Diagnostic value of ultrasonography and TI-201/Tc-99m dual scintigraphy in differentiating between benign and malignant thyroid nodules.

PURPOSE: To evaluate the performance of ultrasonography (US) and TI-201/Tc-99m dual (Tl/Tc) scintigraphy in differentiating between benign and malignant thyroid nodules. METHODS: Eighty-six patients diagnosed to have a thyroid tumor on postoperative histopathologic examination between June 2009 and February 2017 were included in this retrospective study. A radiologist reviewed the US and Tl/Tc scintigraphy reports along with all available clinical and histopathologic information. On Tl/Tc scintigraphy, a nodule in which uptake was higher in the delayed phase than in the surrounding parenchyma was defined as a delayed accumulation pattern and a nodule in which uptake was higher in the delayed phase than in the early phase was defined as a persistent pattern. The Tl/Tc scintigraphy images were evaluated in a blinded manner to assess reproducibility. A statistical analysis was performed to identify features associated with malignancy. Interobserver variability was calculated using the κ statistic. RESULTS: US had higher sensitivity (81.2%), specificity (88.2%), and positive (96.6%) and negative (53.6%) predictive values than Tl/Tc scintigraphy. An ill-defined margin and microcalcification were independent predictors of a malignant thyroid nodule on multivariate logistic regression (P = 0.003 and P = 0.014, respectively). The persistent pattern had high specificity (85.7%) equivalent to that of US but had lower sensitivity (34.7%). The κ values for the delayed accumulation and persistent patterns were 0.66-0.78 and 0.32-0.50, respectively. CONCLUSIONS: An ill-defined margin and microcalcification on US were independent predictors of a malignant thyroid nodule. A persistent pattern seen on Tl/Tc scintigraphy could contribute to the differential diagnosis.

The effects of chemical and radioactive properties of Tl-201 on human erythrocyte glutathione reductase activity.

AIM: The aim of the study was to evaluate the inhibitory effects of thallium-201 ((201)Tl) solution on human erythrocyte glutathione reductase (GR) activity. METHODS: Erythrocyte GR was initially purified by 2',5'-adenosine diphosphate Sepharose-4B affinity and Sephadex G-200 gel filtration chromatography. The purification was monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which showed a single band for the final enzyme preparation. The in vitro and in vivo effects of the (201)Tl solution including Tl(+), Fe(+3) and Cu(+2) metals and the in vitro effects of the radiation effect of the (201)Tl solution and nonradioactive Tl(+), Fe(+3) and Cu(+2) metals on human erythrocyte GR enzyme were studied. Enzyme activity was determined with the Beutler method at 340 nm using a spectrophotometer. All purification procedures were carried out at (+)4 °C. RESULTS: Glutathione reductase was purified 2033-fold at a yield of 28.17%. (201)Tl solution and radiation exposure had inhibitory effects on the enzyme activity. Besides, effects of nonradioactive Tl(+), Fe(+3) and Cu(+2) were studied on enzyme activity in vitro. Furthermore, seven human patients were also used for in vivo studies of (201)Tl solution. CONCLUSION: It was detected in in vitro and in vivo studies that the human erythrocyte GR enzyme is inhibited due to the radiation effect of (201)Tl solution.

Nodular fasciitis of the hand in a young athlete. A case report.

Nodular fasciitis is a rapidly growing mass, with high cellularity and mitotic activity, that can be both clinically and histologically misdiagnosed as a soft tissue sarcoma. Nodular fasciitis of the hand is an extremely rare condition. We report a 17-year-old male hand-ball player with nodular fasciitis in the dominant hand. The patient presented with a rapidly growing mass in his right hand and no history of major trauma. On physical examination, a painful mass measuring 2 cm in diameter was observed in the first web space. Magnetic resonance imaging (MRI) demonstrated a subcutaneous mass with isointensity on T1-weighted images and inhomogeneous high intensity on T2-weighted images. The lesion was inhomogeneously enhanced after intravenous administration of gadolinium. Moreover, thallium-201 scintigraphy showed high uptake at the early phase and no wash-out at the delayed phase. We performed an excisional biopsy. The mass was present subcutaneously and adhered to the interosseous muscle fascia. Although a pathological examination by frozen section during surgery showed a low-grade spindle cell sarcoma, the final histological diagnosis was nodular fasciitis. There was no evidence of local recurrence at the recent follow-up 2 years after the operation. We speculate that repeated small injuries as a result of sports activities played an important causative role in the nodular fasciitis.

Does supplementation of contrast MR imaging with thallium-201 brain SPECT improve differentiation between benign and malignant ring-like contrast-enhanced cerebral lesions?

OBJECTIVE: To determine whether thallium-201 ((201)Tl) brain single photon emission computed tomography (SPECT) could supplement magnetic resonance (MR) imaging diagnostic information by visual comparison of two separate data sets from patients with ring-like contrast-enhanced cerebral lesions. METHODS: A combination of MR imaging and (201)Tl brain SPECT sets obtained from 13 patients (10 men, 3 women) ranging in age from 26 years to 86 years (mean 61.0 years) were retrospectively reviewed. A total of 12 patients had a solitary lesion, and the others had multiple lesions. All but two intracranial foci were pathologically confirmed. The final diagnoses were six glioblastomas, two cerebral metastases from lung cancer, and one each of abscess, resolving hematoma, primary central nervous system lymphoma, toxoplasmosis, and radiation necrosis. The two separate image formats (MR images and SPECT) were shown to ten readers with practical experience. All of the MR images for each patient were shown to each reader first. After interpreting them, the readers were shown the SPECT images. Images were scored in terms of how benign or malignant the foci were on a 5-point scale from "definitely benign" to "definitely malignant." RESULTS: The improvement in the performance of all ten readers was from 67.7% to 93.8% in mean accuracy (P = 0.0028) and from 0.730 to 0.971 in mean Az value (P = 0.0069) after they were shown the (201)Tl brain SPECT images. CONCLUSIONS: (201)Tl brain SPECT should substantially increase confidence in the diagnosis of intracranial lesions with ring-like contrast enhancement when MR imaging does not permit differentiation between benign and malignant disease.