Kidneys Home > Polycystic Kidney Disease Diagnosis
Other Imaging Tests
More powerful and expensive imaging procedures, such as computed tomography (CT scan) and magnetic resonance imaging (MRI), can also detect cysts, but they usually are not required for diagnosis, because the ultrasound provides adequate information. CT scans require X-rays, and sometimes injected dyes are used.
A genetic test can detect mutations in the PKD1 and PKD2 genes. Although this test can detect the presence of the autosomal dominant PKD mutations before cysts develop, its usefulness is limited by two factors; it cannot predict the onset or ultimate severity of the disease, and no absolute cure is available to prevent the onset of the disease.
On the other hand, a young person who knows of a PKD gene mutation may be able to prevent the disease through diet and blood pressure control. The test may also be used to determine whether or not a relative of a person with PKD can safely donate a kidney. Anyone considering genetic testing should receive counseling to understand all the implications of the test.
Ultrasound imaging of the fetus or newborn baby reveals cysts in the kidneys, but does not distinguish between the cysts of autosomal recessive and autosomal dominant PKD. Ultrasound examination of the kidneys of relatives can be helpful. For example, a parent or grandparent with autosomal dominant PKD cysts could help confirm diagnosis of autosomal dominant PKD in a fetus or child. (It is extremely rare, although not impossible, for a person with autosomal recessive PKD to become a parent.) Because autosomal recessive PKD tends to scar the liver, ultrasound imaging of the liver also aids in diagnosis.
Patients with acquired cystic kidney disease usually seek help, because they notice blood in their urine (hematuria). The cysts bleed into the urinary system, which discolors urine. An acquired cystic kidney disease diagnosis is confirmed by using an ultrasound, CT scan, or MRI of the kidneys.