The mCSA was a strong predictor of the preoperative walking ability, leg and back pain, and was directly related to the quality of life of patients with central spinal stenosis.

In diagnostic radiology, medical-grade monochrome displays are usually recommended because of their higher luminance. Standard color displays can be used as a less expensive alternative, but have a lower luminance. The aim of the present study was to compare image quality for these two types of displays. Images of a CDRAD contrast-detail phantom were read by four radiologists using a 2-megapixel (MP) color display (143 cd/m 2 maximum luminance) as well as 2-MP (295 cd/m 2 ) and 3-MP monochrome displays. Thirty lumbar spine radiographs were also read by four radiologists using the color and the 2-MP monochrome display in a visual grading analysis (VGA). Very small differences were found between the displays when reading the CDRAD images. The VGA scores were j0.28 for the color and j0.25 for the monochrome display (p=0.24; NS). It thus seems possible to use color displays in diagnostic radiology provided that grayscale adjustment is used.

A new ultrasound technique for measuring skin thickness in 40 patients with progressive systemic sclerosis (scleroderma) and in 10 healthy control subjects has been evaluated. High frequency (10 MHz) dynamic ultrasound examination was performed at the proximal and middle phalanges of both second fingers. Measurements of the control subjects on two separate occasions demonstrated a good reproducibility of the technique with a standard deviation of 0.06 mm. The skin was thicker in patients with scleroderma 3.3 +/- 0.7 mm (mean +/- SD) compared with control subjects 2.5 +/- 0.2 mm (p less than 0.001). No relation between skin thickness and duration of disease was observed. This method can be used to monitor changes in skin thickness over time.

A review was made of 168 ultrasound guided fine needle biopsies on 145 patients. Fifty-seven biopsies were from the pancreas, 40 biopsies from the liver, 28 from the kidney, 26 from the abdomen and 17 from the retroperitoneum. The total accuracy rate was 66 per cent varying from 50 per cent in abdominal lesions to 83 per cent in hepatic lesions. The differences of the results are discussed as are the indications and the role of ultrasound guided fine needle puncture compared with other modalities.

Fourteen consecutive children with symptoms of transient synovitis of the hip were examined with sonography regarding intracapsular effusion, with scintimetry regarding blood-flow in the proximal femoral epiphysis (PFE) and with intracapsular pressure recording and aspiration. All patients had an intracapsular effusion. Intracapsular pressure was found to depend on the position of the hip. The mean pressure with hips in extension and inward rotation was 22.6 kPa (170 mm Hg) whereas in 45 degrees of flexion it was 2.3 kPa. In two cases scintimetry demonstrated reduced blood flow to the PFE; after aspiration, isotope uptake returned to normal, indicating that increased intracapsular pressure has a harmful effect on circulation to the PFE. Children with transient synovitis should be treated with the hips in 45 degrees of flexion to reduce intracapsular pressure. Forcing the hip in extension causes a risk of ischaemia of the PFE.

In a prospective study during 1981-1983 42 boys aged 3-12 (mean 6.5) years were operated on for a palpable undescended testis. Twelve boys 3-8 (mean 4) years old were operated on for an unpalpable testis and 2 boys for an ectopic testis. The day before operation an ultrasound examination was performed. Reoperations were made on 11 patients and a bilateral operation on 2. In total, 69 ultrasound examinations were made. Comparison of the position at operation and ultrasound showed accordance in 47 of the 55 cases with only a slight variation of the position in 8 cases. Of the 12 non-palpated testes the ultrasonography showed 4 testicles, 3 non-testis-like formations and no finding in 5 cases. Exploration of these 5 latter cases showed an aplasia testis in 4 and a small intraabdominal testis in 1 boy. Preoperative ultrasonography can be recommended in case of an unpalpable testis in a boy not previously operated on in the inguinal area. Ultrasonography is particularly valuable before reaching a decision on hormonal therapy.

In order to improve the basis for ultrasonographic studies of portal hypertension the normal diameters and respiratory variations in the portal vessels were measured in sixty-seven volunteers. In healthy subjects, measurements were made on the portal vein and its major tributaries. The respiratory variations were most prominent in the splenic vein, somewhat less in the superior mesenteric vein and least in the portal vein. There were no significant correlations to weight, age or height. The hypothesis that examinations performed after food intake would give more prominent respiratory variations had to be rejected but showed that the portal vein should be examined under defined conditions regarding alimentary status. The diameters alone of the portal vessels can probably not be used reliably as an indicator of portal hypertension while a respiratory variation of less than 30 per cent in the splenic vein should be considered pathologic and lead to further investigations.

For preoperative localization of enlarged parathyroid glands, several imaging techniques have been used. In this study we demonstrate the feasibility of using ultrasonography with fine needle aspiration for parathyroid hormone assay as a preoperative localization procedure in 21 patients with primary hyperparathyroidism. A single adenoma was found in 18 patients while 3 patients had multiglandular disease. Ultrasonically guided fine needle biopsy was possible in 11 cases. In 8 of these aspirates, a high parathyroid hormone content was found. In all 8 cases the localization was confirmed at surgery. We conclude that the efficiency to preoperatively localize enlarged parathyroid glands is enhanced by fine needle aspiration.