**8. Donors' evaluation**

The number of people waiting for transplantation using cadaveric organs is usually very expressive, worldwide. Therefore kidney transplantation from living donors is becoming more and more frequent. Living donor kidney recipients have a significant increase in graft survival compared to deceased donor recipients. A living donor transplant has the advantage not to require a waiting list and can be performed in a preemptive manner (before the beginning of dialysis treatment). There is also evidence that patients who receive a preemptive transplant have a longer graft survival than patients who remain on dialysis before the transplant. In the past, only genetically related individuals were considered to be potential donors; however, the use of unrelated kidney donors is increasing and the recipients of these kidneys have a better graft survival than recipients of deceased kidney donors [97, 98].

The systematic evaluation of a living donor includes socioeconomic and psychological assessment, medical history and physical examination complemented with laboratory tests

The evaluation of renal anatomy, mainly the vascular details of a living organ, is absolutely crucial, before removing it, surgically [18]. When living donors are considered, possible aortic and/or renal arterial, venous anatomical variants and/or congenital malformations are key factors to decide if a relative could be a potential donor, and moreover, which kidney will be removed, left or right. In addition, a detailed evaluation of collecting system and ureters may

In the past, to obtain all the information required, urologist and nephrologists used to order at least 3 exams: 1- Intravenous urography (IVU) for evaluation of collecting system; 2- voiding cystourethrogram to detect a silent vesicoureteral reflux and its consequences to the kidneys and; 3- abdominal angiography to evaluate aorta and renal arteries. Nowadays, although there is a considerable variation of protocols for potential donors, all this information can be derived from only one technique, multidetector CT (MDCT). The fast scanners recently available allow timing-specific images, in other words it's possible to obtain early images, in the arterial phase, to depict arterial anatomy in detail and, later on, do another scanning during venous phase and later on, on excretory phase to depict pelvicaliceal system and ureters [15]. MDCT is reported to be as accurate as DSA for detecting supranummerary and polar arteries, as well as venous anatomical variations as circumaortic veins, double veins and so on. Some authors, in order to reduce ionizing radiation dose, suggest that the last (excretory) phase, could be replaced by a abdominal plain film, taking advantage of the contrast media in the collecting

Voiding cystourethrogram (VCU) was commonly used for evaluating of living donors, however, several studies have shown that no clinically relevant information is provided for this examination in the great majority of cases. So, VCU is no longer used in most of individuals

, Elen Almeida Romão2

, Mery Kato4

,

Imaging in Kidney Transplantation http://dx.doi.org/10.5772/55074 51

,

and imaging exams.

be obtained and may abbreviate decisions [82].

system and bladder, simulating an late film in IVU (Figure 22).

, Sara Reis Teixeira1

of Medicine of Ribeirao Preto, Ribeirao Preto – SP, Brazil

, Murilo Ferreira de Andrade3

1 Department of Internal Medicine, Division of Radiology, University of Sao Paulo, Faculty

2 Division of Nephrology, University of Sao Paulo, Faculty of Medicine of Ribeirao Preto,

3 Division of Urology, University of Sao Paulo, Faculty of Medicine of Ribeirao Preto,

4 Section of Nuclear Medicine, University of Sao Paulo, Faculty of Medicine of Ribeirao

and Silvio Tucci Jr3

who are candidates for kidney donation [83].

**Author details**

Valdair Francisco Muglia1

Marcelo Ferreira Cassini3

Maria Estela Papini Nardin1

Ribeirao Preto – SP, Brazil

Ribeirao Preto – SP, Brazil

Preto, Ribeirao Preto – SP, Brazil

The organ donor candidate must be an adult with the ability to decide, should have an affective relationship with the recipient and be free from coercion. He should be healthy from both a medical and psychic viewpoint and should be informed about the risks and benefits of donation [99].

**Figure 22.** Split-bolus CT-Urography with MIP reconstruction allows evaluation of pelvicaliceal system and ureters fully distended, as well as renal parenchyma, in a potential kidney-donor.

The systematic evaluation of a living donor includes socioeconomic and psychological assessment, medical history and physical examination complemented with laboratory tests and imaging exams.

The evaluation of renal anatomy, mainly the vascular details of a living organ, is absolutely crucial, before removing it, surgically [18]. When living donors are considered, possible aortic and/or renal arterial, venous anatomical variants and/or congenital malformations are key factors to decide if a relative could be a potential donor, and moreover, which kidney will be removed, left or right. In addition, a detailed evaluation of collecting system and ureters may be obtained and may abbreviate decisions [82].

In the past, to obtain all the information required, urologist and nephrologists used to order at least 3 exams: 1- Intravenous urography (IVU) for evaluation of collecting system; 2- voiding cystourethrogram to detect a silent vesicoureteral reflux and its consequences to the kidneys and; 3- abdominal angiography to evaluate aorta and renal arteries. Nowadays, although there is a considerable variation of protocols for potential donors, all this information can be derived from only one technique, multidetector CT (MDCT). The fast scanners recently available allow timing-specific images, in other words it's possible to obtain early images, in the arterial phase, to depict arterial anatomy in detail and, later on, do another scanning during venous phase and later on, on excretory phase to depict pelvicaliceal system and ureters [15]. MDCT is reported to be as accurate as DSA for detecting supranummerary and polar arteries, as well as venous anatomical variations as circumaortic veins, double veins and so on. Some authors, in order to reduce ionizing radiation dose, suggest that the last (excretory) phase, could be replaced by a abdominal plain film, taking advantage of the contrast media in the collecting system and bladder, simulating an late film in IVU (Figure 22).

Voiding cystourethrogram (VCU) was commonly used for evaluating of living donors, however, several studies have shown that no clinically relevant information is provided for this examination in the great majority of cases. So, VCU is no longer used in most of individuals who are candidates for kidney donation [83].