Portable ultra-low-field MRI for progressive multifocal leukoencephalopathy: Case studies, sensitivity, and potential applications
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Published on: February 19, 2021
Serhat V Okar1, Karan D Kawatra2, Ashley A Thommana1
1Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD, USA.
Background And Objective:
Progressive 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.
Methods:
We 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.
Results:
T2-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.
Discussion:
pULF-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.
Insights
Portable ultra-low-field MRI (pULF-MRI) shows promise for monitoring progressive multifocal leukoencephalopathy (PML). This imaging technique offers moderate-to-high accuracy, potentially reducing patient burden in clinical studies and management.
Area of Science:
- Neuroimaging
- Infectious Diseases
- Medical Technology
Background:
- Progressive multifocal leukoencephalopathy (PML) is a severe JC virus infection causing disability.
- MRI monitoring is crucial for PML treatment assessment but can be burdensome.
- Portable ultra-low-field MRI (pULF-MRI) offers a convenient imaging solution.
Purpose of the Study:
- To evaluate the utility of pULF-MRI as an adjunctive tool in PML.
- To assess pULF-MRI's potential in reducing the burden of clinical study participation and management for PML patients.
Main Methods:
- Paired high-field (HF) and pULF-MRI scans from 11 PML patients were analyzed.
- pULF-MRI images were compared to HF-MRI for diagnostic accuracy.
- Two blinded raters independently assessed image quality and diagnostic performance.
- Longitudinal evaluations, including bedside pULF-MRI, were performed for some patients.
Main Results:
- pULF-MRI detected T2-FLAIR lesions present on HF-MRI with 62% sensitivity and 100% specificity.
- Detection of focal volume loss by pULF-MRI showed 100% sensitivity and 94% specificity.
- Contrast enhancement was visualized similarly on both pULF-MRI and HF-MRI.
- Longitudinal pULF-MRI demonstrated lesion changes consistent with HF-MRI findings.
Conclusions:
- pULF-MRI demonstrates moderate-to-high accuracy in evaluating and monitoring PML.
- The technique shows promise even without direct comparison to HF-MRI.
- pULF-MRI could facilitate PML clinical research and reduce patient management burden.
