Friday, May 6, 2016
Alveolitis and AV malformations on CTA
I am 46 yr old female with Pompe disease. I have been having serial Chest CT scans to follow some nodules. In June the CT showed some possible AV malformations. I had a CTA this week to follow up on this. It did confirm the AV malformations some of which are in the LUL. My pulmonologist also said it showed alveolitis. My PFT`s show a restrictive disease with decreased DLCO ( in the 60`s) and severely reduced MIP and MEP. There has been some mild scarring in the bases of my lungs vs interstitial changes. I have shortness of breath etc. I have never smoked. Can you tell me what alveolitis means and also explain AV malformations? Thanks so much for your help.
Pompe disease causes weakness of the muscles that power the lungs. This can cause inability to take a full breath which is called a "restrictive lung disease". It can also cause a reduced diffusing capacity, (DLCO) but the diffusing capacity adjusted for the lung volume will be normal (DLCO/VA).
Alveolitis means inflammation in the lung and can be caused by pneumonia, aspiration (for example aspiration of liquids or uncontrolled esophageal reflux), or interstitial lung disease. It can be difficult to distinguish alveolitis from edema (for example, fluid buildup from heart failure) just by the CT scan alone as they can look quite similar.
An AVM is an "arteriovenous malformation" when there is an abnormal connection between the large arteries of the lung and the large veins of the lung. This can result in blood "bypassing" the alveoli or air sack of the lung and then the blood is not able to pick up oxygen normally (causing the blood oxygen level to be low). If an AVM is suspected, it can be confirmed by doing a cardiac echogram with injection of agitated saline. A chest CT done both with and without intravenous contrast dye can also be helpful to diagnose the AVM. A pulmonary angiogram (where contrast dye is injected through a catheter that is guided into the blood vessel of the lung) provides final confirmation and radiologist can ablate (destroy) the AVM at the time of the catheterization.
James N Allen, Jr, MD
Clinical Professor of Pulmonary, Allergy, Critical Care & Sleep Medicine
College of Medicine
The Ohio State University