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To determine prospectively the accuracy of a magnetic resonance (MR) perfusion imaging and MR angiography protocol for differentiation of chronic thromboembolic pulmonary arterial hypertension (CTEPH) and primary pulmonary hypertension (PPH) by using parallel acquisition techniques.The study was approved by the institution's internal review board, and all patients gave written consent prior to participation. A total of 29 patients (16 women; mean age, 54 years +/- 17 [+/- standard deviation]; 13 men; mean age, 57 years +/- 15) with known pulmonary hypertension were examined with a 1.5-T MR imager. MR perfusion imaging (temporal resolution, 1.1 seconds per phase) and MR angiography (matrix, 512; voxel size, 1.0 x 0.7 x 1.6 mm) were performed with parallel acquisition techniques. Dynamic perfusion images and reformatted three-dimensional MR angiograms were analyzed for occlusive and nonocclusive changes of the pulmonary arteries, including perfusion defects, caliber irregularities, and intravascular thrombi. MR perfusion imaging results were compared with those of radionuclide perfusion scintigraphy, and MR angiography results were compared with those of digital subtraction angiography (DSA) and/or contrast material-enhanced multi-detector row computed tomography (CT). Sensitivity, specificity, and diagnostic accuracy of MR perfusion imaging and MR angiography were calculated. Receiver operator characteristic analyses were performed to compare the diagnostic value of MR angiography, MR perfusion imaging, and both modalities combined. For MR angiography and MR perfusion imaging, kappa values were used to assess interobserver agreement.A correct diagnosis was made in 26 (90%) of 29 patients by using this comprehensive MR imaging protocol. Results of MR perfusion imaging demonstrated 79% agreement (ie, identical diagnosis on a per-patient basis) with those of perfusion scintigraphy, and results of MR angiography demonstrated 86% agreement with those of DSA and/or CT angiography. Interobserver agreement was good for both MR perfusion imaging and MR angiography (kappa = 0.63 and 0.70, respectively).The combination of fast MR perfusion imaging and high-spatial-resolution MR angiography with parallel acquisition techniques enables the differentiation of PPH from CTEPH with high accuracy.

To determine the accuracy of combined magnetic resonance (MR) imaging and three-dimensional (3D) proton MR spectroscopic imaging in localizing prostate cancer to a sextant of the gland in patients receiving hormone deprivation therapy.Combined MR imaging/3D MR spectroscopic imaging examinations were performed in 16 hormone-treated patients and 48 nontreated matched control patients before radical prostatectomy and step-section histopathologic analysis. At MR imaging, cancer presence within the peripheral zone was assessed on a per sextant basis by two readers. At 3D MR spectroscopic imaging, cancer was identified by using (choline plus creatine)-to-citrate ratios at cutoff values of 2 and 3 SDs above mean normal peripheral zone values. Data were compared by using receiver operating characteristic analysis.There was no significant difference in the ability of combined MR imaging/3D MR spectroscopic imaging to localize prostate cancer in treated versus control patients. For MR imaging alone, the sensitivity and specificity were 91% and 48% (reader 1) and 75% and 60% (reader 2) in treated patients versus 79% and 60% (reader 1) and 84% and 43% (reader 2) in control patients. For 3D MR spectroscopic imaging alone (3 SDs cutoff), higher specificity (treated, 80%; controls, 73%) but lower sensitivity (treated, 56%; controls, 53%) was attained. In treated patients, high sensitivity or specificity (up to 92%) was achieved when either or both modalities indicated cancer.When performed within 4 months after initiating hormone deprivation therapy, combined MR imaging/3D MR spectroscopic imaging had the same accuracy in localizing prostate cancer as in nontreated patients.

To assess the efficacy of combined magnetic resonance (MR) imaging and three-dimensional (3D) proton MR spectroscopic imaging in the detection and localization of prostate cancer.MR imaging and 3D MR spectroscopic imaging examinations were performed in 53 patients with biopsy-proved prostate cancer and subsequent radical prostatectomy with step-section histopathologic examination. The prostate was divided into sextants. At MR imaging, the presence or absence of cancer in the peripheral zone of each sextant was assessed independently by two readers (readers 1 and 2) unaware of the findings at 3D MR spectroscopic imaging and histopathologic examination. At 3D MR spectroscopic imaging, cancer was diagnosed as possible if the ratio of choline plus creatine to citrate exceeded 2 SD above population norms or as definite if that ratio exceeded 3 SDs above the norm.On the basis of sextants, sensitivity and specificity, respectively, for MR imaging were 77% and 61% (reader 1) and 81% and 46% (reader 2) with moderate interreader agreement (kappa = 0.43). The 3D MR spectroscopic imaging diagnosis of definite cancer had significantly higher specificity (75%, P.05) but lower sensitivity (63%, P.05). Receiver operating characteristic analysis showed significantly (P.001) improved tumor localization for both readers when 3D MR spectroscopic imaging was added to MR imaging. High specificity (up to 91%) was obtained when combined MR imaging and 3D MR spectroscopic imaging indicated cancer, whereas high sensitivity (up to 95%) was obtained when either test alone indicated a positive result.The addition of 3D MR spectroscopic imaging to MR imaging provides better detection and localization of prostate cancer in a sextant of the prostate than does use of MR imaging alone.

To detect hepatocyte-selective enhancement of focal lesions with gadoxetic acid at magnetic resonance (MR) imaging and to correlate enhancement in hepatocyte-selective phases with histopathologic findings and in arterial and portal venous phases with biphasic computed tomographic (CT) findings.Study was supported by local ethics committee; all patients gave written informed consent. In 19 men and 14 women recruited in three clinical studies, histopathologic correlation and CT scans of 41 focal lesions (13 primary malignant lesions, 21 metastases, three adenomas, three cases of focal nodular hyperplasia [FNH], and one cystadenoma) and ultrasonographic confirmation of five cysts were available. MR was performed before and during arterial and portal venous phases and in hepatocyte-selective phases 10 and 20 minutes after injection of gadoxetic acid. Enhancement was evaluated in consensus by two observers. Enhancement pattern and morphologic features during arterial and portal venous phases were correlated between gadoxetic acid-enhanced MR and CT images by means of adjusted chi(2) test.Hepatocyte-selective uptake was observed 10 and 20 minutes after injection in FNH (three of three), adenoma (two of three), cystadenoma (one of one), and highly differentiated hepatocellular carcinoma (HCC [grade G1], two of four). Uptake was not detected in metastases (21 of 21), cholangiocarcinoma (three of three), combined hepatocellular cholangiocarcinoma (one of one), undifferentiated carcinoma (one of one), moderately or poorly differentiated HCC (grade G2-G3) (four of four), HCC (grade G1, two of four), adenoma with atypia (one of three), or cysts (five of five). During arterial and portal venous phases, there was high overall agreement rate of 0.963 between gadoxetic acid-enhanced MR and CT (simultaneous 95% confidence interval: 0.945, 0.981).Liver-specific enhancement of focal lesions is hepatocyte selective and correlates with various histopathologic diagnoses regarding presence of certain hepatocytic functions. Arterial and portal venous MR images obtained with gadoxetic acid are comparable to those of CT.

To determine differences in the signal intensity (SI) time courses at oxygen-enhanced magnetic resonance (MR) lung imaging in healthy volunteers and patients with pulmonary diseases and to correlate these differences with pulmonary diffusing capacity.Seventeen patients with pulmonary diseases and 11 healthy volunteers underwent oxygen-enhanced MR imaging while they breathed room air and 100% oxygen. A turbo spin-echo sequence with global or section-selective inversion pulses was used. For postprocessing, SI slope maps during the breathing of 100% oxygen were calculated. Mean SI slope and SI change values were compared with the diffusing capacity of the lung for carbon monoxide (DLCO).The SI slopes were significantly different for patients and volunteers (Por = .05, Mann-Whitney U test). Linear correlations were detected between the DLCO and SI slopes for the section-selective inversion pulse (r(2) = 0.81) and the global inversion pulse (r(2) = 0.74). A lower correlation was associated with the SI change for the section-selective pulse (r(2) = 0.04; global pulse, r(2) = 0.81). Regional differences were seen in the SI slope and SI change maps. These differences correlated with findings on radiographs and computed tomographic scans.The SI slope during the breathing of 100% oxygen allows spatially resolved assessment of the pulmonary diffusion capacity.

To determine if the addition of three-dimensional (3D) proton magnetic resonance (MR) spectroscopic imaging to endorectal MR imaging helps diagnose extracapsular extension (ECE) of prostate cancer.Endorectal MR imaging and 3D MR spectroscopic imaging were performed in 53 patients with prostate cancer before radical prostatectomy. MR imaging studies were evaluated by two independent readers unaware of histopathologic findings. The presence of ECE was graded on a five-point scale. At 3D MR spectroscopic imaging, cancer was diagnosed if the ratio of choline plus creatine to citrate was 2 or more SDs above normal. The accuracy of MR imaging alone was compared with that of combined MR imaging and 3D MR spectroscopic imaging, with use of the step-section histopathologic results as the standard of reference.For the less experienced reader, the addition of 3D MR spectroscopic imaging to MR imaging significantly improved accuracy (area under the receiver operating characteristic curve [Az] = 0.75 vs Az = 0.62, P.05). For the more experienced reader, the addition improved accuracy but not significantly (Az = 0.86 vs Az = 0.78). The addition also reduced interobserver variability (Az = 0.86 vs Az = 0.75).The addition of 3D MR spectroscopic imaging to MR imaging improves accuracy for less experienced readers and reduces interobserver variability in the diagnosis of ECE of prostate cancer.