ARPKD was suspected by the radiologist reporting the CT, but rather on the basis of the ultrasound findings of nephromegaly with innumerable microcysts plus a large, coarsely heterogeneous liver. When renal cysts are so tiny that each acts as a focal interface that bounces sound back to the transducer, they appear hyperechoic rather than anechoic. The CT study added the presence of dilated renal tubules and not much else.

Although the signs on the ultrasound study were pathognomonic for ARPKD, as well as lack of any clinical or radiological sign of a lysosomal/glycogen storage disease, genetic testing was performed nonetheless and confirmed ARPKD.