Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Inflammatory Aortitis: Diagnostic Performance of Aorta Wall Thickness CT-scan Measuring.

Forgues8,  Maia, Giron12,  Jacques, Hitzel11,  Anne, Julian11,  Anne, Payoux11,  Pierre, Adoue10,  Daniel, Degraeve2,  Frédéric

CHG, Albi, France
Hôpital Purpan, Internal Medicine Department, Université de Toulouse
Hôpital Purpan, Nuclear Medicine Department, Université de Toulouse
Hôpital Purpan, Radiology Department, Université de Toulouse
CHG, Auch, France
CHG, Castres, France
CHG, Lannemezan, France
CHG, Pau, France
Hôpital J Ducuing, Toulouse, France
Hôpital Purpan, Infectious Diseases Department, Université de Toulouse
Hôpital Purpan, Internal Medicine Department, Université de Toulouse, Toulouse, France
Hôpital Purpan, Internal Medicine Department, Université de Toulouse, Toulouse

Background:

The measure of the aorta wall thickness (AWT) by computed tomography (CT-scan) is often used as diagnostic criteria for inflammatory aortitis. However, its diagnostic performance has not been studied.

Objective:

to describe the diagnostic performance of AWT for inflammatory aortitis.

Method:

This was a retrospective study from January 2005 to March 2010 including only patients who 1) had received a diagnosis of aortitis (expert diagnosis); 2) had performed a CT-scan and a PET-scan. For each case, one control was selected among patients who had performed a CT-scan and a PET-scan for the diagnosis of lymphoma in our institution. Cases and controls were matched for gender and age. Maximal AWT was measured by the same physician (JG) using a standardized procedure at the ascending aorta, descending thoracic aorta and abdominal aorta. AWT increase was validated only when it was circumferential and extended in the absence of obvious calcified atheroma plaque. The diagnostic performances of three different aortitis definitions were tested. Definition 1: at least one AWT value above the 99° percentile observed in the control group at one of the following site: ascending aorta, thoracic descending aorta and abdominal aorta; definition 2: increase of AWT above the 99° percentile of the maximal value observed in the control group whatever the aorta portion; definition 3: increase of AWT at one site or more above the more discriminating threshold determined using ROC curves.

Results:

Thirty-one aortitis patients (24 women and 7 men) were recorded. Mean age was 58.1 years (range: 20 – 82). They suffered from giant cell arteritis (GCA; n=16), Takayasu arteritis (TA; n=8), ANCA-vasculitis (n=2), spondylarthritis (n=1) or unclassified aortitis (n=4). Among controls, the 99° percentile of AWT was 3 mm at the ascending aorta, 2.6 mm at the descending aorta and 2.7 mm at the abdominal aorta; the 99° percentile of maximal AWT was 3.2 mm. The best discriminating threshold determined by the ROC curves analysis was 2.6 mm, 2.2 mm and 2.4 mm respectively for the ascending, the descending and the abdominal aorta.The diagnostic performances of each definition are reported below.

Table 1. Diagnostic performance of three inflammatory aortitis definitions based on the measure of the aorta wall thickness using computed-tomography.

 SeSpPPVNPV
Definition 17110010077.5
Definition 26110010072
Definition 391,77175,791.7
Se: sensibility; Sp: specificity; PPV: positive predictive value; NPV: negative predictive value

The diagnosis of aortitis had not been mentioned on the routine CT-scan report in 11 patients despite an increased AWT, an arterial wall contrast enhancement and/or peri-aortic edema. All these patients had a clearly abnormal PET-scan vessels imaging. All patients with a maximal AWT below 2 mm had a normal vessel's PET-scan.

Conclusion:

The diagnosis of aortitis is frequently missed on routine CT-scan despite clear abnormalities. PET-scan seemed especially useful when the AWT was thicker than 2 mm and thinner than 3 mm at the ascending aorta, 2.6 mm at the descending aorta and 2.7 mm at the abdominal aorta.

To cite this abstract, please use the following information:
Forgues, Maia, Giron, Jacques, Hitzel, Anne, Julian, Anne, Payoux, Pierre, Adoue, Daniel, et al; Inflammatory Aortitis: Diagnostic Performance of Aorta Wall Thickness CT-scan Measuring. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2027
DOI: 10.1002/art.29792

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