The role of PET/CT in the evaluation of skeletal metastases.

Osseous metastatic disease from malignancy is a common occurrence with significant patient morbidity and mortality as well as increasing health care expenditures. Patient management plans frequently change with the identification of skeletal metastasis and the upstaging of disease status. Bone scintigraphy remains the current mainstay of diagnostic imaging procedures in nuclear medicine for the early detection of skeletal metastasis owing to their high sensitivity. Emerging positron tracers and the increasing use and availability of hybrid single-photon emission computed tomography and positron emission tomography (PET)/computed tomography machines enable physicians to diagnose metastatic disease in bones with superior accuracy. This review introduces the basics of PET and the commonly used positron tracers used to evaluate skeletal metastases.

Aberrant retropharyngeal (submucosal) internal carotid artery: an under-recognized, clinically significant variant.

We present a case of a 71-year-old woman who was incidentally found to have aberrant retropharyngeal internal carotid artery, lying very close to the pharyngeal mucosa, on imaging. Radiologists, otolaryngologists and anaesthetists should be aware of this clinically significant variant which can result in life-threatening bleeding during procedures in the oral cavity or oropharynx.

18F-FDG PET/CT Scan Can Predate Clinical Presentation in Acute Appendicitis.

Acute appendicitis is a clinical diagnosis typically presenting with right lower quadrant pain. We describe the case of an asymptomatic 53-year-old man with stage 2A diffuse large B-cell lymphoma, who underwent F-FDG PET/CT at the completion of chemotherapy. The scan showed complete lymphomatous disease remission. Incidentally, there was increased FDG uptake in a tubular structure adjacent to the cecum. Clinical examination was negative. Subsequently, the patient presented 6 days later with typical acute appendicitis symptoms. This case is interesting wherein increased FDG uptake in the appendix predated the appearance of clinical symptoms.

"Swirl sign" of aggressive angiomyxoma-a lesser known diagnostic sign.

Aggressive angiomyxoma is a rare mesenchymal tumor with high rate of local recurrence, found mainly in the pelvis and perineum of women of reproductive-aged group. We present cases of two patients, with emphasis on the magnetic resonance (MR) imaging characteristics. The clinical presentation was nonspecific. MR imaging revealed characteristic "swirl sign" in T2-weighted sequence. Preoperative diagnosis could not be made in the first patient due to a lack of experience about the diagnosis. Preoperative diagnosis was made in the second case and was helpful for the surgeon to excise the mass completely. Aggressive angiomyxoma should be on the top of a differential diagnosis in the appropriate clinical and imaging scenario.

Extramedullary pulmonary hematopoiesis causing pulmonary hypertension and severe tricuspid regurgitation detected by technetium-99m sulfur colloid bone marrow scan and single-photon emission computed tomography/CT.

Extramedullary pulmonary hematopoiesis is a rare entity with a limited number of case reports in the available literature only. We report the case of a 66-year-old man with known primary myelofibrosis, in whom a Technetium-99m sulfur colloid bone marrow scan with single-photon emission computed tomography (SPECT)/CT revealed a pulmonary hematopoiesis as the cause of pulmonary hypertension and severe tricuspid regurgitation. To the best of our knowledge, this is the first description of Technetium-99m sulfur colloid SPECT/CT imaging in this rare condition.

Extraosseous uptake of technetium-99m methylene diphosphonate by an acute territorial cerebral infarct in a classical biodistribution pattern.

Technetium-99m methylene diphosphonate scintigraphy is usually performed to assess bone lesions, especially skeletal metastases in patients with a history of malignancy. However, it is important to recognize some specific conditions with a unique pattern of tracer uptake, especially in extraosseous locations as they are not related to primary neoplasm or metastases. Diagnosing such unusual presentation is essential as it significantly influences the clinical management. This case report describes an unusual presentation detected in a bone scan of an elderly female patient, who was a treated case of breast cancer and was referred for a bone scan to rule out bone metastases. Incidentally, a large acute territorial cerebral infarct was diagnosed, which was later confirmed by magnetic resonance imaging on diffusion-weighted images. Diagnosis of the typical presentation and timely management saved the patient life.

Isolated retroaortic left innominate vein in an adult without cardiac or aortic anomalies.

Retroaortic innominate vein is an uncommon variant reported in patients with congenital heart disease. However, isolated retroaortic innominate vein without associated cardiac or arch anomalies is extremely rare. We present a case of a 68-year-old man who was found to have this anomalous variant incidentally on computed tomography (CT) of the thorax. We also briefly discuss its associations, embryology, and clinical significance.