Dynamic MRI for imaging tumor microvasculature: Comparison of susceptibility and relaxivity techniques in pelvic tumors

Purpose:To evaluate the relationship between image noise, voxel size, and voxel-wise repeatability of a dynamic contrast agent-enhanced (DCE) computed tomographic (CT) examination for prostate cancer. Materials and Methods:This prospective study was approved by the local research ethics committee, and all patients gave written informed consent. Twenty-nine patients (mean age, 69.1 years; range, 56-80 years) with biopsy-proved prostate cancer underwent two DCE CT examinations within 1 week prior to radiation therapy. Parameter maps of transfer constant ( K trans ), the fraction of blood plasma (v p ) , the fraction of extravascular extracellular space (v e ) , and the fl ux rate constant between the extravascular extracellular space and plasma ( k ep ) were calculated at 15 different image resolutions, with kernel sizes ranging from 0.002 to 2.57 cm 3 . Statistical analysis to quantify the voxel-wise repeatability was performed by using a Bland-Altman analysis on all tracer kinetic model parameter maps of each patient. From this analysis, the within-voxel standard deviation (wSD) was calculated as a function of spatial resolution. Results:A kernel size in the range of 0. Conclusion:There is a high voxel-wise repeatability of the DCE CT imaging technique for prostate cancer for kernel sizes as small as 0.1 cm 3 . With the relationship between kernel size, image noise and voxel-wise repeatability, it becomes possible to estimate for alternative DCE CT protocols (eg, those with a reduced radiation dose) at what kernel size a suffi cient repeatability can be obtained.q RSNA, 2010

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“…Contrary to other studies ( 23,28,31 ), we found that the repeatability of K trans in terms of wCV is the same as v e .…”

Section: Roi Analysis Parameterscontrasting

confidence: 99%

Dynamic Contrast-enhanced CT for Prostate Cancer: Relationship between Image Noise, Voxel Size, and Repeatability

Korporaal

Berg²,

Jeukens³

et al. 2010

Radiology

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“…Previous studies have noted the association between ovarian malignancy and early enhancement following gadolinium injection (13,14), and a recent paper has found that malignant ovarian tumors showed increases in semiquantitative parameters such as enhancement amplitude and maximum slope of enhancement in comparison with benign ovarian tumors (15). Quantitative pharmacokinetic parameters have been calculated from DCE-MRI data at 1.5 T in a variety of pelvic tumors by Lankester et al (30), who assessed the correlations between DCE-MRI and perfusion measurements from a subsequently acquired dynamic susceptibility contrast dataset. The current study builds on the DCE-MRI component of this previous work by assessing metastatic and primary tumors.…”

Section: Discussionmentioning

confidence: 99%

“…The current study builds on the DCE-MRI component of this previous work by assessing metastatic and primary tumors. In addition, both spatial coverage and temporal resolution have been improved due to the use of a fast 3D gradient-echo sequence with parallel imaging: this allowed a temporal resolution of 1.6 sec with a coverage of 10 acquired slices, compared with 12 sec and four slices for Lankester et al (30) and 5 sec and three slices for Thomassin-Naggara et al (15), neither of which would be sufficient to accurately characterize uptake at the rate described above. The reductions in signal-to-noise ratio that result from greater speed are offset by the use of a 3D sequence and an increased magnetic field strength of 3 T.…”

Section: Discussionmentioning

confidence: 99%

Dynamic contrast-enhanced MRI in ovarian cancer: Initial experience at 3 tesla in primary and metastatic disease

et al. 2010

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The aim of this study was to develop and demonstrate a methodology for dynamic contrast-enhanced MRI at 3 T in patients with advanced ovarian cancer and to report the results from pharmacokinetic modeling of the data. Nineteen patients with suspected advanced ovarian carcinoma (FIGO stage 3 or higher) were enrolled in this prospective study. Up to three marker lesions were identified: primary ovarian mass, omental ''cake'', and peritoneal deposits. Dynamic contrastenhanced MRI was performed using a three-dimensional T 1 -weighted gradient-echo acquisition with a temporal resolution of 1.6 sec, following intravenous administration of 0.1 mmol/ kg gadobutrol. Precontrast T 1 mapping, using an inversion-recovery fast gradient-echo sequence, was also performed. Imaging was completed in 18/19 patients, although two were subsequently excluded based on pathology results. Pharmacokinetic modeling of the data was performed according to the extended Kety model, using an arterial input function formed by concatenation of the Fritz-Hansen and Weinmann curves. No statistically significant differences were found between the results for the three marker lesions. In the future, this work will allow kinetic modeling results from ovarian dynamic contrast-enhanced MRI to be correlated with response to treatment. The high temporal resolution allows good characterization of the rapid contrast agent uptake in these vascular tumors.

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“…In untreated breast tumors, K trans is dominated by perfusion because of high first pass extraction related to microvessel immaturity. This has been determined in simulations and by empirical observations in xenografts and in human tumors (11,12). This situation changes once vascular shutdown begins to occur with successful therapy when vascular permeability dominates K trans .…”

mentioning

confidence: 99%

Early Changes in Functional Dynamic Magnetic Resonance Imaging Predict for Pathologic Response to Neoadjuvant Chemotherapy in Primary Breast Cancer

Ah-See

Makris²,

Taylor³

et al. 2008

Clinical Cancer Research

Self Cite

250

188

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Purpose: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) allows noninvasive, in vivo measurements of tissue microvessel perfusion and permeability. We examined whether DCE-MRI done after two cycles of neoadjuvant chemotherapy could predict final clinical and pathologic response in primary breast cancers. Experimental Design: Thirty-seven patients with primary breast cancer, due to receive six cycles of neoadjuvant 5-fluorouracil, epirubicin and cyclophosphamide chemotherapy, were examined using DCE-MRI before neoadjuvant chemotherapy and after two cycles of treatment. Changes in DCE-MRI kinetic parameters (K trans , k ep , v e , MaxGd, rBV, rBF, MTT) were correlated with the final clinical and pathologic response to neoadjuvant chemotherapy.Test-retest variability was used to determine individual patient response. Results: Twenty-eight patients were evaluable for response (19 clinical responders and 9 nonresponders; 11 pathologic responders and 17 nonresponders). Changes in the DCE-MRI kinetic parameters K trans , k ep , MaxGd, rBV, and rBF were significantly correlated with both final clinical and pathologic response (P < 0.01). Change in K trans was the best predictor of pathologic nonresponse (area under the receiver operating characteristic curve, 0.93; sensitivity, 94%; specificity, 82%), correctly identifying 94% of nonresponders and 73% of responders. Change in MRIderived tumor size did not predict for pathologic response. Conclusion: Changes in breast tumor microvessel functionality as depicted by DCE-MRI early on after starting anthracycline-based neoadjuvant chemotherapy can predict final clinical and pathologic response. The ability to identify nonresponders early may allow the selection of patients who may benefit from a therapy change.

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Dynamic MRI for imaging tumor microvasculature: Comparison of susceptibility and relaxivity techniques in pelvic tumors

Cited by 42 publications

References 37 publications

Dynamic Contrast-enhanced CT for Prostate Cancer: Relationship between Image Noise, Voxel Size, and Repeatability

Dynamic Contrast-enhanced CT for Prostate Cancer: Relationship between Image Noise, Voxel Size, and Repeatability

Dynamic contrast-enhanced MRI in ovarian cancer: Initial experience at 3 tesla in primary and metastatic disease

Early Changes in Functional Dynamic Magnetic Resonance Imaging Predict for Pathologic Response to Neoadjuvant Chemotherapy in Primary Breast Cancer

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