Circle of Willis variations may show geographic and ethnic differences. Knowledge of the frequency and types of variation in the population is important for neurosurgeons and in radiological interventional procedures as a guide for entry and in respect of collateral which could develop later.

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Aim The aim of the study was to assess the incidence, localization, depth, length of myocardial bridging (MB) with left anterior descending (LAD), systolic compression ratio, atherosclerotic plaque localization and degree of stenosis by 256-slice multi-detector computed tomography (MDCT). Material and methods Computed tomography (CT) scans from a total of 3947 patients who underwent MDCT were reviewed retrospectively for LAD MB. A diastolic and systolic dataset with the best image quality was selected. Myocardial bridge was defined as a coronary artery with an intra-myocardial course. Myocardial bridging was divided into “deep” or “superficial”. The length and depth of the bridging segment were calculated. For each bridging segment, the presence of atherosclerosis was saved in a 2-cm-long segment proximal to the entry of the bridging segment. The degree of stenosis made by atherosclerotic plaques was determined. Results LAD myocardial bridging was detected in 410 (10.4%) patients. Among these, 97 (23.7%) patients had a deep and 313 (76.3%) patients had a superficial course. The mean LAD MB length was 20.28 ±9.63 mm and the depth was 1.72 ±1.11 mm. The systolic and diastolic mean diameter difference was 0.193 mm and the average compression ratio was 9.44%. Atherosclerotic plaques were found in 167 (40.7%) of 410 LAD MB. Atherosclerotic plaques were found in 50.5% of deep MB and 37.7% of superficial MB. Conclusions 256-slice MDCT coronary angiography has a high sensitivity to show myocardial bridging in LAD localization, to determine length, depth, compression ratio, atherosclerotic plaque localization and degree of stenosis.

Background Osteoporosis is associated with decreases in bone mineral density (BMD) and is diagnosed using dual-energy X-ray absorptiometry (DXA). Computed tomography (CT), performed in routine practice, can also be used to evaluate bone quality without additional cost. Purpose To determine whether Hounsfield units (HU), a standardized CT attenuation coefficient, measured from the femoral head correlated with DXA-measured BMD. Material and Methods We evaluated 82 patients (14 men, 68 women; mean age, 67 years) undergoing femoral DXA and CT (non-enhanced abdominopelvic and hip scans) with 130 kV to determine whether HU correlated with T-scores. HU were measured by two radiologists using the largest spherical region of interest including the medullary bone of the femoral head from the junction point of the most caudal section of the femoral head with the femoral neck in 5-mm axial sections. The correlations of both sides’ HU values with their ages and DXA femur T-score were evaluated. Results HU values obtained from both femoral heads showed significant variation between the osteoporotic and non-osteoporotic groups (both P = 0.000) and strongly correlated with each other and DXA femur T-scores (left r = 0.75, right r = 0.73, respectively). In ROC curve analysis, predictive power of left HU values in identifying patients with osteoporotic femur DXA T-score was 0.905, and for right HU values it was 0.924. Osteoporosis cutoff values were 198 HU and 204 HU for the left and right hips, respectively. Conclusions HU obtained from CT performed in routine practice correlated with the DXA scores, thus providing an alternative method to determine regional bone quality without additional cost. This may be useful when choosing a fixation method, especially in trauma cases with already-performed abdominopelvic or pelvic CT in emergency services.

Türkiye'nin İki Farklı Bölgesindeki Kemik Mineral Yoğunluğu Ölçümlerinin Karşılaştırılması Objective: It was aimed to compare the values of bone mineral density (BMD) measurements made of patients in the osteoporosis (OP) unit in the provinces of Muğla and Erzurum provinces and to determine OP prevelance. Materials and Methods: The data were evaluated of a total of 3862 patients aged over 50 years, who were included in the study. Of patients; ages, sex, and body mass index (BMI) were recorded. Patients in Muğla were included in the 1 st group, and patients in Erzurum were included in the second group. The BMDs of the spine (L1-4) and hip (femur neck) in both groups were measured using the dual energy X-ray absorptiometry (DEXA) method. Results: A total of 3862 patients were included in the study. In group 1, the total number of patients was 2611 and 2518 of them were female, 93 were male. In the group 2, 1251 patients were present and 1093 were female and 158 were male. The mean age was 63.63±8.84 years in group 1 and 65.44±9.26 years in group 2, and the difference was statistically significant (p<0.001). A statistically significant difference was determined between the groups in respect of BMI (p<0.001). A statistically significant difference was determined between the femoral neck T-scores of the cases (p<0.001). Between the females of the two groups, a statistically significant difference was determined in respect of the Lumbar 1-4 T-score but no difference was seen between the males (p<0.001, p=0.726, respectively). Conclusion: The femoral neck BMD values of patients in the Muğla region were found to be significantly lower than those of the patients in the Erzurum region. Despite the significant risk factors for BMD and OP in the Erzurum region of less sunlight and regional differences, the BMD values were determined to be higher. Nutritional habits are thought to be effective in the end. We believe that regional differences and local values are a factor to be considered in the interpretation of BMD.