Vijayanadh Ojili

PURPOSE: To evaluate the role of multidetector CT angiography in the diagnosis and preoperative assessment of pulmonary sequestration with angiographic or surgical correlation. METHODS: Eight patients (5 males, 3 females) in the age range of 2 days to 35 years suspected of having pulmonary sequestration on the basis of clinical history and chest radiographs were included in the study. All patients underwent CT angiography (4 or 16 slice) and MPVR, MIP and 3D volume rendered images were generated. The axial images were also reviewed at soft tissue and lung window settings to evaluate the parenchymal changes. RESULTS: CT angiography showed five pulmonary sequestrations on the left and three on the right, located in the basal segments (n = 7) or paravertebral region (n = 1). Aberrant systemic arterial supply was demonstrated in all cases: from the descending thoracic aorta (n = 2); abdominal aorta (n = 3) and celiac axis (n = 3). Venous drainage into inferior pulmonary veins was demonstrated in 4 patients. The angioarchitecture depicted on CT angiography was confirmed on surgery in five patients and by DSA in two patients who subsequently underwent embolization using PVA particles and/or coils. CONCLUSION: The ability of CT angiography to simultaneously image the arterial supply, venous drainage and parenchymal changes in a single examination makes it the imaging modality of choice for the diagnosis and preoperative assessment of pulmonary sequestration.

Adrenal collision tumors (ACTs) refer to coexistence of two adjacent, but histologically distinct neoplasms involving the adrenal gland without histologic admixture at interface. ACTs include adenoma with myelolipoma, adenoma with metastases, hemangioma with adenoma, and adrenocortical carcinoma with myelolipoma. In addition, hemorrhage into a pre-existing adrenal mass can mimic an ACT, and it is important to differentiate these two pathologies. Accurate characterization of ACTs is difficult, but critical, for correct staging of patients with malignancies and to guide percutaneous biopsy. Magnetic resonance imaging (MRI) and multidetector computed tomography imaging techniques may depict different tumor components separately; however, biopsy may be required in selected patients for confirmation. [(18)F]Fluorodeoxyglucose-positron emission tomography (PET) shows increased uptake in the malignant component of ACTs, and guides percutaneous biopsy. Even in patients requiring percutaneous biopsy for a definite diagnosis, imaging findings can help in guiding the appropriate component to be biopsied. Knowledge of imaging findings of different ACTs and their mimics on MRI, computed tomography, and PET help in optimal patient management.