Positive contrast ventriculography in cats with experimental obstructive hydrocephalus.

Cerebrospinal fluid pathways were studied in both normal and experimental obstructed hydrocephalic cats by positive contrast ventriculography. Either water soluble or insoluble contrast material was injected into the lateral cerebral ventricles, and radiographs were taken of the head and spinal cord. In the normal cat, the contrast material freely flowed throughout the spinal fluid spaces. The contrast material accumulated in the cisterna magna, and from there extended into the cranial and spinal subarachnoid spaces. In the kaolin-induced hydrocephalic cat, the outlets from the fourth ventricle were obstructed, and direct communication between the ventricular system and the subarachnoid spaces no longer existed. In these cats, the contrast material passed directly down the central canal of spinal cord and its movement was followed throughout the entire length of the canal. At the lower lumbar-sacral regions, the material perforated the cord and flowed into the subarachnoid space. At all levels, the central canal was enlarged and local dilatations were seen extending dorsally.     

A Concord chair for improved contrast ventriculography.

This paper describes the adaptation of the G.E.C. Concord X-ray couch for controlled contrast ventriculography. The addition of a chair fixture and head-fixing device coupled with a suitable radiographic procedure has made contrast ventriculography a fairly simple and sure technique.     

Comparative study ofcomputed tomography and ventriculography with water-soluble contrast media

Summary From material of over 10,000 CTs a comparative study of computed tomography and ventriculography with contrast media was carried out. We examined 18 patients with suspected expansive lesions localized in the 3rd ventricle, aqueduct of Sylvius, and 4th ventricle. We have found that CT is the method of choice in these cases and that ventriculography should be reserved for those cases which have clear clinical indications.     

Exercise radionuclide ejection fraction: correlation with exercise contrast ventriculography.

Thirty-one patients with known or suspected coronary artery disease or aortic valvular disease were studied at rest and during supine bicycle exercise with radionuclide and contrast left ventriculography. The radionuclide ejection fractions calculated independently by three observers correlated well at rest (r = 0.96) and with exercise (r = 0.94). The calculated values also correlated well with those obtained for contrast ventriculography using the area-length method Dodge (r = 0.89 at rest and r = 0.90 with exercise). The results suggest that further clinical applications of exercise radionuclide ventriculography are justified.     

Hemodynamic effects of a new iso-osmotic contrast medium in selective left ventriculography

To evaluate the myocardial hemodynamic effects of a new iso-osmotic contrast agent (Hexabrix 160: H 16) a randomized cross-over study was performed comparing Hexabrix 160 with Sodium Meglumine diatrizoate (Radioselectan 76: R 76) in 20 patients with ischemic heart disease. H 16 produced substantially smaller (p less than 0.001) increases in heart rate (68 +/- 11 to 73 +/- 12) than R 76 (69 +/- 12 to 88 +/- 15) and smaller decreases in left systolic ventricular pressure (131 +/- 15 to 128 +/- mmHg) than R 76 (132 +/- 14 to 94 +/- 15 mmHg). Both contrast media resulted in an increase in contractility beginning three to five seconds after the onset of the injection and reached its maximum at 45 seconds. However the increases in contractility was smaller with H 16 than R 76: H 16 caused a significantly smaller (p less than 0.01) increases in V max. (0.1 CIRC/s) than R 76 (0.35 CIR/s). The hemodynamic effects of H 16 were probably in relation with the Frank-starling mechanism. The lowest variation of preload observed (left ventricle end-diastolic pressure: 12 +/- 4 to 14 +/- 5 mmHg) showed that this contrast medium appeared to behave like isotonic serum. These results suggest that H 16 may preferable for digital left ventriculography.     

Hemodynamic effects of high versus low-osmolar contrast media for ventriculography in severe aortic stenosis

The hemodynamic effects of high-(diatrizoate meglumine/sodium) and low-(iopamidol) osmolar constrast administration for left ventriculography were compared in 15 patients with severe aortic valve stenosis. Patients were similar with respect to aortic valve gradient, aortic valve area, age, body surface area, and baseline hemodynamics as well as associated coronary disease and valvular insufficiency. Administration of diatrizoate meglumine/sodium was associated, with a 22% increase in heart rate, and marked (27%) decrease in left ventricular systolic pressure, with a small (15%) increase in left ventricular end diastolic pressure. In contrast, administration of larger volumes of iopamidol was associated with only a slight (9%) increase in heart rate, a small (6%) decrease in left ventricular systolic pressure, and a smaller (6%) increase in left ventricular end diastolic pressure. In patients with severe aortic valve stenosis iopamidol may offer a safer hemodynamic profile than diatrizoate meglumine/sodium.     

Left ventricular ejection fraction determined with the nuclear stethoscope, gamma camera and contrast ventriculography

Left ventricular ejection fractions (EF) were measured with a nuclear stethoscope (NSt, beat-to-beat and ECG gated summation method) and contrast ventriculography (VG) immediately following one another (IFOA) (r X 0.96 and 0.95, respectively, n = 13). NSt and ECG gated gamma camera (MUGA) recordings IFOA were compared (r = 0.97 and 0.96, respectively, n = 23) as were non-IFOA recordings (r = 0.90 and 0.91, respectively, n = 13). Correlation between repeated NSt EF measurements gave: r = 0.91 (n = 22) for both methods. Paired NSt recordings in an invasive test situation (during invasive angiocardiography) and in a noninvasive situation (supine, 30 min of rest) gave for patients with EF less than 50 (mean +/- S.D.): EF invasive = 36 +/- 12, EF noninvasive = 41 +/- 13 (n = 4, p less than 0.05), and for patients with EF greater than or equal to 50: EF invasive = 59 +/- 7, EF noninvasive = 57 +/- 7 (n = 9, N.S.). The mean paired differences (EF noninvasive -EF invasive) in the low (less than 50) and high (greater than or equal to 50) EF range differed significantly: +5.3 versus -1.3, respectively (p less than 0.001). The recordings with the ECG-gated summation method gave similar results. The heart rate (beats min-1) in the noninvasive and invasive situation were (mean +/- S.D.): 68 +/- 11 and 78 +/- 16, respectively (p less than 0.01). We conclude that the patients were in a higher level of stress in the invasive situation. Accordingly ventricles with normal contractility (EF greater than or equal to 50) reacted with a slight increase in EF, and ventricles with compromised function (EF less than 50) reacted with a decrease in EF, compared to the values in the noninvasive situation. Incorporated in a correlation between MUGA and VG are, besides methodologically based differences, test-situation based systematical differences. Consequently the results of MUGA method should be given uncorrected. The results documents the accuracy and reliability of the NSt.