Table 1.
International Standardized Brain Tumor Imaging Protocol (BTIP) minimum image acquisition requirements for 1.5T and 3T MR systems
| Variable | 3D T1w Preb | Ax 2D FLAIRj | Ax 2D DWI | Contrast Injectiona | Ax 2D T2wh,i | 3D T1w Postb |
|---|---|---|---|---|---|---|
| Sequence | IR-GREe,f | TSEc | SS-EPIg | TSEc | IR-GREe,f | |
| Plane | Sagittal/Axial | Axial | Axial | Axial | Sagittal/Axial | |
| Mode | 3D | 2D | 2D | 2D | 3D | |
| TR [ms] | 2100m | >6000 | >5000 | >2500 | 2100m | |
| TE [ms] | Min | 100-140 | Min | 80-120 | Min | |
| TI [ms] | 1100n | 2000-2500k | 1100n | |||
| Flip angle | 10°-15° | 90°/≥160° | 90°/180° | 90°/≥160° | 10°-15° | |
| Frequency | ≥172 | ≥256 | ≥128 | ≥256 | ≥172 | |
| Phase | ≥172 | ≥256 | ≥128 | ≥256 | ≥172 | |
| NEX | ≥1 | ≥1 | ≥1 | ≥1 | ≥1 | |
| FOV | 256mm | 240mm | 240mm | 240mm | 256mm | |
| Slice thickness | ≤1.5mm | ≤4mml | ≤4mml | ≤4mml | ≤1.5mm | |
| Gap/Spacing | 0 | 0 | 0 | 0 | 0 | |
| Diffusion optionsp | b = 0, 500, 1000 s/mm2 ≥3 directions | |||||
| Parallel imaging | Up to 2x | Up to 2x | Up to 2x | Up to 2x | Up to 2x | |
|
Approximate scan time |
5-10 min | 4-8 min | 2-4 min | 4-8 min | 5-10 min |
Ax = Axial; ADC = apparent diffusion coefficient; FLAIR = fluid attenuated inversion recovery; DWI = diffusion-weighted imaging; 3D = three dimensional; TSE = turbo spin echo; EPI = echo planar imaging; SS-EPI = single-shot echo planar imaging; GE-EPI = gradient echo echo planar imaging; 2DFL = two-dimensional FLASH (fast low angle shot) gradient recalled echo; MPRAGE = magnetization prepared rapid gradient-echo; A/P = anterior to posterior; R/L = right to left; NEX = number of excitations or averages; FOV = field of view; TE = echo time; TR = repetition time; TI = inversion time; PD = proton density; DSC = dynamic susceptibility contrast; IR-GRE = inversion-recovery gradient-recalled echo
a0.1 mmol/kg dose injection with a Gadolinium chelated contrast agent. Use of a power injector is desirable at an injection rate of 3-5cc/s
bPost-contrast 3D T1-weighted images should be collected with equivalent parameters to pre-contrast 3D T1-weighted images
cTSE = turbo spin echo (Siemens & Philips) is equivalent to FSE (fast spin echo; GE, Hitachi, Toshiba)
dFL2D = two-dimensional fast low angle shot (FLASH; Siemens) is equivalent to the spoil gradient recalled echo (SPGR; GE) or T1- fast field echo (FFE; Philips), fast field echo (FastFE; Toshiba), or the radiofrequency spoiled steady state acquisition rewound gradient echo (RSSG; Hitachi). A fast gradient echo sequence without inversion preparation is desired
eIR-GRE = inversion-recovery gradient-recalled echo sequence is equivalent to MPRAGE = magnetization prepared rapid gradient-echo (Siemens & Hitachi) and the inversion recovery spoiled gradient-echo (IR-SPGR or Fast SPGR with inversion activated or BRAVO; GE), 3D turbo field echo (TFE; Philips), or 3D fast field echo (3D Fast FE; Toshiba)
fA 3D acquisition without inversion preparation will result in different contrast compared with MPRAGE or another IR-prepped 3D T1-weighted sequences and therefore should be avoided
gIn the event of significant patient motion, a radial acquisition scheme may be used (e.g. BLADE [Siemens], PROPELLER [GE], MultiVane [Philips], RADAR [Hitachi], or JET [Toshiba]); however, this acquisition scheme is can cause significant differences in ADC quantification and therefore should be used only if EPI is not an option. Further, this type of acquisition takes considerably more time
hDual echo PD/T2 TSE is optional for possible quantification of tissue T2. For this sequence, the PD echo is recommended to have a TE < 25ms
iAdvanced sequences can be substituted into this time slot, so long as 3D post-contrast T1-weighted images are collected between 4 and 8 min after contrast injection
j3D FLAIR is an optional alternative to 2D FLAIR, with sequence parameters as follows per EORTC guidelines: 3D TSE/FSE acquisition; TE = 90-140ms; TR = 6000-10000ms; TI = 2000-2500ms (chosen based on vendor recommendations for optimized protocol and field strength); GRAPPA ≤ 2; Fat Saturation; Slice thickness ≤ 1.5mm; Orientation Sagittal or Axial; FOV ≤ 250 mm x 250 mm; Matrix ≥ 244x244
kChoice of TI should be chosen based on the magnetic field strength of the system (e.g. TI ≈ 2000ms for 1.5T and TI ≈ 2500ms for 3T)
lIn order to ensure comparable SNR older 1.5T MR systems can use contiguous (no interslice gap) images with 5mm slice thickness or increase NEX for slice thickness ≤4mm
nFor Siemens and Hitachi scanners. GE, Philips, and Toshiba scanners should use a TI = 400-450ms for similar contrast
mFor Siemens and Hitachi scanners. GE, Philips, and Toshiba scanners should use a TR = 5-15ms for similar contrast
pOlder model MR scanners that are not capable of >2 b-values should use b = 0 and 1000 s/mm2