The ISMRM Open Science Initiative for Perfusion Imaging (OSIPI): Results from the OSIPI-Dynamic Contrast-Enhanced challenge.

PURPOSE: K trans $$ {K}^{\mathrm{trans}} $$ has often been proposed as a quantitative imaging biomarker for diagnosis, prognosis, and treatment response assessment for various tumors. None of the many software tools for K trans $$ {K}^{\mathrm{trans}} $$ quantification are standardized. The ISMRM Open Science Initiative for Perfusion Imaging-Dynamic Contrast-Enhanced (OSIPI-DCE) challenge was designed to benchmark methods to better help the efforts to standardize K trans $$ {K}^{\mathrm{trans}} $$ measurement. METHODS: A framework was created to evaluate K trans $$ {K}^{\mathrm{trans}} $$ values produced by DCE-MRI analysis pipelines to enable benchmarking. The perfusion MRI community was invited to apply their pipelines for K trans $$ {K}^{\mathrm{trans}} $$ quantification in glioblastoma from clinical and synthetic patients. Submissions were required to include the entrants' K trans $$ {K}^{\mathrm{trans}} $$ values, the applied software, and a standard operating procedure. These were evaluated using the proposed OSIP I gold $$ \mathrm{OSIP}{\mathrm{I}}_{\mathrm{gold}} $$ score defined with accuracy, repeatability, and reproducibility components. RESULTS: Across the 10 received submissions, the OSIP I gold $$ \mathrm{OSIP}{\mathrm{I}}_{\mathrm{gold}} $$ score ranged from 28% to 78% with a 59% median. The accuracy, repeatability, and reproducibility scores ranged from 0.54 to 0.92, 0.64 to 0.86, and 0.65 to 1.00, respectively (0-1 = lowest-highest). Manual arterial input function selection markedly affected the reproducibility and showed greater variability in K trans $$ {K}^{\mathrm{trans}} $$ analysis than automated methods. Furthermore, provision of a detailed standard operating procedure was critical for higher reproducibility. CONCLUSIONS: This study reports results from the OSIPI-DCE challenge and highlights the high inter-software variability within K trans $$ {K}^{\mathrm{trans}} $$ estimation, providing a framework for ongoing benchmarking against the scores presented. Through this challenge, the participating teams were ranked based on the performance of their software tools in the particular setting of this challenge. In a real-world clinical setting, many of these tools may perform differently with different benchmarking methodology.

Double inversion recovery to detect cervical spinal cord multiple sclerosis lesions.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) plays a key role in diagnosing and monitoring multiple sclerosis (MS). Double inversion recovery (DIR) is a pulse sequence that has proven highly effective at detecting cortical lesions but is understudied in the spinal cord. We hypothesize that DIR images obtained during brain MRI can be of value in assessing the upper spinal cord of MS patients. METHODS: We retrospectively examined brain MRI exams of 64 patients with established MS, who had also undergone cervical spine MRI. Two blinded MS expert readers, who assessed the scans for lesion numbers and rated lesion visibility and overall image quality, reviewed brain 3-dimensional DIR sagittal and coronal images. Standardized mean contrast-to-noise ratios (C/N) and standard deviation (SD) were calculated in representative lesions for each patient and compared to those of 3-dimensional FLAIR images. RESULTS: For the analysis of lesions categorized as "definite lesions," the sensitivity was 87%, specificity was 61%, and negative predictive value was 80%. On the other hand, for "definite" plus "probable" lesions, the sensitivity was 91%, the specificity was 54%, and negative predictive value was 86%. DIR demonstrated lesions with an average C/N of 7.56 with an SD of 1.77. FLAIR sequence demonstrated lesions with an average C/N of 0.67 and SD of 1.27. CONCLUSIONS: Sagittally acquired brain DIR can provide useful information on upper spinal cord lesions, with high C/N. In theory, this should facilitate the attainment of McDonald's or the Magnetic Resonance Imaging in MS (MAGNIMS) criteria in some cases, without a dedicated cervical spine MRI exam.

Monthly triple-dose gadolinium administration: potential associations with leukopenia, hypophosphatemia, and bone marrow T1 hyperintensity.

OBJECTIVE: Monthly scanning with triple-dose gadopentetate dimeglumine has been shown to be associated with progressive increases in bone T1 hyperintensity, hypophosphatemia, and leukopenia. This study was performed to retrospectively investigate the potential associations among these phenomena. METHODS: This retrospective analysis involved patients who had received monthly triple-dose gadopentetate dimeglumine for up to 2 years as part of treatment for multiple sclerosis. Monthly magnetic resonance imaging scans of the brain (n = 67) were segmented to evaluate the signal intensity in the cranial marrow. Potential associations among the marrow T1 hyperintensity, serum phosphate concentration, and white blood cell count were examined. RESULTS: Patients in the no leukopenia group showed a statistically significant mean monthly increase in the bone marrow signal-to-noise ratio of 0.0430/month. Patients in the leukopenia group showed a mean monthly increase in the bone marrow signal-to-noise ratio of 0.0398/month, but this was not statistically significant. Patients in the hypophosphatemia group were significantly less likely to develop leukopenia than patients who had never developed hypophosphatemia. CONCLUSIONS: Although monthly administration of triple-dose gadopentetate dimeglumine over 13 months has been associated with progressive increases in leukopenia, hypophosphatemia, and T1 signal intensity of bone, this study showed an inverse relationship between leukopenia and hypophosphatemia.