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When a patient presents with symptoms that may be related to polycystic kidney disease (PKD), the physician will perform an in-depth examination to diagnose the condition. In addition to the physical, laboratory, and imaging evaluations, the physician will take a detailed history of family members who had polycystic kidney disease or who exhibited symptoms that may be consistent with PKD because there is such a strong hereditary component to its transmission. Also, if a family history can be established for certain disorders, (e.g., cerebral aneurysms) the patient may be at higher risk for various complications.

The components of a diagnostic evaluation for polycystic kidney disease include:

• Physical Examination
• Laboratory Evaluation
• Imaging Studies

Physical Examination

In addition to taking a family history, the physician will feel the abdomen, sides, and back of the patient, trying to feel any bilateral flank masses or any swelling. The physician will also palpate the liver to evaluate any enlargement which could be associated with hepatic cysts that can form with polycystic kidney disease (PKD).

Blood pressure will be measured since it is so closely linked with PKD and is an early manifestation of the disease, as well as listening for any indication of cardiovascular involvement (e.g., mitral valve prolapse). The physician may also choose to further evaluate a complaint of headaches to assess if they are related to high blood pressure or to an aneurysm.

Laboratory Evaluation

• Complete blood count (CBC)
• Blood urea nitrogen (BUN) and creatinine clearance tests show how effectively the kidneys are functioning.
• Hematocrit test to indicate elevated levels of erythropoietin secreted from cysts
• Serum chemistry profile including blood levels of calcium and phosphorus
• Parathyroid hormone value test
• Urinalysis and/or urine culture
• Genetic studies of the DNA of the patient if needed to confirm a diagnosis of PKD. The accuracy of these studies is 99% or higher.
• Renal stone profile test

Imaging Studies

Ultrasound

Ultrasound (US) of the kidneys (and other organs where there may be cysts related to PKD) is the most useful imaging technique and can detect cysts as small as 2 cm in size. The advantage of US over other imaging modalities is that it does not require the use of radiation and contrast dyes. In addition, it is relatively inexpensive to perform. Ultrasound is safe and can be used to detect cysts on the kidneys of fetuses.

Computed Tomography Scan

A computed tomography (CT) scan is more sensitive than ultrasound and can detect cysts as small as 1.0 cm. in size. CT is not used routinely for diagnosis of PKD because it is expensive and involves radiation. It may be used in doubtful cases of PKD in children or in complicated cases.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is also more sensitive than ultrasound and can detect cysts as small as 1.0 cm. in size. MRI is also helpful in identifying renal cell carcinoma that occurs rarely in the general population but more frequently among people with acquired PKD. Note that this does not apply for people with ADPKD, ARPKD, or MCKD.