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A 55-year-old man was a hepatocellular carcinoma patient, diagnosed by sonography and a biopsy. Because of his musculoskeletal tenderness, a bone scan was performed to exclude skeletal metastasis. A subsequent F-FDG PET/CT scan revealed that the unilateral abnormal uptake seen on the bone scan was actually a mineralized tendon. A mineralized tendon is easily detectable using Tc-MDP; therefore, it is imperative to differentiate between bone lesions and mineralized tendons. In addition, few studies have reported F-FDG uptake in a calcified tendon.

A 54-year-old woman had a primary breast sarcoma with rapid enlargement in 3 months. The mass became so huge that it was more than 20 cm in diameter and occupied the entire right breast on presentation. Extraosseous uptake was present in this mass and demonstrated a unique picture, mimicking the posture of a racing driver who holds a helmet under the armpit, on the bone scan.

Purpose: Head CT and MRI show characteristic changes in the syndrome of acute bilateral basal ganglia lesions in patients with diabetic uremia. However, they do not provide further insight into the underlying pathophysiology. To further clarify the biologic mechanism of the syndrome, F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) was used in 2 patients., Methods: PET studies were performed in 2 diabetic uremic patients with acute movement disorders. The cerebral glucose metabolic rates in these 2 patients were compared with 11 normal age-matched controls. The images were further analyzed with statistical parametric mapping to identify regions of significant metabolic abnormality., Results: The cases showed markedly reduced glucose metabolism in the bilateral basal ganglia, especially in the bilateral putamens, where the glucose uptake was nearly absent., Conclusions: FDG-PET correlates better with the clinical conditions and provides more pathophysiological information than head CT or MRI scans in bilateral basal ganglia lesions in patients with diabetic uremia. We propose that acute exacerbation of a long-term glucose utilization failure in the basal ganglia cells produced these lesions.

It is well-known that fluorodeoxyglucose (FDG) is taken up by different tumors and active inflammation. Focal uptake of FDG may cause false-positive results in certain benign or physiologic conditions. However, the misdiagnosis of laryngeal cancer resulting from FDG secretion in saliva has not been reported previously. In the current report, a 34-year-old man was admitted for a checkup and was misdiagnosed as having laryngeal cancer as a result of FDG secretion in saliva before the patient rinsed his mouth with a glass of water and swallowed the saliva with water.

Tuberculosis (TB) remains a major cause of skeletal infection in many parts of the world. Bone scintigraphy is an excellent screening test for bone lesions and Ga-67 scintigraphy is a useful tool for detecting inflammatory lesions. This study determined the value of bone and Ga-67 scans in patients with skeletal TB. Tc-99m MDP and Ga-67 whole-body scans were performed in 24 patients with proved skeletal TB. Twenty-six TB lesions were found in these 24 patients, 8 in the spine, 5 in the knee, 5 in the wrist, 4 in the ankle, 2 in the elbow, 1 in the finger, and 1 in the sacroiliac joint. Of the 26 TB lesions, Tc-99m MDP bone imaging detected 24 and Ga-67 scans revealed 23. The sensitivity rates were 92% (24 of 26) and 88.5% (23 of 26) for bone scans and Ga-67 scans, respectively. When the scans were evaluated in combination, the detection sensitivity was 96.1% (25 of 26). Two lesions that the bone scan failed to detect were in the spine. Ga-67 imaging failed to detect two spinal lesions and one lesion in the knee. The detection sensitivities of bone and gallium scans were high for skeletal TB, although neither scan was specific for TB lesions. Either the bone or Ga-67 scan can be used in the clinical setting as a convenient screening test to detect multiple sites of bone involvement in TB, and to indicate the sites for further detailed evaluation by CT, MRI, or biopsy.

Tc-99m tetrofosmin SPECT imaging of the head and neck was performed on 10 patients with nasopharyngeal carcinoma (NPC) and 10 controls. There was no abnormal nasopharyngeal uptake of tetrofosmin in the 10 controls. In the patients with NPC, 3/10 (30%) of the cases had no abnormal uptake and 7/10 (70%) had increased nasopharyngeal uptake. Considering our preliminary study, we find that Tc-99m tetrofosmin SPECT of the head and neck may be helpful in the detection of NPC. However, further study with a larger number of patients is needed to ascertain the value of Tc-99m tetrofosmin SPECT in such cases.

During the last two decades, there has been a trend to use low-dose I-131 ablation therapy in patients with thyroid carcinoma without metastases. However, information regarding the incidence of acute adverse reactions in patients after low-dose radioiodine therapy has not been reported. In this study, the acute radiation effects after low-dose radioiodine ablation therapy in postsurgical differentiated thyroid cancer patients was evaluated. Fifty-six patients with differentiated thyroid cancer were prospectively evaluated. None of these patients had evidence of a distant metastasis. All patients received 40 mCi (1480 MBq) I-131 MIBG orally and were evaluated for symptoms and signs by a physician on the second and seventh days after therapy. Xerostomia and nausea were the most common complaints with the same incidence rate of 5.35%. Gastralgia occurred at a frequency of 3.57%. Pain in the thyroid bed, tenderness over a parotid gland, submandibular glands, change in taste, and vomiting all were found at a frequency of 1.78%. Maximum reactions generally occurred 24-48 hours after therapy. All the symptoms except for xerostomia resolved completely in most patients within a week. In comparison with high-dose ablation therapy published in the literature, the incidence of radiation reactions in low-dose radioiodine therapy was much lower. It was concluded that in patients without lymph node or distant metastases, low-dose I-131 MIBG therapy may be recommended to avoid the high incidence of local complications after high-dose treatment.

Bone scintigraphy plays an important role in the early detection of bone metastases in patients with nasopharyngeal carcinoma and serial scans may aid the clinician to assess the therapeutic response. A superscan is a pattern described as abnormal bone scan, indicating extensive bony metastases associated with various neoplastic diseases. Bone scans from 407 patients with nasopharyngeal carcinoma were reviewed retrospectively. Only six superscans (1.5%) were found. The appearance of a superscan is frequently accompanied by an abnormal titer of serological markers IgG-VCA and IgA-VCA, liver metastases, and poor survival. Although a superscan rarely occurs in nasopharyngeal carcinoma, its appearance may represent a poor prognosis in these patients.