Yazar "Candur, Mehmet" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Opportunistic assessment of bone mineral density using computed tomography in pediatric liver transplant recipients
    (Springer, 2026) Dag, Nurullah; Tasolar, Sevgi; Ulubaba, Hilal Er; Candur, Mehmet; Yilmaz, Sezai
    Pediatric liver transplant (LT) recipients are at increased risk of impaired bone mineral accrual due to chronic liver disease, growth disturbances, and post-transplant metabolic factors. Although dual-energy X-ray absorptiometry (DXA) remains the reference method for evaluating bone mineral density (BMD), opportunistic assessment using routine abdominal computed tomography (CT) has emerged as a potential adjunct tool. This study aimed to evaluate the potential of using routine abdominal CT scans to assess bone health in pediatric LT recipients by comparing lumbar vertebral Hounsfield unit (HU) values with those obtained using DXA. This retrospective study included 62 pediatric LT recipients who underwent both abdominal CT and lumbar spine DXA within a 3-month period. HU values were measured at vertebral levels L1-L4 in both the sagittal and axial planes. DXA z-scores were classified according to International Society for Clinical Densitometry pediatric guidelines. Correlation and receiver operating characteristic (ROC) analyses were performed to determine the diagnostic performance of HU values. Patients with low bone mineral density had significantly lower sagittal HU values (p < 0.05). Moderate correlation was found between sagittal mean HU and DXA z-scores (r = 0.429, p = 0.003), whereas weaker correlation was observed for axial HU values (r = 0.266, p = 0.037). ROC analysis demonstrated a moderate discriminative ability for sagittal HU (AUC = 0.713, p = 0.016), with an optimal cut-off value of 188 HU yielding 83% sensitivity and 68% specificity.
  • Küçük Resim Yok
    Öğe
    Opportunistic Bone Health Assessment Using Contrast-Enhanced Abdominal CT: A DXA-Referenced Analysis in Liver Transplant Recipients
    (Mdpi, 2025) Dag, Nurullah; Ulubaba, Hilal Er; Tasolar, Sevgi; Candur, Mehmet; Akbulut, Sami
    Objective: This study aimed to investigate the relationship between computed tomography (CT)-derived Hounsfield Unit (HU) measurements and dual-energy X-ray absorptiometry (DXA) and to evaluate the feasibility of using contrast-enhanced abdominal CT as a complementary tool in the assessment of bone health in liver transplant recipients. Methods: This retrospective descriptive and analytical study included adult liver transplant recipients who underwent both contrast-enhanced abdominal CT and DXA within a three-month interval. HU measurements were obtained from sagittal and axial reformatted images at the lumbar spine (L1-L4) and femoral neck. All CT examinations were performed using a standardized venous-phase protocol. DXA-derived T-scores from the lumbar spine and femur served as the reference standard. Correlation analyses and receiver operating characteristic (ROC) curves were used to evaluate associations between HU values and BMD, as well as the diagnostic performance of HU in identifying low bone density. Results: A total of 259 recipients (mean age 55.7 +/- 14.4 years; 62.9% male) were included. Based on lumbar spine DXA, 17.8% had normal BMD, 36.7% were osteopenic, and 45.5% were osteoporotic. CT-derived HU values at both the lumbar spine and femoral neck were significantly lower in patients with reduced BMD and showed a graded decline across worsening DXA categories. HU values demonstrated positive correlations with corresponding T-scores. Diagnostic performance for detecting osteoporosis was fair, with AUCs of 0.700 (sagittal), 0.698 (axial), and 0.751 (femoral). Conclusion: Contrast-enhanced abdominal CT provides useful ancillary information for opportunistic bone health assessment. CT-derived HU values offer a rapid and cost-effective complementary tool but should not replace DXA in the diagnostic evaluation of osteoporosis