Living donor liver transplantation (LDLT) is a good solution to the donor liver shortage in the Netherlands. In cases of severe liver disease, LDLT has substantial survival benefits, fewer (future) complications, and an improved quality of life.

Donor screening is extensive to minimize risks for both donors and recipients. The liver's blood vessels are assessed using CT and the bile ducts with MRCP. Blood vessel assessment can also be performed using MRCP, which would make the CT unnecessary. Before CT can be removed from the screening procedure, the correlation between blood vessel assessment on CT and MRCP must be clarified.

It is hypothesized that CT is equally adequate in assessing liver blood vessels to MRCP.

Research methods:

Data, CT-and MRCP images will be extracted from HiX. Screenshots of the images will be made. All personal data will be blacked out using Microsoft Powerpoint 16.90.2. The CT- and MRCP-images will be coded at random with different codes for the CT and MRCP of the same donor. These coded images will be shared with the radiologist through Castor. He will count the blood vessels and look for focal liver lesions. He will register his findings in Castor and share this file with the study coordinator.

Analysis:

Normality will be tested using the Shapiro-Wilk test. Homogeneity of variances will be tested using the F-test. A QQ-plot will be used to check for outliers. For the baseline donor characteristics, sex differences will be investigated for age, weight, height, and BMI using the unpaired samples t-test or Mann-Whitney test.

Similarities and differences between blood vessel assessment on CT and MRCP will be thoroughly described.

The mean (Standard Deviation (SD)) number of total essential blood vessels will be calculated for CT and for MRCP. The correlations between CT and MRCP will be calculated by the following formula: (mean number on CT)/(mean number on MRCP)*100(%). For the mean correlation, the average of all donors' correlations will be taken. A table showing the means (SD) and min-max of the number of total essential blood vessels, and the correlation will be made. The distribution of correlations will be shown in a bar chart. The paired samples t-test will be used to test for differences in the mean number of total essential blood vessels on MRCP and CT. The same analysis will be done for the hepatic arteries, hepatic veins, and focal liver lesions. Subgroup analyses will be carried out for sex, age, weight, height, and BMI using the unpaired samples t-test, Welch's t-test, or Mann-Whitney test Statistical analyses will be carried out using RStudio 2024.09.1, GraphPad Prism 9.5.0, and Microsoft Excel version 16.90.2. P<0.05 indicates statistical significance.

Recruitment and informed consent procedures:

The transplant coordinator and/or transplant surgeon will inform participants about the study and will ask their written informed consent. Living liver donors are followed-up annually for life. The participants will be informed during a follow-up consult. All donors who are, for whatever reason, not visiting the Erasmus MC anymore for follow-up are contacted by phone. If the donor considers participating, a Patient Information Form (PIF) will be sent by mail. The donors can return the signed PIF through mail.

Donors can withdraw their informed consent at any time and for any reason if they wish to do so without any consequences. They can withdraw through phone, mail, or in person.

Privacy protection:

Subject's privacy is protected by using coded data. In the database subjects are referred to as numbers. These numbers are chosen at random. Which number belongs to which subject is registered in a key table with a password. This password is only known by the principal investigator and the research team. The database in which the data is stored (Castor), meets the requirements set for data security. The handling of personal data is in compliance with the Dutch Data Protection Act (in Dutch: 'Algemene Verordening Gegevensbescherming (AVG)). Only the code number will be used for study documentation, progress reports, and research publications.

Inclusion Criteria:

In order to be eligible to participate in this study, a subject must meet all of the following criteria:

• Living liver donation between May 2004 and June 2026
• Written informed consent

In order to be eligible for LDLT, a subject needed to meet all of the following criteria:

• 18-60 years old
• Physical and mental well-being
• Body Mass Index (BMI) <33 kg/m2
• No active drugs or other substances use

Exclusion Criteria:

There are no exclusion criteria for this study.

Exclusion criteria for LDLT were:

Absolute exclusion criteria

• Medical conditions (for instance heart disease and bleeding or clotting disorders)
• History of liver disease
• Previous/active malaria infection
• Financial incentive or indications of pressure
• Unable to cooperate with designated long-term follow-up
• Severe psychiatric disease or psychological instability
• Active alcoholism or frequent heavy alcohol use or drugs use/abuse
• Unable to give informed consent
• History of dementia or other neurological degenerative disorders
• Persons with rabies or persons bitten in the past 6 months by an animal and that are treated as if the animal is rabid
• Persons with syphilis
• Human immunodeficiency virus-positive persons. Relative exclusion criteria
• BMI >33 kg/m2
• Smoking

The population consists of adult living liver donors at the Erasmus MC.

Study protocol, documentation, data management plan, data analysis plan, script to assess data, scripts to analyse data, scripts to generate tables and figures in the publication.

(Underlying) data will be made available alongside with the publication. It will be available for 10 years.

Access to the data and images is approved by the head of department and principal investigator. This access is temporarily. To whom and when access approved is registered.

The PI will verify the authenticity of the requesting researcher and will check whether their intentions are in line with the informed consent and whether the intended methodology is suitable and will approve the request before providing access to the data.

Other researchers could express their interest in the dataset through countersigned DTA. After meeting the sharing and reuse conditions as described above and approval of the PI, data access will be provided through the data repository.