In vivo magnification angiography

Pulmonary angiography and the diagnosis of pulmonary embolism

Pulmonary angiography is the definitive study for the identification of embolism. The development of accurate noninvasive methods for the detection of deep venous thrombosis has altered the indications for angiography. Many angiographic techniques have been developed, providing the opportunity to tailor the angiogram to the clinical situation of individual patients. Strict criteria must be used for interpretation of angiographic studies, and using state of the art equipment will diminish technically unsatisfactory examinations. CT and MR angiography will assume a significantly larger role in the identification of PE in the very near future. MR may become the method of choice, because it is the one noninvasive technique that shows promise for the study of both the deep venous system of the legs and pelvis and the pulmonary circulation.

Quantitation of pulmonary emboli with pulmonary cineangiography: preliminary report

Pulmonary angiography is considered the definite method of diagnosing pulmonary emboli. It is hypothesized that pulmonary cineangiography is superior to conventional pulmonary angiography for quantitation of pulmonary emboli. The present study was undertaken to test the hypothesis. Six patients with an age range from 27 to 70 years with documented pulmonary emboli by pulmonary angiogram, had pulmonary cineangiograms. Pulmonary angiogram defined pulmonary emboli in nine major vessels in the six patients; while, pulmonary cineangiogram revealed another 10 major vessels with pulmonary emboli, which were either not detected or considered equivocal by the conventional pulmonary angiography. The pulmonary embolic score as an index of the extent of pulmonary emboli was 24 (mean 4 +/- 2.52 1SD) by the conventional pulmonary angiography, while the score was 60 (mean 10 +/- 3.22 1SD) by the pulmonary cineangiography, P less than 0.2. Thus, in cases with pulmonary emboli, pulmonary cineangiogram is superior to conventional pulmonary angiogram for the quantitation of pulmonary emboli.

Intrarenal backflow and renal perfusion during increased intrapelvic pressure in excised porcine kidneys

The effect of increased intrapelvic pressure on renal perfusion was examined by simple magnified angiography of freshly excised artificially perfused kidneys of adult Danish Landrace pigs. In all kidneys control angiography was performed at normal intrapelvic pressure (0-5 mmHg). Intrapelvic pressure was raised by retrograde ureteral perfusion of saline in 9 kidneys. Repeat angiography was performed at an intrapelvic pressure of 30-35 mmHg (4 kidneys), 50-55 mmHg (5 kidneys) or 0-5 mmHg (4 kidneys). Angiography demonstrated a delay in arterial filling in kidneys with increased intrapelvic pressure. Perfusate flow measurements showed a corresponding fall in perfusion flow. Retrograde ureteral perfusion was repeated at similar pressures using contrast medium. Intrarenal backflow (IRB) was demonstrated in all 9 kidneys with elevated intrapelvic pressure. IRB localized to 84 per cent of the compound papillae and to 40 per cent of the simple papillae, and was independent of the level of elevated intrapelvic pressure. One-third of the papillae with IRB had absent or markedly decreased arterial filling in the corresponding lobe at angiography. A third retrograde ureteral perfusion was done with a mixture of barium sulphate and gelatin in 4 kidneys. Light microscopy demonstrated that the primary pathway for IRB was canalicular. The contrast medium entered the interstice by three routes: (1) Tubular leakage in the papilla and the corticomedullary region, (2) tears originating in the papilla itself and (3) tears in the calyceal fornix with extension into the parenchyma.

Magnification lymphography

Magnification lymphography was performed on 37 patients, 22 of whom were suffering from bladder carcinoma, and compared with non-magnification lymphograms by two observers independently. The magnification lymphograms were performed on a Siemens Microfocus Bi 125/3/50 RG tube with a 0.1 mm focal spot. In six of the 37 patients (16%) significant extra information was found on the magnification lymphograms compared to the non-magnification lymphograms. In 31 out of 37 patients (84%), the intranodal detail shown was better in the magnification radiographs. Against the additional information gained must be weighed the disadvantages of magnification lymphography which include increased radiation dose, lengthening of procedure time, increased cost and the critical nature of exposure factors. In conclusion, magnification lymphography has a place and the disadvantages seem to be outweighed by the advantages.

Magnification renal arteriography

Magnification selective renal arteriograms were performed on 24 patients, 12 of whom were hypertensive, and compared with non-magnification arteriograms by two observers independently. The magnification angiograms were performed on a Siemens Microfocus Bi 125/3/50 RG tube with a 0.1 mm focal spot. Of the 24 patients examined, information crucial to the diagnosis was found only on the magnification films in three patients (12.5%). Extra information compared with the nonmagnification films was found in the magnification films in 12 patients (50%). No additional information was discovered in the remaining nine patients (37.5%). The magnification angiograms enabled the interlobular vessels to be visualized--this was not possible on the non-magnification films. Against the additional information gained must be weighed the disadvantages of magnification arteriography which include increased radiation dose and lengthening of procedure time plus additional injections of contrast. In conclusion, there is a place for magnification renal arteriography and the advantages seem to outweigh the disadvantages.

Angiography of the spinal cord. A review of contemporary techniques and applications

✓ The authors present a current review of the development, techniques, and applications of angiographic studies of the spinal cord, with special emphasis on selective arteriography.