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Purpose: To prospectively determine whether pharmacokinetic magnetic resonance (MR) imaging parameters correlate with histologic mean vessel density (MVD), mean vessel area (MVA), and mean interstitial area (MIA) and whether these parameters enable differentiation of prostate cancer, chronic prostatitis, and normal prostate tissue., Materials and Methods: This study was approved by the institutional review board, and informed consent was obtained from all patients. Thirty-five patients with biopsy-proved prostate cancer were examined with a dynamic contrast material-enhanced inversion-prepared dual-contrast gradient-echo sequence (temporal resolution, 1.65 seconds) at 1.5 T to calculate blood volume, interstitial volume, and blood flow. These parameters were correlated with MVD, MVA, and MIA in 95 areas (prostate cancer, n = 36; chronic prostatitis, n = 27; normal prostate tissue, n = 32). For each MR area, five 1-mm(2) squares (original magnification, x100) of the matching histologic area were analyzed. The Wilcoxon signed-rank test was used for statistical analysis., Results: Blood volume correlated poorly with MVD (Spearman correlation coefficient, 0.252; P = .014) but did not correlate at all with MVA (P = .759). Interstitial volume did not correlate with MIA (P = .507). Blood volume differed between patients with prostate cancer and those with a normal prostate (1.49% vs 0.84%, respectively; P < .001). Interstitial volume differed between patients with chronic prostatitis and those with a normal prostate (39.00% vs 22.59%, respectively; P = .022). Blood flow differed between patients with prostate cancer and those with a normal prostate (0.97 mL/[cm(3) x min(-1)] vs 0.34 mL/[cm(3) x min(-1)], respectively; P < .001), between patients with prostate cancer and those with chronic prostatitis (0.97 mL/[cm(3) x min(-1)] vs 0.60 mL/[cm(3) x min(-1)], respectively; P = .026), and between patients with chronic prostatitis and those with a normal prostate (0.60 mL/[cm(3) x min(-1)] vs 0.34 mL/[cm(3) x min(-1)], respectively; P = .023)., Conclusion: Blood volume and interstitial volume did not reliably correlate with the histologic parameters. Only blood flow enabled differentiation of prostate cancer, chronic prostatitis, and normal prostate tissue., ((c) RSNA, 2009.)

Purpose: To prospectively evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography in helping predict ovarian artery supply of uterine fibroids by using postembolization conventional aortography as the reference standard., Materials and Methods: The protocol for the study was approved by the institutional review board, and each patient gave informed consent. Ninety consecutive women (mean age, 42.5 years; range, 33-63 years) underwent MR angiography before uterine artery embolization (UAE). The number and origin of the ovarian arteries were determined. Ovarian artery supply of fibroids was graded as very unlikely, possible, or very likely by using a scoring system based on a combination of MR angiographic findings. MR angiographic results were compared with those of conventional aortography performed after UAE in all patients and followed by selective angiography in case of a suspected ovarian artery supply of fibroids. Analysis of the association between MR angiographic grading and conventional angiography as the standard of reference was performed with a chi(2) trend test. Sensitivity and specificity, including exact 95% confidence intervals (CIs), of MR angiography were determined., Results: MR angiography depicted 18 ovarian arteries (four bilateral, 10 unilateral), one with an atypical origin. Five ovarian arteries were classified as very likely; three, as possible; and 10, as very unlikely sources of arterial fibroid supply. Seven (39%) of 18 ovarian arteries detected at MR angiography were visible at conventional aortography. Fibroid supply was verified at selective angiography in five ovarian arteries in five (6%) of 90 patients. There was a strong association between MR angiographic grading and the results of conventional angiography (P = .002). Sensitivity of MR angiography in depicting ovarian artery supply (grade, possible or very likely) was 100% (five of five, 95% CI: 48%; 100%) and specificity was 77% (10 of 13, 95% CI: 46%; 95%)., Conclusion: Contrast-enhanced MR angiography can help predict ovarian artery supply of uterine fibroids., ((c) RSNA, 2006.)

Purpose: To compare a superparamagnetic iron oxide (SPIO), VSOP-C184, with a gadopentetate dimeglumine with regard to signal-enhancing effects on T1-weighted dynamic magnetic resonance (MR) images and with another SPIO contrast medium with regard to signal-reducing effects on delayed T2-weighted MR images., Materials and Methods: All experiments were approved by the responsible Animal Care Committee. Twenty rabbits (five for each contrast agent and dose) implanted with VX-2 carcinoma were imaged at 1.5 T. VSOP-C184 at 0.015 and 0.025 mmol Fe/kg was compared with gadopentetate dimeglumine at 0.15 mmol Gd/kg and ferucarbotran at 0.015 mmol Fe/kg. The imaging protocol comprised a T1-weighted dynamic gradient-echo (GRE) MR before injection and at 6-second intervals for up to 42 seconds after injection and a T2-weighted turbo spin-echo MR before and 5 minutes after injection. Images were evaluated quantitatively, and contrast media were compared by using nonparametric analysis of variance., Results: At dynamic T1-weighted GRE MR imaging with 0.015-mmol Fe/kg VSOP-C184, 0.025-mmol Fe/kg VSOP-C184, gadopentetate dimeglumine, and ferucarbotran, the median peak contrast-to-noise ratio (CNR) was 20.7 (25th percentile, 16.3; 75th percentile, 22.6), 24.2 (25th percentile, 19.3; 75th percentile, 28.5), 16.4 (25th percentile, 13.7; 75th percentile, 20.3), and 14.0 (25th percentile, 11.4; 75th percentile, 16.8), respectively. Both doses of VSOP-C184 yielded significantly higher CNR (P < .05) than the other two agents. At T2-weighted turbo spin-echo imaging with 0.015-mmol Fe/kg VSOP-C184, 0.025-mmol Fe/kg VSOP-C184, gadopentetate dimeglumine, and ferucarbotran, the median CNR was 15.0 (25th percentile, 13.4; 75th percentile, 21.3), 15.7 (25th percentile, 14.5; 75th percentile, 19.8), 11.3 (25th percentile, 8.2; 75th percentile, 12.2), and 15.7 (25th percentile, 12.5; 75th percentile, 22.4), respectively. There was no significant difference between VSOP-C184 and ferucarbotran; both had a significantly higher CNR than did gadopentetate dimeglumine., Conclusion: VSOP-C184 produces higher liver-to-tumor contrast at dynamic T1-weighted imaging than does gadopentetate dimeglumine; at delayed T2-weighted imaging, the contrast is comparable to that achieved with ferucarbotran., (RSNA, 2006)

Purpose: To prospectively evaluate the correlation between a three-dimensional (3D) delayed enhancement magnetic resonance (MR) imaging sequence and a two-dimensional (2D) delayed enhancement MR imaging sequence for noninvasive assessment of myocardial viability in pigs and patients., Materials and Methods: The pig and patient studies were approved by the responsible authorities, and patients gave written informed consent. MR imaging was performed by using a rapid 3D inversion-recovery balanced steady-state free precession sequence and a 2D segmented inversion-recovery fast low-angle shot sequence as the reference standard. Fourteen pigs with reperfused (n=7) or nonreperfused (n=7) myocardial infarction and 17 patients (13 men, four women; mean age, 64.9 years+/-8.6 [standard deviation]) suspected of having myocardial infarction were included. Linear regression analysis and Bland-Altman analysis were used to compare the infarction volumes., Results: In 10 of the 14 pigs the induction of myocardial infarction was successful. In these pigs, altogether 81 segments with myocardial infarction were demonstrated by both MR sequences, and agreement between the two sequences for classification of transmural extent of myocardial infarction was 99.7%. The infarction volume determined by using 3D MR imaging (4.64 cm3+/-2.48) in the pigs highly correlated with that of 2D MR imaging (4.65 cm3+/-2.39, r=0.989, P<.001) and that of staining by using triphenyltetrazolium chloride (4.67 cm3+/-2.44, r=0.996, P<.001). Thirteen of the 17 patients examined showed myocardial infarction in 34 myocardial segments with both sequences, and agreement between the two sequences for classification of transmural extent of myocardial infarction was 98.6%. In the patients, the infarction volume determined with both sequences highly correlated (9.71 cm3+/-7.47 for the 3D sequence vs 10.01 cm3+/-8.04 for the 2D sequence, r=0.982, P<.001). The breath-hold time necessary for the 3D MR imaging (21.0+/-2.3 seconds) was significantly shorter than that for 2D MR imaging (188.3+/-20.2 seconds, P<.001)., Conclusion: Myocardial infarction volumes obtained with the 3D MR imaging sequence are highly correlated and in good agreement with volumes obtained with the 2D MR imaging standard approach and reduced the acquisition time by a factor of nine., (Copyright (c) RSNA, 2006.)

The authors evaluated a magnetic resonance (MR) imaging-compatible biopsy device comprising a needle guide that can be visualized with MR imaging and manipulated mechanically from outside the MR unit. With approval from the local ethics committee and patient consent, this device was tested in 12 patients by using a closed 1.5-T MR unit and a body phased-array coil. Patients had elevated prostate-specific antigen levels (6-60 ng/mL) and one or more areas in the prostate that were suspicious for carcinoma at prebiopsy MR imaging. Biopsy was performed with transrectal access and with the patient prone. A 16-gauge MR imaging-compatible needle was successfully positioned with the device, and between six and nine tissue cores were obtained in each patient. In one patient, two suspicious basal areas could not be reached with the device. Histologic analysis showed prostate cancer in five patients and prostatitis in six. No complications were observed. The device enabled MR imaging-guided core-needle biopsy of prostate areas suspicious for cancer on MR images., ((c) RSNA, 2004.)

Purpose: To prospectively evaluate ferumoxtran-10-enhanced magnetic resonance (MR) imaging for nodal staging in patients with urinary bladder cancer., Materials and Methods: Fifty-eight patients with proved bladder cancer were enrolled. Results of MR imaging performed before and after injection of ferumoxtran-10 were compared with histopathologic results in surgically removed lymph nodes. High-spatial-resolution three-dimensional T1-weighted magnetization-prepared rapid acquisition gradient-echo (voxel size, 1.4 x 1.4 x 1.4 mm) and T2*-weighted gradient-echo (voxel size, 0.8 x 0.8 x 3.0 mm) sequences were performed before and 24 hours after injection of ferumoxtran-10 (2.6 mg iron per kilogram of body weight). On precontrast images, lymph nodes were defined as malignant by using size and shape criteria (round node, >8 mm; oval, >10 mm axial diameter). On postcontrast images, nodes were considered benign if there was homogeneous decrease in signal intensity and malignant if decrease was absent or heterogeneous. Qualitative evaluation was performed on a node-to-node basis. Sensitivity, specificity, predictive values, and accuracy were evaluated with logistic regression analysis., Results: In 58 patients, 172 nodes imaged with use of ferumoxtran-10 were matched and correlated with results of node dissection. Of these, 122 were benign and 50 were malignant. With nodal size and shape criteria, accuracy, sensitivity, specificity, and positive and negative predictive values on precontrast images were 92%, 76%, 99%, 97%, and 91%, respectively; corresponding values on postcontrast images were 95%, 96%, 95%, 89%, and 98%. In the depiction of pelvic metastases, sensitivity and negative predictive value improved significantly at postcontrast compared with those at precontrast imaging, from 76% to 96% (P < .001) and from 91% to 98% (P < .01), respectively. At postcontrast imaging, metastases (4-9 mm) were prospectively found in 10 of 12 normal-sized nodes (<10 mm); these metastases were not detected on precontrast images. Postcontrast images also showed lymph nodes that were missed at pelvic node dissection in two patients., Conclusion: Ferumoxtran-10-enhanced MR imaging significantly improves nodal staging in patients with bladder cancer by depicting metastases even in normal-sized lymph nodes.

Purpose: To evaluate the safety and efficacy of gadoxetic acid disodium-enhanced magnetic resonance (MR) imaging for the detection of focal liver lesions, with results of histopathologic examination and/or intraoperative ultrasonography used as a standard of reference., Materials and Methods: One hundred sixty-nine patients who were known to have or suspected of having focal liver lesions and were scheduled for liver surgery were included in this study. Results in 131 patients could be included in the efficacy analysis. MR imaging was performed before and immediately and 20 minutes after bolus injection of 0.025 mmol/kg of the liver-specific hepatobiliary contrast agent gadoxetic acid. T1-weighted gradient-echo (with and without fat saturation and including dynamic data sets) and T2-weighted fast spin-echo/turbo spin-echo sequences were performed. All images were evaluated on site and by three independent and blinded off-site reviewers. Lesion matching based on the standard-of-reference results was performed. Differences in lesion detection with precontrast and with postcontrast MR images were assessed with the two-sided Wilcoxon signed rank test., Results: Gadoxetic acid was well tolerated. In the on-site review, the number of patients in whom all lesions were correctly matched increased from 89 of 129 patients at precontrast MR imaging to 103 of 129 patients at postcontrast MR imaging. In the off-site evaluation, the number of patients in whom all lesions were correctly matched and the corresponding sensitivity values increased from 72 (55.8%), 68 (52.7%), and 66 (51.2%) with the precontrast images to 88 (68.2%), 69 (53.5%), and 76 (58.9%) with the postcontrast images for readers 1, 2, and 3, respectively. Two of the three blinded readers showed a statistically significant difference in lesion detection between precontrast and postcontrast MR imaging (P <.001 and P =.008). A large number of additionally correctly detected and localized lesions were smaller than 1 cm., Conclusion: MR imaging with gadoxetic acid is safe and improves lesion detection and localization., (Copyright RSNA, 2004)

Purpose: To determine the role of magnetic resonance (MR) imaging performed with a combined endorectal body phased-array coil for patients with elevated prostate-specific antigen (PSA) levels or suspicious free-to-total PSA ratios in whom prior transrectal ultrasonographically (US) guided biopsy findings were negative for prostate cancer., Materials and Methods: Forty-four patients with PSA levels greater than 4 ng/mL or free-to-total PSA ratios lower than 15% but negative biopsy findings were examined with T1- and T2-weighted MR imaging at 1.5 T with a combined endorectal body phased-array coil. All patients underwent digital rectal examination (DRE) and transrectal US. Thirty-eight patients underwent repeat biopsy after MR imaging. The accuracy of MR imaging for detection of prostate cancer was assessed prospectively. Retrospectively, MR imaging findings were correlated with individual biopsy site findings. MR imaging and biopsy results were correlated by using a cross table to calculate sensitivity, specificity, and positive predictive value (PPV). Retrospective analysis results were evaluated with receiver operating characteristic analysis. A P value of less than.05 indicated significance (chi(2) test according to Pearson)., Results: At prospective analysis, MR imaging had a sensitivity of 83% and a PPV of 50% for detection of prostate cancer; these values were 33% and 67%, respectively, for DRE and 33% and 57%, respectively, for transrectal US. At retrospective site-by-site analysis, MR imaging results did not correlate significantly with individual biopsy site findings (P =.126); sensitivity was 65% and PPV was 12%., Conclusion: In this patient population, MR imaging has higher sensitivity for detection of prostate cancer than DRE or transrectal US., (Copyright RSNA, 2002)

Purpose: To evaluate the signal-enhancing characteristics of monomer-coated very small superparamagnetic iron oxide (SPIO) particles used as a blood pool contrast medium for magnetic resonance (MR) angiography in the coronary arteries., Materials and Methods: The particles used in this study were coated with citrate as the monomer (VSOP-C91). The particles have a total diameter of 7 nm and show the following relaxivities at 0.47 T: T1, 19 L/mmol. sec(-1); T2, 29 L/mmol. sec(-1). Fifteen cardiac MR examinations were performed at 1.5 T in five pigs. Images were acquired from immediately to 35 minutes (equilibrium phase) after intravenous injection of gadopentetate dimeglumine, gadobenate dimeglumine, and the very small SPIO particles (n = 5 for each substance)., Results: Immediately after administration of gadopentetate dimeglumine, gadobenate dimeglumine, and the very small SPIO particles, respectively, increases in the signal-to-noise ratio in blood were 94%, 103%, and 102% and in myocardium were 83%, 83%, and 29% (P <.05, very small SPIO particles versus the low-molecular-weight gadolinium-based compounds). Differences in the blood-to-myocardium contrast-to-noise ratio and visualization of the coronary arteries and their branches were also significant., Conclusion: VSOP-C91 significantly improves visualization of the coronary arteries at MR angiography from immediately to 35 minutes after injection.

In 45 patients with coronary bypass grafts, the breath-hold interval with and that without preoxygenation was measured. Its effect on depiction of the distal graft anastomosis at electron-beam tomography was evaluated. Preoxygenation prolonged the breath-hold interval in most patients, thereby allowing greater anatomic coverage including more distal anastomoses. Preoxygenation may improve scanning of coronary bypass grafts and increase detectability of graft stenoses.