What is the best investigation for the workup of Autosomal Dominant Polycystic Kidney Disease (ADPKD)?

The best investigation for the workup of Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a renal ultrasound (US). This imaging modality is particularly well-suited for the diagnosis of ADPKD due to its ability to visualize the characteristic cysts that form in the kidneys. Ultrasound is a non-invasive, readily available, and cost-effective tool that can efficiently identify kidney enlargement and cysts, which are key diagnostic criteria for this condition.

In patients with a family history consistent with ADPKD, an ultrasound can be used effectively in both adults and children to confirm the diagnosis, especially since the presence of multiple renal cysts is integral to the condition's clinical definition. Furthermore, the absence of radiation exposure makes it a preferable first-line investigation, especially for younger patients.

While other options like CT scan can also show cysts and provide detailed information about kidney structure, they involve radiation exposure and are typically reserved for cases where complications arise or in specific circumstances where more detailed imaging is necessary. BUN and creatinine levels may provide information regarding kidney function but do not specifically diagnose ADPKD. Urinalysis can offer insights into kidney health and the presence of blood or protein but lacks the specificity required to diagnose ADPK