Effect of MR imaging of the wrist on clinical diagnosis.
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Biomedical subjects
Publications and source records attributed to Shigeru Ehara.
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Spontaneous regression of diffuse B-cell type lymphoma of the lumbar vertebra is reported. A 61-year-old woman experienced spontaneous disappearance of a large psoas mass associated with an infiltrating process of the lumbar vertebrae. The biopsy of the residual change after spontaneous regression revealed reactive foamy histiocytes and small lymphocytes with no atypia. The lesion recurred 7 months later with no systemic treatment in the interim, when the diagnosis of lymphoma was finally made. Spontaneous regression may be related to potentiation of the host immune response, which affects tumor growth.
PURPOSE: This study aims to evaluate the usefulness of single shot fast spin echo diffusion-weighted MR imaging (DWSSFSE) in differentiating malignant metastatic tumor infiltration of vertebral bone marrow from benign vertebral fracture edema. MATERIALS AND METHODS: Forty-six consecutive patients with 59 acute osteoporotic or traumatic vertebral fractures (mean age = 59) and 31 patients with 98 vertebral metastasis including 20 pathologic fractures (mean age = 53) were included in this study. Diffusion-weighted MR images were obtained by single-shot fast spin echo technique with diffusion gradient (b = 500 s/mm2, TR/TE: 5002/99) by using a 1.5 T MR scanner (Signa MR/i; GE Medical Systems, Milwaukee, WI, USA). T1- and T2-weighted images and short inversion time inversion-recovery (STIR) images were available in all 157 lesions, while contrast-enhanced images were available in 98 metastatic lesions. We evaluated signal intensity patterns on DWSSFSE in 157 lesions, which showed low signal intensity on T1-weighted images in both benign fractures and metastasis. The lesions on DWSSFSE were categorized as low, intermediate, and high signal intensity relative to presumed normal vertebra by concordant inspection of two experienced musculoskeletal radiologists. RESULTS: In benign fractures, DWSSFSE images showed low signal intensity in 56 vertebrae (95%) in 43 patients (93%) and intermediate signal intensity in only 3 vertebrae (5%) in 3 patients (7%). On the other hand, metastases most commonly had low signal intensity in 57 vertebrae (58%) in 25 patients (80%), intermediate signal intensity in 35 vertebrae (36%) in 16 patients (52%), and high signal intensity in 6 vertebrae (6%) in 3 patients (10%). Thus, intermediate and high signal intensities are far more common than benign fractures. Such differences in signal intensity were statistically significant (chi-square test, P < .05). High or intermediate signal intensity on DWSSFSE was highly specific for the diagnosis of metastatic tumor infiltration of the spine (sensitivity: 42%; specificity: 95%; true positive rate: 93%; false negative rate: 52%). CONCLUSIONS: DWSSFSE of the spine may be useful in differentiating metastatic tumor infiltration of vertebral bone marrow from benign fracture edema.
OBJECTIVE: The purpose of this study was to evaluate the use of multislice CT in the evaluation of vascular patency in patients during hepatic arterial infusion chemotherapy of liver tumors. MATERIALS AND METHODS: Thirty-three patients were prospectively examined by CT angiography through the indwelling catheter and port system. Visibility of hepatic arteries and vascular patency were graded 0 to 3 and were compared with digital subtraction angiography (DSA). RESULTS: Average visualization scores of CT angiography and DSA were 1.7 and 2.5, respectively, in common hepatic artery (CHA) and proper hepatic artery (PHA), 2.5 and 2.3 in right hepatic artery (RHA), 2.6 and 2.6 in left hepatic artery (LHA), 2.3 and 2.2 in segmental RHA, and 2.1 and 2.0 in segmental LHA. Stenoses were found in proximal hepatic arteries in 9 on CT angiography and 13 on DSA. Stenoses were found in branches of the hepatic artery in 21 on CT angiography and 16 on DSA. CONCLUSION: The authors' results indicate that multislice CT angiography of the hepatic arteries is equivalent to DSA and may demonstrate vascular complications of hepatic arterial infusion chemotherapy.
BACKGROUND AND PURPOSE: A reduction in the area of the substantia nigra (SN) has been shown in patients with Parkinson disease. The substantia nigra is anteroinferolateral to the red nucleus, and it is important to precisely locate its true anatomic location to accurately measure SN area. Our purpose was to determine the exact location of the substantia nigra by correlating imaging and anatomic findings. We also attempted to quantitate SN area in patients with Parkinson disease compared with that in healthy control subjects on the basis of proton density-weighted spin-echo (SE) and fast short inversion time inversion-recovery (STIR) MR imaging findings. METHODS: In four healthy volunteers, dual-echo SE and fast STIR MR images were obtained in three orthogonal planes and an oblique coronal plane. These images were correlated with anatomic specimens to determine the location of the SN. The area of the SN was also measured on oblique coronal fast STIR images obtained at a plane perpendicular to the SN in 22 patients with Parkinson disease and in 22 age- and sex-matched healthy volunteers. RESULTS: The true anatomic location of the SN, anteroinferolateral to the red nucleus, was accurately identified, not on T2-weighted images, but on proton density-weighted SE images and fast STIR images as an area of hyperintense gray matter. The hypointense area seen on T2-weighted images corresponded to the anterosuperior aspect of the SN and to the adjacent crus cerebri. No statistically significant differences were noted in the size of the SN when the oblique coronal images of patients with Parkinson disease were compared with those of the control groups. CONCLUSION: The SN is located mainly beneath the red nucleus. Its location cannot be determined on the basis of T2-weighted imaging results but rather on the basis of proton density-weighted SE or fast STIR findings. SN volume loss is not found in Parkinson disease, and this finding is compatible with that of recent pathology reports in the literature.