Cystic Fibrosis: Diagnostic Tests

Routine Tests Done at our Center

At each clinic visit the patient undergoes various different tests that include pulmonary and dietary evaluations.

These routine tests include:

  • Measurement and recording of weight & height
  • Oxygen saturation
  • Sputum culture
  • Pulmonary functions
  • General blood tests once every 3-6 months
  • Chest x-ray and stomach sonogram once a year

More Information about Diagnostic Tests

Sweat Test
A simple, relatively painless test that measures the amount of salt in the sweat. A high level normally means cystic fibrosis

Nasal Potential Difference
Evaluates the electrical potential of the nasal membranes. This test enables us to diagnose CF in patients whose sweat test is borderline or within normal limits.

Genetic Testing
A blood test that examines the DNA for the presense of mutations (the CFTR gene in the case of CF)

Allergic Bronchopulmonary Aspergillosis (ABPA)
The presence of this fungus in the lungs can be detected through blood/skin tests.

Vitamin A & E Tests

Immunoreactive Trysinogen (IRT)
This supplies information about pancreatic function.

Stool Elastase Levels
Measures the amount of elastase in stool (feces) to help evaluate whether a person's pancreas is functioning properly.

Stool Collection for Fat Analysis

Chest X-ray
Using low doses of radiation to make a picture of the inside the body.

CT Scans
Computerized imaging test looking at soft tissues in the body. allowig a 3-dimentional look at the scanned organ.

A bronchoscope is used to visualize the airways.

Lung function tests
Also called spirometry, measures how much air is breathed in and out, and how fast. This is done by breathing out as hard and fast as possible into a tube attached to a machine that records the breath.

Lung volume measurement
This involves sitting in a glass booth and breathing in and out through a tube. The booth senses changes in pressure that tell doctors how much air he’s breathing into his lungs.

Pulse oximetry
a small sensor is clipped to the fingertip to measure the amount of oxygen in the blood.

Sputum test
the lab looks for bacteria, or other foreign pathogens.

Genetic Testing
The test given through the health maintenance organizations (HMO or "kupat cholim") for CF carriers is currently offered according to origin. More than 95% of Ashkenazi and Tunisian carriers can be detected, as well as about 85-90% of carriers of Moroccan, Turkish and Georgian origin. Where only one of the partners in a couple is Ashkenazi, that partner is tested first. The standard test is not offered to couples where one or both partners are of Iraqi, Kurdish or Yemenite origin since this test doesn't identify enough of the CF mutations (there are over 2000) to be reliable. Someone wanting to undergo whole genome sequencing may do so privately. Sometimes, under appropriate circumstances, one may be reimbursed from the kupah.