How To’s – ASL Perfusion & DCE Permeability
The goal is to quantify the perfusion and permeability parameters of a brain tumor using DCE and ASL.
Two sequences are used to compute perfusion and permeability: pASL for CBF estimate and T1-weighted DCE for fBV and kPS quantitation.
Part I: the CBF estimate from pASL
First, in the “DataBase” Tab, click on the patient name “Meningiome”, then click on the serie date “20131016 ” and double-click on the serie name ‘ASL_SinglePhase”. The serie will be loaded and displayed:
Once done, go to the “Series Processing” Tab, in the “MR Perfusion / Permeability” Tab, and in the “DCE / ASL” Tab:
Then click on “Compute ASL”. The software will batch process the loaded serie with Brain Extraction, Motion Correction:
Then Registration to Template, and will compute the CBF from pASL:
Computed CBF serie name is: “aBF_reg_MoC_Msk_ASL_SinglePhase-Map”. Go to the “DataBase” Tab, and double-click on it to load and display it. Change the 3D View mode to MPR View by clicking on the “MPR/3D” button in the “MPR/3D Display” Tab:
Transparency of the map can be changed by clicking on the Transparency List-Box in the “Overlays” Tab:
Part II: quantifying the Permeability from T1-w DCE
As DCE in T1-w can be used either in Brain or other body organs (Breast, Prostate, …), automated processes such as Brain Extraction, Motion Correction and Template Registration are not automatically performed by the software, and have to be set manually.
First you need to load and display the T1-w DCE Dynamic sequence. In the “DataBase” Tab, click on the patient name “Meningiome”, then click on the serie date “20131016” then double-click on the serie name “T1 DYNAMIQUES”. The serie will be loaded and displayed:
Then you need to extract the Brain. In the “Image Tools” Tab, click on “Multi-Volume Brain Extract” button. A new serie”Msk_T1_DYNAMIQUES” will be generated in the local DataBase:
Double-click on this serie to load and display it, then click on the “Motion Artifact Correction”.
A new serie called “MoC_Msk_T1_DYNAMIQUES” will be generated in the local DataBase. Double-click on it to load and display, then click on “Register to Template”:
A new serie called “Reg_MoC_Msk_T1_DYNAMIQUES” will be generated. Double-click on it to load and display:
This serie has to be thresholded. First right-click on the Right Image zone, select the “Native Series” menu, “Explorer” sub-menu and “Navigate” item:
Left click on this image and move the mouse from top to bottom to change the slice location until you see the brain. Then select by right click on this image the “Adjust” menu, “Threshold” item, and left click from left to right to adjust the threshold until you see the brain only:
You can also navigate through time, either by going on the “Navigate” item and left click from left to right, or by moving the “Time” Slider:
Once everything is set, you can click on the “Compute DCE” button to compute fBV and kPS. After computing, a new serie will be created in the local DataBase called “fBV_Reg_MoC_Msk_T1_DYNAMIQUES-Map”. Double-click on it to load and display:
You can set VOI on the lesion. Go to the “ROI/VOI Drawing” Tab, select “Red” in the VOI Color area, and draw on the MPR around the lesion. VOI values will be displayed on the VOI Grid on the right of the screen: