Dose reduction in computed tomography by individualized scan protocols.

PURPOSE: To find a method of adjusting the mAs-value in relation to the size of the patient undergoing computed tomography (CT) examination as a means of minimizing the radiation dose to the patient. MATERIAL AND METHODS: A correction factor to be applied on the tube charge for each patient was calculated using two mathematical methods. This approach was tested on 4 Perspex phantoms of different sizes and geometries. Noise was measured in the images with and without use of the correction factors. Retrospectively, correction factors were calculated for 12 CT examinations of the abdomen and the dose reduction was estimated for these patient studies. RESULTS: The variations in noise measured in the images of the different phantoms were dramatically reduced by both methods. The retrospectively performed patient study showed that the largest correction factor was 7 times greater than the smallest, which means that a dose reduction factor of 7 is possible in the extreme case. CONCLUSION: Our proposed methods of adjusting the applied tube charge (mAs-value) in relation to the size of the patient can be used on the vast majority of CT systems. The potential for dose reduction is great, especially for small patients.

Clinical efficacy of budesonide in the treatment of eczematous external otitis.

Sixty patients with mild to moderate forms of eczematous otitis externa were treated with budesonide and placebo in a double-blind controlled study using parallel groups. Each treatment period was preceded by otomicroscopic examination and thorough cleaning of the ear canal. The symptoms and signs were assessed with a score system ranging from 0 (no symptoms/signs) to 3 (severe symptoms/signs). Budesonide treatment was associated with a reduction in severity of all symptoms recorded and a marked improvement in erythema, swelling and discharge. Mechanical cleaning of the ear canal and placebo was not a sufficient treatment for this group of patients.

Acute myopericarditis. A long-term follow-up study.

A follow-up study was made of 29 patients aged 21 to 45 years, some 15-158 months after acute myopericarditis. The mean follow-up period was 72.9 months. The follow-up investigation included recording of history, physical examination, laboratory tests, radiologic examination of the heart and lungs and electrocardiography. All but one of the patients were fit for fulltime work. Nine had residual cardiac symptoms, but the physical examination was negative in all but 2 of them. One patient had chronic cardiac insufficiency and hepatic enlargement. Another had sinus tachycardia and cardiac enlargement of moderate degree and impaired working capacity in relation to heart size. Cardiac murmurs without clinical significance were audible in three cases. The resting ECG was pathologic in only 6 cases. Orthostatic ECG evoked ECG abnormalities in 6 more cases. Exercise tolerance tests showed reduced working capacity in relation to heart volume in 5 of the 29 cases (17%). Four of these 5 patients had cardiac enlargement. There was thus good correlation between increase in heart volume and reduction of physical capacity. The prognosis in regard to cardiac function was good, as was also found in other comparable series in which the observation time was somewhat shorter.