Interobserver and intraobserver agreement in radiographic diagnosis of osteoporosis

Osteoporosis is a common bone disorder which means paucity of bone particularly of trabecular bone. This leads to increased tendency to fractures and bone pains. The radiological diagnostic workup usually starts from plain x-rays followed by bone mass measurement techniques. To determine the inter- and intra-observer agreement in plain x-ray diagnosis of osteoporosis using a standardized grading system. It was a cross-sectional analytical study conducted from May 2004 to June 2005 at Radiology department Dow University of Health Sciences and Civil Hospital, Karachi and Osteoporosis Diagnostic Clinic Karachi. Plain non digital x-rays of femur of post menopausal females [a group known to be at risk of and clinically suspected with osteoporosis] were independently read by three qualified professionals-two radiologists and a nuclear physician specialized in osteoporosis diagnosis. Standardized radiological grades of osteoporosis [Singh Index] were assigned to plain x-rays of pelvis and femur. Kappa statistics were used to determine inter- and intra-observer agreement by computing k-value. A total of 98 patients were included in the study. All were post menopausal females with age of 59 +/- 6.5 years Kappa [k-] value for inter-observer agreement ranged from 0.21 to 0.44. For intra-observer agreement, it was 0.69 to 0.78. The inter- and intra-observer agreement for diagnosis of osteoporosis on plain x-rays alone is markedly low, necessitating the use of multiple and sensitive techniques rather than plain x-rays alone

Radiographic morphometry of the osteoporotic femur: comparison with densitometry

To determine the accuracy of radiographic morphometry i.e. grading of osteoporosis on plain x-rays of femur [Singh index] compared with bone densitometry by dual energy x-ray absorptiometry [DEXA] in post menopausal females. From May 2004 to June 2005 at Radiology Department, Dow University of Health Sciences [DUHS], and Civil Hospital Karachi [CHK] in collaboration with Osteoporosis Diagnostic Clinic, Karachi. Post menopausal females referred for evaluation of clinically suspected osteoporosis by both plain x-rays and DEXA were included in the study. Those with history of previous trauma or radiation, other systemic disease with bony component, advanced degenerative disease, metastatic disease and bony metallic implants or prosthesis, were excluded. A standardized system of grading skeletal osteoporosis on plain x-rays of femur/pelvis [Singh index grades 1-6] was exercised. Bone mineral density and T-score were determined on DEXA. Sensitivity and specificity of each assessed was determined against the gold standard T-score. There were 98 patients in all with mean age of 59 +/- 6.5 years and mean post menopausal interval of 9.66 +/- 6.52 years. The predominant distribution was, 26.5% in grade 6 and 31% in grade 3. Nineteen had normal T-score [>-1], 49 were osteopenic [T- score between -1.00 and -2.5] and 30 were osteoporotic with T-score below -2.5. For grade 3 and below, the sensitivity and specificity of Singh index [SI] were 55% and 84% respectively. For SI grades 4 and above, the values were 44% and 97% respectively. Singh index or radiographic morphometry grading of osteoporosis is fairly accurate for advanced osteoporosis with high specificity. The sensitivity is low requiring use of bone densitometry for early detection

Situs ambiguous

The case of a female child is described who presented with recurrent respiratory infections and 'recurrent right subphrenic abscess". Detailed radiological work-up identified situs ambiguous abdominis with bronchiectasis, duodenal malrotation, umbilical hernia and spina bifida