Chao-Jung Wei

Differentiating Benign and Malignant Soft Tissue Masses by Magnetic Resonance Imaging: Role of Tissue Component Analysis

Background: There is a variable degree of accuracy in discriminating benign from malignant soft tissue masses based on signal intensity and morphologic characteristics by magnetic resonance imaging (MRI). The aim of this study was to determine the utility of detailed component pattern assessment, in addition to morphologic study, for differentiating benign from malignant soft tissue masses by MRI. Methods: The imaging features of 118 histologically proven soft tissue masses were analyzed according to: (1) signal characteristics: (a) high T1 matrix; (b) low T2 matrix; (c) fibrous tissue signal; (d) calcification; (e) myxoid signal tissue; (f) fatty signal tissue; (g) cystic signal; (h) necrotic signal; (i) septations; (j) vascular signal void signal; (k) fat rim; and (l) hemorrhage; and according to (2) morphologic assessment: (a) lesion size (maximal diameter) in centimeters (cm); (b) lesion depth in cm; (c) margins; (d) peritumoral edema; (e) bone involvement; (f) marginal capsule or pseudocapsule; and (g) neurovascular bundle involvement. Univariate and multivariate analyses followed by stepwise logistic regression of combination of imaging features were performed. The predictive value of each imaging feature and various combinations of imaging features were determined. Results: In univariate analysis, T2 low signal matrix, fibrous tissue, calcification, necrosis, septum, fat rim sign, peritumoral edema, and hemorrhage showed statistically significant differences between benign and malignant masses (p < 0.05). The positive predictive value of necrosis for malignancy was 84.8%, and its specificity was 90.9%. In multivariate analysis, the best model for predicting malignant masses was the combination of necrosis, maximal mass diameter, peritumoral edema, and absent fibrosis, absent calcification, and lack of fat rim. The combination of these parameters resulted in the most correct diagnoses of malignancy, with a sensitivity of 84.2%, specificity of 64.0%, and accuracy of 74.8%, whereas the accuracy of models consisting of component character and morphologic feature were 74.3% and 70.9%, respectively. Conclusion: MRI is useful in determining whether a soft tissue mass is malignant or not. Traditional morphologic assessment was reinforced by detailed component characterization analysis. The parameters favoring malignancy were large lesion size, peritumoral edema, necrosis, and absent calcification, absent fibrosis, and lack of fat rim.

Tumor and tumor-like lesions of duodenum: CT and barium imaging features

Neoplasms of the duodenum, either primary or secondary, are uncommon. However, imaging diagnosis for presurgical evaluation is extremely important due to complex regional anatomy. Computed tomography (CT) and barium-based double contrast examination (UGI series) are most frequently employed to evaluate the tumor invasion and intraluminal mucosal pattern. In this pictorial review, the CT and UGI series imaging features of benign and malignant duodenal tumors and tumor-like lesions are demonstrated and discussed.

Congenital pelvic arteriovenous malformation: two cases and MR findings

Congenital pelvic arteriovenous malformation (PAVM) is rare. We present two cases with emphasis on the imaging features. Magnetic resonance angiography (MRA) demonstrates comparable details of the vascular abnormalities as conventional angiography, which should be reserved for pre-embolization evaluation.

Aberrant Ascending Pharyngeal Artery Mimicking a Partially Occluded Internal Carotid Artery

Doppler sonography has become a primary imaging modality for the diagnosis of carotid arterial stenosis. Carotid stenting for a severely stenotic but not completely occluded carotid artery is becoming an alternative to carotid endarterectomy in selected groups of patients. The authors discuss a case of complete occlusion of the internal carotid artery associated with an ipsilateral aberrant ascending pharyngeal artery originating from the proximal internal carotid artery, which mimicked a stenotic internal carotid artery on sonography. Meticulous Doppler sonographic examination may provide clues for this extraordinary condition, yet angiography is indicated for a definite diagnosis.

Diagnostic Value of Unenhanced Computerized Tomography Urography in the Evaluation of Acute Renal Colic

This study prospectively evaluated the diagnostic value of unenhanced computerized tomography (CT) urography in patients with acute renal colic. Fifty‐nine patients with clinical manifestations of acute renal colic underwent unenhanced helical CT to evaluate urinary tract abnormalities. Reformatted three‐dimensional CT urography was performed in all patients. The findings were correlated with ureteroscopy, surgical findings, histopathologic findings, and clinical course. CT urography detected urinary abnormalities in 57 of 59 patients with the clinical manifestation of acute renal colic, including 45 cases of urolithiasis, three urinary malignancies, one congenital abnormality, and eight ureteral strictures (due to chronic inflammation or fibrosis). CT urography showed negative findings in the urinary system in two patients, and after clinical follow‐up, urinary abnormality was excluded in these patients. Incidental findings of extrarenal disease were noted in six patients (pulmonary abnormalities, n = 2; gallstones, n = 4). Only one patient with urolithiasis was misdiagnosed as having a renal tumor by CT urography. The sensitivity and specificity of CT urography in diagnosing urolithiasis was 97.8% (44/45) and 100% (14/14), respectively. Three‐dimensional CT urography is a newly developed modality to evaluate anomalies of the urinary tract. The highly accurate diagnostic value of CT urography makes it a suitable alternative or substitutive modality in patients with acute flank pain.