Indium-111-labeled white blood cell scanning is often used in the investigation of pyrexia of unknown origin (PUO) to locate an otherwise occult source of sepsis. From a series of 166 white blood cell studies performed for sepsis, 28 cases of true PUO were identified and reviewed. The sensitivity was 60% and specificity 70%, with a positive predictive value of 38% and negative predictive value of 90%. Only 11% of studies revealed a pyogenic cause for PUO. These results are discussed and the potential role of gallium scanning in PUO is raised.

SUMMARY Oesophageal motor responses to intraluminal distension were studied manometrically in 16 healthy volunteers and in nine patients with disordered swallowing, who had prolonged oesophageal clearance without structural abnormality. In the normal subjects distension was associated with an increased number of secondary contractions above the balloon, decrease of all contractile activity below the balloon and was accompanied by an aborally propulsive force which occurred independently of the perception of discomfort. Cholinergic blockade abolished the proximal distension induced contractile response, but did not affect primary peristalsis. Despite normal sensory thresholds, proximal excitatory responses to distension were absent in six and distal inhibition was absent in seven patients. These results show that the normal human oesophagus responds to distension with a proximal enhancement of propulsive motor activity, mediated through a cholinergic pathway. This may be defective in some patients with disordered oesophageal transit. Investigation of the motor responses to intraluminal distension may thus be a useful adjunct to standard manometry for studying patients with suspected oesophageal clearance dysfunction and might allow identification of disordered enteric nervous control.

The unreliability of radiological examination in excluding or confirming a suspected scaphoid fracture after carpal trauma is a well-recognised diagnostic problem. This paper explores the role of isotope bone imaging (IBI) in the early identification of carpal bone injury. Abnormal generalized uptake of activity may be seen within the carpus, possibly as a consequence of diffuse soft tissue injury, particularly if imaging is performed within 48 hours of trauma. A focal area of increased uptake related to one carpal bone is suggestive of fracture though the part which ligamentous injury, localized periosteal reaction or incomplete cortical infarction may play in the production of such radionuclide appearances is uncertain. Ninety-nine patients with suspected recent scaphoid fracture but no demonstrable abnormality on radiological examination were subjected to IBI, using 555 MBq (15 mCi) of 99Tcm methylene diphosphonate. Abnormal focal increased uptake (AFIU) was found in 47 patients, this being localized to the scaphoid bone in 26. Of these 47 cases, 19 (42%) showed subsequent radiological evidence of fracture. The results of IBI, in our experience, can only be reliably interpreted if imaging is performed at least 48 hours after injury, though in cases of fracture AFIU may persist for several years. Using this technique, the possibility of fracture can be confidently excluded in that group of patients who show no AFIU. In selected cases of carpal trauma, IBI provides a satisfactory alternative means of identifying the presence and site of localized injury within the carpus and may be used to confidently exclude those patients with non-osseous symptomatology.

A serial study on 32 patients with bone metastases following cancer of the breast or prostate was performed over three years. Up to ten sets of images (average of four) per patient were obtained during this period using 99Tcm methylene diphosphonate as the radiopharmaceutical. Ninety-three paired serial images of individual lesions were qualitatively assessed for change by three physicians in nuclear medicine and the results were compared with the quantitative results from computer analysis. The reproducibility of the quantitative approach was determined by the analysis of 20 paired lesions by three physicists. It was found that quantitative changes in uptake of less than 20% between images were generally not detected by the medical observers; a change of 41% had only a 95% probability of being identified as change by the physicians. Although much more reproducible in determining changes in individual lesions, the quantitative approach was found to be inferior to the qualitative assessment of overall change in the majority of cases which involve multiple lesions. The basic assumption that uptake varies proportionally with progression of the bone lesion is discussed an is considered in some instances to be untenable. The conclusion is drawn that the determination of progression from changes of uptake in longstanding lesions is uncertain and is subsidiary in importance to the detection of new lesions.

No abstract