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Zhao Y, Hubbard L, Malkasian S, Abbona P, Molloi S. Dynamic pulmonary CT perfusion using first-pass analysis technique with only two volume scans: Validation in a swine model. PLoS One 2020; 15:e0228110. [PMID: 32049969 PMCID: PMC7015394 DOI: 10.1371/journal.pone.0228110] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/07/2020] [Indexed: 12/02/2022] Open
Abstract
PURPOSE To evaluate the accuracy of a low-dose first-pass analysis (FPA) CT pulmonary perfusion technique in comparison to fluorescent microsphere measurement as the reference standard. METHOD The first-pass analysis CT perfusion technique was validated in six swine (41.7 ± 10.2 kg) for a total of 39 successful perfusion measurements. Different perfusion conditions were generated in each animal using serial balloon occlusions in the pulmonary artery. For each occlusion, over 20 contrast-enhanced CT images were acquired within one breath (320 x 0.5mm collimation, 100kVp, 200mA or 400mA, 350ms gantry rotation time). All volume scans were used for maximum slope model (MSM) perfusion measurement, but only two volume scans were used for the FPA measurement. Both MSM and FPA perfusion measurements were then compared to the reference fluorescent microsphere measurements. RESULTS The mean lung perfusion of MSM, FPA, and microsphere measurements were 6.21 ± 3.08 (p = 0.008), 6.59 ± 3.41 (p = 0.44) and 6.68 ± 3.89 ml/min/g, respectively. The MSM (PMSM) and FPA (PFPA) perfusion measurements were related to the corresponding reference microsphere measurement (PMIC) by PMSM = 0.51PMIC + 2.78 (r = 0.64) and PFPA = 0.79PMIC + 1.32 (r = 0.90). The root-mean-square-error for the MSM and FPA techniques were 3.09 and 1.72 ml/min/g, respectively. The root-mean-square-deviation for the MSM and FPA techniques were 2.38 and 1.50 ml/min/g, respectively. The CT dose index for MSM and FPA techniques were 138.7 and 8.4mGy, respectively. CONCLUSIONS The first-pass analysis technique can accurately measure regional pulmonary perfusion and has the potential to reduce the radiation dose associated with dynamic CT perfusion for assessment of pulmonary disease.
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Affiliation(s)
- Yixiao Zhao
- Department of Radiological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Logan Hubbard
- Department of Radiological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Shant Malkasian
- Department of Radiological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Pablo Abbona
- Department of Radiological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Sabee Molloi
- Department of Radiological Sciences, University of California Irvine, Irvine, California, United States of America
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Li K, Chen GH. Statistical properties of cerebral CT perfusion imaging systems. Part II. Deconvolution-based systems. Med Phys 2019; 46:4881-4897. [PMID: 31495935 DOI: 10.1002/mp.13805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 08/28/2019] [Accepted: 08/28/2019] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The purpose of this work was to develop a theoretical framework to pinpoint the quantitative relationship between input parameters of deconvolution-based cerebral computed tomography perfusion (CTP) imaging systems and statistical properties of the output perfusion maps. METHODS Deconvolution-based CTP systems assume that the arterial input function, tissue enhancement curve, and flow-scaled residue function k(t) are related to each other through a convolution model, and thus by reversing the convolution operation, k(t) and the associated perfusion parameters can be estimated. The theoretical analysis started by deriving analytical formulas for the expected value and autocovariance of the residue function estimated using the singular value decomposition-based deconvolution method. Next, it analyzed statistical properties of the "max" and "arg max" operators, based on which the signal and noise properties of cerebral blood flow (CBF) and time-to-max ( t max ) are quantitatively related to the statistical model of the estimated residue function [ k * ( t ) ] and system parameters. To validate the theory, CTP images of a digital head phantom were simulated, from which signal and noise of each perfusion parameter were measured and compared with values calculated using the theoretical model. In addition, an in vivo canine experiment was performed to validate the noise model of cerebral blood volume (CBV). RESULTS For the numerical study, the relative root mean squared error between the measured and theoretically calculated value is ≤0.21% for the autocovariance matrix of k * ( t ) , and is ≤0.13% for the expected form of k * ( t ) . A Bland-Altman analysis demonstrated no significant difference between measured and theoretical values for the mean or noise of each perfusion parameter. For the animal study, the theoretical CBV noise fell within the 25th and 75th percentiles of the experimental values. To provide an example of the theory's utility, an expansion of the CBV noise formula was performed to unveil the dominant role of the baseline image noise in deconvolution-based CBV. Correspondingly, data of the three canine subjects used in the Part I paper were retrospectively processed to confirm that preferentially partitioning dose to the baseline frames benefits both nondeconvolution- and deconvolution-based CBV maps. CONCLUSIONS Quantitative relationships between the statistical properties of deconvolution-based CTP maps, source image acquisition and reconstruction parameters, contrast injection protocol, and deconvolution parameters are established.
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Affiliation(s)
- Ke Li
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, 53705, USA.,Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI, 53792, USA
| | - Guang-Hong Chen
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, 53705, USA.,Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI, 53792, USA
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Kim J, Kim J, Kim HC, Kim K, Lee J, Kang E, Kim H, Min B, Ronco C. Three-Dimensional Dialysate flow Analysis in a Hollow-Fiber Dialyzer by Perfusion Computed Tomography. Int J Artif Organs 2018; 31:553-60. [DOI: 10.1177/039139880803100611] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Perfusion computed tomography (PCT) is a means to rapidly and easily evaluate cerebral perfusion in patients presenting with acute stroke symptoms, which provides insights into capillary-level hemodynamics. In this study, we used PCT to analyze the 3-dimensional dialysate flow in a low-flux hemodialyzer equipped with a standard fiber bundle. The dynamic CT studies were performed with 64-channel multi-detector row CT (MDCT) at a dialysate flow rate of 500 ml/min and a 1.0 ml/sec injection rate of contrast agent. Central volume principle was used to calculate hydrodynamic parameters by deconvolution of time-density curves (TDCs). Functional maps of dialysate flow (DF), dialysate volume (DV), and mean transit time (MTT) could quantitatively describe the dialysate flow maldistribution, variations in fiber packing, and perfusion pressure distribution in a hemodialyzer, respectively. PCT by means of analysis was able to overcome the limitations of conventional imaging techniques for analyzing dialysate flow distributions in hollow-fiber dialyzers. Not only local hydrodynamic phenomena at microscopic level but also macroscopic flow behavior of dialysate were visualized quantitatively. Therefore, we concluded that PCT is a quantitative analysis method to provide better insights into hydrodynamics of hollow-fiber dialyzers and is expected to contribute to optimization of artificial kidneys.
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Affiliation(s)
- J.C. Kim
- Interdisciplinary Program in Bioengineering Major, Seoul National University, Seoul
| | - J.H. Kim
- Interdisciplinary Program in Bioengineering Major, Seoul National University, Seoul
| | - H.-C. Kim
- Department of Radiology, Seoul National University Hospital, Seoul
| | - K.G. Kim
- Department of Biomedical Engineering, Division of Basic and Applied Sciences, National Cancer Center, Gyeong-Gi-Do - Republic of Korea
| | - J.C. Lee
- Interdisciplinary Program in Bioengineering Major, Seoul National University, Seoul
| | - E. Kang
- Department of Internal Medicine, Chung-Ang University Hospital, Seoul
| | - H.C. Kim
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Seoul
- Institute of Medical & Biological Engineering, Medical Research Center, Seoul National University, Seoul - Republic of Korea
| | - B.G. Min
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Seoul
- Institute of Medical & Biological Engineering, Medical Research Center, Seoul National University, Seoul - Republic of Korea
| | - C. Ronco
- Department of Nephrology, Dialysis and Transplantation, St. Bortolo Hospital, International Renal Research Institute Vicenza (IRRIV), Vicenza - Italy
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Lundsgaard Hansen M, Fallentin E, Axelsen T, Lauridsen C, Norling R, Svendsen LB, Nielsen MB. Interobserver and Intraobserver Reproducibility with Volume Dynamic Contrast Enhanced Computed Tomography (DCE-CT) in Gastroesophageal Junction Cancer. Diagnostics (Basel) 2016; 6:diagnostics6010008. [PMID: 26838804 PMCID: PMC4808823 DOI: 10.3390/diagnostics6010008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/20/2016] [Accepted: 01/26/2016] [Indexed: 01/05/2023] Open
Abstract
The purpose of this study was to assess inter- and intra-observer reproducibility of three different analytic methods to evaluate quantitative dynamic contrast-enhanced computed tomography (DCE-CT) measures from gastroesophageal junctional cancer. Twenty-five DCE-CT studies with gastroesophageal junction cancer were selected from a previous longitudinal study. Three radiologists independently reviewed all scans, and one repeated the analysis eight months later for intraobserver analysis. Review of the scans consisted of three analysis methods: (I) Four, fixed small sized regions of interest (2-dimensional (2D) fixed ROIs) placed in the tumor periphery, (II) 2-dimensional regions of interest (2D-ROI) along the tumor border in the tumor center, and (III) 3-dimensional volumes of interest (3D-VOI) containing the entire tumor volume. Arterial flow, blood volume and permeability (ktrans) were recorded for each observation. Inter- and intra-observer variability were assessed by Intraclass Correlation Coefficient (ICC) and Bland-Altman statistics. Interobserver ICC was excellent for arterial flow (0.88), for blood volume (0.89) and for permeability (0.91) with 3D-VOI analysis. The 95% limits of agreement were narrower for 3D analysis compared to 2D analysis. Three-dimensional volume DCE-CT analysis of gastroesophageal junction cancer provides higher inter- and intra-observer reproducibility with narrower limits of agreement between readers compared to 2D analysis.
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Affiliation(s)
- Martin Lundsgaard Hansen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
- Department of Radiology, Koege and Roskilde Hospital, DK-4000 Roskilde, Denmark.
| | - Eva Fallentin
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
| | - Thomas Axelsen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
| | - Carsten Lauridsen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
- Metropolitan University College, Radiography Education, Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Rikke Norling
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
| | - Lars Bo Svendsen
- Department of Surgery, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
| | - Michael Bachmann Nielsen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, DK-2100 Copenhagen, Denmark.
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Copen WA, Lev MH, Rapalino O. Brain perfusion: computed tomography and magnetic resonance techniques. HANDBOOK OF CLINICAL NEUROLOGY 2016; 135:117-135. [PMID: 27432662 DOI: 10.1016/b978-0-444-53485-9.00006-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebral perfusion imaging provides assessment of regional microvascular hemodynamics in the living brain, enabling in vivo measurement of a variety of different hemodynamic parameters. Perfusion imaging techniques that are used in the clinical setting usually rely upon X-ray computed tomography (CT) or magnetic resonance imaging (MRI). This chapter reviews CT- and MRI-based perfusion imaging techniques, with attention to image acquisition, clinically relevant aspects of image postprocessing, and fundamental differences between CT- and MRI-based techniques. Correlations with cerebrovascular physiology and potential clinical applications of perfusion imaging are reviewed, focusing upon the two major classes of neurologic disease in which perfusion imaging is most often performed: primary perfusion disorders (including ischemic stroke, transient ischemic attack, and reperfusion syndrome), and brain tumors.
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Affiliation(s)
- William A Copen
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Michael H Lev
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Otto Rapalino
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Merali Z, Wong T, Leung J, Gao MM, Mikulis D, Kassner A. Dynamic contrast-enhanced MRI and CT provide comparable measurement of blood-brain barrier permeability in a rodent stroke model. Magn Reson Imaging 2015; 33:1007-12. [PMID: 26117703 DOI: 10.1016/j.mri.2015.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/25/2015] [Accepted: 06/21/2015] [Indexed: 11/29/2022]
Abstract
In the current management of acute ischemic stroke (AIS), clinical criteria are used to estimate the risk of hemorrhagic transformation (HT), which is a devastating early complication. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and computed tomography (DCE-CT) may serve as physiologically-based decision making tools to more reliably assess the risk of HT. Before these tools can be properly validated, the comparability of the blood-brain barrier (BBB) permeability measurements they generate should be assessed. Sixteen rats were subjected to a transient middle cerebral artery occlusion before successively undergoing DCE-CT and DCE-MRI at 24-hours. BBB permeability (K(trans)) values were generated from both modalities. A correlation of R=0.677 was found (p<0.01) and the resulting relationship was [DCE-CT=(0.610*DCE-MRI)+4.140]. A variance components analysis found the intra-rat coefficient of variation to be 0.384 and 0.258 for K(trans) values from DCE-MRI and DCE-CT respectively. Permeability measures from DCE-CT were 22% higher than those from DCE-MRI. The results of this study demonstrate for the first time comparability between DCE-CT and DCE-MRI in the assessment of AIS. These results may provide a foundation for future clinical trials making combined use of these modalities.
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Affiliation(s)
- Zamir Merali
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Teser Wong
- Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jackie Leung
- Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Meah MingYang Gao
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - David Mikulis
- Division of Neuroradiology, Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Andrea Kassner
- Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.
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La Fontaine MD, McDaniel LS, Kubicek LN, Chappell RJ, Forrest LJ, Jeraj R. Patient characteristics influencing the variability of distributed parameter-based models in DCE-CT kinetic analysis. Vet Comp Oncol 2015; 15:105-117. [PMID: 25702795 DOI: 10.1111/vco.12143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 01/07/2015] [Accepted: 01/13/2015] [Indexed: 12/17/2022]
Abstract
Kinetic parameter variability may be sensitive to kinetic model choice, kinetic model implementation or patient-specific effects. The purpose of this study was to assess their impact on the variability of dynamic contrast-enhanced computed tomography (DCE-CT) kinetic parameters. A total of 11 canine patients with sinonasal tumours received high signal-to-noise ratio, test-double retest DCE-CT scans. The variability for three distributed parameter (DP)-based models was assessed by analysis of variance. Mixed-effects modelling evaluated patient-specific effects. Inter-model variability (CVinter ) was comparable to or lower than intra-model variability (CVintra ) for blood flow (CVinter :[4-28%], CVintra :[28-31%]), fractional vascular volume (CVinter :[3-17%], CVintra :[16-19%]) and permeability-surface area product (CVinter :[5-12%], CVintra :[14-15%]). The kinetic models were significantly (P<0.05) impacted by patient characteristics for patient size, area underneath the curve of the artery and of the tumour. In conclusion, DP-based models demonstrated good agreement with similar differences between models and scans. However, high variability in the kinetic parameters and their sensitivity to patient size may limit certain quantitative applications.
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Affiliation(s)
- M D La Fontaine
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
| | - L S McDaniel
- Department of Statistics, University of Wisconsin, Madison, WI, USA
| | - L N Kubicek
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - R J Chappell
- Department of Statistics, University of Wisconsin, Madison, WI, USA
| | - L J Forrest
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - R Jeraj
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
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8
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Souza FF, Smith A, Araujo C, Jagannathan J, Johnston C, O’Regan K, Shinagare A, Ramaiya N. New targeted molecular therapies for cancer: radiological response in intrathoracic malignancies and cardiopulmonary toxicity: what the radiologist needs to know. Cancer Imaging 2014; 14:26. [PMID: 25608887 PMCID: PMC4331831 DOI: 10.1186/1470-7330-14-26] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 03/13/2014] [Indexed: 01/13/2023] Open
Abstract
The emergence of new novel therapeutic agents which directly target molecules that are uniquely or abnormally expressed in cancer cells (molecular targeted therapy, MTT) has changed dramatically the treatment of cancer in recent years. The clinical benefit associated with these agents is typically limited to a subset of treated patients, who in many cases are defined by a specific genomic mutations and expression lesion within their tumor cells. All these new therapy modalities represent new challenges to radiologists as their mechanism of action and side effect profiles differ from conventional chemotherapy agents. In this article we will discuss radiological patterns of response to molecular targeted therapies MTT in lung cancer, typical and atypical radiological responses of targeted molecular therapy for other intra thoracic malignancies, cardiopulmonary toxicity and other side effects of molecular targeted therapy MTT in the thorax.
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Affiliation(s)
- Frederico F Souza
- Department of Radiology, University Of Mississippi Medical Center, 2500 North State Street, Jackson, MS, USA
| | - Andrew Smith
- Department of Radiology, University Of Mississippi Medical Center, 2500 North State Street, Jackson, MS, USA
| | - Cyrillo Araujo
- Department of Radiology, University Of Mississippi Medical Center, 2500 North State Street, Jackson, MS, USA
| | - Jyothi Jagannathan
- Department of Imaging And Nuclear Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA, USA
| | - Ciaran Johnston
- Department of Imaging And Nuclear Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA, USA
| | - Kevin O’Regan
- Department of Imaging And Nuclear Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA, USA
| | - Atul Shinagare
- Department of Imaging And Nuclear Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA, USA
| | - Nikhil Ramaiya
- Department of Imaging And Nuclear Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA, USA
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Miles KA. Acute cerebral stroke imaging and brain perfusion with the use of high-concentration contrast media. Eur Radiol 2013; 13 Suppl 5:M117-20. [PMID: 14989620 DOI: 10.1007/s00330-003-2104-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acute cerebral stroke remains a major cause of death among adults and the emergence of new therapies has created a need for early and rapid imaging at a time when conventional CT is either normal or demonstrates subtle abnormalities that are easy to misinterpret. Perfusion CT uses the temporal changes in cerebral and blood attenuation during a rapid series of images acquired without table movement following an intravenous bolus of contrast medium to generate images of mean transit time (MTT) cerebral blood volume (CBV) and perfusion. Reduced perfusion with preserved CBV is indicative of reversible ischaemia, whereas a matched reduction in perfusion and CBV implies infarction. The CT perfusion imaging can positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, provide an indication as to prognosis and potentially select those patients for whom thrombolysis is appropriate. Perfusion CT offers a powerful adjunct to MDCT based imaging of cerebrovascular disease, but further clinical validation is required.
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Affiliation(s)
- K A Miles
- Wesley Research Institute, 2nd Floor Day Care Centre, The Wesley Hospital, Brisbane, Australia.
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10
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Iezzi R, Santoro M, Dattesi R, La Torre M, Tinelli G, Snider F, Bonomo L. Foot CT perfusion in patients with peripheral arterial occlusive disease (PAOD): A feasibility study. Eur J Radiol 2013; 82:e455-64. [DOI: 10.1016/j.ejrad.2012.12.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 12/08/2012] [Accepted: 12/14/2012] [Indexed: 11/24/2022]
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Nabavi DG, Dittrich R, Kloska SP, Nam EM, Klotz E, Heindel W, Ringelstein EB. Window narrowing: a new method for standardized assessment of the tissue at risk-maximum of infarction in CT based brain perfusion maps. Neurol Res 2013; 29:296-303. [PMID: 17509230 DOI: 10.1179/016164107x158956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
BACKGROUND Mapping of brain perfusion using bolus tracking methods is increasingly used to assess the amount and severity of cerebral ischemia in acute stroke. Using relative perfusion maps, however, it is difficult to identify the tissue at risk-maximum (TARM) of infarction with sufficient reliability and reproducibility. METHODS We analysed 76 perfusion computed tomography (PCT) derived maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and time-to-peak (TTP) in 40 acute stroke patients using multidetector row technology and standard software (Somatom VolumeZoom, Siemens, Germany). 'Window narrowing' of the color maps was performed until color homogenisation of the contralateral unaffected hemisphere was reached. Tissue still depictable on the affected hemisphere after sufficient window narrowing was defined as the TARM. We analysed presence and size of the TARM on PCT maps, its relative perfusion values by comparison with contralateral, mirrored tissue, and its correlation with occurrence and final size of cerebral infarction on follow-up imaging. RESULTS An ischemic area was visible in 64, 58.9 and 72.6% on the conventional CBF, CBV and TTP maps, respectively. After window narrowing, a TARM was present in 56.8, 54.1 and 63.0% of slices comprising 11.9, 11.6 and 21.1% of the ipsilateral hemisphere (CBF, CBV and TTP), respectively. The relative perfusion values were 38.7 (CBF) and 43.0% (CBV) for the entire ischemic area and 11.3 (CBF) and 13.3% (CBV) for the TARM. Definite cerebral infarction was visible on 68.1% of the target slices comprising 23.7 +/- 22.9% of the ipsilateral hemisphere. The size of the TARM correlated slightly better with the final infarction size (r=0.74-0.82) than the entire ischemic area (r=0.61-0.79). With respect to the occurrence of cerebral infarction, the presence of a TARM on CBF maps showed the best positive (97.9%) and negative (72.7%) predictability. DISCUSSION On PCT maps, window narrowing provides a standardized display of the TARM in peracute stroke. The severely reduced values of relative CBF and CBV suggest the TARM to indicate tissue most prone to infarction.
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Affiliation(s)
- Darius G Nabavi
- Department of Neurology University of Münster, Münster, Germany.
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Computed Tomography (CT) Perfusion in Abdominal Cancer: Technical Aspects. Diagnostics (Basel) 2013; 3:261-70. [PMID: 26835679 PMCID: PMC4665537 DOI: 10.3390/diagnostics3020261] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 03/21/2013] [Accepted: 03/25/2013] [Indexed: 12/22/2022] Open
Abstract
Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed table position. Advances in reconstruction algorithms make it possible to reduce the radiation dose for each examination to acceptable levels. Regarding abdominal imaging, CT perfusion is still considered a research tool, but several studies have proven it as a reliable non-invasive technique for assessment of vascularity. CT perfusion has also been used for tumor characterization, staging of disease, response evaluation of newer drugs targeted towards angiogenesis and as a method for early detection of recurrence after radiation and embolization. There are several software solutions available on the market today based on different perfusion algorithms. However, there is no consensus on which protocol and algorithm to use for specific organs. In this article, the authors give an introduction to CT perfusion in abdominal imaging introducing technical aspects for calculation of perfusion parameters, and considerations on patient preparation. This article also contains clinical cases to illustrate the use of CT perfusion in abdominal imaging.
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Assessment of the Tracer Delay Effect in Whole-Brain Computed Tomography Perfusion. J Comput Assist Tomogr 2013; 37:212-21. [DOI: 10.1097/rct.0b013e31828004bb] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Ng CS, Waterton JC, Kundra V, Brammer D, Ravoori M, Han L, Wei W, Klumpp S, Johnson VE, Jackson EF. Reproducibility and comparison of DCE-MRI and DCE-CT perfusion parameters in a rat tumor model. Technol Cancer Res Treat 2012; 11:279-88. [PMID: 22417064 DOI: 10.7785/tcrt.2012.500296] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and computed tomography (DCE-CT) provide independent measures of biomarkers related to tumor perfusion. We compared the reproducibilities and absolute values of DCE-MRI and DCE-CT biomarkers in the same tumors in an animal model, to investigate the physiologic validity of both approaches. DCE-MRI and DCE-CT were each performed sequentially on three consecutive days in each of twelve rats bearing C6 glioma xenografts. DCE-MRI yielded endothelial transfer constant (K(trans)), extracellular, extravascular space volume fraction (v(e)), and contrast agent reflux rate constant (k(ep)); and DCE-CT, blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS) using Tofts and deconvolution physiological models, with 6.6 and 0.4 seconds temporal resolutions, respectively. Variability in DCE-CT and DCE-MRI were evaluated by variance components analysis. Intra-rat coefficients of variation for DCE-CT parameters BF, BV, MTT and PS were 25%, 22%, 18% and 23%; and for DCE-MRI parameters K(trans), k(ep) and v(e) were 23%, 16% and 20%, respectively. Mean (±SD) BF, BV, MTT and PS were: 44.6 (±13.7) ml min(-1) 100 g(-1), 5.7 (±1.5) ml 100 g(-1), 10.8 (±2.3) seconds, and 14.6 (±4.7) ml min(-1) 100 g(-1), respectively. Mean (±SD) K(trans), k(ep) and v(e) were: 0.21 (±0.05) min(-1), 0.68 (±0.14) min(-1), and 0.29 (±0.06), respectively. Permeability estimates from DCE-MRI (K(trans)) were 44% higher than from DCE-CT (PS), despite application of appropriate corrections. DCE-MRI and DCE-CT biomarkers of tumor perfusion have similar reproducibilities suggesting that they may have comparable utility, but their derived parameter values are not equivalent.
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Affiliation(s)
- Chaan S Ng
- Department of Radiology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.
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d’Esterre CD, Fainardi E, Aviv RI, Lee TY. Improving Acute Stroke Management with Computed Tomography Perfusion: A Review of Imaging Basics and Applications. Transl Stroke Res 2012; 3:205-20. [DOI: 10.1007/s12975-012-0178-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/09/2012] [Accepted: 04/12/2012] [Indexed: 10/28/2022]
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Abstract
Computed tomographic perfusion (CTP) imaging is an advanced modality that provides important information about capillary-level hemodynamics of the brain parenchyma. CTP can aid in diagnosis, management, and prognosis of acute stroke patients by clarifying acute cerebral physiology and hemodynamic status, including distinguishing severely hypoperfused but potentially salvageable tissue from both tissue likely to be irreversibly infarcted ("core") and hypoperfused but metabolically stable tissue ("benign oligemia"). A qualitative estimate of the presence and degree of ischemia is typically required for guiding clinical management. Radiation dose issues with CTP imaging, a topic of much current concern, are also addressed in this review.
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Affiliation(s)
- Angelos A Konstas
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
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Copen WA, Schaefer PW, Wu O. MR perfusion imaging in acute ischemic stroke. Neuroimaging Clin N Am 2012; 21:259-83, x. [PMID: 21640299 DOI: 10.1016/j.nic.2011.02.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Magnetic resonance (MR) perfusion imaging offers the potential for measuring brain perfusion in acute stroke patients, at a time when treatment decisions based on these measurements may affect outcomes dramatically. Rapid advancements in both acute stroke therapy and perfusion imaging techniques have resulted in continuing redefinition of the role that perfusion imaging should play in patient management. This review discusses the basic pathophysiology of acute stroke, the utility of different kinds of perfusion images, and research on the continually evolving role of MR perfusion imaging in acute stroke care.
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Affiliation(s)
- William A Copen
- Department of Radiology, Division of Neuroradiology, Massachusetts General Hospital, GRB-273A, 55 Fruit Street, Boston, MA 02114, USA.
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Reproducibility of Perfusion Parameters Obtained From Perfusion CT in Lung Tumors. AJR Am J Roentgenol 2011; 197:113-21. [DOI: 10.2214/ajr.10.5404] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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19
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Miles KA. Molecular imaging with dynamic contrast-enhanced computed tomography. Clin Radiol 2010; 65:549-56. [PMID: 20541654 DOI: 10.1016/j.crad.2010.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 04/15/2010] [Accepted: 04/22/2010] [Indexed: 01/10/2023]
Abstract
Dynamic contrast-enhanced computed tomography (DCE-CT) is a quantitative technique that employs rapid sequences of CT images after bolus administration of intravenous contrast material to measure a range of physiological processes related to the microvasculature of tissues. By combining knowledge of the molecular processes underlying changes in vascular physiology with an understanding of the relationship between vascular physiology and CT contrast enhancement, DCE-CT can be redefined as a molecular imaging technique. Some DCE-CT derived parameters reflect tissue hypoxia and can, therefore, provide information about the cellular microenvironment. DCE-CT can also depict physiological processes, such as vasodilatation, that represent the physiological consequences of molecular responses to tissue hypoxia. To date the main applications have been in stroke and oncology. Unlike some other molecular imaging approaches, DCE-CT benefits from wide availability and ease of application along with the use of contrast materials and software packages that have achieved full regulatory approval. Hence, DCE-CT represents a molecular imaging technique that is applicable in clinical practice today.
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Affiliation(s)
- K A Miles
- Clinical Imaging Sciences Centre, Brighton & Sussex Medical School, University of Sussex, Falmer, Brighton, UK.
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Tichauer KM, Elliott JT, Hadway JA, Lee DS, Lee TY, St. Lawrence K. Using near-infrared spectroscopy to measure cerebral metabolic rate of oxygen under multiple levels of arterial oxygenation in piglets. J Appl Physiol (1985) 2010; 109:878-85. [DOI: 10.1152/japplphysiol.01432.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Improving neurological care of neonates has been impeded by the absence of suitable techniques for measuring cerebral hemodynamics and energy metabolism at the bedside. Currently, near-infrared spectroscopy (NIRS) appears to be the technology best suited to fill this gap, and techniques have been proposed to measure both cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2). We have developed a fast and reliable bolus-tracking method of determining CMRO2 that combines measurements of CBF and cerebral venous oxygenation [venous oxygen saturation (CSvO2)]. However, this method has never been validated at different levels of arterial oxygenation [arterial oxygen saturation (SaO2)], which can be highly variable in the clinical setting. In this study, NIRS measurements of CBF, CSvO2, and CMRO2 were obtained over a range of SaO2 in newborn piglets ( n = 12); CSvO2 values measured directly from sagittal sinus blood samples were collected for validation. Two alternative NIRS methods that measure CSvO2 by manipulating venous oxygenation (i.e., head tilt and partial venous occlusion methods) were also employed for comparison. Statistically significant correlations were found between each NIRS technique and sagittal sinus blood oxygenation ( P < 0.05). Correlation slopes were 1.03 ( r = 0.91), 0.73 ( r = 0.73), and 0.73 ( r = 0.81) for the bolus-tracking, head tilt, and partial venous occlusion methods, respectively. The bolus-tracking technique displayed the best correlation under hyperoxic (SaO2 = 99.9 ± 0.03%) and normoxic (SaO2 = 86.9 ± 6.6%) conditions and was comparable to the other techniques under hypoxic conditions (SaO2 = 40.7 ± 9.9%). The reduced precision of the bolus-tracking method under hypoxia was attributed to errors in CSvO2 measurement that were magnified at low SaO2 levels. In conclusion, the bolus-tracking technique of measuring CSvO2, and therefore CMRO2, is accurate and robust for an SaO2 > 50% but provides reduced accuracy under more severe hypoxic levels.
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Affiliation(s)
- Kenneth M. Tichauer
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
| | - Jonathan T. Elliott
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
| | - Jennifer A. Hadway
- Imaging Division, Lawson Health Research Institute,
- Imaging Research Laboratories, Robarts Research Institute, and
| | - David S. Lee
- Department of Paediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Ting-Yim Lee
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
- Imaging Research Laboratories, Robarts Research Institute, and
| | - Keith St. Lawrence
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
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Shan F, Zhang Z, Zeng M, Hu J, Bai C. [Advanced NSCLC first pass perfusion at 64-slice CT: reproducibility of volume-based quantitative measurement]. ZHONGGUO FEI AI ZA ZHI = CHINESE JOURNAL OF LUNG CANCER 2010; 13:494-9. [PMID: 20677648 PMCID: PMC6000689 DOI: 10.3779/j.issn.1009-3419.2010.05.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
背景与目的 本研究旨在探讨进展期非小细胞肺癌(non-small cell lung cancer, NSCLC)首过法CT灌注(CT perfusion, CTP)的可重复性。 方法 在本院行首过法CTP检查(8×5 mm层厚),且经病理证实的进展期NSCLC患者14例,肿瘤最大径≤3 cm及>3 cm各7例,均在24 h内行第二次CTP扫描。采用组内相关系数(intraclass correlation coefcient, ICC)及Bland-Altman法评价CTP检查的可重复性。 结果 两组进展期NSCLC的血流速度(blood flow, BF)、血容量(blood volume, BV)及表面通透性(permeability surface area product, PS)值的ICC均>0.75;对比剂的平均通过时间(mean transit time, MT)的ICC均 < 0.75。≤3 cm的进展期NSCLC组的BF、BV、MT及PS的可重复系数(repeatability coefficient, RC)及RC值95%变化区间依次为56%(-39%-53%)、45%(-29%-62%)、114%(-83%-145%)、78%(-57%-98%);>3 cm组的BF、BV、MTT及PS的RC及RC值95%变化区间依次为46%(-48%-45%)、30%(-33%-26%)、-59%(-54%-64%)、33%(-18%-48%)。 结论 去卷积法首过法CTP参数BF及BV可重复性较好,用于评价进展期NSCLC抗血管生成治疗疗效时,可根据肿瘤大小,应用不同的可重复性标准区别对待。
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Affiliation(s)
- Fei Shan
- Department of Radiology, the Third Affiliated Hospital of Suzhou University, Changzhou 213003, China
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Latchaw RE, Alberts MJ, Lev MH, Connors JJ, Harbaugh RE, Higashida RT, Hobson R, Kidwell CS, Koroshetz WJ, Mathews V, Villablanca P, Warach S, Walters B. Recommendations for imaging of acute ischemic stroke: a scientific statement from the American Heart Association. Stroke 2009; 40:3646-78. [PMID: 19797189 DOI: 10.1161/strokeaha.108.192616] [Citation(s) in RCA: 286] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Xu J, Liang Z, Hao S, Zhu L, Ashish M, Jin C, Fu D, Ni Q. Pancreatic adenocarcinoma: dynamic 64-slice helical CT with perfusion imaging. ACTA ACUST UNITED AC 2009; 34:759-66. [PMID: 19672566 DOI: 10.1007/s00261-009-9564-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 05/16/2009] [Accepted: 06/25/2009] [Indexed: 12/14/2022]
Abstract
BACKGROUND Perfusion CT is able to outline blood perfusion changes in a tissue. Thus, in lesions of the tissues of the pancreas, this offers to increase the accuracy of CT diagnosis. In this study, our aim was to explore the perfusion characteristics of normal pancreas and pancreatic adenocarcinoma. METHODS Dynamic 64-slice helical CT was conducted in 36 patients with non-pancreatic disease and in 40 patients with histopathologically proven pancreatic adenocarcinoma. Perfusion parameters including blood flow (BF), blood volume (BV), and permeability surface area product (PS) were recorded. RESULTS There was no significant difference noted between the distribution of BF, BV, and PS values in different regions of the pancreas, namely the head, neck, body, and tail (P > 0.05). The BF, BV, and PS of normal pancreas were recorded as 135.24 +/- 48.36 ml min(-1) 100 g(-1), 200.55 +/- 54.96 ml 100 g(-1), and 49.75 +/- 24.27 ml min(-1) 100 g(-1), respectively. BF, BV, and PS values of the tumor tissue of pancreatic adenocarcinoma decreased significantly compared to normal pancreas (P < 0.05). CONCLUSIONS Normal pancreas appears homogenous on perfusion CT. A significant decrease of BF, BV, and PS was observed in pancreatic adenocarcinoma. Dynamic 64-slice helical CT with perfusion imaging should be considered a potential modality to increase the accuracy of CT diagnosis for pancreatic adenocarcinoma.
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Affiliation(s)
- Jin Xu
- Department of General Surgery, Pancreatic Disease Institution, Huashan Hospital, Fudan University, Shanghai 200040, China
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Abstract
Breast cancer is a complex disease and molecular imaging may contribute to better management through providing new insight for early detection. Fluorodeoxyglucose (FDG)-PET/CT has made great strides as a functional anatomic technique and recently gained attention in the diagnosis, staging, and follow-up of breast cancer. FDG-PET and CT complement each other's strengths in integrated FDGPET/CT. One-stop-shop whole-body FDG-PET/CT coupled with integrated FDG-PET/CT mammography has also been advocated.
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Ziegelitz D, Starck G, Mikkelsen IK, Tullberg M, Edsbagge M, Wikkelsö C, Forssell-Aronson E, Holtås S, Knutsson L. Absolute quantification of cerebral blood flow in neurologically normal volunteers: Dynamic-susceptibility contrast MRI-perfusion compared with computed tomography (CT)-perfusion. Magn Reson Med 2009; 62:56-65. [DOI: 10.1002/mrm.21975] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Ahmed AS, Zellerhoff M, Strother CM, Pulfer KA, Redel T, Deuerling-Zheng Y, Royalty K, Consigny D, Niemann DB. C-arm CT measurement of cerebral blood volume: an experimental study in canines. AJNR Am J Neuroradiol 2009; 30:917-22. [PMID: 19299488 DOI: 10.3174/ajnr.a1513] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral blood volume (CBV) is an important parameter in estimating the viability of brain tissue following an ischemic event. We tested the hypothesis that C-arm CT measurements of CBV would correlate well with those made with perfusion CT (PCT). MATERIALS AND METHODS CBV was measured in 12 canines by using PCT and C-arm CT. Two measurements with each technique were made on each animal; a different injection protocol was used for each of these techniques. PCT was performed by using a 64-section V-scanner. C-arm CT was performed by using a biplane Artis dBA system. PCT images were transferred to a commercially available workstation for postprocessing and analysis; C-arm CT images were transferred to a commercially available workstation for postprocessing and analysis by using prototype software. From each animal, 2 sections from each technique were selected for analysis. RESULTS There was good agreement of both the color maps and absolute numbers between the 2 techniques. The maximum and mean deviations of values between the 2 techniques for the first 5 animals were 30.20% and 7.82%; for the second 7 animals, these values were 26.79% and 7.40%. The maximum and mean deviations between the 2 C-arm CT studies performed on the first 5 animals were 33.15% and 12.24%; for the second 7 animals, these values were 41.15% and 10.89%. CONCLUSIONS In these healthy animals, measurement of CBV with C-arm CT compared well with measurements made with PCT.
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Affiliation(s)
- A S Ahmed
- University of Wisconsin Hospitals and Clinics, Madison, Wis., USA
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27
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Kambadakone AR, Sahani DV. Body perfusion CT: technique, clinical applications, and advances. Radiol Clin North Am 2009; 47:161-78. [PMID: 19195541 DOI: 10.1016/j.rcl.2008.11.003] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Perfusion CT has made tremendous progress since its inception and is gradually broadening its applications from the research realm into routine clinical care. This has been particularly noteworthy in the oncological setting, where perfusion CT is emerging as a valuable tool in tissue characterization, risk stratification and monitoring treatment effects especially assessing early response to novel targeted therapies. Recent technological advancements in CT have paved ways to overcome the initial limitations of restricted tissue coverage and radiation dose concerns. In this article, the authors review the basic principles and technique of perfusion CT and discuss its various oncologic and non-oncological clinical applications in body imaging.
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Affiliation(s)
- Avinash R Kambadakone
- Division of Abdominal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, White 270, Boston, MA 02114, USA
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Paul RK, Lum DP, Consigny DW, Grinde JR, Grist TM. CT Perfusion in the Treatment of a Swine Model of Unilateral Renal Artery Stenosis: Validation with Microspheres. J Vasc Interv Radiol 2009; 20:513-23. [DOI: 10.1016/j.jvir.2008.12.420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 12/20/2008] [Accepted: 12/22/2008] [Indexed: 10/21/2022] Open
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Konstas AA, Goldmakher GV, Lee TY, Lev MH. Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 2: technical implementations. AJNR Am J Neuroradiol 2009; 30:885-92. [PMID: 19299489 DOI: 10.3174/ajnr.a1492] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
CT perfusion (CTP) is a functional imaging technique that provides important information about capillary-level hemodynamics of the brain parenchyma and is a natural complement to the strengths of unenhanced CT and CT angiography in the evaluation of acute stroke, vasospasm, and other neurovascular disorders. CTP is critical in determining the extent of irreversibly infarcted brain tissue (infarct "core") and the severely ischemic but potentially salvageable tissue ("penumbra"). This is achieved by generating parametric maps of cerebral blood flow, cerebral blood volume, and mean transit time.
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Affiliation(s)
- A A Konstas
- Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
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Konstas AA, Goldmakher GV, Lee TY, Lev MH. Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 1: Theoretic basis. AJNR Am J Neuroradiol 2009; 30:662-8. [PMID: 19270105 DOI: 10.3174/ajnr.a1487] [Citation(s) in RCA: 185] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
CT perfusion (CTP) is a functional imaging technique that provides important information about capillary-level hemodynamics of the brain parenchyma and is a natural complement to the strengths of unenhanced CT and CT angiography in the evaluation of acute stroke, vasospasm, and other neurovascular disorders. CTP is critical in determining the extent of irreversibly infarcted brain tissue (infarct "core") and the severely ischemic but potentially salvageable tissue ("penumbra"). This is achieved by generating parametric maps of cerebral blood flow, cerebral blood volume, and mean transit time.
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Affiliation(s)
- A A Konstas
- Department of Radiology, Massachusetts General Hospital, Boston, Mass. 02114, USA.
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31
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Murphy AM, Xenocostas A, Pakkiri P, Lee TY. Hemodynamic effects of recombinant human erythropoietin on the central nervous system after subarachnoid hemorrhage: reduction of microcirculatory impairment and functional deficits in a rabbit model. J Neurosurg 2009; 109:1155-64. [PMID: 19035736 DOI: 10.3171/jns.2008.109.12.1155] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The authors investigated the hemodynamic effects of recombinant human erythropoietin (rhEPO) after subarachnoid hemorrhage (SAH) in rabbits. METHODS The authors used male New Zealand White rabbits in this study divided into the following groups: SAH plus saline (16 rabbits), SAH plus low-dose rhEPO (16 rabbits; 1500 IU/kg on Day 0 and 500 IU/kg on Days 2 and 4), SAH plus high-dose rhEPO (10 rabbits; 1500 IU/kg on Days 0, 2, 4, and 6), and sham (6 rabbits). Computed tomography perfusion studies and CT angiography were performed for 1 hour after SAH on Day 0, and once each on Days 2, 4, 7, 9, and 16 after SAH. Assessments of neurological function and tissue histology were also performed. RESULTS The mortality rate was significantly lower after rhEPO treatment (12%) than after saline treatment (44%) (p < 0.05). Neurological outcomes in the low-dose and high-dose rhEPO groups were better than in the saline group after SAH (p < 0.05), and the cerebral blood flow in the high-dose rhEPO group was greater than that in the saline group (p < 0.05). The mean transit time was significantly lower on Days 2 and 4 in the low-dose and high-dose rhEPO groups than in the saline group, but increased significantly on Day 7 in both groups (p < 0.05). The hematocrit increased significantly from baseline values in the high-dose and low-dose rhEPO groups on Days 4 and 7, respectively (p < 0.05). CONCLUSIONS Treatment with rhEPO after experimental SAH is associated with improved cerebral blood flow and microcirculatory flow as reflected by lower mean transit times. Improved tissue perfusion correlated with reduced mortality and improved neurological outcomes. Further investigation of the impact of increasing hematocrit on hemodynamic changes is needed.
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Affiliation(s)
- Amanda M Murphy
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada
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Goh V. Quantitative Assessment of Colorectal Cancer Perfusion: Perfusion Computed Tomography and Dynamic Contrast Enhanced Magnetic Resonance Imaging. COLORECTAL CANCER 2009. [DOI: 10.1007/978-1-4020-9545-0_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Decaminada N, Pernter P, Imondi A, Tomassini A. CT Perfusion Evaluation of Cerebral Haemodynamics before and after Cranioplasty. Neuroradiol J 2008; 21:459-71. [PMID: 24256951 DOI: 10.1177/197140090802100402] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Accepted: 05/13/2008] [Indexed: 11/16/2022] Open
Abstract
CT Perfusion imaging is usually applied to assess perfusion abnormalities in acute stroke. This prospective study applied the technique to monitor cerebral haemodynamics before and after cranioplasty. Cranioplasty is the surgical correction of a skull defect using autologous or heterologous material to obtain cosmetic repair, restoration of brain protection and neurological improvement (1). As far as we know the effect of cranioplasty on cerebral haemodynamics flow has been analysed by CT perfusion only in one article (2). We tested the examination as method of monitoring intracranial haemodynamics in a larger number of patients evaluating its reliability and efficacy. We prospectively examined cerebral haemodynamics with Perfusion CT before and after (two weeks, three and six months) cranioplasty in ten patients. The data evaluation of dynamic CT was done by an application software package on a workstation (Leonardo) permitting the use of visual assessment combined with quantitative analysis with ROIs. There was a comparison of CBF, CBV and TTP values between the regions of interest and mirror-image control regions, and in the three different examinations for each patient. After cranioplasty there was clearly an improvement in neurological symptoms and CT perfusion in the majority of cases showed a slight increase in CBF, CBV and decrease of TTP in the cerebral parenchyma close to the cranioplasty, not only on the symptomatic side but also on the opposite side. Even though there was neurological improvement and improved cranial perfusion from the first to the last examinations, our data were not statistically significant. The method is easily reproducible, well tolerated by all patients but has several limitations related to data processing and radiation exposure.
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Affiliation(s)
- N Decaminada
- Radiology Department, Bolzano Central Hospital; Bolzano, Italy -
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Perfusion MDCT Enables Early Detection of Therapeutic Response to Antiangiogenic Therapy. AJR Am J Roentgenol 2008; 191:133-9. [DOI: 10.2214/ajr.07.2848] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Functional CT of squamous cell carcinoma in the head and neck: repeatability of tumor and muscle quantitative measurements, inter- and intra-observer agreement. Eur Radiol 2008; 18:2241-50. [DOI: 10.1007/s00330-008-0990-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 03/17/2008] [Accepted: 03/27/2008] [Indexed: 10/22/2022]
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Gaudiello F, Colangelo V, Bolacchi F, Melis M, Gandini R, Garaci FG, Cozzolino V, Floris R, Simonetti G. Sixty-four-section CT cerebral perfusion evaluation in patients with carotid artery stenosis before and after stenting with a cerebral protection device. AJNR Am J Neuroradiol 2008; 29:919-23. [PMID: 18296553 DOI: 10.3174/ajnr.a0945] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Brain tissue viability depends on cerebral blood flow (CBF) that has to be kept within a narrow range to avoid the risk of developing ischemia. The aim of the study was to evaluate by 64-section CT (VCT) the cerebral perfusion modifications in patients with severe carotid stenosis before and after undergoing carotid artery stent placement (CAS) with a cerebral protection system. MATERIALS AND METHODS Fifteen patients with unilateral internal carotid stenosis (>or=70%) underwent brain perfusional VCT (PVCT) 5 days before and 1 week after the stent-placement procedure. CBF and mean transit time (MTT) values were measured. RESULTS Decreased CBF and increased MTT values were observed in the cerebral areas supplied by the stenotic artery as compared with the areas supplied by the contralateral patent artery (P < .001). A significant normalization of the perfusion parameters was observed after the stent-placement procedure (mean pretreatment MTT value, 5.3 +/- 0.2; mean posttreatment MTT value, 4.3 +/- 0.18, P < .001; mean pretreatment CBF value, 41.2 mL/s +/- 2.1; mean posttreatment CBF value, 47.9 mL/s +/- 2.9, P < .001). CONCLUSIONS PVCT is a useful technique for the assessment of the hemodynamic modifications in patients with severe carotid stenosis. The quantitative evaluation of cerebral perfusion makes it a reliable tool for the follow-up of patients who undergo CAS.
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Affiliation(s)
- F Gaudiello
- Department of Diagnostic Imaging and Interventional Radiology, University of Tor Vergata, Rome, Italy.
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Faria SC, Ng CS, Hess KR, Phongkitkarun S, Szejnfeld J, Daliani D, Charnsangavej C. CT Quantification of Effects of Thalidomide in Patients with Metastatic Renal Cell Carcinoma. AJR Am J Roentgenol 2007; 189:378-85. [PMID: 17646464 DOI: 10.2214/ajr.07.2164] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Our objective was to use functional CT to evaluate the effects of thalidomide in patients with metastatic renal cell carcinoma. SUBJECTS AND METHODS Patients with proven metastatic renal cell carcinoma were examined prospectively with functional CT. Functional CT studies (cine mode, 4 x 5 mm) were performed through the tumor after i.v. administration of a bolus of contrast material before and every 12 weeks after treatment with thalidomide. Quantitative values for blood flow, blood volume, mean transit time, and permeability-surface area product were calculated with commercial software. The average difference in percentage change in functional CT parameters from pretreatment to 12 and 24 weeks after treatment and the median difference in percentage change in functional CT parameters between response groups were assessed. We also tested whether percentage changes in functional CT parameters 12 weeks after treatment correlated with time to progression of disease and size of the perfused lesion. RESULTS Sixteen patients with a total of 23 tumors underwent at least one follow-up functional CT examination. Blood flow, blood volume, and permeability-surface area product decreased significantly 12 weeks (-18%, p = 0.0039; -15%, p = 0.0350; -24%, p = 0.0010) and 24 weeks (-28%, p = 0.017; -19%, p = 0.0300; -25%, p = 0.0031) after treatment with thalidomide. Time to progression correlated significantly with percentage change in blood flow (r = -0.34; p = 0.040) and permeability-surface area product (r = -0.36, p = 0.023) at 12 weeks. Responders had a significantly larger decrease in blood flow 12 weeks after treatment than did nonresponders (-29% vs -6%; p = 0.032). We also found a significant correlation between decrease in size of the perfused lesion and percentage decrease in blood flow 12 weeks after treatment (r = 0.50; p = 0.019). CONCLUSION Changes in functional CT parameters 12 weeks after treatment may be useful for monitoring the effects of thalidomide and predicting treatment outcome among patients with metastatic renal cell carcinoma. Further study with a larger clinical trial is needed.
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Affiliation(s)
- Silvana C Faria
- Department of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA.
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Turk AS, Grayev A, Rowley HA, Field AS, Turski P, Pulfer K, Mukherjee R, Haughton V. Variability of clinical CT perfusion measurements in patients with carotid stenosis. Neuroradiology 2007; 49:955-61. [PMID: 17646976 DOI: 10.1007/s00234-007-0276-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Accepted: 06/25/2007] [Indexed: 01/06/2023]
Abstract
INTRODUCTION CT perfusion imaging (pCT) may be used to detect and monitor hemodynamic abnormalities due to cerebrovascular disease. The magnitude of variability in clinical measurements has been insufficiently evaluated. The purpose of this study was to measure the long-term variability of clinical pCT measurements in patients with cerebrovascular disease. METHODS pCT parameters were calculated for the cerebral hemisphere contralateral to a carotid stenosis before and after stent treatment of stenosis in 33 consecutive patients. Mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) calculated from pCT data from both a small and large region of interest (ROI) using both manual and automated methods were compared before and after stent treatment. Differences between the first and second measurement were tested for statistical significance with at-test. Variability was calculated as the standard deviation of the differences divided by the mean of the pre- and post-stent treatment values. To adjust for proportional bias, the Bland-Altman analysis was applied. RESULTS The differences between the two measurements of MTT, CBF, and CBV averaged 2.5 to 7.7% when a manual method was used and was higher with automatic methods (p > 0.07). The variability of the values was 18% for MTT, 19% for CBV, and 25% for CBF with the large ROI and the manual method of calculation. The magnitude was larger when the small ROI and automatic methods were employed. CONCLUSION Longitudinal measurements of MTT, CBV, or CBF by pCT may vary by 20-25%. To detect changes in treatment-related changes in perfusion, pCT studies must be designed to achieve statistical significance based on this variability.
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Affiliation(s)
- Aquilla S Turk
- Department of Radiology, University of Wisconsin Hospital and Clinics, Madison, WI, USA.
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Hakimé A, Peddi H, Hines-Peralta AU, Wilcox CJ, Kruskal J, Lin S, de Baere T, Raptopoulos VD, Goldberg SN. CT perfusion for determination of pharmacologically mediated blood flow changes in an animal tumor model. Radiology 2007; 243:712-9. [PMID: 17517930 DOI: 10.1148/radiol.2433052048] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE To prospectively compare single- and multisection computed tomographic (CT) perfusion for tumor blood flow determination in an animal model. MATERIALS AND METHODS All animal protocols and experiments were approved by the institutional animal care and use committee before the study was initiated. R3230 mammary adenocarcinoma was implanted in 11 rats. Tumors (18-20 mm) were scanned with dynamic 16-section CT at baseline and after administration of arsenic trioxide, which is known to cause acute reduction in blood flow. The concentration of arsenic was titrated (0-6 mg of arsenic per kilogram of body weight) to achieve a defined blood flow reduction (0%-75%) from baseline levels at 60 minutes, as determined with correlative laser Doppler flowmetry. The mean blood flow was calculated for each of four 5-mm sections that covered the entire tumor, as well as for the entire tumor after multiple sections were processed. Measurements obtained with both methods were correlated with laser Doppler flowmetry measurements. Interobserver agreement was determined for two blinded radiologists, who calculated the percentage of blood flow reduction for the "most representative" single sections at baseline and after arsenic administration. These results were compared with the interobserver variability of the same radiologists obtained by summing blood flow changes for the entire tumor volume. RESULTS Overall correlations for acute blood flow reduction were demonstrated between laser Doppler flowmetry and the two CT perfusion approaches (single-section CT, r=0.85 and r(2)=0.73; multisection CT, r=0.93 and r(2)=0.87; pooled data, P=.01). CT perfusion disclosed marked heterogeneity of blood flow, with variations of 36% +/- 13 between adjacent 5-mm sections. Given these marked differences, interobserver agreement was much lower for single-section CT (standard deviation, 0.22) than for multisection CT (standard deviation, 0.10; P=.01). CONCLUSION Multisection CT perfusion techniques may provide an accurate and more reproducible method of tumor perfusion surveillance than comparison of single representative tumor sections.
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Affiliation(s)
- Antoine Hakimé
- Laboratory for Minimally Invasive Tumor Therapy, Beth Israel Deaconess Medical Center, 1 Deaconess Rd, WCC 308B, Boston, MA 02215, USA
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Goh V, Halligan S, Bartram CI. Quantitative tumor perfusion assessment with multidetector CT: are measurements from two commercial software packages interchangeable? Radiology 2007; 242:777-82. [PMID: 17325066 DOI: 10.1148/radiol.2423060279] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively determine the level of agreement between tumor blood volume and permeability measurements obtained with two commercially available perfusion computed tomographic (CT) software packages. MATERIALS AND METHODS This study was performed with institutional review board approval; informed consent was obtained from all participants. A total of 44 patients (24 men, 20 women; mean age, 68 years; range, 28-87 years) with proved colorectal cancer were examined prospectively with multi-detector row CT. A 65-second tumor perfusion study was performed after intravenous bolus injection of contrast material. Tumor blood volume and permeability were determined with two methods: adiabatic approximation of distributed parameter analysis and Patlak analysis. Agreement between the results was determined by using Bland-Altman statistics. Within-patient variation was determined by using analysis of variance. RESULTS The mean values for permeability and blood volume, respectively, were 13.9 mL x 100 mL(-1) x min(-1) +/- 3.7 (standard deviation) and 6.1 mL/100 mL +/- 1.5, as calculated with distributed parameter analysis, and 17.4 mL x 100 mL(-1) x min(-1) +/- 7.3 and 10.1 mL/100 mL +/- 4.2, as calculated with Patlak analysis. The mean difference and 95% limits of agreement, respectively, were -3.6 mL x 100 mL(-1) x min(-1) and -18.4 to 11.2 mL x 100 mL(-1) x min(-1) for permeability and -3.9 mL/100 mL and -10.9 to 3.0 mL/100 mL for blood volume. The coefficient of variation was 37.4% for permeability and 46.5% for blood volume. CONCLUSION There was disagreement between the methods used to estimate tumor vascularity, which indicated the measurement techniques were not directly interchangeable.
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Affiliation(s)
- Vicky Goh
- Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, England
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Grand S, Lefournier V, Krainik A, Bessou P, Tropres I, Chabardes S, Hoffmann D, Le Bas JF. Imagerie de perfusion : principes et applications cliniques. ACTA ACUST UNITED AC 2007; 88:444-71. [PMID: 17457257 DOI: 10.1016/s0221-0363(07)89846-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
MR and CT imaging techniques provide both morphological data and functional data. MR and recently CT perfusion have substantially modified the treatment of acute stroke. CT perfusion offers new opportunities to improve the management strategy in vasospasm after subarachnoid hemorrhage. Both are also helpful for the diagnosis of brain tumors and the assessment of treatment effects.
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Affiliation(s)
- S Grand
- Service de Neuroradiologie et Unité IRM, CHU Grenoble, France.
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Dennis Cheong LH, Markus Tan CK, Koh TS, Tchoyoson Lim CC, Bisdas S. Functional Imaging: Dynamic Contrast-Enhanced CT using a Distributed-Parameter Physiologic Model for Accessing Stroke and Intracranial Tumor. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:294-7. [PMID: 17282171 DOI: 10.1109/iembs.2005.1616402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Functional imaging has the potential to be a practical and widely-available method of studying the pathphysiology of disease using modern CT and MRI technologies. With the high temporal resolution achievable by these technologies, a two-compartment distributed-parameter model, which more accurate represents the tracer concentration within the vascular space, was applied on two patients' data with intracranial tumor and stroke. The parametric maps successfully generated were more informative than the current commercial software packages and the commonly used lumped-parameter compartmental models.
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Affiliation(s)
- L H Dennis Cheong
- Center for Modeling and Control of Complex Systems, Nanyang Technological University, Singapore; Center for Signal Processing, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore. E-mail:
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Chaves C, Hreib K, Allam G, Liberman RF, Lee G, Caplan LR. Patterns of Cerebral Perfusion in Patients with Asymptomatic Internal Carotid Artery Disease. Cerebrovasc Dis 2006; 22:396-401. [PMID: 16888382 DOI: 10.1159/000094858] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Accepted: 04/19/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The perfusion profile of patients with asymptomatic internal carotid artery (ICA) disease has not been well studied. The purpose of this study is to describe the perfusion patterns of patients with asymptomatic ICA disease using computed tomography perfusion (CTP) and its potential value in identifying patients at higher risk for transient ischemic attacks (TIAs) or strokes. METHODS We analyzed 32 patients with asymptomatic high grade ICA disease who had CTP and computed tomography angiography (CTA) of the head and neck. Twenty-four patients had severe ICA stenosis and eight had ICA occlusion. The degree of ipsilateral external carotid artery (ECA) and contralateral ICA stenosis, patency of the anterior communicating artery (ACOM), A1 segment and posterior communicating artery (PCOM) were evaluated in all patients. RESULTS Sixteen patients had normal CTP and the other 16 patients had cerebral hypoperfusion, characterized by abnormalities in one or more of the three perfusion maps. Ipsilateral hypoplastic A1 segment was more frequent in the group with cerebral hypoperfusion (p = 0.025). Ipsilateral TIAs occurred in two patients, both with cerebral hypoperfusion. CONCLUSION Cerebral hypoperfusion is present in half of the patients with asymptomatic ICA disease, predominantly in patients with a hypoplastic ipsilateral A1 segment. These patients likely represent a higher-risk group for symptomatic brain ischemia.
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Affiliation(s)
- Claudia Chaves
- Department of Neurology, Lahey Clinic, Burlington, MA, USA.
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Ng QS, Goh V, Klotz E, Fichte H, Saunders MI, Hoskin PJ, Padhani AR. Quantitative assessment of lung cancer perfusion using MDCT: does measurement reproducibility improve with greater tumor volume coverage? AJR Am J Roentgenol 2006; 187:1079-84. [PMID: 16985160 DOI: 10.2214/ajr.05.0889] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To date, quantitative assessment of tumor vascularity using perfusion CT has been limited to a single tumor level, with the potential for measurement error in heterogeneous tumors. We aimed to determine if greater z-axis tumor coverage improves the reproducibility of perfusion CT measurements in lung cancer. SUBJECTS AND METHODS Paired perfusion studies were performed on 10 patients who had histologically confirmed advanced non-small cell lung cancer. Using 16-MDCT, multiple sequential volumetric acquisitions encompassing the entire tumor were acquired after infusion of i.v. contrast material. Using Patlak analysis, median values of tumor permeability (mL/100 mL/min) and blood volume (mL/100 mL) were measured for 10-mm z-axis coverage, and for 40-mm z-axis coverage in each of the paired perfusion studies. Measurement reproducibility was evaluated using Bland-Altman statistics. RESULTS Mean difference (95% limits of agreement) for tumor permeability was 1.4 (-4.0 to 6.8) for 10-mm coverage and 0.8 (-3.6 to 5.2) for 40-mm coverage. Mean difference (95% limits of agreement) for blood volume was 1.9 (-5.1 to 8.9) for 10-mm coverage and 1.4 (-3.7 to 6.6) for 40-mm coverage. The coefficient of variation for permeability was 18.7% for 10-mm coverage, improving to 11.9% for 40-mm coverage. The coefficient of variation for blood volume was 41.7% for 10-mm coverage, improving to 32.6% for 40-mm coverage. CONCLUSION Our results show that an improvement in tumor perfusion measurement reproducibility may be achieved with greater z-axis coverage.
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Affiliation(s)
- Quan Sing Ng
- Marie Curie Research Wing, Mount Vernon Hospital, Northwood, Middlesex, United Kingdom
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Abstract
Functional imaging using multidetector row computed tomography and dynamic contrast-enhanced magnetic resonance imaging are increasingly advocated for assessment of tumor vascularity because these techniques provide excellent anatomic imaging and reliable quantitative perfusion data and are easily incorporated into routine examinations. However, differences in acquisition techniques, mathematical analysis, measurement parameters, and propensity to artifacts influence the choice of imaging modality, which is explored in this review.
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Affiliation(s)
- V Goh
- Paul Strickland Scanner Centre, Mount Vernon Hospital, Rickmansworth Road, Northwood, Middlesex HA6 2RN, United Kingdom.
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Goh V, Halligan S, Hugill JA, Bartram CI. Quantitative Assessment of Tissue Perfusion Using MDCT: Comparison of Colorectal Cancer and Skeletal Muscle Measurement Reproducibility. AJR Am J Roentgenol 2006; 187:164-9. [PMID: 16794171 DOI: 10.2214/ajr.05.0050] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE The purposes of this study were to determine the reproducibility of quantitative colorectal cancer perfusion measurements using dynamic contrast-enhanced MDCT, and to compare this with measurements from skeletal muscle. SUBJECTS AND METHODS Ten patients (mean age, 67 years; six men, four women) with histologically proven colorectal cancer were examined prospectively using 4-MDCT. Perfusion studies (cine mode; 4 x 5 mm collimation; 1 acquisition/s; 65 seconds total) were performed through the tumor epicenter after IV bolus contrast administration (iopamidol 340, 100 mL; 5 mL/s) and repeated within 48 hours. Quantitative values for blood volume, blood flow, mean transit time, and permeability were determined using commercial software. Two regions of interest were studied on the axial image: one within the tumor and another within the left gluteal muscle. Measurement reproducibility was assessed using Bland-Altman statistics. RESULTS For the tumor, the mean difference (95% limits of agreement) was -0.04 mL/100 g tissue (-2.50, 2.42); 8.80 (-50.5, 68.0) mL/100 g tissue/min; -0.99 (-8.19, 6.20) seconds; and 1.20 (-5.42, 7.83) mL/100 g tissue/min for blood volume, blood flow, mean transit time, and permeability, respectively. For muscle, the mean difference (95% limits of agreement) was 0.02 (-1.40, 1.43), 6.60 (-11.2, 24.3), -3.76 (-16.87, 9.35), and 1.30 (-4.68, 7.28), respectively. CONCLUSION Quantitative perfusion measurements are reproducible. Measurements from tumor are less variable than from skeletal muscle.
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Affiliation(s)
- Vicky Goh
- Paul Strickland Scanner Centre, Mt. Vernon Hospital, Northwood, United Kingdom
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Goh V, Halligan S, Gartner L, Bassett P, Bartram CI. Quantitative colorectal cancer perfusion measurement by multidetector-row CT: does greater tumour coverage improve measurement reproducibility? Br J Radiol 2006; 79:578-83. [PMID: 16823062 DOI: 10.1259/bjr/18842556] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The purpose of this study was to determine if greater z-axis tumour coverage improves the reproducibility of quantitative colorectal cancer perfusion measurements using CT. A 65 s perfusion study was acquired following intravenous contrast administration in 10 patients with proven colorectal cancer using a four-detector row scanner. This was repeated within 48 h using identical technical parameters to allow reproducibility assessment. Quantitative tumour blood volume, blood flow, mean transit time and permeability measurements were determined using commercially available software (Perfusion 3.0; GE Healthcare, Waukesha, WI) for data obtained from a 5 mm z-axis tumour coverage, and from a 20 mm z-axis tumour coverage. Measurement reproducibility was assessed using Bland-Altman statistics, for a 5 mm z-axis tumour coverage, and 20 mm z-axis tumour coverage, respectively. The mean difference (95% limits of agreement) for blood volume, blood flow, mean transit time and permeability were 0.04 (-2.50 to +2.43) ml/100 g tissue; +8.80 (-50.5 to +68.0) ml/100 g tissue/min; -0.99 (-8.19 to +6.20) seconds; and +1.20 (-5.42 to +7.83) ml/100 g tissue/min, respectively, for a 5 mm coverage, and -0.04 (-2.61 to +2.53) ml/100 g tissue; +7.40 (-50.3 to +65.0) ml/100 g tissue/min; -2.46 (-12.61 to +7.69) seconds; and -0.23 (-8.31 to +7.85) ml/100 g tissue/min, respectively, for a 20 mm coverage, indicating similar levels of agreement. In conclusion, increasing z-axis coverage does not improve reproducibility of quantitative colorectal cancer perfusion measurements.
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Affiliation(s)
- V Goh
- Intestinal Imaging Centre, St Mark's Hospital, Harrow, UK
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Soustiel JF, Mor N, Zaaroor M, Goldsher D. Cerebral perfusion computerized tomography: influence of reference vessels, regions of interest and interobserver variability. Neuroradiology 2006; 48:670-7. [PMID: 16718460 DOI: 10.1007/s00234-006-0099-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2005] [Accepted: 03/30/2006] [Indexed: 11/30/2022]
Abstract
INTRODUCTION There are still no standardized guidelines for perfusion computerized tomography (PCT) analysis. METHODS A total of 61 PCT studies were analyzed using either the anterior cerebral artery (ACA) or the middle cerebral artery (MCA) as the arterial reference, and the superior sagittal sinus (SSS) or the vein of Galen (VG) as the venous reference. The sizes of regions of interest (ROI) were investigated comparing PCT results obtained using a hemispheric ROI combined with vascular pixel elimination with those obtained using five smaller ROIs located over the cortex and basal ganglia. In addition, interobserver variations were explored using a standardized protocol. RESULTS MCA-based measurements of cerebral blood flow (CBF) and blood volume (CBV) were in accordance with those obtained with the ACA except in 16 patients with ischemic stroke, in whom CBF was overestimated by the ipsilateral MCA. Venous maximal intensity was significantly lower with the VG when compared with the SSS, resulting in overestimation of CBF and CBV. However, in 13.3% of patients the VG ROI yielded higher maximal intensities than the SSS ROI. There was no difference in PCT results between hemispheric ROI and averaged separate ROI when vascular pixel elimination was used. Finally, interobserver variations were as high as 11% for CBF and 12% for CBV. CONCLUSION The present results suggest that pathological rather than anatomical considerations should dictate the choice of the arterial ROI. For venous ROI, although SSS seems to be adequate in most instances, deep cerebral veins may occasionally generate higher maximal intensities and should therefore be selected. Importantly, significant user-dependency should be taken into account.
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Affiliation(s)
- Jean F Soustiel
- Department of Neurosurgery, Rambam Medical Center, Faculty of Medicine, Technion Israel Institute of Technology, Haifa, 31096, Israel.
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Ng QS, Goh V, Fichte H, Klotz E, Fernie P, Saunders MI, Hoskin PJ, Padhani AR. Lung Cancer Perfusion at Multi–Detector Row CT: Reproducibility of Whole Tumor Quantitative Measurements. Radiology 2006; 239:547-53. [PMID: 16543594 DOI: 10.1148/radiol.2392050568] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Institutional review board approval and informed consent were obtained for this study. The aim of the study was to prospectively assess, in patients with lung cancer, the reproducibility of a quantitative whole tumor perfusion computed tomographic (CT) technique. Paired CT studies were performed in 10 patients (eight men, two women; mean age, 66 years) with lung cancer. Whole tumor permeability and blood volume were measured, and reproducibility was evaluated by using Bland-Altman statistics. Coefficient of variation of 9.49% for permeability and 26.31% for blood volume and inter- and intraobserver variability ranging between 3.30% and 6.34% indicate reliable assessment with this whole tumor technique.
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Affiliation(s)
- Quan-Sing Ng
- Marie Curie Research Wing and Paul Strickland Scanner Centre, Mount Vernon Hospital, Rickmansworth Rd, Northwood, Middlesex, England
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