Differentiation between Osteoporotic and Metastatic Vertebral Compression Fractures by MRI

PURPOSE: To evaluate the MRI findings helpful in differentiating between osteoporosis and metastatic vertebral compression fracture. MATERIALS AND METHODS: This study involved 52 patients with nontraumaticvertebral compression fracture; 23 had osteoporosis and 29, metastatic diseases. We retrospectively analyzed signal abnormality and the extent to which bone marrow was seen within the involved vertebral body, sharpness of margin of abnormal signal intensity, morphological characteristics of the vertebral endplate, and the presence or absence of posterior element involvement and paraspinal mass, as seen on T1- and T2*-weighted MR images. For statistical analysis, the chi-square test was used. RESULTS: In 14 of 23 patients (61%) with osteoporotic benign compression, and 27 of 29 (93%) with metastatic compression fracture, the bone marrow of the compressed vertebral body showed both low signal intensity on T1-weighted image and high signal intensity on T2-weighted image. In 13 of 14 osteoporotic compression fractures, the extent of abnornal bone marrow signal was incomplete, but in 20 of 27 metastatic compression fractures, this was complete. In all 13 cases of osteoporosis, incomplete abnormal signal showed a sharp margin, whereas in five of seven metastatic compression fractures, this margin was ill-defined. Morphologically, the endplate was concave in 20 of 23 osteoporosis cases (87%), but was angled in 13 of 29 metastatic compression fractures (45%). Only the latter showed vertebral posterior element involvement (21/29) and paraspinal mass (16/29). CONCLUSION: The extent of signal abnormality, margin of compressed bone marrow, morphologic characteristics of the endplate, and the presence or absence of posterior element involvement and paraspinal mass on T1- and T2*-weighted MR images, as described above, may be helpful in differentiating between benign osteoporotic and malignant metastatic compression fractures.

Correlation of Elevated Tumor Markers and Hepatic and Nodal Metastases on CT in Postgastrectomy Patients for Gastric Cancer

PURPOSE: The evaluation of tumor recurrence or metastasis in postgastrectomy cancer patients usually depends on a serum tumor marker test or radiologic study, but in both cases, accuracy is difficult to determine. The purpose of this study was to evaluate the relationship between abdominal CT and serum tumor markers. MATERIALS AND METHODS: In 337 cases involving 226 patients who had undergone curative surgery for gastric cancer, we compared serum tumor markers and CT for the evaluation of metastasis. Among these 337 cases, CEA level was measured in 317, CA 19-9 level in 166, and both of these in 146. The cutoff level for serum carcinoembryonic antigen (CEA) and CA19-9 were 10 ng/ml and 33 U/ml, respectively. RESULTS: CEA level was elevated in 59 of 317 cases (18.6 %) and that of CA 19-9 in 58 of 166 (34.9 %). Slightly higher overall senstivity and specificity was observed for CEA than for CA 19-9 (72.9 % vs 67.2 %, 83.3 % vs 70.4 %, respectively). Among the total of 337 cases, liver or lymph node metastases were detected in 91 cases (27.0 %) on CT. Negative predictive value was significantly higher in CEA than in CA 19-9 (93.1 % vs 80 %, respectively) (p < 0.01), but positive predictive value was lower (50 % vs 54.9 %, respectively). On CT scan, there was a significant relationship between serum tumor marker level and hepatic and nodal metastasis ; specificity and positivity of serum tumor markers were both higher than sensitivity and negativity. CONCLUSION: Follow-up CT less useful when tumor markers levels are not elevated, but when these are elevated in postgastrectomy cancer patients, meticulous radiologic evaluation is necessary for the early detection of residual or recurrent tumors.

Dynamic CT Findings of Eosinophilic Hepatic Abscess and Its Clinical Course

PURPOSE: To evaluate dynamic CT features and its clinical courses of eosinophilic hepatic abscess. MATERIALS AND METHODS: Two-phase dynamic CT findings and the clinical courses of 13 pathologically proven cases of eosinophilic abscess were reviewed. All patients showed peripheral eosinophilia, and diagnoses were confirmed by ultrasound-guided biopsy(n=9) or operation(n=4). In two of the four patients who underwent segmental hepatectomy, worms of the species Fasciola hepatica were detected. Follow-up CT scans after treatment with antibiotics or praziquantel were available in seven and eight patients, respectively. RESULT: All hepatic lesions were found ina subcapsular location or in contact with Glisson's capsule around the bile duct. Arterial-dominant phase CT(n=11)demonstrated clusters of ill-defined low density masses without rim enhancement. Late-phase CT(n=13) more clearly depicted clustering lesions with enhancing rims and diminution of the low-density area. Follow-up CT scans aftertreatment with antibiotics(n=7) showed no change in the lesions in three patients and slight shrinkage of the mainmass with additional new lesions in four. On CT scans of nine patients performad after praziquantel therapy, hepatic masses were seen in all patients to be very slightly smaller after improvement of peripheral hypereosinophilia. CONCLUSION: Two-phase dynamic CT features appear to be helpful for the diagnosis ofeosinophilic hepatic abscess in patients with peripheral eosinophilia. Parasitic infestation by Fasciola hepaticafor example, is the presumed cause of such abscesses, though further studies are required.

Focal Nodular Hyperplasis in Liver / 영남의대학술지

Focal nodular hyperplasia is a benign hepatic tumor mainly composed of nodules of hepatocytes and Kupffer cells separated by fibrous septa. In general, it is difficult to differentiate focal nodular hyperplasia and hepatocellular carcinoma on ultrasonography, conventional CT(computerized tomography), and angiography. But IV bolus CT is of particular value in the diagnosis of focal nodular hyperplasia because it can divide enhanced CT into early and late phase and can characterize tumor vascularity and analyze any intratumoral elements. In our case, it was seen as a hypoechoic mass lesion on ultrasonograpl'hy and hyperdense mass lesion on early-phase IV bolus CF and isodense mass, lesion on late-phase IV bolus CT. On angiography, hypertrophy of the feeding artery and tumor staining were well visualized. The patient underwent operation and the mass was pathologically confirmed to a focal nodular hyperplasia. We report the first case of focal nodular hyperplasia on IV bolus CT in Korea.