Kirsten R Carlaw,Mark Moussad,
Detecting Perirenal Haematoma in Renal Transplants with Contrast Enhanced Ultrasound: A Systematic Review
Radiology and Medical Diagnostic Imaging
2024
2613-7836
http://dx.doi.org/10.31487/j.RDI.2024.01.01
https://www.sciencerepository.org/detecting-perirenal-haematoma-in-renal_RDI-2024-1-101 
Abstract: Background: Routine B mode ultrasound (B-US) is the current standard for early postoperative assessment of the transplanted kidney but has limited efficacy at detecting and assessing perirenal haematomas (PH), especially overtime. We aim to investigate the diagnostic accuracy of contrast enhanced ultrasound (CE-US) in detecting and assessing PH in kidney transplants. 
Method: Articles were identified using the EMBASE, Medline, Cochrane and Scopus databases. CE-US findings were compared to B-US and biopsy in some instances. CE-US parameters investigated included arrival time of contrast medium and echogenicity/intensity. 
Results: 2,146 studies were screened of which 4 observational studies were included. Grzelak et al. 2013 was the only study that reported on the accuracy of both CE-US (33.3%) and B-US in initially detecting the presence of PH (15.7%). Grzelak et al. 2013 reported a significant increase in mean signal intensity of CE-US (- 31.44.4 dB) compared to B-US (-5.7 3.2 dB) when observing the difference in echogenicity between PH and kidney parenchyma (p <0.001). Similarly, Grzelak et al. 2012, a statistical difference in mean echogenicity between B-US (-5 3.2 dB) and CE-US (-31.0 4.4 dB) with p value <0.001. Fischer et al. 2005, reported an increase in mean intensity in the main renal artery of PH group with CE-US by 15.3 6.3 dB, and an increase in mean intensity if the renal cortex by 9.2 3.9 dB. Fischer et al. 2006, demonstrated an increase in mean intensity in the main renal artery of PH group with CE-US by 15.9 6.0 dB and the interlobar artery by 15.9 4.3 dB, and an increase in mean intensity if the renal cortex by 9.5 3.6 dB. Grzelak et al. 2013 reported the range of PH size as 4-33 mm in B-US vs 7-44 mm with CE-US. Similarly, Grzelak et al. 2012 reported the range of PH as 4-30 mm in B-US compared to 7-38 mm in CE-US. Fischer et al. 2005 and 2006 noted that in 3/6 and 5/7 patients respectively CE-US clearly improved delineation and volume determination of PH.
Conclusion: CE-US can be a method for detection and assessment of PH size, however further studies are required to support CE-US as a superior imaging technique to B-US in evaluating PH.Keywords: Renal transplant, contrast-enhanced ultrasound, perirenal haematoma, B-mode ultrasound