Comparison of phased-array and body coils for MR imaging of liver.

AIMS AND OBJECTIVES: To compare liver lesion conspicuity using torso phased-array (TPA) and body coils with two pulse sequences. METHODS: Sixty patients with 125 focal hepatic lesions underwent T2-weighted fast spin-echo (T2-FSE) and fast multiplanar inversion recovery (FMPIR) imaging with a standard body coil and with a TPA coil. The first 30 patients were scanned identically in both coils with four acquisitions; the second 30 were scanned with four acquisitions in the body coil and two in the TPA coil. RESULTS: Liver-lesion contrast-to-noise (C/N) was significantly higher for the TPA coil both with four acquisitions (P< 0.001) and with two acquisitions (P < 0.002) using FMPIR, compared to with four acquisitions in the body coil. Liver-lesion C/N for T2-FSE was equivalent in both coils. Liver-lesion C/N was significantly higher (P<0.01) for FMPIR than T2-FSE both in the body coil and in the TPA coil. CONCLUSION: Liver-lesion C/N was significantly higher using the TPA coil rather than the body coil. Imaging time can be reduced by decreasing the number of acquisitions with the TPA coil.

Comparison of two algorithms and their associated charges when evaluating adrenal masses in patients with malignancies.

OBJECTIVE: This study was performed to compare two proposed algorithms used when evaluating an adrenal mass discovered during staging evaluation of a patient with a known malignancy. Such evaluation was meant to lead to determination of the relative charges associated with each algorithm. SUBJECTS AND METHODS: Fifty-four patients with known malignancies who required evaluation of an adrenal mass underwent both chemical shift imaging (CSI) and CT-guided for CSI. The hospital charges incurred for each procedure and any associated complications were normalized using national relative-value scale charges and conversion factors. A decision analysis was performed to compare the relative charges that would have been incurred if adrenal MR imaging had been performed in all patients, followed by CT-guided biopsy only in those patients with MR findings not diagnostic of adrenocortical adenoma, and the relative charges incurred if only CT-guided adrenal biopsy had been performed in every patient. RESULTS: Twenty-three (43%) of 54 adrenal masses were shown to be metastases by CT-guided biopsy. The sensitivity and specificity of CSI for the diagnosis of adrenocortical adenoma were 94% and 100%, respectively. The charges incurred by performing MR imaging as the initial examination with subsequent CT-guided biopsy only in those patients with CSI findings not diagnostic of adenoma would have been similar to those incurred by first performing CT-guided adrenal biopsy in every patient. CONCLUSION: CSI is an accurate, noninvasive technique for evaluating adrenal masses in patients with cancer. If CT-guided biopsy is used only when CSI is not diagnostic of adrenocortical adenoma, the associated charges would be virtually the same as when CT-guided biopsy is performed as the first test in every patient. Moreover, biopsies could have been avoided in 54% of these patients.

Portal vein evaluation with US: comparison to angiography combined with CT arterial portography.

PURPOSE: To compare ultrasound (US) to angiography combined with computed tomography during arterial portography (CTAP) in the preoperative evaluation of the portal vein. MATERIALS AND METHODS: Sixty-three consecutive patients being considered for hepatic resection underwent color and spectral Doppler US and angiography with CTAP before surgery. The main, right, and left portal veins were evaluated separately. A total of 187 veins were assessed for encasement, occlusion, or thrombosis. RESULTS: At surgery, 41 portal veins were abnormal. US allowed detection of 38 of 41 (93%) involved portal veins with 93% sensitivity, 99% specificity, 97% positive predictive value, and 98% negative predictive value. Angiography with CTAP allowed diagnosis of 37 of 41 (90%) involved portal veins with 90% sensitivity, 99% specificity, 95% positive predictive value, and 97% negative predictive value. CONCLUSION: US is comparable to angiography combined with CTAP in evaluation of the portal vein.

CT bone window photography in patients with cancer.

PURPOSE: To assess the utility of routinely photographing computed tomographic (CT) bone windows in patients with cancer. MATERIALS AND METHODS: The impression section of body CT reports were reviewed in 4,683 patients with cancer (2,240 female and 2,443 male patients, aged 2 months to 97 years [mean, 55 years]). RESULTS: The presence of definite or possible bone metastasis was mentioned in 523 (11.2%) patients. No prior radiologic examination was available in 165 patients. In the 358 patients who had undergone previous radiologic examinations, findings were positive in 271 and normal or indeterminate in 87. In 252 (5.4%) patients, CT with bone windows may have been needed for diagnosis of bone metastasis: 110 had extensive nonosseous metastases, 77 had no osseous metastasis, 19 had bone findings that were not followed up radiologically, and 46 had bone lesions that were new findings. These new lesions were visible on scans photographed at soft-tissue windows in 45 (97.8%) patients. CONCLUSION: Routine photography of CT bone windows is not necessary in patients with cancer.