Magnetic resonance imaging appearance of soft-tissue metastases: our experience at an orthopedic oncology center.

OBJECTIVE: To assess the prevalence and magnetic resonance imaging appearance of metastasis presenting as a soft-tissue mass. MATERIALS AND METHODS: A retrospective chart review was performed on 51 patients who presented to an orthopedic oncology center with soft-tissue masses, with a histology-proven diagnosis of soft-tissue metastasis, over a 14-year period. Their magnetic resonance imaging, primary origin, and follow-up have been assessed. RESULTS: Soft-tissue metastasis was identified in patients ranging from 18 to 85 years old. Most (80%) of the masses were located deep to the deep fascia. In our cohort of patients, melanoma was the most common primary malignancy contributing to soft-tissue metastasis (21.8%). Among soft-tissue metastasis from solid organs, breast and lung were the most frequent (9.1% each). Five patients had soft-tissue metastases from an unknown primary. CONCLUSION: Imaging diagnosis of soft-tissue metastases is challenging as it can demonstrate imaging appearances similar to primary soft-tissue sarcoma. The presence of a known malignancy may not be evident in everyone, and even if available, histopathology will be necessary for diagnosis if this is the only site of recurrence/metastasis to differentiate from a primary soft-tissue sarcoma. Moreover, soft-tissue metastasis may be the initial presentation of a malignancy. Primary malignancies with soft-tissue metastasis carry a poor prognosis; hence, prompt diagnosis and management in essential.

Diagnostic imaging of hepatocellular carcinoma at community hospitals and their tertiary referral center in the era of LI-RADS: a quality assessment study.

PURPOSE: To assess guideline compliance and quality of hepatocellular carcinoma, (HCC) diagnostic imaging within community hospitals (CH) and their Tertiary referral center (TRC) in a moderately high incidence region. METHODS: Initial diagnostic workup CT/MRI scans of 251 patients (122 CH, 112 TRC, 17 Non-TRC academic) with HCC over a 15-month period were assessed for Liver reporting and Data System (LI-RADS) guideline compliance. 269 scans (182 CT, 87 MRI) were qualitatively evaluated by 2 independent blinded radiologists for arterial timing, overall image quality, noise and sharpness, with quantification of interobserver variability. The contrast enhancement ratio (CER) for the largest HCC on each scan was calculated using pre- and post-contrast images. RESULTS: 103/104 (99%) of TRC and 44/78 (56%) of CH CTs adhered to LI-RADS imaging guidelines (P < 0.0001). Lack of delayed phase accounted for 32/34 (94%) of noncompliant CH CTs. Regarding MRI, 19/19 (100%) of TRC and 60/68 (88%) of CH scans were adherent (P = 0.12). For both modalities, overall image quality, noise and sharpness were rated significantly higher for TRC than CH. There was moderate interobserver agreement with intraclass correlation coefficient of 0.73, 0.70 and 0.63, respectively. Arterial-phase timing was rated adequate for CT in 75/104 TRC (72%) and 10/68 (14%) CH scans (P < 0.0001) and for MRI in 8/19 (42%) TRC and 23/68 (33%) CH scans (P = 0.17). The CER was significantly higher for TRC versus CH (2.9 vs. 1.9, P < 0.001) and MRI (0.9 vs. 0.7, P = 0.03). CONCLUSIONS: Community hospital HCC diagnostic scans significantly lag in critical quality parameters of tumor enhancement, arterial phase timing, perceived image quality, and LI-RADS CT technique compliance compared to a TRC.

MRI features of combined hepatocellular- cholangiocarcinoma versus mass forming intrahepatic cholangiocarcinoma.

BACKGROUND: Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare primary liver tumor, which has overlapping imaging features with mass forming intra-hepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC). Previous studies reported imaging features more closely resemble ICC and the aim of our study was to examine the differential MRI features of cHCC-CC and ICC with emphasis on enhancement pattern observations of gadolinium enhanced MRI. METHODS: Institutional review board approval with consent waiver was obtained for this retrospective bi-centric study. Thirty-three patients with pathologically proven cHCC-CC and thirty-eight patients with pathologically proven ICC, who had pre-operative MRI, were identified. MRI images were analyzed for tumor location and size, T1 and T2 signal characteristics, the presence/absence of: cirrhosis, intra-lesional fat, hemorrhage/hemosiderin, scar, capsular retraction, tumor thrombus, biliary dilatation, degree of arterial enhancement, enhancement pattern, pseudocapsule and washout. Associations between MRI features and tumor type were examined using the Fisher's exact and chi-square tests. RESULTS: Strong arterial phase enhancement and the presence of: washout, washout and progression, intra-lesional fat and hemorrhage were all strongly associated with cHCC-CC (P < 0.001). While cHCC-CC had a varied enhancement pattern, the two most common enhancement patterns were peripheral persistent (n = 6) and heterogeneous hyperenhancement with washout (n = 6), compared to ICC where the most common enhancement patterns were peripheral hypoenhancement with progression (n = 18) followed by heterogeneous hypoenhancement with progression (n = 14) (P < 0.001). CONCLUSION: The cHCC-CC enhancement pattern seems to more closely resemble HCC with the degree of arterial hyperenhancement and the presence of washout being valuable in differentiating cHCC-CC from ICC. However the presence of washout and progression, in the same lesion or a predominantly peripheral /rim hyperenhancing mass were also seen as important features that should alert the radiologist to the possibility of a cHCC-CC.

Image-guided percutaneous splenic biopsy and drainage.

Percutaneous splenic biopsy and drainage are relatively safe and accurate procedures. The risk of major complication (1.3%) following percutaneous splenic biopsy does not exceed that of other solid intra-abdominal organ biopsies, and it has less morbidity and mortality than splenectomy. Both computed tomography and ultrasound can be used to provide image guidance for biopsy and drainage. The safety profile of fine-needle aspiration cytology is better than core needle biopsy, but core biopsy has superior diagnostic accuracy.