National audit of the sensitivity of double-contrast barium enema for colorectal carcinoma, using control charts For the Royal College of Radiologists Clinical Radiology Audit Sub-Committee.

AIM: To audit the sensitivity of double-contrast barium enema (DCBE) for colorectal carcinoma, as currently practised in UK departments of radiology. METHODS: As part of its programme of national audits, the Royal College of Radiologists Clinical Radiology Audit Sub-Committee undertook a retrospective audit of the sensitivity of DCBE for colorectal carcinoma during 2002. The following targets were set: demonstration of a lesion > or =95%; correct identification as a carcinoma > or =90%. RESULTS: Across the UK, 131 departments took part in the audit, involving 5454 examinations. The mean demonstration rate was 92.9% and the diagnosis rate was 85.9%, slightly below the targets set. The equivocal rate (lesion demonstrated, but not defined as malignant) was 6.9%, the perception failure rate was 2.8% and the technical failure rate was 4.4%. Control-chart methodology was used to analyze the data and to identify any departments whose performance was consistent with special-cause variation. CONCLUSION: When compared with the diagnosis rate (84.6%) and demonstration rate (92.7%) reported in the Wessex Audit 1995, [Thomas RD, Fairhurst JJ, Frost RA. Wessex regional audit: barium enema in colo-rectal carcinoma. Clin Radiol 1995;50:647-50.] a similar level of performance was observed in the NHS today, implying that the basic process for undertaking and reporting DCBE has remained relatively unchanged over the last few years. Improvement in the future will require fundamental changes to the process of reporting DCBE, in order to minimize the perception failure rate and accurately to describe lesions, so reducing the equivocal rate. Control-chart methodology has a useful role in identifying strategies to deliver continual improvement.

Bone marrow scintigraphy in the diagnosis of post-traumatic avascular necrosis of bone.

A series of 19 patients, who were clinically suspected of developing avascular necrosis of bone following fracture, were entered into a pilot study comparing the use of bone marrow scintigraphy with conventional skeletal scintigraphy. Two-phase bone scintigraphy, using 600 MBq of 99Tcm-HMDP, and perfusion and late-phase nanocolloid scintigraphy, using 370 MBq of 99Tcm-nanocolloid, were performed on each patient. In both methods, photon deficiency at the site of interest was taken to indicate avascularity. The perfusion phase of both methods was found to be unhelpful. Agreement between methods was obtained in 18 patients (95%). Six patients had abnormal nanocolloid scans, one of which was normal on the conventional bone scintigram. The remaining 13 patients had no evidence to suggest avascularity in either method. Three of the patients with abnormal scans have had hip replacement surgery following which avascularity of the femoral head was confirmed. 99Tcm-nanocolloid scintigraphy is thus shown to be a very sensitive method of demonstrating avascularity of bone following trauma.

Bone scintigraphy and radiography in the early recognition of diabetic osteopathy.

Twenty-seven diabetic patients with clinical evidence of neuropathy were investigated by foot radiography, two-phase bone scintigraphy, biothesiometry and cardiovascular autonomic function testing. Typical signs of diabetic osteopathy on radiography were found in 10 subjects (37%), the degree of radiographic abnormality correlating with the severity of neurological impairment. Furthermore, all diabetics with evidence of severe neuropathy showed some evidence of osteopathy on foot radiographs. In all 10 cases of diabetic osteopathy diagnosed radiographically, abnormalities were shown on scintigraphy. In addition, five other patients showed scintigraphic abnormalities, without corresponding changes on radiography, and in this group the neurological impairment was less severe. Although confirmatory longitudinal studies are necessary, it seems likely that the earliest changes of diabetic neuropathic osteopathy may thus be recognized on bone scintigraphy, at a time when conventional radiographs are normal. This stage of diabetic osteopathy is associated with a lesser degree of neurological impairment.