Dataset Information

MRI Shrimp Sign in Cerebellar Progressive Multifocal Leukoencephalopathy: Description and Validation of a Novel Observation.

ABSTRACT:

Background and purpose

There are no validated imaging criteria for the diagnosis of progressive multifocal leukoencephalopathy in the cerebellum. Here we introduce the MR imaging shrimp sign, a cerebellar white matter lesion identifiable in patients with cerebellar progressive multifocal leukoencephalopathy, and we evaluate its sensitivity and specificity.

Materials and methods

We first identified patients with progressive multifocal leukoencephalopathy seen at Massachusetts General Hospital between 1998 and 2019 whose radiology reports included the term "cerebellum." Drawing on a priori knowledge, 2 investigators developed preliminary diagnostic criteria for the shrimp sign. These criteria were revised and validated in 2 successive stages by 4 additional blinded investigators. After defining the MR imaging shrimp sign, we assessed its sensitivity, specificity, positive predictive value, and negative predictive value.

Results

We identified 20 patients with cerebellar progressive multifocal leukoencephalopathy: 16 with definite progressive multifocal leukoencephalopathy (mean, 46.4 [SD, 9.2] years of age; 5 women), and 4 with possible progressive multifocal leukoencephalopathy (mean, 45.8 [SD, 8.5] years of age; 1 woman). We studied 40 disease controls (mean, 43.6 [SD, 21.0] years of age; 16 women) with conditions known to affect the cerebellar white matter. We defined the MR imaging shrimp sign as a T2- and FLAIR-hyperintense, T1-hypointense, discrete cerebellar white matter lesion abutting-but-sparing the dentate nucleus. MR imaging shrimp sign sensitivity was 0.85; specificity, 1; positive predictive value, 1; and negative predictive value, 0.93. The shrimp sign was also seen in fragile X-associated tremor ataxia syndrome, but radiographic and clinical features distinguished it from progressive multifocal leukoencephalopathy.

Conclusions

In the right clinical context, the MR imaging shrimp sign has excellent sensitivity and specificity for cerebellar progressive multifocal leukoencephalopathy, providing a new radiologic marker of the disease.

SUBMITTER: Adra N

PROVIDER: S-EPMC8191663 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature

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Publications

MRI Shrimp Sign in Cerebellar Progressive Multifocal Leukoencephalopathy: Description and Validation of a Novel Observation.

Adra N N Goodheart A E AE Rapalino O O Caruso P P Mukerji S S SS González R G RG Venna N N Schmahmann J D JD

AJNR. American journal of neuroradiology 20210513 6

<h4>Background and purpose</h4>There are no validated imaging criteria for the diagnosis of progressive multifocal leukoencephalopathy in the cerebellum. Here we introduce the MR imaging shrimp sign, a cerebellar white matter lesion identifiable in patients with cerebellar progressive multifocal leukoencephalopathy, and we evaluate its sensitivity and specificity.<h4>Materials and methods</h4>We first identified patients with progressive multifocal leukoencephalopathy seen at Massachusetts Gener ...[more]

PMID: 33985948

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Project description:Background and objectiveProgressive multifocal leukoencephalopathy (PML) is a severe, disabling infection caused by JC virus reactivation. PML-related disability complicates the MRI monitoring needed to assess treatment interventions in clinical trial or compassionate use settings. Portable ultra-low-field MRI (pULF-MRI) offers a convenient approach when such frequent imaging is needed. We evaluated the potential utility of pULF-MRI as an adjunctive tool for decreasing the burden of clinical study participation and clinical management in PML.MethodsWe examined paired high-field (HF) and pULF-MRI scans from 11 patients, aged 49 ± 15 years. pULF-MRI images with corresponding HF-MRI were coupled to depict key imaging findings of PML, including three patients with longitudinal evaluations, one with bedside pULF-MRI. The images were then independently assessed by two blinded raters, not involved in image acquisition or initial evaluations, who sequentially rated diagnostic accuracy of pULF-MRI scans compared to the HF-MRI. Longitudinal evaluations were performed for three patients, one with bedside pULF-MRI.ResultsT2-FLAIR lesions were detected with pULF-ULF in all cases when present on HF-MRI. Median sensitivity and specificity were 62% and 100%, respectively. T1WI hypointense areas showed similar performance. Focal volume loss was present in 8/11 HF-MRI scans, with sensitivity and specificity of detection by pULF-MRI of 100% and 94%, respectively. Contrast enhancement was seen in a single case on both pULF- and HF-MRI. Follow-up pULF-MRI showed lesion changes in two cases, and stable findings in one case, consistent with HF-MRI.DiscussionpULF-MRI shows promise in evaluation and monitoring of PML, showing moderate-to-high accuracy even when evaluations were unaided by HF-MRI. Our results highlight a potential application of pULF-MRI for facilitating participation in PML clinical research and more generally as a way to reduce burden of clinical management for this disabled patient population.

Dataset Information

MRI Shrimp Sign in Cerebellar Progressive Multifocal Leukoencephalopathy: Description and Validation of a Novel Observation.

Background and purpose

Materials and methods

Results

Conclusions

Publications

MRI Shrimp Sign in Cerebellar Progressive Multifocal Leukoencephalopathy: Description and Validation of a Novel Observation.

Similar Datasets

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