Faculty Bibliography

Primary lesions of the tubular bones of the digits are not uncommon, and the vast majority of these lesions are benign. Benign intramedullary lesions such as enchondromas are frequently discovered incidentally, unless they are associated with a pathologic fracture. Expansile lesions or lesions that are pedunculated and protrude from the cortex may manifest with pain and functional deficits from local inflammatory reactions. Systemic disorders such as sarcoidosis and local soft-tissue lesions with involvement of adjacent bone may mimic primary phalangeal bone tumors. Primary or secondary malignant lesions of the phalanges, most commonly chondrosarcomas, are extremely rare, and their characterization may require the use of multiple modalities, including radiography, computed tomography, and magnetic resonance imaging. Although ultrasonography is extremely useful in the evaluation of soft-tissue lesions of the hand, its role in the evaluation of osseous lesions is limited. The authors describe the imaging features of the most common benign osseous and chondral lesions of the fingers, including enchondromas, cystic lesions, and osteochondromas. In addition, they discuss malignant entities that may occur in the fingers (eg, chondrosarcomas and metastatic lesions) and commonly encountered mimics of primary osseous lesions (eg, glomus tumors, intraosseous epidermal inclusion cysts, infectious entities, and manifestations of systemic diseases). They also discuss the advantages and disadvantages of the most commonly used imaging modalities in differentiating benign from malignant lesions.

Although traumatic and iatrogenic bile leaks are rare, they have become more prevalent in recent years due to an increased propensity toward nonsurgical management of patients with liver trauma and an overall increase in the number of hepatobiliary surgeries being performed. Because clinical signs and symptoms of bile leaks are nonspecific and delay in the recognition of bile leaks is associated with high morbidity and mortality rates, imaging is crucial for establishing an early diagnosis and guiding the treatment algorithm. At computed tomography or ultrasonography, free or contained peri- or intrahepatic low-attenuation (low-density) fluid in the setting of recent trauma or hepatobiliary surgery should raise suspicion for a bile leak. Hepatobiliary scintigraphy and magnetic resonance (MR) cholangiopancreatography with hepatobiliary contrast agents can help detect active or contained bile leaks. MR cholangiopancreatography with hepatobiliary contrast agents has the added advantage of being able to help localize the bile leak, which in turn can help determine if endoscopic management is sufficient or if surgical management is warranted. Endoscopic retrograde cholangiopancreatography may provide diagnostic confirmation and concurrent therapy when nonsurgical management is pursued. A multimodality imaging approach is helpful in diagnosing traumatic or iatrogenic biliary injuries, accurately localizing a bile leak, and determining appropriate treatment.

OBJECTIVE: The objective of our study was to identify the significance of lung nodules reported on abdominal CT. MATERIALS AND METHODS: Abdominal CT reports from a 1-year period were reviewed for the terms "nodule," "nodular," or "mass" in reference to the lung bases. Patients with prior chest or abdominal CT examinations were excluded; the study population included patients with an initial abdominal CT study and at least one follow-up chest or abdominal CT examination. Two thoracic radiologists characterized nodules in consensus. Radiology and clinical records were reviewed for nodule growth and clinical diagnoses. RESULTS: The term "nodule," "nodular," or "mass" in reference to the lung bases was reported in 364 of 12,287 abdominal CT studies (3%). Of 125 patients with no prior CT examination, 42 had undergone follow-up chest CT, abdominal CT, or both. Common imaging indications included abdominal pain (13/42, 31%) and preexisting malignancy (n = 7, 16.7%). Regardless of the indication for imaging, 16 (38.1%) had malignancy that was known (n = 13) or newly diagnosed (n = 3) on the initial abdominal CT. Three of 42 patients (7.1%) had malignant nodules representing metastatic disease: Nodule growth was seen in one patient with preexisting colon cancer, one patient with newly diagnosed metastatic pancreatic cancer, and a third with known bladder cancer. The latter patient had suspected lung metastases that were confirmed on chest CT 1 day later. Three of the 16 patients (18.8%) with preexisting or newly diagnosed cancer had malignant nodules. No malignant nodules were identified without such history. Six patients (14.3%) had an infection. CONCLUSION: Lung nodules incidentally detected on abdominal CT were rarely malignant and were seen only in the setting of an underlying abdominal malignancy. Knowledge of such history is of critical importance to both the clinician and the radiologist. Dedicated chest CT is most useful when assessing pulmonary nodules in patients with localized malignancy.