Keywords:
Arteries / Aorta, Vascular, CT-Angiography, Comparative studies, Dissection
Authors:
S. Kandel, N. K. Bhullar, T. Chung, S. Mathur, B. J. Wintersperger, P. Rogalla; Toronto, ON/CA
DOI:
10.26044/ecr2019/C-3138
Methods and materials
We did a retrospective review,
for which consent was waived from the REB,
and searched for studies performed between Jan 2007 and February 2018 that used a "CT chest dissection protocol" (NC-CT followed by a CE-CT).
100 CT imaging studies were selected for review by a radiologist who was not involved in further imaging interpretation,
of which 50 patients were reported negative and 50 patients positive for aortic dissections.
Patients with treated dissection/intramural hematoma indicated on the requisition were excluded. All patients were imaged on Canon CT scanners (Aquilion 64,
Prime,
Aquilion One and Vision) using 100 or 120kV (depending on the patient’s BMI),
0.5 ms rotation time and tube current modulation.
The dissection protocol consisted of an unenhanced CT chest from above the aortic arch to the diaphragm using 1 and 3 x 2.4 mm slice thickness. Following the injection of 80 ml of contrast material (either Visipaque 350 or Ultravist 380) at a flow rate of 5ml/s a CT chest starting above the level of the clavicles and ending at the level of the diaphragm using 2 mm x 2 mm slices thickness was completed.
Three blinded chest radiologists (with 25,
2,
and 2 years of experience) initially reviewed all 100 NC-CT studies in random order and decided whether or not they could identify a dissection flap and their level of confidence on a scale of 1 (not confident) to 10 (confident).
Other diagnosis of acute aortic syndrome were also recorded.
The CE-CT was then reviewed and the radiologists documented whether this changed their diagnosis.
The patients’ age,
gender,
and severity of atherosclerotic calcifications (CalcScore; 0=none,
1=minimal,
2=mild,
3=moderate,
4=severe),
as well as further management and mortality rate,
were assessed.
A ROC analysis was performed by reader,
pooled and separately for all patients,
as well as for patients above 60 (Group 1) and below age 60 (Group 2).