Magnetic Resonance Imaging Vessel Wall Sequences in the Detection of Mucormycosis-Associated Vasculitis: A New Sequence to Show an Old Invasive Infection

We hereby present the first documented case report in which high-resolution vessel wall imaging (HR-VWI) represented a cornerstone for the diagnosis of an important infectious disease with invasion of intra and extra cranial structures, bone erosion and vascular complications.

A 54-year-old woman with HIV infection, untreated diabetes and systemic arterial hypertension presented bilateral ptosis, papilledema, ophthalmoplegia, headache and nasal discharge. CT disclosed invasive sinusopathy in maxillary, frontal, ethmoidal and sphenoidal sinuses with bone erosions bilaterally involving the left eye. Compression of the left internal carotid artery and small superior cerebellar artery pseudoaneurysm were also observed.

MRI showed mucosal thickening of both the frontal, left maxillary and sphenoidal sinuses and several intra and extra cranial collections. Foci of hyperintensity on FLAIR and T2-weighted sequences, bilaterally in the corona radiata, in the left superior parietal lobe and in the pons were observed. There were also areas with diffusion restriction in the left parietal lobe, compatible with vasculitis.

MRI and Angio-MRI HR-VWI ([Fig. 1] and [Fig. 2]) showed pseudoaneurysms and inflammation of the left carotid artery from its petrous portion to the supraclinoid segment. The wall of the left carotid presented concentric diffuse thickening with contrast enhancement suggesting vasculitis. Empyema extensions could be observed in masticatory spaces, bilateral orbital cavities and intracranially. Cerebrospinal fluid analysis showed inflammatory aspects such as pleocytosis with 157 leukocytes per cubic millimeter, a cellular profile with 92% lymphocytes and elevation of total protein. The patient viral load for HIV was undetectable and she presented CD4 levels of 1319.

Fig. 1

Fig. 2

A tissue fragment measuring 1.8 × 1.5 × 0.5 cm was obtained by endoscopic endonasal surgery and, despite negative culture results, the diagnosis of invasive mucormycosis was confirmed with fungal structures detected in routine staining ([Fig. 3]), Grocott ([Fig. 4]) and periodic acid-Schiff staining. Debridement and abscesses drainage were performed during the procedure. The patient received amphotericin for 30 days and was discharged in good health with a daily dose of 450 mg of fluconazole.

Fig. 3

Fig. 4

Days later the patient returned to our service due to loss of consciousness. A new CT showed bilateral nucleocapsular lesions. She evolved with bilateral amaurosis, coma and death.

Traditionally, intracranial arterial pathology has been evaluated with luminal imaging, CT angiography or conventional angiography. More recently, the use of HR-VWI has allowed submillimeter evaluation of arterial walls and has been proven useful in vasculitis evaluation due to its ability to demonstrate the enhancement in the area of inflammation and due to a high sensitivity and specificity. In this case, smooth and concentric vessel wall enhancement related to inflammation was observed. HR-VWI can also distinguish causes of arterial narrowing and characterize unstable intracranial aneurysms. However, it is important to consider that clinical and laboratory correlations observed in our case, in which cerebrospinal fluid showed inflammation and infection, corroborated the infectious nature of the alterations in HR-VWI.