Dynamic CT in the evaluation of physiologic status of renal transplants

A clinical application of iodine quantitation using digital fluorography

A preliminary clinical study of 20 patients is described in which a method of iodine quantitation in vitro using digital fluoroscopy was applied to the intravenous urogram. It was possible to quantitate iodine levels, in terms of mass thickness, in both the renal parenchyma and collecting system in 38 of 40 kidneys studied (20 patients). In the two kidneys on which measurements could not be made, the cause of failure was subtraction artefact due to movement of bowel gas, compounded in one case by poor renal opacification. The variations of iodine mass thickness against time were plotted and their forms were similar to dynamic computed tomography and magnetic resonance imaging studies of transplanted kidneys. Potential clinical applications of this method, in particular the functional assessment of the dilated upper urinary tract, are suggested based on its ability to offer quantitative information in addition to anatomical images.

Radionuclide evaluation of renal transplants

In this review article, the following topics are treated: the radiopharmaceuticals 99mTc-diethylenetriaminepentaacetic acid (DTPA), 131I-orthoiodohippurate (OIH), 99mTc-mercaptoacetyltriglycine (MAG3), 67Ga-citrate, radioiodinated fibrinogen, 99mTc-sulfur colloid, 111In-labelled white cells and platelets; gamma camera methods based on images, on first pass and on tubular transit; blood clearance methods; and the diagnosis of surgical complications, acute rejection (AR), acute tubular necrosis (ATN), chronic rejection (CR), and cyclosporine-A (CYA) toxicity.

Duplex ultrasound in the assessment of renal transplant complications

Duplex ultrasound was performed on 21 patients with renal transplants to assess the feasibility of detection of complications and, in particular, acute rejection and vascular abnormalities. A comparison of the results of Doppler waveform analysis in the transplant renal artery and morphological features on real time scanning in the detection and follow up of acute rejection was made. It was noted that there were characteristic alterations of Doppler shift spectral pattern in acute rejection, and these characteristics were more accurate, appeared earlier and showed a more consistent response to anti-rejection treatment than morphological changes demonstrated by real time ultrasound. Three patients had vascular abnormalities correctly predicted by duplex ultrasound and confirmed by angiography. These findings suggest that duplex ultrasound should be the investigation of choice in the initial assessment and follow up of renal transplant.

Diagnosis of disease in renal allografts: correlation between ultrasound and histology

Ultrasound was compared with histology in 66 cases to assess the accuracy of sonography in demonstrating abnormality in renal allografts. Patients with suspected acute, chronic or acute and chronic rejection, acute tubular necrosis and glomerulonephritis in the transplant kidney were included in the study. It was noted in this trial that ultrasound is less accurate at demonstrating abnormality in the grafted kidney than has been suggested previously in the literature. It was concluded that, where doubt exists, even when ultrasound examination is normal, biopsy should be considered.