In this study we examined the delivered activity of radiopharmaceuticals injected into patients and the various factors which lead to incomplete delivery. Four commonly used 99Tcm radiopharmaceuticals were included, namely pertechnetate, methylene diphosphonate (MDP), macro-aggregated albumin (MAA) and tetrofosmin. There was no appreciable residual activity after injection of pertechnetate and MDP other than that due to the dead space in syringes (0.06 ml, 4% of measured activity). However, there was considerable residual activity following an MAA injection. This was particularly dependent on the radiopharmaceutical residence time in the syringe prior to injection. If MAA was pre-dispensed there was up to 80% of activity remaining in the syringe following injection. We have shown that this activity is not bound and can be decreased by agitating the syringe prior to the injection. For tetrofosmin, the activity remaining in the syringe was shown to be mostly due to adsorption of the tetrofosmin onto the plastic syringe (up to 30% of the activity); in particular, onto the rubber plunger. The amount of binding probably depends on the formulation of the rubber plunger and the plastic barrel, which varies between manufacturers. Of the three commonly used syringe brands (Becton-Dickinson, Sherwood, and Braun syringes) the Braun syringes were shown to have the least binding (6%) and would be most suitable for tetrofosmin injection. We recommend the use of Braun syringes for tetrofosmin. We also recommend that pre-dispensed MAA injections should be gently agitated before injection into the patient. No special precautions are necessary for pertechnetate or MDP injections.

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It is unclear whether bile acid absorption is affected by ileoanal pouch construction. Bile acid absorption was measured in the abdomen of 16 patients with pouches (nine with good and seven with poor pouch function based on a clinical score) and in six patients with an end ileostomy using a radiolabelled synthetic bile acid (75SeHCAT) enema and dynamic scintigraphy. The median (interquartile range) 75SeHCAT absorption was 81 (79-87) per cent in patients with ileostomy, 46 (43-53) per cent in patients having well functioning pouches, and 24 (18-38) per cent in the group with poor pouch function (P < 0.01). Log transformation of the absorption curves revealed a two-component uptake (fast component t1/2 = 1.4-7.2 min; slow component t1/2 = 16-144 min) in all patients with ileostomy, in eight of nine patients with pouches with good function, and in one of seven patients with a poorly functioning pouch (P < 0.05); in the other six patients with poorly functioning pouches, only the slow component of absorption was present. This test showed significantly reduced bile acid absorption in patients with an ileoanal pouch and gave an objective discrimination between well and poorly functioning pouches.

A method for predicting postoperative respiratory function following lung resection has been used in 11 patients with both histologically proven bronchial carcinoma and chronic obstructive airways disease, in order to assess their fitness for surgical treatment. Quantitative ventilation and perfusion scintigrams were used to measure the amount of functioning tissue in each lung. These data were used in conjunction with spirometric measurements to calculate the likely functional effect of pneumonectomy. There was a high degree of correlation (r) between predicted and measured lung function for both FEV1 (r = 0.75, P less than 0.01) and FVC (r = 0.88, P less than 0.01). The postoperative FEV1 was within 150 ml of the predicted value in 45% of the patients. In the remaining patients the actual volumes were greater than predicted by 210-540 ml. For FVC the results were within 150 ml of predicted in 45% of patients and in the remainder actual volumes were greater by 160-650 ml. Both sets of calculations underestimated lung volumes by an average of 200 ml. The method is shown to be accurate, simple, non-invasive, and readily available and brings a degree of objectivity to an important decision that is often based mainly on clinical assessment.

This work is concerned with the cleaning and disinfection by heat of stainless-steel and polypropylene bedpans, which had been soiled with either a biological contaminant, human serum albumin (HSA) labelled with technetium-99m 99m(Tc), or a bacteriological contaminant, streptococcus faecalis mixed with Tc-labelled HSA. Results of cleaning and disinfection achieved with a Test Machine and those achieved by procedures adopted in eight different wards of a general hospital are reported. Bedpan washers installed in wards were found to be less efficient than the Test Machine, at least partly because of inadequate maintenance. Stainless-steel and polypropylene bedpans gave essentially the same results.