Body disappearance and liver mean transit time of 99m-Tc-diethyl-IDA.

The body disappearances and the liver mean transit times of a hepatobiliary tracer, 99mTc-diethyl IDA, were measured from 100 cholescintigraphies of 98 patients. Fifteen patients had no hepatobiliary disease; their mean body disappearance was 6.6, SD 1.1%/min, and mean liver mean transit time 32, SD 19 min. The values within 2 SDs, disappearance greater than or equal to 4.4%/min and mean transit time less than or equal to 70 min, were used as reference values. Disappearance constants below 4.4%/min were observed 29% and mean transit times exceeding 70 min in 49% of the examinations performed on patients with some hepatobiliary abnormality. The calculated parameters were compared with the levels of serum bilirubin and ASAT. Disappearance constants below 4.4%/min were seen in 33% and mean transit times exceeding 70 min in 55% of the patients who had either abnormal serum bilirubin or ASAT due to a hepatobiliary disease. The correlation between the serum bilirubin and the disappearance was -0.13, and between ASAT and body disappearance it was -0.28. The corresponding correlation coefficients of serum bilirubin and ASAT with the liver mean transit times were 0.33 and 0.44. Long mean transit times in relation to bilirubin and ASAT were seen in some acute cases. Short mean transit times in relation to bilirubin and ASAT were seen with falling serum levels of the latter.

A gamma camera method for quantitation of split renal function in children followed for vesicoureteric reflux.

A method for quantitative estimation of split renal function using a computerized gamma camera system is described. 42 children and adolescents with existing or preexisting vesicoureteric reflux and recurrent urinary tract infection were investigated. Total renal clearance of DTPA was calculated with a disappearance curve derived from the largest extrarenal area in the field of view of a gamma camera with diverging collimator. Split renal function was estimated with the slopes of second phase renograms. The plasma disappearance clearance of DTPA, calculated using one compartment model with two late blood samples, gave similar results with the clearance estimated from the body disappearance curves. The proportional planimetric renal parenchymal areas had good correlation with the split clearance estimated from renogram slopes. The method offers data on renal function and urinary tract dynamics which is very valuable in the follow-up of children with recurrent urinary tract infection and vesicoureteric reflux.

The effect of bronchography on pulmonary ventilation.

Using a gamma camera and the Xenon-133 washout method the reduction in lung function during unilateral bronchography was assessed in eleven patients. A considerable reduction in the washout rate was observed in the lung examined with bronchography both absolutely and compared with the opposite lung. Some improvement occurred after coughing out the contrast medium. It is concluded that the ventilatory function of the lungs is considerably impaired during bronchography and this should be borne in mind when referring patients with reduced lung function for this examination.

Enhancement of abnormality in gamma images using Kohonen filters.

A new method of processing digital images consists of a numerical filter which suppresses normal features producing an enhancement of the abnormality. The resulting filtered image aids the observer in the recognition of the abnormality. The filter is developed from verified normal images in the computer memory. The enhancement of pathologic accumulations with respect to surrounding activity was improved on the average by a factor of 2.6 for 13 lateral brain images.

Reduction of motion unsharpness in coronary angiography using rare-earth oxysulfide intensifying screens and green-sensitive X-ray film.

During cardiac cycle the coronary arteries move rapidly; the maximum velocity can exceed 400 mm/s. To eliminate the motion unsharpness, exposure times under ten milliseconds are necessary. Using new rare-earth oxysulfide intensifying screens and fast green sensitive X-ray film the exposure times can be reduced to as little as 2 milliseconds. Thus the motion unsharpness can be almost completely eliminated, producing enhanced resolution and better diagnostic accuracy.

Vena cava umbrella filter: experimental, hemodynamic and embolization studies.

The Mobin-Uddin umbrella filter was placed into the inferior vena cava of mongrel dogs. Studies on hemodynamics and embolization were performed using blood flow and pressure determinations, cineangiography, and radiopaque emboli. Initially flow and pressure remained unaffected by the filter. At 70 minutes flow was only one fourth of the initial IVC flow. Immediately after positioning of the filter emboli up to 6 mm in diameter bypassed the filter, and smaller emboli passed through the perforations in the filter. Thrombus formation on the surface of the umbrella was already noted within one hour. At autopsy after two hours all the perforations were occluded by thrombus on both sides of the filter, and one week later the infrarenal vena cava was completely occluded by firm organized thrombus below and above the filter.

Regional renal blood flow in hypertensive patients.

Renal blood flow measurements in three regions of each kidney were carried out in eighteen hypertensive patients using the radioactive Xenon-133 washout technique in conjunction with renal angiography. It was found that the regional differences were generally small but differences existed in four patients significant in spite of normal angiographic findings. The reduction in blood flow in the two kidneys was generally of the same degree which implies a uniform response to the elevated blood pressure.

[The radiological diagnosis of uterine myomas (author's transl)]. / Zur Röntgendiagnose des Uterusmyoms

From the above it will be seen that radiological examination in general is valuable in the diagnosis of uterine myomas; if the disease is advanced, then radiological diagnosis provides no difficulties. The preoperative radiological diagnosis of uterine myomas is particularly indicated in the following situations: 1. Suspicion of a submucous myoma, particularly if there may have been bleeding. 2. If accurate elucidation of the anatomy in the myomatous uterus is desirable pre-operatively, as for instance in cases of sterility when a conservative operation, such as enucliation may be planned. 3. For the differentiation between ovarian and uterine tumours when a tumour has been found in the pelvis.