Other authors have advocated for the use of superparamagnetic iron oxide given intravenously to assess for inflammatory changes in the aortic wall [25,26]. Continued innovation has allowed advancement in sequences and techniques such as 4-D MRI for evaluation of TAAA or dissection, most commonly used at academic institutions. Discussion of Procedures by Variant Variant 1: Follow-up of known thoracoabdominal aortic aneurysm or dissection without repair. Without or with new symptoms. Aortography Chest Abdomen Pelvis Aortogram with digital subtraction angiography (DSA) for evaluation of the thoracic and abdominal aorta has a sensitivity of up to 90% and a specificity of 95% for acute aortic pathology [27]. Although it has the advantage of allowing immediate intervention if an abnormality is identified, aortography is an invasive procedure that is now typically performed for treatment after diagnosis of a new or worsening aortic pathology. Additionally, a 2003 study comparing MR angiography (MRA) with angiography suggested increased accuracy of MRA in assessing vessel diameter: a key component of follow-up for TAAA or dissection [28]. CT Chest, Abdomen, and Pelvis With IV Contrast There is no relevant literature regarding venous phase CT chest, abdomen, and pelvis for the follow-up of known thoracoabdominal aneurysm or dissection, because most follow-up imaging for known dissection or aneurysm uses an arterially timed contrast bolus in the form of a CT angiography (CTA) (discussed below). However, contrast- enhanced CT can provide information regarding the size and extent of aortic pathology as well as evaluate for extravascular pathology. If venous phase or unenhanced CT has already been performed, additional imaging with CTA may not be required in some patients.
Thoracoabdominal Aneurysm or Dissection Treatment Planning and Follow Up. Other authors have advocated for the use of superparamagnetic iron oxide given intravenously to assess for inflammatory changes in the aortic wall [25,26]. Continued innovation has allowed advancement in sequences and techniques such as 4-D MRI for evaluation of TAAA or dissection, most commonly used at academic institutions. Discussion of Procedures by Variant Variant 1: Follow-up of known thoracoabdominal aortic aneurysm or dissection without repair. Without or with new symptoms. Aortography Chest Abdomen Pelvis Aortogram with digital subtraction angiography (DSA) for evaluation of the thoracic and abdominal aorta has a sensitivity of up to 90% and a specificity of 95% for acute aortic pathology [27]. Although it has the advantage of allowing immediate intervention if an abnormality is identified, aortography is an invasive procedure that is now typically performed for treatment after diagnosis of a new or worsening aortic pathology. Additionally, a 2003 study comparing MR angiography (MRA) with angiography suggested increased accuracy of MRA in assessing vessel diameter: a key component of follow-up for TAAA or dissection [28]. CT Chest, Abdomen, and Pelvis With IV Contrast There is no relevant literature regarding venous phase CT chest, abdomen, and pelvis for the follow-up of known thoracoabdominal aneurysm or dissection, because most follow-up imaging for known dissection or aneurysm uses an arterially timed contrast bolus in the form of a CT angiography (CTA) (discussed below). However, contrast- enhanced CT can provide information regarding the size and extent of aortic pathology as well as evaluate for extravascular pathology. If venous phase or unenhanced CT has already been performed, additional imaging with CTA may not be required in some patients.