Hashimoto thyroiditis and Takayasu aortitis: visualization of the thyroid gland and ring appearance of the mediastinum on F-18-FDG PET.

A woman with Hashimoto thyroiditis, treated with levothyroxine for 4 years, complained of chest pain that radiated to the neck and had progressively worsened for 2 months. CT of the chest showed circumferential thickening of the ascending aorta and aortic arch, compatible with Takayasu arteritis. She underwent F-18 FDG PET imaging, which revealed an abnormal thyroid gland and a ring-like appearance of the mediastinum.

F-18 FDG PET demonstrates crossed cerebellar diaschisis 20 years after stroke.

Stroke produces an area of focal damage and distant areas of reduced blood blow and metabolism termed diaschisis. Tc-99m ECD and HMPAO brain SPECT have demonstrated crossed cerebellar diaschisis (CCD) in patients with cerebral cortical infarct. SPECT findings reflect abnormal cerebral blood flow. CCD as shown on F-18 FDG PET reflects abnormal reflects glucose metabolism. We present the case of a patient with laryngeal cancer who also had a stroke in the left cerebral hemisphere involving the territory of the middle cerebral artery 20 years ago. This patient underwent PET, including the head and neck. A current brain F-18 FDG PET exhibited hypometabolism in the contralateral cerebellum (CCD) as well as hypometabolism of the primary insult in the left cerebral hemisphere. These findings reflect partial impairment or diminished glucose metabolism in the primary insult to the cerebrum and contralateral cerebellum. In addition, this patient illustrates that on PET imaging, CCD could be demonstrated 20 years after a stroke.

Gastric-emptying scintigraphy of type III hiatal hernia: a case report.

We present the case of a 76-y-old man with mixed (type III) paraesophageal hernia confirmed by endoscopy and CT of the chest who underwent a radionuclide gastric-emptying study that showed accumulation of the radiotracer in the herniated stomach and esophagus in the thorax and accelerated gastric emptying. A scintigraphic gastric-emptying study may be an option for noninvasively demonstrating gastroesophageal accumulation of tracer in patients with hiatal hernia.

99mTc-Depreotide chest SPECT demonstrates pulmonary metastases from renal cell carcinoma.

99mTc-Depreotide has been used on single pulmonary nodules to identify somatostatin receptor-positive lung cancer. We report that pulmonary metastases of a 78-y-old man with postradical nephrectomy for renal cell carcinoma were detected by (99m)Tc-depreotide chest SPECT. Thus, (99m)Tc-depreotide chest SPECT can be used to diagnose secondary lung cancer, such as pulmonary metastases from renal cell carcinoma with somatostatin receptor-positive tumor, other than primary lung cancer. Depending on whether the (99m)Tc-depreotide was positive for pulmonary metastases, the patient underwent an appropriate therapy without further invasive procedures.

Photon-deficient Mass on FDG-PET Scan in Renal Cell Carcinoma: A Case Report.

F-18 Fluorodeoxyglucose Positron Emission Tomography imaging (F-18 FDG PET) detects malignancies depending on the uptake profile of glycolysis of tumors; however, the role of FDG PET is limited in the evaluation of primary renal malignancy because of low FDG uptake by renal cell carcinoma and also because normal urinary excretion of FDG seen in the images. A patient with renal cell carcinoma whose FDG PET imaging study incidentally shows a photon-deficient mass in the upper pole of the right kidney is present here. The diagnosis is also validated by the histopathological findings of tumor necrosis, hemorrhage, and scars.