IB Neuro is the recommended national standard in MR DSC (dynamic susceptibility contrast) perfusion imaging.
It is an MR DSC algorithm that: 1) is the only algorithm that automatically generates quantitative parameter maps independent of scanner platform, field strength, time point, or patient, 2) is the only commercially available platform used in multi-center clinical trials, 3) is the only platform validated with biopsy tissue samples. The proven contrast leakage correction algorithm, proven superior over other commercial platforms, can be turned off for processing stroke data. The built-in standardization (quantification) algorithm enables more consistent processing by eliminating inherent variability that is introduced when manually drawing reference ROIs for tissue normalization. The standardization technique built into IB Neuro has proven superior over manual tissue normalization approaches.
Also, IB Neuro is the DSC perfusion algorithm validated for a single-dose (no pre-load) of Gadolinium-based contrast agent using the "low-flip" angle method published in 2019. When collected according to this protocol, data from 3T scanners can provide output parameter maps consistent with the accepted "double-dose" (of Gad) standard.
Despite its widespread use, MRI-DSC imaging has been plagued by inconsistent and suboptimal ways of acquiring and processing DSC-MRI data resulting in mixed opinions regarding its usefulness. Instead, IB Neuro has been honed and developed, over two decades, to account for subtle nuances in data acquisition and post-processing. It is the only MRI-DSC platform that offers truly quantitative output regardless of scanner platform, field strength, or time point and is the only commercial platform validated with tissue biopsy samples by multiple institutions.
IB Neuro is designed for seamless integration within the clinical workflow. The application can be networked as an additional node, residing between the scanner and the PACS. Acquired DICOM images are sent to the application, an array of DSC perfusion parameters are generated, and the resulting output and reports are automatically sent to the PACS for subsequent viewing. The quantitative output, exclusive to IB Neuro, enables longitudinal comparison and complete standardization across healthcare.
For 1.5T Scanners: Pulse Sequence: GRE-EPI (gradient-echo, echo planar imaging)Plane / Mode: Axial (Oblique Axial) / 2D Dosing Protocol (preload + bolus): “1 + 1” (pre-load, T1w+C, DSC bolus) “0 + 1” (DSC bolus, T1w+C)* Repetition Time: 1 – 1.5 sec Echo Time (TE): 45 ms (40 ms – 50 ms) Flip Angle (FA): “1 + 1” dosing: 60° (60°- 65°) or 30° (30°- 35°) “0 + 1” dosing: 30° (30°- 35°)* Total Time Points: 120 Baseline Time Points: 50 (30 – 50) Field of View: (220mm– 240mm) Acquisition Matrix: >/= 96 x 96 (96-128 x 96-128) Slice Thickness: 4 mm (4mm–5mm)- as needed for tumor coverage Slice Gap: 0mm (0mm-1mm) – as needed for tumor coverage Parallel Imaging: ≤ 2x (GRAPPA/SENSE/CAIPI) *Note: The 0+1 dosing acquisition protocol has not yet been experimentally validated at 1.5T. It has been experimentally validated at 3T. For 3T Scanners: Pulse Sequence: GRE-EPI (gradient-echo, echo planar imaging) Plane / Mode: Axial (Oblique Axial) / 2D Dosing Protocol (preload + bolus): “1 + 1” (pre-load, T1w+C, DSC bolus) “0 + 1” (DSC bolus, T1w+C) Repetition Time: 1 – 1.5 sec Echo Time (TE): 30o FA: 30 ms (25 ms – 35 ms) 60o FA: 30 ms (20 ms – 35 ms) Flip Angle (FA) “1 + 1” dosing: 60° (60°- 65°) or 30° (30°- 35°) “0 + 1” dosing: 30° (30°- 35°) Total Time Points: 120 Baseline Time Points: 50 (30 – 50) Field of View: (220mm– 240mm) Acquisition Matrix: 128 x 128 (96–128 x 96-128) Slice Thickness: 3 mm (3mm–5mm)- as needed for tumor coverage Slice Gap: 0mm (0mm-1mm) – as needed for tumor coverage Parallel Imaging: ≤ 2x (GRAPPA/SENSE/CAIPI) Post-Processing: IB Neuro’s leakage correction (BSW-based) For the “1+1” dosing protocol: 1. Perform the standard pre- and post-contrast brain imaging. Typically, a standard dose of Gd-chelated contrast agent (0.1 mmole /kg) is used for the post-contrast imaging. Note: The contrast that was administered for the standard post-contrast brain imaging acts as a “loading dose” to diminish T1 leakage effects that might occur during acquisition of the DSC data. See the references listed below describing the utility of using a pre-load of contrast agent for DSC-MRI studies (1-3). 2. Start the sequence. After collecting the recommended number of baseline timepoints, inject a bolus of a Gd-chelated contrast agent (typically 0.1mmole/kg at 3-5cc/sec, using a power injector) while the scanning continues. Note there should be at least 40 seconds of post-bolus signal, which is necessary for adequate correction of any contrast-agent leakage effects. For the “0+1” dosing protocol: Acquire the DSC-MRI data during the first injection of contrast agent according to step #2 above. The standard collection of post-contrast MRI data will follow the DSC-MRI acquisition. The administration and total dose of the contrast agent used must be in accordance with FDA guidelines. Literature Cited: 1. Schmainda KM, Rand SD, Joseph AM, et al. Characterization of a first-pass gradient-echo spin-echo method to predict brain tumor grade and angiogenesis. Am J Neuroradiol 2004; 25:1524-1532. 2. Boxerman J, Schmainda KM, Weisskoff RM. Relative cerebral blood volume maps corrected for contrast agent extravasation significantly correlate with glioma tumor grade whereas uncorrected maps do not. Am J Neuroradiol 2006; 27:859-867. 3. Jackson A. Analsyis of dynamic contrast enhanced MRI. The British Journal of Radiology 2004; 77:S154-S166. 4. Semmineh NB, Bell LC, Stokes AM, Hu LS, Boxerman JL, Quarles CC. Optimization of acquisition and analysis methods for clinical dynamic susceptibility contrast MRI using a population-based digital reference object. AJNR Am J Neuroradiol 2018 Oct 11 [Epub ahead of print.] 5. Boxerman JL, Rosen BR, Weisskoff RM. Signal-to-noise analysis of cerebral blood volume maps from dynamic NMR imaging studies. J Magn Reson Imaging. 1997; 7(3):528-37. Limitations A minimum number of baseline time points of 30 is recommended.