measurement using a modified two-compartment model. Iothalamate clearance was used to measure reference total GFR, which was apportioned into single-kidney GFR by renal blood flow. Renal perfusion was also calculated using a conventional deconvolution algorithm. Validation of GFR and perfusion and inter-observer reproducibility, were conducted by using the Pearson correlation and Bland-Altman analysis. Results Both the two-compartment model and iothalamate clearance detected in ARAS patients lower GFR in the stenotic compared to the contralateral and EH kidneys. GFRs measured by DCE-CT and iothalamate clearance showed a close match (r = 0.94, P<0.001, and mean difference 2.5±12.2mL/min). Inter-observer bias and variation in model-derived GFR (r = 0.97, P<0.001; mean difference, 0.3±7.7mL/min) were minimal. Renal perfusion by deconvolution agreed well with that by the compartment model when the blood transit delay from abdominal aorta to kidney was negligible. Conclusion The proposed two-compartment model faithfully depicts contrast dynamics using DCE-CT and may provide a reliable tool for measuring human single-kidney GFR and perfusion.
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Affiliation(s)
- Kai Jiang
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Christopher M. Ferguson
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Abdelrhman Abumoawad
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Ahmed Saad
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Stephen C. Textor
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Lilach O. Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
- * E-mail:
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Computed Tomography Perfusion Measurements in Renal Lesions Obtained by Bayesian Estimation, Advanced Singular-Value Decomposition Deconvolution, Maximum Slope, and Patlak Models: Intermodel Agreement and Diagnostic Accuracy of Tumor Classification. Invest Radiol 2019; 53:477-485. [PMID: 29762256 DOI: 10.1097/rli.0000000000000477] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVES The aims of this study were to evaluate the agreement of computed tomography (CT)-perfusion parameter values of the normal renal cortex and various renal tumors, which were obtained by different mathematical models, and to evaluate their diagnostic accuracy. MATERIALS AND METHODS Perfusion imaging was performed prospectively in 35 patients to analyze 144 regions of interest of the normal renal cortex and 144 regions of interest of renal tumors, including 21 clear-cell renal cell carcinomas (RCC), 6 papillary RCCs, 5 oncocytomas, 1 chromophobe RCC, 1 angiomyolipoma with minimal fat, and 1 tubulocystic RCC. Identical source data were postprocessed and analyzed on 2 commercial software applications with the following implemented mathematical models: maximum slope, Patlak plot, standard singular-value decomposition (SVD), block-circulant SVD, oscillation-limited block-circulant SVD, and Bayesian estimation technique. Results for blood flow (BF), blood volume (BV), and mean transit time (MTT) were recorded. Agreement and correlation between pairs of models and perfusion parameters were assessed. Diagnostic accuracy was evaluated by receiver operating characteristic (ROC) analysis. RESULTS Significant differences and poor agreement of BF, BV, and MTT values were noted for most of model comparisons in both the normal renal cortex and different renal tumors. The correlations between most model pairs and perfusion parameters ranged between good and perfect (Spearman ρ = 0.79-1.00), except for BV values obtained by Patlak method (ρ = 0.61-0.72). All mathematical models computed BF and BV values, which differed significantly between clear cell RCCs, papillary RCCs, and oncocytomas, which introduces them as useful diagnostic tests to differentiate between different histologic subgroups (areas under ROC curve, 0.83-0.99). The diagnostic accuracy to discriminate between clear-cell RCCs and the renal cortex was the lowest based on the Patlak plot model (area under ROC curve, 0.76); BF and BV values obtained by other algorithms did not differ significantly in their diagnostic accuracy. CONCLUSIONS Quantitative perfusion parameters obtained from different mathematical models cannot be used interchangeably. Based on BF and BV estimates, all models are a useful tool in the differential diagnosis of kidney tumors, with the Patlak plot model yielding a significantly lower diagnostic accuracy.
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Braunagel M, Ortner F, Schönermarck U, Habicht A, Schindler A, Stangl M, Strobl FF, Reiser M, Clevert DA, Trumm C, Helck A. Dynamic CTA in Native Kidneys Using a Multiphase CT Protocol-Potential of Significant Reduction of Contrast Medium. Acad Radiol 2018; 25:842-849. [PMID: 29545025 DOI: 10.1016/j.acra.2017.11.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/19/2017] [Accepted: 11/20/2017] [Indexed: 12/26/2022]
Abstract
RATIONALE AND OBJECTIVE The objective of this study was to assess an optimized renal multiphase computed tomography angiography (MP-CTA) protocol regarding reduction of contrast volume. MATERIALS AND METHODS Thirty patients underwent MP-CTA (12 phases, every 3.5 seconds, 80 kV/120 mAs) using 30 mL of contrast medium. The quality of MP-CTA was assessed quantitatively measuring vessel attenuation, image noise, and contrast-to-noise ratio. MP-CTA was evaluated qualitatively regarding depiction of vessels, cortex differentiation, and motion artifacts (grades 1-4, 1 = best). Mean effective radiation dose was registered. Results were compared to standard renal computed tomography angiography (CTA) (80 mL). Student t test was applied, if variables followed normal distribution. For other variables, nonparametric Mann-Whitney U test was used. RESULTS All acquisitions were successfully performed, and no patient had to be excluded from the study. MP-CTA enabled high attenuation (aorta: 503 ± 91 HU, renal arteries: 450 ± 73 HU/456 ± 72 HU) at adequate image noise (13.7 ± 1.5) and good contrast-to-noise ratio (34.2 ± 10.2). Good attenuation of renal veins was observed (286 ± 43 HU/282 ± 42 HU). Arterial enhancement was significantly higher compared to renal CTA (aorta: 396 ± 90 HU, renal arteries: 331 ± 74 HU/333 ± 80 HU; P < .001). MP-CTA protocol enabled good image quality of renal arteries (1.5 ± 0.6) and veins (1.7 ± 0.6). Cortex differentiation and motion artifacts were ranked 1.8 ± 0.8 and 1.6 ± 0.8. The mean effective radiation dose was 9 mSv (MP-CTA). CONCLUSIONS Compared to standard renal CTA, the renal MP-CTA enabled the significant reduction of contrast volume and simultaneously provided a significantly higher arterial attenuation.
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Affiliation(s)
- Margarita Braunagel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Florian Ortner
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Ulf Schönermarck
- Department of Internal Medicine IV, Ludwig-Maximilians-University Hospital (LMU),Munich, Germany
| | - Antje Habicht
- Transplant Center, Ludwig-Maximilians-University Hospital (LMU),Munich, Germany
| | - Andreas Schindler
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Manfred Stangl
- Department of Surgery, Ludwig-Maximilians-University Hospital (LMU), Munich, Germany
| | - Frederik F Strobl
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Maximilian Reiser
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Dirk A Clevert
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Christoph Trumm
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany
| | - Andreas Helck
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital (LMU), Marchioninistr. 15, 81377Munich, Germany.
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Determination of glomerular filtration rate (GFR) from fractional renal accumulation of iodinated contrast material: a convenient and rapid single-kidney CT-GFR technique. Eur Radiol 2018; 28:2763-2771. [DOI: 10.1007/s00330-017-5289-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 12/06/2017] [Accepted: 12/27/2017] [Indexed: 10/18/2022]
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You S, Ma X, Zhang C, Li Q, Shi W, Zhang J, Yuan X. Determination of single-kidney glomerular filtration rate (GFR) with CT urography versus renal dynamic imaging Gates method. Eur Radiol 2017; 28:1077-1084. [PMID: 28971295 DOI: 10.1007/s00330-017-5061-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 08/07/2017] [Accepted: 09/06/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To present a single-kidney CT-GFR measurement and compare it with the renal dynamic imaging Gates-GFR. MATERIALS AND METHODS Thirty-six patients with hydronephrosis referred for CT urography and 99mTc-DTPA renal dynamic imaging were prospectively included. Informed consent was obtained from all patients. The CT urography protocol included non-contrast, nephrographic, and excretory phase imaging. The total CT-GFR was calculated by dividing the CT number increments of the total urinary system between the nephrographic and excretory phase by the products of iodine concentration in the aorta and the elapsed time, then multiplied by (1- Haematocrit). The total CT-GFR was then split into single-kidney CT-GFR by a left and right kidney proportionality factor. The results were compared with single-kidney Gates-GFR by using paired t-test, correlation analysis, and Bland-Altman plots. RESULTS Paired difference between single-kidney CT-GFR (45.02 ± 13.91) and single-kidney Gates-GFR (51.21 ± 14.76) was 6.19 ± 5.63 ml/min, p<0.001, demonstrating 12.1% systematic underestimation with ±11.03 ml/min (±21.5%) measurement deviation. A good correlation was revealed between both measurements (r=0.87, p<0.001). CONCLUSION The proposed single-kidney CT-GFR correlates and agrees well with the reference standard despite a systematic underestimation, therefore it could be a one-stop-shop for evaluating urinary tract morphology and split renal function. KEY POINTS • A new CT method can assess split renal function • Only using images from CT urography and the value of haematocrit • A one-stop-shop CT technique without additional radiation dose.
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Affiliation(s)
- Shan You
- Department of Graduate, Hebei North University, 11 Diamond South Road, High-tech Zone, Zhangjiakou City, Hebei Province, 075000, People's Republic of China
| | - XianWu Ma
- Department of Radiology, Qiqihar Chinese Medicine Hospital, 23 Ping An Nan Jie, Tiefeng District, Qigihar City, Heilongjiang Province, 161005, People's Republic of China
| | - ChangZhu Zhang
- Department of Radiology, Qiqihar Chinese Medicine Hospital, 23 Ping An Nan Jie, Tiefeng District, Qigihar City, Heilongjiang Province, 161005, People's Republic of China
| | - Qiang Li
- Department of Radiology, Qiqihar Chinese Medicine Hospital, 23 Ping An Nan Jie, Tiefeng District, Qigihar City, Heilongjiang Province, 161005, People's Republic of China
| | - WenWei Shi
- Department of Radiology, The 309th Hospital of Chinese People`s Liberation Army, 17 Heishanhu Road, Haidian District, Beijing, 100091, People's Republic of China
| | - Jing Zhang
- Department of Radiology, The 309th Hospital of Chinese People`s Liberation Army, 17 Heishanhu Road, Haidian District, Beijing, 100091, People's Republic of China
| | - XiaoDong Yuan
- Department of Radiology, The 309th Hospital of Chinese People`s Liberation Army, 17 Heishanhu Road, Haidian District, Beijing, 100091, People's Republic of China.
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Liu D, Liu J, Wen Z, Li Y, Sun Z, Xu Q, Fan Z. 320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study. PLoS One 2017; 12:e0171235. [PMID: 28182709 PMCID: PMC5300209 DOI: 10.1371/journal.pone.0171235] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/17/2017] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection. METHODS Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared. RESULTS The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044). CONCLUSIONS This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values.
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Affiliation(s)
- Dongting Liu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Jiayi Liu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zhaoying Wen
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yu Li
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zhonghua Sun
- Department of Medical Radiation Sciences, Curtin University, Perth, Australia
| | - Qin Xu
- School of Public Health, Capital Medical University, Beijing, China
| | - Zhanming Fan
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
- * E-mail:
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Fifty Years of Technological Innovation: Potential and Limitations of Current Technologies in Abdominal Magnetic Resonance Imaging and Computed Tomography. Invest Radiol 2016; 50:584-93. [PMID: 26039773 DOI: 10.1097/rli.0000000000000173] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Magnetic resonance imaging (MRI) has become an important modality for the diagnosis of intra-abdominal pathology. Hardware and pulse sequence developments have made it possible to derive not only morphologic but also functional information related to organ perfusion (dynamic contrast-enhanced MRI), oxygen saturation (blood oxygen level dependent), tissue cellularity (diffusion-weighted imaging), and tissue composition (spectroscopy). These techniques enable a more specific assessment of pathologic lesions and organ functionality. Magnetic resonance imaging has thus transitioned from a purely morphologic examination to a modality from which image-based disease biomarkers can be derived. This fits well with several emerging trends in radiology, such as the need to accurately assess response to costly treatment strategies and the need to improve lesion characterization to potentially avoid biopsy. Meanwhile, the cost-effectiveness, availability, and robustness of computed tomography (CT) ensure its place as the current workhorse for clinical imaging. Although the lower soft tissue contrast of CT relative to MRI is a long-standing limitation, other disadvantages such as ionizing radiation exposure have become a matter of public concern. Nevertheless, recent technical developments such as dual-energy CT or dynamic volume perfusion CT also provide more functional imaging beyond morphology.The aim of this article was to review and discuss the most important recent technical developments in abdominal MRI and state-of-the-art CT, with an eye toward the future, providing examples of their clinical utility for the evaluation of hepatic and renal pathologies.
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Optimizing Contrast Media Injection Protocols in State-of-the Art Computed Tomographic Angiography. Invest Radiol 2015; 50:161-7. [DOI: 10.1097/rli.0000000000000119] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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13
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Recent Technological Advances in Computed Tomography and the Clinical Impact Therein. Invest Radiol 2015; 50:119-27. [DOI: 10.1097/rli.0000000000000125] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ogul H, Bayraktutan U, Kizrak Y, Pirimoglu B, Yuceler Z, Sagsoz ME, Yilmaz O, Aydinli B, Ozturk G, Kantarci M. Abdominal perfusion computed tomography. Eurasian J Med 2015; 45:50-7. [PMID: 25610249 DOI: 10.5152/eajm.2013.09] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 06/16/2012] [Indexed: 01/03/2023] Open
Abstract
The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis.
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Affiliation(s)
- Hayri Ogul
- Department of Radiology, School of Medicine, Atatürk University, Erzurum, Turkey
| | | | - Yesim Kizrak
- Department of Radiology, School of Medicine, Atatürk University, Erzurum, Turkey
| | - Berhan Pirimoglu
- Department of Radiology, School of Medicine, Atatürk University, Erzurum, Turkey
| | - Zeynep Yuceler
- Department of Radiology, School of Medicine, Atatürk University, Erzurum, Turkey
| | - M Erdem Sagsoz
- Department of Biophysics, School of Medicine, Atatürk University, Erzurum, Turkey
| | - Omer Yilmaz
- Department of General Surgery, School of Medicine, Atatürk University, Erzurum, Turkey
| | - Bulent Aydinli
- Department of General Surgery, School of Medicine, Atatürk University, Erzurum, Turkey
| | - Gurkan Ozturk
- Department of General Surgery, School of Medicine, Atatürk University, Erzurum, Turkey
| | - Mecit Kantarci
- Department of Radiology, School of Medicine, Atatürk University, Erzurum, Turkey
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Zöllner FG, Zimmer F, Klotz S, Hoeger S, Schad LR. Functional imaging of acute kidney injury at 3 Tesla: investigating multiple parameters using DCE-MRI and a two-compartment filtration model. Z Med Phys 2014; 25:58-65. [PMID: 24629306 DOI: 10.1016/j.zemedi.2014.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 01/10/2014] [Accepted: 01/10/2014] [Indexed: 11/28/2022]
Abstract
OBJECT To investigate how MR-based parameters reflect functional changes in kidneys with acute kidney injury (AKI) using dynamic contrast enhanced MRI and a two-compartment renal filtration model. MATERIALS AND METHODS MRI data of eight male Lewis rats were analyzed retrospectively. Five animals were subjected to AKI, three native rats served as control. All animals underwent perfusion imaging by dynamic contrast-enhanced MRI. Renal blood volume, glomerular filtration rate (GFR) as well as plasma and tubular mean transit times were estimated from regions-of-interest drawn in the renal cortex. Differences between healthy kidneys and kidneys subjected to AKI were analyzed using a paired t-test. RESULTS Significant differences between ischemic and healthy kidneys could only be detected for the glomerular filtration rate. For all other calculated parameters, differences were present, however not significant. In rats with AKI, average single kidney GFR was 0.66 ± 0.37 ml/min for contralateral and 0.26 ± 0.12 ml/ min for diseased kidneys (P = 0.0254). For the healthy control group, the average GFR was 0.39 ± 0.06 ml/min and 0.41 ± 0.11 ml/min, respectively. Differences between diseased kidneys of AKI rats and ipsilateral kidneys of the healthy control group were significant (P = 0.0381). CONCLUSION Significant differences of functional parameters reflecting damage of the renal tissue of kidneys with AKI compared to the contralateral, healthy kidneys could only be detected by GFR. GFR might be a useful parameter that allows for a spatially resolved detection of abnormal changes of renal tissue by AKI.
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Affiliation(s)
- Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
| | - Fabian Zimmer
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sarah Klotz
- Department of Medicine V, University Medical Centre Mannheim, Heidelberg University, Mannheim, Germany
| | - Simone Hoeger
- Department of Medicine V, University Medical Centre Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Helck A, Schönermarck U, Habicht A, Notohamiprodjo M, Stangl M, Klotz E, Nikolaou K, la Fougère C, Clevert DA, Reiser M, Becker C. Determination of split renal function using dynamic CT-angiography: preliminary results. PLoS One 2014; 9:e91774. [PMID: 24618919 PMCID: PMC3950217 DOI: 10.1371/journal.pone.0091774] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 02/13/2014] [Indexed: 12/28/2022] Open
Abstract
Objectives To determine the feasibility of a dynamic CT angiography-protocol with regard to simultaneous assessment of renal anatomy and function. Methods 7 healthy potential kidney donors (58±7 years) underwent a dynamic computed tomography angiography (CTA) using a 128-slice CT-scanner with continuous bi-directional table movement, allowing the coverage of a scan range of 18 cm within 1.75 sec. Twelve scans of the kidneys (n = 14) were acquired every 3.5 seconds with the aim to simultaneously obtain CTA and renal function data. Image quality was assessed quantitatively (HU-measurements) and qualitatively (grade 1–4, 1 = best). The glomerular filtration rate (GFR) was calculated by a modified Patlak method and compared with the split renal function obtained with renal scintigraphy. Results Mean maximum attenuation was 464±58 HU, 435±48 HU and 277±29 HU in the aorta, renal arteries, and renal veins, respectively. The abdominal aorta and all renal vessels were depicted excellently (grade 1.0). The image quality score for cortex differentiation was 1.6±0.49, for the renal parenchyma 2.4±0.49. GFR obtained from dynamic CTA correlated well with renal scintigraphy with a correlation coefficient of r = 0.84; P = 0.0002 (n = 14). The average absolute deviation was 1.6 mL/min. The average effective dose was 8.96 mSv. Conclusion Comprehensive assessment of renal anatomy and function is feasible using a single dynamic CT angiography examination. The proposed protocol may help to improve management in case of asymmetric kidney function as well as to simplify evaluation of potential living kidney donors.
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Affiliation(s)
- Andreas Helck
- Institute for Clinical Radiology, University Hospital Grosshadern (LMU), Munich, Germany
- * E-mail:
| | - Ulf Schönermarck
- Department of Internal Medicine IV, University Hospital Grosshadern (LMU), Munich, Germany
| | - Antje Habicht
- Transplant Center Munich, University Hospital Grosshadern (LMU), Munich, Germany
| | - Mike Notohamiprodjo
- Institute for Clinical Radiology, University Hospital Grosshadern (LMU), Munich, Germany
| | - Manfred Stangl
- Department of Surgery, University Hospital Grosshadern (LMU), Munich, Germany
| | - Ernst Klotz
- Siemens Healthcare, Computed Tomography, Forchheim, Germany
| | - Konstantin Nikolaou
- Institute for Clinical Radiology, University Hospital Grosshadern (LMU), Munich, Germany
| | - Christian la Fougère
- Department of Nuclear Medicine, University Hospital Grosshadern (LMU), Munich, Germany
| | - Dirk Andrè Clevert
- Institute for Clinical Radiology, University Hospital Grosshadern (LMU), Munich, Germany
| | - Maximilian Reiser
- Institute for Clinical Radiology, University Hospital Grosshadern (LMU), Munich, Germany
| | - Christoph Becker
- Institute for Clinical Radiology, University Hospital Grosshadern (LMU), Munich, Germany
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Chen C, Liu Q, Hao Q, Xu B, Ma C, Zhang H, Shen Q, Lu J. Study of 320-slice dynamic volume CT perfusion in different pathologic types of kidney tumor: preliminary results. PLoS One 2014; 9:e85522. [PMID: 24465588 PMCID: PMC3897451 DOI: 10.1371/journal.pone.0085522] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 11/27/2013] [Indexed: 12/18/2022] Open
Abstract
Objective To investigate microcirculatory differences between pathologic types of kidney tumor using 320-slice dynamic volume CT perfusion. Methods Perfusion imaging with 320-slice dynamic volume CT was prospectively performed in 85 patients with pathologically proven clear cell renal cell carcinoma (RCC) (n = 66), papillary RCC (n = 7), chromophobe RCC (n = 5), angiomyolipoma (AML) with minimal fat (n = 7), or RCC (n = 78). Equivalent blood volume (Equiv BV), permeability surface-area product (PS; clearance/unit volume = permeability), and blood flow (BF) of tumor and normal renal cortex were measured and analyzed. Effective radiation dose was calculated. Results There was a significant difference in all three parameters between tumor and normal renal cortex (P<0.001). Equiv BV was significantly different between RCC and AML with minimal fat (P = 0.038) and between clear cell RCC and AML with minimal fat (P<0.001). Mean Equiv BV and BF were significantly higher in clear cell RCC than in papillary RCC (P<0.001 for both) and mean Equiv BV was higher in clear cell RCC than in chromophobe RCC (P<0.001). The effective radiation dose of the CT perfusion protocol was 18.5 mSv. Conclusion Perfusion imaging using 320-slice dynamic volume CT can be used to evaluate hemodynamic features of the whole kidney and kidney tumors, which may be useful in the differential diagnosis of these four pathologic types of kidney tumor.
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Affiliation(s)
- Chao Chen
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Qi Liu
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Qiang Hao
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Bing Xu
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Chao Ma
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Huojun Zhang
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Qianjin Shen
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
| | - Jianping Lu
- Department of Radiology, Changhai Hospital of Shang hai, The second Military Medical University, Shanghai, China
- * E-mail:
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Computed tomography perfusion imaging of renal cell carcinoma: systematic comparison with histopathological angiogenic and prognostic markers. Invest Radiol 2013; 48:183-91. [PMID: 23328912 DOI: 10.1097/rli.0b013e31827c63a3] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The aim of this study was to systematically analyze the correlation between computed tomography (CT) perfusion and histopathological angiogenic and prognostic markers in patients with renal cell carcinoma (RCC). MATERIAL AND METHODS Fifteen patients (12 men; mean age, 64.5 ± 9.4 years) with RCC underwent contrast-enhanced CT perfusion imaging (scan range, 10 cm; scan time, 40 seconds; dual-source 128-section CT) 1 day before surgery. The procedure for surgical specimen processing was modified to obtain an exact match with CT images. Microvessel density (MVD) was quantified by CD34 staining, and lymphatic vessel density (LVD) was stained with D2-40 antibodies. The CT perfusion values blood flow (BF), blood volume (BV), and flow extraction product (K(Trans)) were calculated using the maximum-slope and a delay-corrected modified Patlak approach and were correlated to MVD and LVD. The relationship between CT perfusion and the prognostic markers pT stage, Fuhrman grade, and tumor necrosis was evaluated. RESULTS Histopathology revealed varying high MVD but low or absent intratumoral LVD. The BF and BV of RCC, both including and excluding necrotic regions, showed significant correlations with MVD (r = 0.600-0.829, P < 0.05 each). Significant correlations between MVD and K(Trans) were found only in small tumor areas exhibiting no necrosis (r = 0.550, P < 0.05). No significant correlation was found between BF, BV, and K(Trans) with intratumoral LVD (P = 0.35-0.82). With higher pT stage and Fuhrman grade, BF, BV, and K(Trans) were lower, similar to the MVD, but without reaching statistical significance. Blood flow, BV, and K(Trans) were significantly higher in RCCs with less than 50% necrosis than in those with 50% or grater necrosis (P < 0.05 each). CONCLUSION Our study indicates that BF and BV from CT perfusion reflect blood vessels of RCC. Computed tompgraphic perfusion parameters differ significantly depending upon the degree of tumor necrosis.
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Tyson R, Logsdon SA, Werre SR, Daniel GB. Estimation of feline renal volume using computed tomography and ultrasound. Vet Radiol Ultrasound 2012; 54:127-32. [PMID: 23278991 DOI: 10.1111/vru.12007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 11/14/2012] [Indexed: 11/27/2022] Open
Abstract
Renal volume estimation is an important parameter for clinical evaluation of kidneys and research applications. A time efficient, repeatable, and accurate method for volume estimation is required. The purpose of this study was to describe the accuracy of ultrasound and computed tomography (CT) for estimating feline renal volume. Standardized ultrasound and CT scans were acquired for kidneys of 12 cadaver cats, in situ. Ultrasound and CT multiplanar reconstructions were used to record renal length measurements that were then used to calculate volume using the prolate ellipsoid formula for volume estimation. In addition, CT studies were reconstructed at 1 mm, 5 mm, and 1 cm, and transferred to a workstation where the renal volume was calculated using the voxel count method (hand drawn regions of interest). The reference standard kidney volume was then determined ex vivo using water displacement with the Archimedes' principle. Ultrasound measurement of renal length accounted for approximately 87% of the variability in renal volume for the study population. The prolate ellipsoid formula exhibited proportional bias and underestimated renal volume by a median of 18.9%. Computed tomography volume estimates using the voxel count method with hand-traced regions of interest provided the most accurate results, with increasing accuracy for smaller voxel sizes in grossly normal kidneys (-10.1 to 0.6%). Findings from this study supported the use of CT and the voxel count method for estimating feline renal volume in future clinical and research studies.
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Affiliation(s)
- Reid Tyson
- Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA.
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Meinel FG, Nikolaou K, Weidenhagen R, Hellbach K, Helck A, Bamberg F, Reiser MF, Sommer WH. Time-resolved CT angiography in aortic dissection. Eur J Radiol 2012; 81:3254-61. [DOI: 10.1016/j.ejrad.2012.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 02/26/2012] [Accepted: 03/05/2012] [Indexed: 11/24/2022]
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CT Angiography of the Renal Arteries: Comparison of Lower-Tube-Voltage CTA With Moderate-Concentration Iodinated Contrast Material and Conventional CTA. AJR Am J Roentgenol 2012; 199:96-102. [PMID: 22733899 DOI: 10.2214/ajr.11.7450] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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22
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Reiner CS, Goetti R, Burger IA, Fischer MA, Frauenfelder T, Knuth A, Pfammatter T, Schaefer N, Alkadhi H. Liver perfusion imaging in patients with primary and metastatic liver malignancy: prospective comparison between 99mTc-MAA spect and dynamic CT perfusion. Acad Radiol 2012; 19:613-21. [PMID: 22285400 DOI: 10.1016/j.acra.2011.12.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 12/23/2011] [Accepted: 12/29/2011] [Indexed: 12/28/2022]
Abstract
RATIONALE AND OBJECTIVES To prospectively analyze the correlation between parameters of liver perfusion from technetium99m-macroaggregates of albumin (99mTc-MAA) single photon emission computed tomography (SPECT) with those obtained from dynamic CT perfusion in patients with primary or metastatic liver malignancy. MATERIALS AND METHODS Twenty-five consecutive patients (11 women, 14 men; mean age 60.9 ± 10.8; range: 32-78 years) with primary (n = 5) or metastatic (n = 20) liver malignancy planned to undergo selective internal radiotherapy underwent dynamic contrast-enhanced CT liver perfusion imaging (four-dimensional spiral mode, scan range 14.8 cm, 15 scans, cycle time 3 seconds) and 99m)Tc-MAA SPECT after intraarterial injection of 180 MBq 99mTc-MAA on the same day. Data were evaluated by two blinded and independent readers for the parameters arterial liver perfusion (ALP), portal venous perfusion (PVP), and total liver perfusion (TLP) from CT, and the 99mTc-MAA uptake-ratio of tumors in relation to normal liver parenchyma from SPECT. RESULTS Interreader agreements for quantitative perfusion parameters were high for dynamic CT (r = 0.90-0.98, each P < .01) and 99mTc -MAA SPECT (r = 0.91, P < .01). Significant correlation was found between 99mTc-MAA uptake ratio and ALP (r = 0.7, P < .01) in liver tumors. No significant correlation was found between 99mTc-MAA uptake ratio, PVP (r = -0.381, P = .081), and TLP (r = 0.039, P = .862). CONCLUSION This study indicates that in patients with primary and metastatic liver malignancy, ALP obtained by dynamic CT liver perfusion significantly correlates with the 99mTc-MAA uptake ratio obtained by SPECT.
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Affiliation(s)
- Caecilia S Reiner
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistr. 100, CH-8091 Zurich, Switzerland
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CT perfusion of renal cell carcinoma: impact of volume coverage on quantitative analysis. Invest Radiol 2012; 47:33-40. [PMID: 21730874 DOI: 10.1097/rli.0b013e31822598c3] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE To assess the feasibility, image quality, and radiation dose of computed tomography (CT) renal perfusion imaging in the adaptive 4-dimensional (4D)-spiral mode in patients with renal cell carcinoma (RCC), and to compare quantitative measurements between 2-dimensional regions-of-interest (2D-ROI) and 3-dimensional volumes-of-interest (3D-VOI). MATERIALS AND METHODS Twenty-one patients (13 male; age, 67.4 ± 9.5 years) with 24 histologically proven RCCs underwent CT perfusion imaging (100 kV, 100 mAs/rotation, scan range 10 cm, examination time 40.17 seconds) in a 4D-spiral mode with dual-source 128-slice CT. The ability to suspend respiration during CT perfusion imaging was visually monitored. Two independent readers assessed motion artifacts of CT perfusion imaging data sets on a 4-point scale before and after automated motion correction. Qualitative (enhancement pattern) and quantitative perfusion analysis (blood flow [BF], blood volume [BV], flow extraction product [KTrans]) were performed in the tumor and in healthy ipsi- and contralateral renal cortex applying the maximum-slope and a modified Patlak approach for quantitative analysis in 2D-ROI and 3D-VOI, the latter including the entire RCCs. RESULTS Of the 21 patients, 8 (38%) could suspend respiration throughout the perfusion scan. Of 21 RCCs, 18 (86%) were completely included in the scan range. Motion artifacts were significantly reduced after automated motion correction (P < 0.001). All 24 RCCs could be included in the qualitative perfusion analysis, and 22 of 24 (92%) were eligible for quantitative perfusion analysis. Enhancement was homogenous in 4 (17%), peripheral in 4 (17%), and heterogeneous in 16 (66%) tumors (good interobserver agreement, κ=0.74). A high correlation was found between the 2 readers regarding quantitative perfusion parameters (r=0.93-0.94, P < 0.01). Quantitative measurements in 3D-VOIs revealed significantly lower BV, BF, and K in RCCs than in normal renal cortex (P < 0.001). In solid tumor periphery, BV was similar to the renal cortex (P=0.299), while BF and K were significantly lower (P < 0.01 and <0.001) in tumor tissue. Comparison of tumor measurements in 3D-VOIs with those obtained from 2D-ROIs revealed considerable differences in perfusion parameters beyond the 95% confidence limits in 46% to 68% of the tumors. KTrans was significantly higher in the contralateral than in healthy ipsilateral renal cortex (P < 0.01). Estimated effective radiation dose of the CT perfusion protocol was 16.3 mSv. CONCLUSION CT perfusion imaging using an adaptive 4D-spiral mode is feasible and enables, after use of automated motion correction, the reliable analysis of renal perfusion in patients with RCCs. Considerable tumor heterogeneity was found, with differences in perfusion parameters between 2D-ROI and 3D-VOI analysis, reinforcing the use of volumetric techniques for perfusion imaging and analysis. Differences between ipsi- and contralateral healthy renal cortex KTrans suggest a compensatory increase in glomerular filtration rate in the healthy contralateral kidney.
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Kim DH, Kim SH, Im SA, Han SW, Goo JM, Willmann JK, Lee ES, Eo JS, Paeng JC, Han JK, Choi BI. Intermodality comparison between 3D perfusion CT and 18F-FDG PET/CT imaging for predicting early tumor response in patients with liver metastasis after chemotherapy: preliminary results of a prospective study. Eur J Radiol 2012; 81:3542-50. [PMID: 22459347 DOI: 10.1016/j.ejrad.2012.02.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/19/2012] [Accepted: 02/25/2012] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To evaluate the feasibility of 3D perfusion CT for predicting early treatment response in patients with liver metastasis from colorectal cancer. METHODS Seventeen patients with colon cancer and liver metastasis were prospectively enroled to undergo perfusion CT and 18F-FDG-PET/CT before and after one-cycle of chemotherapy. Two radiologists and three nuclear medicine physicians measured various perfusion CT and PET/CT parameters, respectively from the largest hepatic metastasis. Baseline values and reduction rates of the parameters were compared between responders and nonresponders. Spearman correlation test was used to correlate perfusion CT and PET/CT parameters, using RECIST criteria as reference standard. RESULTS Nine patients responded to treatment, eight patients were nonresponders. Baseline SUVmean30 on PET/CT, reduction rates of 30% metabolic volume and 30% lesion glycolysis (LG30) on PET/CT and blood flow (BF) and flow extraction product (FEP) on perfusion CT after chemotherapy were significantly different between responders and nonresponders (P=0.008-0.046). Reduction rates of BF (correlation coefficient=0.630) and FEP (correlation coefficient=0.578) significantly correlated with that of LG30 on PET/CT (P<0.05). CONCLUSION CT perfusion parameters including BF and FEP may be used as early predictors of tumor response in patients with liver metastasis from colorectal cancer.
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Affiliation(s)
- Dong Hyun Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
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Tofts PS, Cutajar M, Mendichovszky IA, Peters AM, Gordon I. Precise measurement of renal filtration and vascular parameters using a two-compartment model for dynamic contrast-enhanced MRI of the kidney gives realistic normal values. Eur Radiol 2012; 22:1320-30. [PMID: 22415410 DOI: 10.1007/s00330-012-2382-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 11/25/2011] [Accepted: 12/04/2011] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To model the uptake phase of T(1)-weighted DCE-MRI data in normal kidneys and to demonstrate that the fitted physiological parameters correlate with published normal values. METHODS The model incorporates delay and broadening of the arterial vascular peak as it appears in the capillary bed, two distinct compartments for renal intravascular and extravascular Gd tracer, and uses a small-vessel haematocrit value of 24%. Four physiological parameters can be estimated: regional filtration K ( trans ) (ml min(-1) [ml tissue](-1)), perfusion F (ml min(-1) [100 ml tissue](-1)), blood volume v ( b ) (%) and mean residence time MRT (s). From these are found the filtration fraction (FF; %) and total GFR (ml min(-1)). Fifteen healthy volunteers were imaged twice using oblique coronal slices every 2.5 s to determine the reproducibility. RESULTS Using parenchymal ROIs, group mean values for renal biomarkers all agreed with published values: K ( trans ): 0.25; F: 219; v ( b ): 34; MRT: 5.5; FF: 15; GFR: 115. Nominally cortical ROIs consistently underestimated total filtration (by ~50%). Reproducibility was 7-18%. Sensitivity analysis showed that these fitted parameters are most vulnerable to errors in the fixed parameters kidney T(1), flip angle, haematocrit and relaxivity. CONCLUSIONS These renal biomarkers can potentially measure renal physiology in diagnosis and treatment. KEY POINTS • Dynamic contrast-enhanced magnetic resonance imaging can measure renal function. • Filtration and perfusion values in healthy volunteers agree with published normal values. • Precision measured in healthy volunteers is between 7 and 15%.
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Affiliation(s)
- Paul S Tofts
- Brighton and Sussex Medical School, Falmer, Sussex BN1 9PX, UK.
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Current status and guidelines for the assessment of tumour vascular support with dynamic contrast-enhanced computed tomography. Eur Radiol 2012; 22:1430-41. [PMID: 22367468 DOI: 10.1007/s00330-012-2379-4] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 11/23/2011] [Accepted: 11/24/2011] [Indexed: 12/13/2022]
Abstract
Dynamic contrast-enhanced computed tomography (DCE-CT) assesses the vascular support of tumours through analysis of temporal changes in attenuation in blood vessels and tissues during a rapid series of images acquired with intravenous administration of iodinated contrast material. Commercial software for DCE-CT analysis allows pixel-by-pixel calculation of a range of validated physiological parameters and depiction as parametric maps. Clinical studies support the use of DCE-CT parameters as surrogates for physiological and molecular processes underlying tumour angiogenesis. DCE-CT has been used to provide biomarkers of drug action in early phase trials for the treatment of a range of cancers. DCE-CT can be appended to current imaging assessments of tumour response with the benefits of wide availability and low cost. This paper sets out guidelines for the use of DCE-CT in assessing tumour vascular support that were developed using a Delphi process. Recommendations encompass CT system requirements and quality assurance, radiation dosimetry, patient preparation, administration of contrast material, CT acquisition parameters, terminology and units, data processing and reporting. DCE-CT has reached technical maturity for use in therapeutic trials in oncology. The development of these consensus guidelines may promote broader application of DCE-CT for the evaluation of tumour vascularity. Key Points • DCE-CT can robustly assess tumour vascular support • DCE-CT has reached technical maturity for use in therapeutic trials in oncology • This paper presents consensus guidelines for using DCE-CT in assessing tumour vascularity.
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Determination of Glomerular Filtration Rate Using Dynamic CT-Angiography: Simultaneous Acquisition of Morphological and Functional Information: Erratum. Invest Radiol 2010. [DOI: 10.1097/rli.0b013e3181ed8593] [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]
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Performance Assessment of Dynamic Spiral Scan Modes With Variable Pitch for Quantitative Perfusion Computed Tomography. Invest Radiol 2010; 45:378-86. [DOI: 10.1097/rli.0b013e3181dfda9f] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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