Changes in the Regional Cerebral Blood Flow in Postlingual Deaf Patients Measured by ECD-SPECT: Preliminary Study / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cochlear implantation improves hearing ability in adults with profound deafness. Using non-invasive functional brain imaging methods, it is now possible to assess regional blood flow and activity of auditory cortex which might be correlated to the outcome of cochlear implantation. The aim of this study was to measure the regional cerebral blood flow in patients with postlingual deafness utilizing controls in a variety of methods. SUBJECTS AND METHOD: Six postlingual deaf adults who were planned to undertake cochlear implantation and 12 normal controls were examined with technetium-99m-labeled ethyl cysteinate dimer single-photon emission computed tomography (99mTc-ECD-SPECT). Images of the regional cerebral blood flow were processed by statistical parametric mapping and analyzed by unpaired t-test. RESULTS: The analysis of the SPECT images of the 6 deaf patients showed decreased cerebral blood flow in both superior, middle temporal and inferior prefrontal lobes compared with controls (p<0.001). Also this decreased auditory cortical blood flow was greater in left hemisphere in all patients. CONCLUSION: The degree of remaining activity of auditory cortex and the lateralization of the dominant auditory hemisphere, which may influence on the outcome of cochlear implantation, could be measured by ECD-SPECT.

Differentiation of Bone Metastases and Fractures using 24 hour / 3 hour Radio-uptake Ratio in Bone Scintigraphy / 대한핵의학회잡지

PURPOSE: We evaluated the usefulness of 24 hour/3 hour radio-uptake ratio, lesion to non-lesion ratio, in differentiating bony metastases from acute (<2 months) and healing ( 2 months) fractures. MATERIALS AND METHODS: Sixty-three patients (age range: 26-81, 32 males, 31 females) having 90 lesions (30 bone metastases, 30 acute fractures, 30 healing fractures) were included. Bone scans were obtained 3 and 24 hours after administration of 740 MBq of 99mTc-MDP. The ratio of radio-uptake in the lesion to normal area was measured as 24/3 hour radio-uptake ratio ([lesion/non-lesion RUR at 24 hour]/[lesion/non-lesion RUR at 3 hour], 24/3 RUR) and analyzed clinical significance in differentiating bone metastases from acute or healing fractures. RESULTS: Mean 24/3 RUR were 1.22+/-0.18 for bone metastases, 1.25+/-0.14 for acute fractures, and 0.99+/-0.15 for healing fractures. 24/3 RUR values of bone metastases and acute fractures were not significantly different. But 24/3 RUR values of bone metastases and healing fractures, and those of acute and healing fractures were found to be significantly different (p<0.001). When 24/3 RUR of 1.0 was considered as the cut off point separating metastases from fracture, a sensitivity of 100% (30/30) was obtained. The specificity was 0% (0/30) in separating metastases from acute fractures, and 47% (14/30) in separating metastases from healing fractures. When 24/3 RUR of 1.2 was considered as the cut off point, sensitivity of 53% (16/30) in the diagnosis of bone metastasis, and specificity of 37% (11/30) in separating metastases from acute fractures, and 100% (30/30) in separating metastases from healing fractures were obtained. CONCLUSION: 24/3 RUR is useful in differentiating bone metastases from healing fractures, but not in differentiating bone metastases from acute fractures. A 24/3 RUR of less than 1.0 suggests healing fractures. A 24/3 RUR of more than 1.2 suggests bone metastases or acute fractures.