Evaluation of gray scale sonography and Doppler sonography findings in patients with renal transplant rejection

This study was conducted to compare the sonographic (gray scale) findings with those of Doppler sonography in patients with rejection of kidney transplant. This was a cross-sectional study performed in Hasheminejhad Educational and Therapeutic Center in Tehran. Sonography and then Doppler sonography were performed and primary creatinin level and if needed sequential creatinin levels, were checked. We used a scanner (AU4 mod) with 3.5 and 7.5 MHz probes. The most common morphologic signs in sonography were increased antro-posterior diameter of allografts in 19 cases (31.4%). Other common morphologic signs consisted of increased cortical echogenicity in 18cases (30%), increased prominanance of the renal pyramid or hypoechogenicity of pyramid in 12 cases (20%), decreased echogenicity of rejected kidney sinus in 7cases (11/7%). The rarest morphologic sign was focal cortical hypoechogenicity in 2cases (3/4%). Thirty one patients (51.7%) had positive sonographic findings, 47 patients (78/3%) had Resistive Index (RI) ≥0.8 and 13 patients (21/7%) had Resistive Index≥0.9. Those with age range of 51-65 years had the highest frequency among all the patients and revealed positive findings in both methods of sonography. In 23.4% of the patients creatinin level was normal. 46 patients (76.6%) had early and fourteen other patients had late onset rejection of the transplant. Doppler sonography (RI) is the best and most sensitive non invasive method for precise and early diagnosis of renal allograft rejection. RI≥.0.8 has eliminated need of taking biopsy. Findings of sonography were less sensitive than those of Doppler sonography.