Improved detectability of acute and subacute brainstem infarctions by combining standard axial and thin-sliced sagittal DWI

Abstract

Background and purposeMost false negative findings in DWI of ischemic stroke are in patients with minor deficits clinically localized to the brainstem. Our goal was to evaluate the benefit of a thin-sliced sagittal DWI in addition to conventional axial DWI at 1.5T for the detection of brainstem infarctions.MethodsData of patients with symptoms consistent with acute and subacute brainstem infarction and an MRI examination including standard axial DWI and thin-sliced sagittal DWI were retrospectively analyzed. Patients with the later diagnosis of a TIA, an inflammation or a tumor of the brainstem were excluded from analysis. Diffusion restrictions were identified by two independent raters blinded for the final clinical diagnosis in three separate reading steps: First, only axial DWI, secondly only sagittal DWI, and lastly both DWIs together. Presence and size of DWI-lesions were documented for each plane. Differences between the observers were settled in consensus in a separate joint reading.ResultsOf 73 included patients, 46 patients were clinically diagnosed with brainstem infarction. Inter-observer agreement was excellent for the detection of brainstem lesions in axial and sagittal DWI (kappa = 0.94 and 0.97). In 28/46 patients (60.9%) lesions were detected in the axial plane alone, whereas in 6 more patients (73.9%) lesions were detected in the review of both sequences together. All lesions undetectable in the axial plane were smaller than 5 mm in cranio-caudal direction.ConclusionsThin-sliced sagittal DWI in addition to axial DWI improves the detection rate of brainstem infarction with little additional expenditure of time.

Sagittal diffusion-weighted imaging in preventing the false-negative diagnosis of acute brainstem infarction: Confirmation of the benefit by anatomical characterization of false-negative lesions

“…Recently, it has been reported that combining standard axial and thin-sliced sagittal DWI improve the detectability of acute BI, although the cause of the improvement has not been studied. [19] In the present study, we also showed that the FN diagnosis of acute BI can be prevented by combining thin- section sagittal DWI with standard axial DWI. We found that the combination showed high sensitivity and specificity for the diagnosis of acute BI.…”

“…The lesions were mainly located in the pons, consistent with a previous report. [8,19] When the second magnetic resonance imaging (MRI) was performed 7 days after the initial MRI, all six patients were shown to have infarction lesions on axial DWI.…”

“…Hence, reducing the rate of FN-BIs is of great interest. Recently, it has been shown that combing axial and thin-sliced sagittal DWI improves the detectability of acute BIs,[19] although the cause for the benefit has not been studied.…”

Characteristics and resource needs in patients with vestibular symptoms: a comparison of patients with symptoms of unknown versus determined origin

“…In the context of vestibular symptoms, choosing the right MRI sequence is of the utmost importance: MRI according to a conventional stroke protocol is less sensitive than a HINTS-plus to detect small strokes causing vestibular symptoms [ 32 ]. Where a brainstem infarction is suspected, thin-sliced 3 mm diffusion-weighted imaging (DWI) sequences should be added, as they have a higher sensitivity for the detection of acute and subacute brainstem infarctions [ 33 ]. If imaging reveals an underlying pathology, targeted treatment can be initiated to reduce further invalidity.…”

Diffuse astrocytoma and the diagnostic dilemma of an unusual phenotype: A case report

“…The lesion was not restricted in DWIs and showed slightly high SI on the ADC map, further decreasing the likelihood of infarction [7 , 10] . The lesion showed predominantly low SI and slightly high SI on ADC.…”