Transient Neurologic Deficit After Acetazolamide Challenge for Computed Tomography Perfusion Imaging

Measurement of cerebrovascular reserve by multimodal imaging for cerebral arterial occlusion or stenosis patients: protocol of a prospective, randomized, controlled clinical study

Background

Cerebrovascular reactivity (CVR) is the change in cerebral blood flow in response to a vaso-active stimulus, and may assist the treatment strategy of ischemic stroke. However, previous studies reported that a therapeutic strategy for stroke mainly depends on the degree of vascular stenosis with steady-state vascular parameters (e.g., cerebral blood flow and CVR). Hence, measurement of CVR by multimodal imaging techniques may improve the treatment of ischemic stroke.

Methods/design

This is a prospective, randomized, controlled clinical trial that aimed to examine the capability of multimodal imaging techniques for the evaluation of CVR to improve treatment of patients with ischemic stroke. A total of 66 eligible patients will be recruited from Renji Hospital, Shanghai Jiaotong University School of Medicine. The patients will be categorized based on CVR into two subgroups as follows: CVR > 10% group and CVR < 10% group. The patients will be randomly assigned to medical management, percutaneous transluminal angioplasty and stenting, and intracranial and extra-cranial bypass groups in a 1:1:1 ratio. The primary endpoint is all adverse events and ipsilateral stroke recurrence at 6, 12, and 24 months after management. The secondary outcomes include the CVR, the National Institute of Health stroke scale and the Modified Rankin Scale at 6, 12, and 24 months.

Discussion

Measurement of cerebrovascular reserve by multimodal image is recommended by most recent studies to guide the treatment of ischemic stroke, and thus its efficacy and evaluation accuracy need to be established in randomized controlled settings. This prospective, parallel, randomized, controlled registry study, together with other ongoing studies, should present more evidence for optimal individualized accurate treatment of ischemic stroke.

Trial registration

Chinese Clinical Trial Registry, ID: ChiCTR-IOR-16009635; Registered on 16 October 2016.

All items are from the World Health Organization Trial Registration Data Set and registration in the Chinese Clinical Trial Registry: ChiCTR-IOR-16009635.

Intracerebral steal phenomenon in symptomatic carotid artery disease

BACKGROUND AND PURPOSE

Intracerebral steal is a paradoxical vasodilatory response that reduces cerebral blood flow (CBF) in hemodynamically compromised brain tissue when blood is rerouted to more healthy areas. The aim of our study was to investigate the presence and extent of steal in patients with steno-occlusive internal carotid artery (ICA) disease, and to assess its relation with collateral blood flow through the circle of Willis (CoW).

MATERIALS AND METHODS

Thirty-eight patients with symptomatic steno-occlusive ICA disease underwent MRI examination with arterial spin labeling (ASL) perfusion imaging before and after a vasodilatory challenge. Intracerebral steal was defined as a decline in CBF after acetazolamide. Collateral flow via the CoW was assessed with time-of-flight and flow direction MR angiography (MRA) through the CoW was assessed with 2D phase-contrast MRA's.

RESULTS

Eight of 38 patients (21%) had steal in the hemisphere ipsilateral to the symptomatic ICA (mean tissue volume with steal, 6.9 ± 4.1 mL; mean CVR, -11 ± 30%). Cerebrovascular reactivity (CVR) was lower in the middle cerebral artery flow territory of the affected hemisphere in patients with steal compared those without (P = 0.002). Collateral blood flow was impaired in 4 of the 8 patients with steal. These patients had a larger area of steal (P = 0.002).

CONCLUSIONS

Intracerebral steal occurs in patients with obstructive ICA disease and can be assesses at brain tissue level with ASL perfusion MRI. Its presence is related to more severely declined CVR in the surrounding brain tissue area and the volume is associated with impaired primary collateral blood flow through the CoW.

Significance of dynamic magnetic resonance sialography in prognostic evaluation of saline solution irrigation of the parotid gland for the treatment of xerostomia

PURPOSE

To evaluate the clinical significance of dynamic magnetic resonance (MR) sialographic images in prognostic evaluation of saline solution irrigation of the parotid gland for the treatment of xerostomia.

MATERIALS AND METHODS

Morphologic findings and functional parameters were evaluated by use of dynamic MR sialography before saline solution irrigation of the parotid gland for the treatment of xerostomia in 17 patients. In addition, the MR sialographic data before the saline solution irrigation treatment in patients with improvement of salivary secretion and the sensation of dry mouth after irrigation treatment were compared with data in patients without improvement.

RESULTS

The maximum changing ratio in the group of patients with improvement after treatment was significantly higher (P = .042) than that in the group of patients without improvement. In addition, high correlations were found between the changing ratio and improvement on the visual analog scale for dry mouth sensation after treatment (Pearson r = 0.63, P = .001) and improvement of salivary flow rate (Pearson r = 0.77, P = .001). Moreover, in 12 patients with improvement of salivary flow rate after the saline solution irrigation treatment, the maximum changing ratio before the saline solution irrigation treatment was over 1.2. However, no significant differences in other parameters, including the detectable ductal area, were found between the group of patients with improvement after treatment and the group without improvement.

CONCLUSIONS

Our study suggests that dynamic MR sialography might be useful for the prognostic evaluation of saline solution irrigation of the parotid gland for the treatment of xerostomia.

Dynamic magnetic resonance sialography as a new diagnostic technique for patients with Sjogren's syndrome

OBJECTIVE

To evaluate the clinical utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with Sjögren's syndrome.

METHODS

The morphological findings and various kinds of functional parameters in volunteers on dynamic MR sialographic images were compared with those in five patients with definite Sjögren's syndrome.

RESULTS

On the MR sialographs of all five patients with Sjögren's syndrome, the so-called 'apple-tree appearance' was seen. The difference in two functional parameters using the dynamic MR sialographic data was elucidated between the two groups. The maximum area of the detectable ducts in the group of patients was significantly smaller (P < 0.001) than that in the group of volunteers. The ratio of change in the detectable ducts in the group of patients was significantly lower (P = 0.011) than that in the group of volunteers.

CONCLUSIONS

Our study suggests that dynamic MR sialographic data in addition to MR sialographic images might be useful for the diagnosis of Sjögren's syndrome.