The role of diffusion weighted MR imaging for differentiation between Graves' disease and Hashimoto thyroiditis.

OBJECTIVE: The aim of this study was to evaluate the usefulness of diffusion-weighted magnetic resonance imaging (DWMRI) for differentation between Graves' disease and Hashimoto's thyroiditis. PATIENTS AND METHODS: Fifty patients (27 Graves diseases and 23 Hashimoto thyroiditis) and twenty healthy volunteers were examined using T1, T2 and DWMRI. The patients were diagnosed on the basis of physical findings and the results of thyroid function tests and serological tests. Circular ROIs were positioned on the bilateral thyroid lobes and isthmus. All measurements were repeated three different b values including 100, 600 and 1000 s/mm2 in all cases. ADC (Apparent diffusion coefficient) maps were calculated automatically with the MR system. RESULTS: Mean ADC values were 2.93 × 10-3, 1.97 × 10-3 and 1.62 × 10-3 mm2/s in the healthy volunteers; 3.47 × 10-3, 2.25 × 10-3 and 1.64 × 10-3 mm2/s in Graves' disease; 2.53 × 10-3, 1.76 × 10-3, 1.28 × 10-3 mm2/s in Hashimoto thyroiditis for b100, b600 and b1000, respectively. The ADC values of the Graves diseases were higher than healty volunteers and Hashimoto thyroiditis. ADC values were statistically significant for differentation between Hashimoto thyroiditis and Graves' disease all b values (p < 0.05). CONCLUSIONS: DWMRI is fast sequence and does not require contrast agent. Quantitative assessment of the lesion is possible using ADC map. So, DWMRI may be useful differentiation of the Hashimoto thyroiditis and Graves' disease.

Paranasal sinus computed tomography findings in patients treated for lepromatous leprosy.

AIM: Nasal and paranasal sinus involvement is common in lepromatous leprosy and is of considerable epidemiological significance. The aim of this study was to investigate paranasal sinus abnormalities in treated lepromatous leprosy cases and to evaluate the findings in comparison with those of previous studies. MATERIALS AND METHODS: Thirty-eight patients who had been treated for lepromatous leprosy were included. All patients had been treated with dapsone and rifampicine for six months, and followed with dapsone, rifampicine and clofamizine for a minimum of two years. All patients received a clinical examination, a coronal computed tomography (CT) examination of the paranasal sinuses and ethmoidal sinus endoscopy, in order to investigate the involvement of the paranasal sinuses in the leprosy. Ethmoidal sinus biopsies were taken in 18 of the 21 cases of ethmoidal sinus involvement noted on CT scan. RESULTS: Twenty-three patients had sino-nasal symptoms. Endoscopic examination showed different pathologies in 21 of these patients. Abnormalities in the paranasal CT images were observed in 27 patients. The ethmoidal, maxillary, frontal and sphenoid sinuses were affected in 21, 18, three and two patients, respectively. Various degrees of nasal septum perforation were noted in 18 cases. In six of the 18 patients biopsied, the biopsy specimen showed involvement by lepromatous leprosy. CONCLUSION: These findings suggest that although these lepromatous leprosy patients had been treated, persistent infection was still commonly encountered. Paranasal sinus CT examination is a useful method for the evaluation of patient response to treatment and follow up; however, a CT scan alone cannot determine whether the leprosy is active.