The Role of Imaging in Diagnosis and Monitoring of Large Vessel Vasculitis

Brain computed tomography perfusion alterations in patients with Takayasu arteritis with steno-occlusive carotid arteries: a retrospective study

INTRODUCTION/OBJECTIVE

Data on computed tomography perfusion (CTP) in Takayasu arteritis (TAK) patients are limited. Herein, we used CTP combined with computed tomography angiography (CTA) to investigate the brain hemodynamic status in TAK patients with stenosis/occlusive carotid arteries.

METHODS

We retrospectively analyzed 49 TAK patients with carotid artery stenosis or occlusion who had ischemic manifestations and completed a one-stop aortic CTA and brain CTP at Xijing Hospital between 2021 and 2023. Hemodynamic parameters, including cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to maximum (Tmax), were compared between groups using independent samples t-test or the Mann-Whitney U test. Relationships among CTP parameters and disease activity were evaluated by correlation analyses.

RESULTS

Among 49 patients (43 females; age 38.7 ± 11.1 years), 15 had common carotid artery occlusion (four bilateral, six right, and five left). Compared with the non-occlusion group, the occlusion group had longer MTT and Tmax (p < 0.05) but showed no differences in CBV and CBF values. Patients with different degrees of lesions on two sides of the carotid artery (n = 31) had lower mean CBF on the severely affected side than on the contralateral side (p = 0.022). In contrast, mean MTT (p = 0.036) and Tmax (p = 0.024) were longer. Patients with more severe ischemic symptoms had longer Tmax than patients with mild symptoms (p < 0.05). Tmax was moderately correlated with disease activity indices (p < 0.05).

CONCLUSIONS

Alterations in cerebral hemodynamic perfusion were observed in TAK patients. The implications of these findings in evaluating brain ischemia and dysfunction require further investigation. Key Points • Alterations in cerebral hemodynamic perfusion were observed in TAK patients. • Compared with patients without common carotid artery occlusion, patients with occlusion had longer MTT and Tmax values. • In patients with different degrees of lesions on the two sides of the carotid artery, the severely affected side had a lower CBF and prolonged MTT and Tmax than the contralateral side. • Patients with moderate-to-severe ischemic manifestations had a longer Tmax than patients with mild symptoms, and MTT and Tmax correlated with disease activity indices.

Imaging Challenges and Developments in Large-vessel Vasculitis

Vascular imaging is an integral part of large-vessel vasculitis (LVV) evaluation and management. Several imaging modalities are currently employed in clinical practice including vascular ultrasound, computed tomography angiography, MRI and magnetic resonance angiography, and 18F-fluorodeoxyglucose PET. Well-established roles for imaging in LVV include disease diagnosis and assessment of luminal lesions reflecting vascular damage. The ability of imaging to determine treatment response, monitor disease activity, and predict future arterial damage is an area of active research.

Multiple systemic arterial aneurysms in large-vessel vasculitis

Large-vessel vasculitis (LVVs) is a rare inflammatory disease that predominantly affects young females' aorta and its main branches, coronary arteries, and pulmonary arteries. Clinical manifestations result from vascular stenosis, occlusion, and dilation, sometimes complicated by aneurysm rupture or dissection. Early diagnosis and treatment of LVVs are paramount to reducing the risk of ischemic complications such as visual loss and strokes, vascular stenosis and occlusion, and aortic aneurysm formation. The diagnosis of LVVs is often challenging because the presenting clinical features are nonspecific in many cases and are often shared by different types of autoimmune and inflammatory diseases including other systemic vasculitides. Prompt identification of vasculitides is important because they are associated with an increased risk of mortality. Left undiagnosed or mismanaged, these conditions may result in serious adverse outcomes that might otherwise have been avoided or minimized. We report a rare case of the LVVs with multisystemic vascular aneurysms and catastrophic complications of ruptured abdominal aortic aneurysm. Our case highlights that an early diagnosis of the diverse manifestations of vasculitis and a high index of clinical suspicion is essential to avoid delays in disease recognition that may result in permanent or life-threatening morbidity.