Does the presence of macroscopic intralesional fat exclude malignancy? An analysis of 613 histologically proven malignant bone lesions.

OBJECTIVE: To determine if macroscopic intralesional fat detected in bone lesions on CT by Hounsfield unit (HU) measurement and on MRI by macroscopic assessment excludes malignancy. MATERIALS AND METHODS: All consecutive CT-guided core needle biopsies (CNB) of non-spinal bone lesions performed at a tertiary center between December 2005 and September 2021 were reviewed. Demographic and histopathology data were recorded. All cases with malignant histopathology were selected, and imaging studies were reviewed. Two independent readers performed CT HU measurements on all bone lesions using a circular region of interest (ROI) to quantitate intralesional fat density (mean HU < -30). MRI images were reviewed to qualitatively assess for macroscopic intralesional fat signal in a subset of patients. Inter-reader agreement was assessed with Cronbach's alpha and intraclass correlation coefficient. RESULTS: In 613 patients (mean age 62.9 years (range 19-95 years), 47.6% female), CT scans from the CNB of 613 malignant bone lesions were reviewed, and 212 cases had additional MRI images. Only 3 cases (0.5%) demonstrated macroscopic intralesional fat on either CT or MRI. One case demonstrated macroscopic intralesional fat density on CT in a case of metastatic prostate cancer. Two cases demonstrated macroscopic intralesional fat signal on MRI in cases of chondrosarcoma and osteosarcoma. Inter-reader agreement was excellent (Cronbach's alpha, 0.95-0.98; intraclass correlation coefficient, 0.90-0.97). CONCLUSION: Malignant lesions rarely contain macroscopic intralesional fat on CT or MRI. While CT is effective in detecting macroscopic intralesional fat in primarily lytic lesions, MRI may be better for the assessment of heterogenous and infiltrative lesions with mixed lytic and sclerotic components. CLINICAL RELEVANCE STATEMENT: Macroscopic intralesional fat is rarely seen in malignant bone tumors and its presence can help to guide the diagnostic workup of bone lesions. KEY POINTS: • Presence of macroscopic intralesional fat in bone lesions has been widely theorized as a sign of benignity, but there is limited supporting evidence in the literature. • CT and MRI are effective in evaluating for macroscopic intralesional fat in malignant bone lesions with excellent inter-reader agreement. • Macroscopic intralesional fat is rarely seen in malignant bone lesions.

Association of aspirin and other non-steroidal anti-inflammatory drugs with bleeding complications in image-guided musculoskeletal biopsies.

OBJECTIVE: To evaluate the safety of continuing aspirin and other non-steroidal anti-inflammatory drugs (NSAID) in patients undergoing image-guided musculoskeletal biopsies. MATERIAL AND METHODS: Prior to October 2017, patients undergoing image-guided musculoskeletal biopsy had aspirin and NSAIDs withheld for the preceding 5-7 days. The policy changed in October 2017 based on new guidelines from the Society of Interventional Radiology such that aspirin and other NSAIDs were not withheld. A retrospective review of patient records was performed for all biopsies prior to and after the policy change to assess for differences in biopsy-related bleeding complications. Additional clinical and biopsy factors including age, gender, liver disease, coagulopathy, biopsy tissue type, and histological diagnosis were assessed. RESULTS: In the pre-policy change group, there were 1853 total biopsies with 43 biopsy-related bleeding complications (2.3%). Within this group, 362 patients were on aspirin with 7 bleeding complications (1.9%) and 260 patients were on NSAIDs with 5 bleeding complications (1.9%). There were 409 total biopsies in the post-policy change group and 7 bleeding complications (1.7%). Within this group, 71 patients were on aspirin with 1 bleeding complication (1.4%). No bleeding complications were recorded in patients on NSAIDs (0%). There was no significant difference in bleeding complication between the pre- and post-policy change groups overall (p = 0.58) and in patients on aspirin (p = 1.00) or other NSAIDs (p = 1.00). CONCLUSION: Bleeding complications for musculoskeletal biopsies are rare. Leaving patients on aspirin or other NSAIDs during a musculoskeletal biopsy does not increase the incidence of bleeding complications.

Diagnostic yield of percutaneous biopsy for sclerotic bone lesions: Influence of mean Hounsfield units.

PURPOSE: To identify whether there was an association between Hounsfield units of sclerotic bone lesions and diagnostic yield of biopsy. METHOD: All core needle biopsies of sclerotic bone lesion were identified from a database. Pathology reports were reviewed to determine whether the biopsy was diagnostic or non-diagnostic. RESULTS: 91 patients were included in the study group. The yield for lesions with mean HU≥500 was significantly lower than those with a mean HU≤500 (40% vs. 69.6%, p<0.05). CONCLUSION: Lesions with a mean HU>500 are more likely to have a non-diagnostic biopsy than a diagnostic biopsy.

Early Peribiliary Hyperenhancement on MRI in Patients with Primary Sclerosing Cholangitis: Significance and Association with the Mayo Risk Score.

The aims of this study are to assess any relationship between peribiliary hyperenhancement on MRI in patients with primary sclerosing cholangitis (PSC) and their Mayo risk score and to assess which timing of peribiliary hyperenhancement correlates best with the Mayo risk score. In this HIPAA-compliant, IRB-approved retrospective study, 101 patients who underwent MRI for known or suspected PSC were identified. Of those, 62 patients (mean age 48 years; 40 males) were diagnosed with PSC by a hepatologist based on findings on MRI, ERCP, and/or liver biopsy, and comprise the final cohort. Data were recorded on whether peribiliary hyperenhancement was present, the post-contrast phase and the extent of involvement. The components to calculate the Mayo risk score were recorded. Statistical analysis was performed using the student T test, Fisher's exact test, and the Kaplan-Meier estimate. Of 62 patients, 41 (66.1%) patients had a low-Mayo risk score (<0), 14 (22.6%) had an intermediate-risk score (≤2 and >0), and 7 (11.3%) had a high-risk score (>2). On MRI, 29 (46.8%) patients demonstrated arterial peribiliary hyperenhancement. Both the presence and extent of peribiliary hyperenhancement showed significant associations with Mayo risk score (p < 0.01). Using the combined end point of liver transplantation or death, there was a statistically significant difference in survival times between those with and those without arterial peribiliary hyperenhancement (p < 0.05). The presence of arterial peribiliary hyperenhancement in patients with PSC on MRI is associated with higher Mayo risk scores and may suggest a poorer prognosis.

Correlation between the size of incidental thyroid nodules detected on CT, MRI or PET-CT and subsequent ultrasound.

PURPOSE: The aim of this study was to assess the relationship between size of thyroid nodules at computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography CT (PET-CT), and size at ultrasound. MATERIALS AND METHODS: We performed a retrospective review of thyroid ultrasound studies over a 2-year period. RESULTS: A total of 307 patients were included in the study. There was a statistically significant difference between the size of nodules measured on ultrasound compared with cross-sectional imaging (P < .001). American College of Radiology white paper recommendations would have decreased ultrasound referrals by 24% without any additional missed malignancies. CONCLUSION: Cross-sectional imaging underestimates the size of thyroid nodules; however, the difference is small and likely not clinically significant.

Posterior cruciate ligament tears in Taiwan: an analysis of 140 surgically treated cases.

INTRODUCTION: Posterior cruciate ligament (PCL) tears are commonly due to motor vehicle accidents or sports-related trauma but can differ geographically. We report the various causes, types, and associated injuries of PCL tears in Taiwan. METHODS: One hundred forty patients with arthroscopically treated PCL tears were reviewed. RESULTS: Scooter-related trauma was the most common cause of PCL tear in our series and is typically an isolated ligamentous injury. High-velocity motor vehicle accidents accounted for a small percentage of PCL tears. CONCLUSION: Scooter-related PCL tears are common in Taiwanese patients and are often isolated ligamentous injuries similar to low-velocity sports-related PCL injuries.

Imaging features of bariatric surgery and its complications.

Diagnostic imaging features of the most commonly performed types of bariatric surgery, which are gastric banding, sleeve gastrectomy, and Roux-en-Y gastric bypass, are reviewed as well as imaging diagnosis of their complications. Although upper gastrointestinal series remains the first-line imaging test for assessing postoperative anatomy and complications, the important role of multidetector computed tomography in diagnosis of serious complications is highlighted.

Pancreatic surgery: a multidisciplinary assessment of the value of intraoperative US.

PURPOSE: To assess the value of intraoperative ultrasonography (US) for different types of pancreatic surgery. MATERIALS AND METHODS: An institutional review board-approved, HIPAA-compliant retrospective review with waiver of informed consent was performed to evaluate all cases of pancreatic surgery with intraoperative US or laparoscopic US that occurred at a single institution during a 10-year period. Surgical notes, radiologic images, and clinical data for each surgical procedure and subsequent clinical course were reviewed by pancreatic surgeons and radiologists. Presumptive diagnosis, type of surgical procedure performed, and final pathologic data were recorded. A relative value score was established by consensus and assigned to each case with a grade of 0-3, which indicated the value of the intraoperative or laparoscopic US. The type of operation and pathologic data were compared in each of the value score groups. Categoric variables were compared by using either χ(2) or Fisher exact test. RESULTS: One hundred ninety-three intraoperative or laparoscopic US procedures were performed in 189 patients. Of the patients, there were 102 men and 87 women. The mean age was 57.8 years (range, 18-86 years). Intraoperative or laparoscopic US value scores were as follows: value score 0, 3.6%; value score 1, 11.9%; value score 2, 31.1%; and value score 3, 53.4%. The most common contribution that resulted in a high score (value score 3) was facilitation of technical performance of the surgery (n = 60). High value score was significantly associated with performance of pancreatitis-related surgery (P < .001). The surgical indication that most commonly resulted in a low value score of 0 or 1 was staging of pancreatic cancers. All cases that received a score of 0 occurred in the laparoscopic adenocarcinoma surgical setting (staging or pancreatic biopsy). CONCLUSION: Intraoperative or laparoscopic US can be a valuable procedure in multiple types of surgical procedures that involve the pancreas and shows clear patterns of value in the different types of surgery.