Skill mix and role extension initiatives have highlighted the difficulty of establishing quality standards for the accuracy of plain film reporting. An acceptable performance might be one which is indistinguishable from that of a group of experienced consultant radiologists. In order to assess the feasibility of setting such a standard, the variation between experienced observers must first be established. This study examines the variation found between three observers with the three major types of plain film examination. 402 plain film examinations (205 skeletal, 100 chest and 97 abdominal) performed on accident and emergency patients were reported retrospectively and independently by three experienced radiologists. The clinical data supplied on the request cards were available to the readers. Each examination was categorized by each reader as being normal, as showing significant abnormality relevant to the current clinical problem, or as showing insignificant or irrelevant abnormality. Concordance between all three readers was found in 51%, 61% and 74% of abdominal, chest and skeletal radiographs, respectively. Weighted kappa values confirmed that the level of agreement between pairs of observers was higher with skeletal radiographs (kappa w = 0.76-0.77) than with chest (kappa w = 0.63-0.68), or abdominal (kappa w = 0.50-0.78) examinations. However, the frequency of major disagreements (at least one reader reporting "normal" and one reporting "relevant abnormality") was similar for abdominal (11%), chest (12%) and skeletal (10%) radiographs. When the reports were reclassified into only two groups--either significantly abnormal or not--pairs of observers disagreed on 9-10% of skeletal, 11-19% of chest and 8-18% of abdominal cases. The average incidence of errors per observer was estimated to be in the range 3-6%. The magnitude of interobserver variation in plain film reporting is considerable, and must be taken into account when designing assessment techniques and setting quality standards for this activity.

A case of vilious adenoma of the common hepatic duct causing obstructive jaundice, where the diagnosis was made by ultrasound guided percutaneous biopsy is reported. At surgery ultrasonography was used to define the extent and operability of the tumour.

No abstract

Five cases of septic sacroiliitis diagnosed by magnetic resonance imaging (MRI) are presented. Imaging was performed between 2 and 14 days after onset of symptoms and consisted of varying combinations of coronal short tau inversion recovery (STIR), axial T2-weighted spin echo (SE), and coronal and axial pre- and postcontrast T1-weighted SE scans. Abnormalities included demonstration of sacroiliac joint effusions, bone oedema and adjacent inflammation as high signal on STIR and T2-weighted SE scans, and identification of abscesses in two cases as rim-enhancing lesions anterior to the joint on gadolinium-enhanced T1-weighted SE scans. The role of MRI and other forms of imaging in septic sacroiliitis is discussed.

The os subtibiale is a rare, genuine accessory bone and normal variant related to the posterior colliculus of the medial malleolus. Only one example was found in the radiographs of the ankles of 700 patients examined. It can be differentiated from other ossicles in this region by its relatively large size, its rounded and well-defined shape, and its posterior position. Ossicles related to the anterior colliculus, which forms the tip of the malleolus, are smaller and were present in 15 ankles (2.1%). These may represent unfused secondary ossification centres. Post-traumatic ossification is the probable explanation for the small, angular and less well-defined ossified elements encountered. The overall incidence of ossification in the subtibial region in the 700 ankles studied was 4.6%.