Magnetic Resonance Imaging in Intramural Hematoma and Penetrating Ulcer of Aortic Wall

MRI is an ideal tool for the diagnosis of intramural hematoma as well as for visualizing the presence of accompanying plaques. Often an intramural hematoma looks like a half moon, less frequently surrounding the complete circumference of the vessel (Figure 11.22). Furthermore, it is well known that in MRI metabolites of hemoglobin (oxihemoglobin, deoxihemoglobin, metahemoglobin, hemosiderin) have different magnetic properties. This allows the differentiation between acute bleeding (less than 7 days) when deox-ihemoglobin is prevalent and recent bleeding (8 days) where metahemoglobin is the main determinant of signal. In chronic hematoma (>three months), hemosiderin can be detected. Similarly to other chronic pathologies of the aorta, the dimensions of the vessel are a major determinant of prognosis. MRI is an excellent technique for describing morphology, age, and complications (such as changes on the time). The excellent possibilities together with the lack of contraindications make MRI the first methodology of choice for the intramural hematoma follow-up5,18,19,26,69,81,87-93.

In regard to the penetrating ulcer of the aortic wall, invasive angiography is the preferred technique for diagnostic purposes; reliable results can also be achieved by CT and MRI. CT has the advantage of visualizing the calcified plaque and any superficial interruptions or dislodgement of the plaque. MRI offers the possibility of identifying the presence of penetrating ulcers despite small dimensions and the presence or absence of an intramural bleeding. With CEMRA, a plus in the profile of the vessel can be appreciated (Figure 11.23(a),

Finally, if the patient has been treated by positioning an endovascular prosthesis, the aim of the MRI study is to verify the position of the endovascular device, the relationship with the main arterial branches, and the presence of periprosthesis leak. If the material of the prosthesis is MRI compatible, MRI has an high degree of reproducibility and can be suggested as a first-choice diagnostic procedure18,19,26,69,83-85.

Figure 11.22. Three-dimensional CEMRA of thoracic aorta in a patient with aortic hematoma.
Aortic Penetrating Ulcer

Figure 11.23. (a) Three-dimensional CEMRA of thoracic aorta in a patient with penetrating ulcer of the thoracic aorta. (b) The analysis of partitions allows an accurate definition of the ulcer.

Figure 11.23. (a) Three-dimensional CEMRA of thoracic aorta in a patient with penetrating ulcer of the thoracic aorta. (b) The analysis of partitions allows an accurate definition of the ulcer.

Table 11.1. Late complications of aortic dissection and follow-up evaluation

Late complications:

• Progressive aortic insufficiency

• Aneurysm formation and rupture

• Recurrent dissection or progression of dissection

• Leakages at anastomoses/stent sites

• Malperfusion

Patients at particularly high risk:

• Those with Marfan syndrome—very high risk of recurrent dissection or of aneurysm formation with rupture

• Those with a patent false lumen—increased incidence of late complications and death

Follow-up evaluation:

• Regular outpatients visits and imaging controls at 1, 3, 6, and 12 months and thereafter every year

• Optimal BP control < 135/80 mm Hg with beta blockers

• First choice is MRI, second choice CT, and third TEE

Source: Modified from references 18 and 96.

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