Neuromorphological Scan Review Rating Guide

using ImageEval toolH. Jeremy Bockholt

20081203

General Instructions• For each image in a scan session

– Step through each slice in the plane of acquisition– Note if the scan is complete– Note if motion exists within or across the slice– Rate SNR of image, {0-2}– Rate CNR of image, {0-2}– Note pockets of lowered SNR or CNR and downgrade the overall rating if excessive amounts of lowered

SNR/CNR are encountered• Think of this as all scans start out at a 2 and get downrated accordingly, a 0 of either SNR or CNR would also likely

indicate that the overall rating is a 0 and that image should not be used for the reason indicated (i.e., SNR or CNR).– Note any flow artifact or inhomogeneity– Indicate if any lesions or variants are found– Make a note of any large problems or issued encountered– Rate the overall image, {0-2}

• N.b., the overall rating reflects all issues, so if you choose 2, any issue such as motion or inhomogeneity is assumed to be minor; alternatively, you may have SNR=2,CNR=2, but overall of 1 with motion or inhomogeneity turned on, this would indicate that the scan has excellent SRN, and CNR, but suffers from motion and inhomogeneity artifacts for it to be overall excellent. Finally, rate the overall a 0 if any of the checked issues with the image make the scan not usable.

– Remember to Click Evaluation Complete when finished rating each scan of the imaging sessions– Use the built-in tool tips and following guide for any further questions

Lesion

Note the presence of lesions on all types of sequences, indicate also when they are hyperintense on T2

Banding Artifact

Pd image example of banding artifact from a 2D acquisition of a pd t2 paired sequence. There is inhomogeneity across slices that will need to be corrected in 2D to fix this issue. The rater should select inhomogeneity when this issue is found.

T1 Example

SNR=1CNR=2

Scan is free of motion artifact susceptibility artifact, bias and other problems

Overall=2

T2 ExampleMotion artifact within slice

T2 Example

SNR=1CNR=2

Scan is free of motion artifact susceptibility artifact, bias and other problems

Overall=2

Pd Example

SNR=1CNR=2No motion artifact within slice or across slicesNo susceptibility artifact or flow artifactNo InhomogeneityOverall=2

T2 Example Misalignment

SNR=1CNR=2T2 MisalignmentMotion artifact also found within sliceNo flow artifactFull Brain coverageOverall=1

Cut-off example

To indicate image is cut off, select no to full brain coverage

Above Pd Slight posterior cut-off notedSNR=1, CNR=2, no motion within across slices nor inhomogeneity, Overall=1

Example Variants

EnlargedVirchow-Robin Spaces

Cortical Atrophy notedMake a note of anything that appears abnormal in terms of anatomy by selecting the normal variant flag, if possible make a note of what the normal variant is by using the notes field

Example Flow Artifact

Arterial flow or ventricular flow should be indicated as flow artifact

T2 Example

SNR=1CNR=2Scan is free of motion within and across slicesNo inhomogeneityNo flow artifactOverall=2

T1 Example

CNR=2SNR=2No motion, flow, susceptibility artifactsOverall=2

T1 Example

SNR=1CNR=1Inhomogeneity notedMotion artifact notedNo flow artifactOverall=1