Diagnostic value of proton MR spectroscopy in peripheral arterial occlusive disease: a prospective evaluation.

OBJECTIVE: The objective of the present study was to determine the detectability of metabolic alterations in patients with peripheral arterial occlusive disease (PAOD) using proton MR spectroscopy (hydrogen-1 MR spectroscopy). SUBJECTS AND METHODS: Twenty-seven people were included in this study: 10 patients with PAOD and a pain-free walking distance of less than 200 m served as the patient group and 17 young healthy subjects served as a control group. Hydrogen-1 MR spectroscopy was performed on a 1.5-T scanner using an extremity coil and a point-resolved spectroscopy (PRESS) sequence (TR/TE, 1,500/30; 256 repetitions). For the patient group, a voxel was localized in the gastrocnemius muscle of the diseased leg. The data were processed using standard 1H MR spectroscopy tools. The identification of resonances detected on all MR spectra was made: intramyocellular lipids at 1.2 ppm, extramyocellular lipids at 1.6 ppm, lactate at 4.1 ppm, glucose with two main peaks at 3.4 and 3.8 ppm, choline at 3.2 ppm, and creatine at 3.0 and 3.9 ppm. To avoid operator bias, three spectral intensities were measured after correcting baseline and phase of MR spectra each time. The creatine signal was used as an internal reference; thus, all spectra were scaled relative to creatine. We compared the resultant intensity ratios between the two groups using the Mann-Whitney U test. RESULTS: The lactate-creatine quotient was higher in the patient group, with a ratio of 1.6, than in the control group, with a ratio of 0.6. The glutamate-creatine ratio was higher in the patient group than in the control group (1.3 vs 0.8, respectively). All other ratios were higher in the control group. The best ratio for differentiating between healthy subjects and patients with PAOD was the glucose-lactate ratio. The patient group had a glucose-lactate quotient of 5.4, whereas the control group had a glucose-lactate quotient of 21.5 (p = 0.001). CONCLUSION: Proton MR spectroscopy has the potential to allow identification of patients who have PAOD on the basis of altered muscle metabolism.

Multislice computed tomography angiography of the abdominal arteries: comparison between computed tomography angiography and digital subtraction angiography findings in 52 cases.

Since the introduction of multislice CT scanners, CT angiography (CTA) has become a powerful tool for imaging the vascular system. We compare conventional angiography to CTA in the diagnosis of morphological changes in the abdominal aorta and its branches. A retrospective analysis of 52 patients who underwent both multislice CT angiography (MSCTA) and digital subtraction angiography before surgical treatment is presented. All CT examinations were performed after administration of 100 mL contrast medium with a collimation of 4 x 1 mm and a pitch of 7. A standardized evaluation of the axial, multiplanar and 3D reconstructions was performed by two experienced radiologists. Stenoses were classified as high-grade and low-grade, and aneurysms, occlusions and arteriosclerosis were evaluated. The CTA findings were compared with conventional angiography. All aneurysms, occlusions, stenoses and calcifications were diagnosed correctly by CTA in axial and multiplanar projections (sensitivity 1.0; specificity 1.0). The degree of stenosis was overestimated in three cases when using axial projections. Three-dimensional volume-rendered CTA showed a sensitivity of 0.91 for aneurysms, 0.82 for stenoses, 0.75 for occlusions and 0.77 for calcifications. The specificity was 1.0 in all cases. Multislice CT angiography seems to be similar to conventional digital subtraction angiography for abdominal vessels if multiplanar projections are used.

Frontolimbic brain abnormalities in patients with borderline personality disorder: a volumetric magnetic resonance imaging study.

BACKGROUND: Dual frontolimbic brain pathology has been suggested as a possible correlate of impulsivity and aggressive behavior. One previous study reported volume loss of the hippocampus and the amygdala in patients with borderline personality disorder. We measured limbic and prefrontal brain volumes to test the hypothesis that frontolimbic brain pathology might be associated with borderline personality disorder. METHODS: Eight unmedicated female patients with borderline personality disorder and eight matched healthy controls were studied. The volumes of the hippocampus, amygdala, and orbitofrontal, dorsolateral prefrontal, and anterior cingulate cortex were measured in the patients using magnetic resonance imaging volumetry and compared to those obtained in the controls. RESULTS: We found a significant reduction of hippocampal and amygdala volumes in borderline personality disorder. There was a significant 24% reduction of the left orbitofrontal and a 26% reduction of the right anterior cingulate cortex in borderline personality disorder. Only left orbitofrontal volumes correlated significantly with amygdala volumes. CONCLUSIONS: While volume loss of a single brain structure like the hippocampus is quite an unspecific finding in neuropsychiatry, the patterns of volume loss of the amygdala, hippocampus, and left orbitofrontal and right anterior cingulate cortex might differentiate borderline personality disorder from other neuropsychiatric conditions.