Transcript NIH PCKD/Emory University

NIH PCKD/Emory University
MRI Imaging
Report 1/31/2000
Overview
• 2 Patients Scanned with NIH Protocol
• Both: Comparison with “Old Protocol”
– Visual comparison
– No SNR measurements performed
• No Breathhold Flow Quantification (Yet)
– Philips scanner should be capable
– Little experience; Validation experiments?
T2-Weighted Multi-Slice (#1)
Old Protocol (3 mm)
Multiple Breathholds
NIH Protocol (5 mm)
Single Breathhold
T2-Weighted Multi-Slice (#2)
Old Protocol (3 mm)
Multiple Breathholds
NIH Protocol (5 mm)
Single Breathhold
T2-Weighted Imaging: Remarks
• 3 mm slice thickness resolves cysts better
• Fat Suppression useful, works well
• Multiple-breathhold: registration needed
– Kidney “rigid object”: overlap + affine Xform
– Avoid misregistration between interlaced stacks
• Role in image analysis?
T1-Weighted 3-D (PRE-#1)
Old Protocol (2.5/5 mm)
=40 Single Breathhold
NIH Protocol (2.5/5 mm)
=12 Single Breathhold
T1-Weighted 3-D (PRE-#2)
Old Protocol (2.5/5 mm)
=40 Single Breathhold
NIH Protocol (2.5/5 mm)
=12 Single Breathhold
T1-Weighted 3-D (POST-#1)
Old Protocol (2.5/5 mm)
=40 90 s post-Gado
NIH Protocol (2.5/5 mm)
=12 120 s post-Gado
T1-Weighted 3-D (POST-#2)
Old Protocol (2.5/5 mm)
=40 60 s post-Gado
NIH Protocol (2.5/5 mm)
=12 120 s post-Gado
T1-Weighted 3-D
heart
liver
Ghost artifact due to heart motion (?)
Apply pre-saturation slab anterior to
volume to reduce intensity?
T1-Weighted Imaging: Remarks
• NIH protocol (=12) better overall SNR
– Pre- & post-contrast: more complex image
– Segmentation easier? (CNR measurements)
• Coil placement important! Difficult?
• Pre-saturation slabs? Added acq. time?
• Older patients:
– Many breathholds taxing to patient
– Only 90 or 120 s post contrast?