ABSTRACT
Objective To evaluate the sensitivity and specificity of plain radiography in the diagnosis of vascular calcification in maintenance hemodialysis (MHD) patients. Methods Multi-slice computed tomography (MSCT) was used as the reference standard in the assessment of vascular calcification in MHD patients. A total of 54 MHD patients, 26 male and 28 female, mean age (60.4±13.3) years, underwent both MSCT and plain radiography of lateral abdomen and pelvis to evaluate abdominal aortic calcification, bilateral iliac and femoral artery calcification. Abdominal aorta was divided into upper and lower segment by L2-L3 intervertebral space. The severity of vascular calcification by MSCT was graded from score 0 to 5. Two independent radiologists analyzed the results of plain radiography and MSCT, and inter-observer agreements were calculated by using K statistics. Results According to the results of MSCT, the calcification rate of abdominal aorta was 86.1%, and the calcification rate of iliac and femoral artery was 74.5%. There was significant difference of the calcification rate between large artery and muscular arteries. Inter-observer agreement of calcification was excellent (K =0.864-0.893). Compared with MSCT, the specificity of plain radiography with regard to detection of abdominal aortic, iliac and femoral calcification were 100%. The sensitivity of plain radiography was different according to the different MSCT score, which was as follows: MSCT score ≥ grade 1: 60.2% and 24.8% for lateral abdomen radiography to detect abdominal aortic calcification and pelvic radiography to detect iliac, femoral calcification respectively; MSCT score ≥ grade 2: 76.9% and 43.5% respectively; MSCT score grade 3: 100% and 74.4% respectively. Conclusions The sensitivity of plain radiography in the assessment of vascular calcification increases with the severity of calcification. The sensitivity in the assessment of abdominal aortic calcification is higher than that of iliac and femoral artery calcification. Plain radiography can be used to detect moderate to severe vascular calcification in MHD patients.