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Thyroglossal duct cyst is a common congenital cyst in the neck. The incidence of primary carcinoma of the thyroglossal duct is less than 1% in all age groups. We present the case of a 63-year-old man with rapid expansion of a known thyroglossal duct cyst with mixed solid/cystic components. F-FDG PET/CT showed a large anterior neck mass with a non-FDG-avid cystic component and a hypermetabolic heterogeneous mass on the right side confirmed by histopathology to be squamous cell carcinoma. Although rare, F-FDG PET/CT can assist with evaluating the extent of malignant involvement in thyroglossal duct cyst squamous cell carcinoma.

The importance of evaluating nonfunctional adrenal masses in the right clinical setting is discussed. A 60-year-old man was initially diagnosed of having a localized lung carcinoma. Metastatic work-up showed an adrenal mass that was not deemed to be related to the lung primary. Although biochemical testing revealed that the adrenal mass was nonfunctional, adrenal scintigraphy was not performed. On resection, the lung neoplasm was shown to be a poorly differentiated adenocarcinoma. Radiologic follow-up of the adrenal finding was recommended. A year later, the patient presented with an abdominal mass that was visualized by bone scintigraphy and, on resection, proved to be adrenocortical carcinoma. In retrospect, the lung mass was a metastasis of an adrenocortical carcinoma.

Technetium-99m labeled human serum albumin has been shown to detect protein leakage into the bowel. A case of a young adult is presented with endoscopic and pathological correlation of scintigraphic findings supporting Menètrier's disease.

A 42-year-old woman presented with intermittent low back and left lower extremity pain. The blood flow and blood pool images of bone scintigraphy showed a large focus of increased activity in the right lower abdomen. Computed tomography showed an enlarged uterus displaced to the right side of the pelvis. At surgery, the uterus was found to be involved with adenomyosis. Three-phase bone scintigraphy consisting of blood flow and blood pool images over the anterior pelvis may be a valuable diagnostic aid in the evaluation of lower back or pelvic pain of a woman.

A 50-year-old woman presented with low back pain. Bone scintigraphy showed a focus of increased activity in the upper pole of the left kidney. Subsequent Ga-67 citrate scintigraphy demonstrated this same abnormal focus as a region of increased activity. Ultrasonography showed a renal mass in the upper pole of the left kidney. At surgery a transitional cell carcinoma of the upper pole of the left kidney was found.

The role of technetium-99m pertechnetate imaging in acute testicular torsion is well appreciated. Manual testicular detorsion under local anesthesia may be performed in the nuclear medicine clinic by the urology service immediately following initial diagnostic scintigraphy. Following manual testicular detorsion, continued images of the testes are obtained up to 30 minutes without having to reinject the patient with technetium-99m pertechnetate. Reperfusion of the affected testicle will be dramatically noted if the manual detorsion is successful. Four cases are presented to illustrate this.

The value of adding an extra view of the kidneys immediately following brain imaging with Tc-99m glucoheptonate was investigated in a two-year retrospective study at our institution. Between October 1982 and October 1984, 561 individuals underwent Tc-99m glucoheptonate brain imaging with the added renal view. Twenty-nine of these individuals (5.2%) demonstrated renal abnormalities. The abnormal renal findings were clinically correlated in 24 of these persons. Sixteen (67%) of these 24 individuals were unaware of any renal abnormality. Useful information can be obtained from renal images incidental to brain imaging at no added expense or radiation exposure to the patient, and at a minimal cost in time to the imaging clinic.

Abdominal varices consisting of a caput medusae and dilated mesenteric veins resulted in pooling of Tc-99m tagged red blood cells (RBC) within these dilated vessels in a 57-year-old man with severe Laennec's cirrhosis. The atypical radiotracer localization within the abdomen mimicked an acute gastrointestinal hemorrhage. Clinical suspicion and careful evaluation of scintigraphic gastrointestinal bleeding studies will avoid false-positive interpretations.

Twenty rabbits with chronic osteomyelitis of the tibia were treated for eight weeks and then scanned with Tc-99m MDP and Ga-67 citrate. All were sacrificed and bacteriologic cultures of the tibia were obtained. All rabbits had positive Tc-99m MDP scans at the end of treatment despite thirteen cures of osteomyelitis. Eight had negative gallium scans and negative cultures. Five of the twelve positive gallium scans had negative cultures, while seven had positive cultures. Tc-99m MDP alone is not sensitive enough to be useful in predicting the cure of osteomyelitis, and combining Tc-99m MDP and Ga-67 citrate scintigrams offers no additional information over the Ga-67 citrate scintigram alone in follow-up of osteomyelitis.

A 26-year-old man with congenital syphilis presented with increased periosteal uptake of Tc-99m MDP during bone scintigraphy. In addition, bowing of the tibias and apparent shortening of the tibias were seen on the bone scan. Corresponding abnormalities were noted on roentgenography of the lower extremities.

Cerebral computed tomography, with and without iodinated contrast, revealed the appearance and evolution of lesions in a 32-year-old man with multiple sclerosis. Two areas were enhanced with contrast, with one showing a mild mass effect and rim of enhancement. Serial brain scintigraphy using technetium-99m glucoheptonate, following the computed tomography, showed the appearance and regression of corresponding regions of increased uptake. Computed tomography one day prior to brain scintigraphy failed to demonstrate a region of increased accumulation of radiotracer. One week later, however, evidence of a corresponding unenhanced defect was noted on computed tomography. Clinical correlation is given additionally.

The clinical and morphologic findings in the case of a 47-year-old man with fibrosing mediastinitis, most probably due to histoplasmosis, are described. Radionuclide angiography demonstrated obstruction of the superior vena cava with collateral vascularization. Computed tomography demonstrated a large calcific mass interposed between the pulmonary artery and superior vena cava suggesting potential pulmonary vasculature involvement. For this reason, pulmonary scintigraphy was performed which showed right lung perfusion and ventilation defects. Radionuclide angiography and pulmonary scintigraphy complement each other in determining the extent of vascular involvement with fibrosing mediastinitis. However, contrast venography is necessary to correctly delineate the anatomy of the obstructed superior vena cava and its collaterals.

Bone, brain, and gallium scintigrams are presented of a 48-year-old man with biopsy-proven cerebral amyloidosis. Brain scintigraphy revealed a well-circumscribed accumulation of Tc-99m pertechnetate in the amyloidoma. Bone scintigraphy using Tc-99m methylenediphosphonate likewise exhibited increased activity in the same area. Gallium-67 citrate, however, failed to localize within the amyloidoma.

Six cases of osteomyelitis due to Coccidioides immitis are presented. The cases reported demonstrate the importance of performing both bone and gallium imaging to avoid missing the osseous coccidioidal lesions.

A case of anaerobic hepatic abscess (Bacteroides fragilis), which initially was imaged as a cold defect on Ga-67 citrate scintigraphy and, following percutaneous drainage, became Ga avid, is presented. Proposed mechanisms for this occurrence are given.

A 25-year-old woman demonstrated Ga-67 citrate accumulation within a facial cutaneous lesion and two subcutaneous nodules within the right lower extremity. Cultures of the facial lesion and one of the subcutaneous nodules grew Sporothrix schenckii. Ga-67 citrate uptake has not been reported previously with this fungal infection. Ga-67 citrate scintigraphy was helpful in defining the extent of the disease, following its course, and determining the response to therapy.

A 16 year-old boy presented with a firm mass within the left thigh. Ga-6 7 citrate and bone scintigraphy revealed soft tissue radiotracer accumulation within the mass lesion. Radiographs and xerography of the left thigh revealed calcification within the soft tissue mass typical of myositis ossificans. The patient's clinical course was uneventful.

Gallium-67 citrate scintigraphy of a 26-year-old woman with systemic sarcoidosis demonstrated abnormal radiotracer uptake within multiple biopsy-proven sarcoidal cutaneous lesions and within both lobes of the thyroid gland. The etiology of the thyroidal uptake of the Ga-67 was uncertain but it may represent sarcoidal involvement of the gland.

A case of gallbladder perforation imaged during morphine-augmented cholescintigraphy is presented. Tc-99m DISIDA imaging dramatically demonstrated the bile leak. Whether morphine sulfate contributed to the perforation of the gallbladder is debatable.

Eight cases of pulmonary embolism were evaluated with Ga-67 citrate scintigraphy. Of the eight patients, all but one showed evidence of abnormal Ga-67 citrate localization within involved regions of the lung as demonstrated by ventilation-perfusion lung scintigraphy. The sole patient who did not demonstrate Ga-67 localization within the lung had marked breast accumulation of the radiotracer which may have obscured lung parenchymal uptake. Since Ga-67 citrate is known to accumulate within inflammatory lung processes, this radiotracer would not have a specific role in differentiating pulmonary embolism from these conditions. This study disagrees with the results of other studies in the medical literature that describe such a role.

A 47-year-old man presented with the clinical findings of acute cholecystitis. During hepatobiliary scintigraphy using Tc-99m DISIDA, a persistent photopenic defect was noted within the inferior portion of the liver in the region of the gallbladder. Abdominal ultrasonography revealed large gallstones with acoustic shadowing within a normal-sized gallbladder. Eleven large gallstones were found within a normal-sized intrahepatic gallbladder at surgery.

Prolonged fasting (NPO) and total parenteral nutrition (TPN) have been reported to result in an unacceptable number of false-positive hepatobiliary scintigrams for acute cholecystitis. Based on these reports, the clinical usefulness of the hepatobiliary scan in diagnosing acute cholecystitis in the critically ill postoperative patient who has been NPO or on TPN has been questioned. Patients who were either on prolonged fasting or total parenteral nutrition and who had no history of hepatobiliary disease were prospectively studied to assess the value of the Tc-99m diisopropyl-iminodiacetic acid (DISIDA) scan without pretreatment with cholecystokinin (CCK) in such a setting. Of the 17 persons studied, nine had been on total parenteral nutrition for at least five days and eight had been fasting for at least five days prior to imaging. Seven of the nine individuals on TPN (78%) and six of the eight individuals who were NPO (75%) had normal hepatobiliary scintigraphy. The results suggest that hepatobiliary imaging with Tc-99m DISIDA has a lower false-positive rate in individuals on TPN or NPO than previously has been reported and that it has clinical efficacy in ruling out the diagnosis of acute cholecystitis in these individuals.