Abstract: FR-PO425
Magnetic Resonance Elastography (MRE) with Arterial Spin Labeling (ASL) Kidney Blood Flow for Noninvasive Evaluation of Diabetic Nephropathy
Session Information
- Diabetic Kidney Disease: Clinical - I
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 602 Diabetic Kidney Disease: Clinical
Authors
- Brown, Robert S., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Sun, Maryellen, Lowell General Hospital, Lowell, Massachusetts, United States
- Stillman, Isaac Ely, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Russell, Teresa L., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Rosas, Sylvia E., Joslin Diabetes Center, Boston, Massachusetts, United States
- Wei, Jesse L., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
Background
Noninvasive quantitative measurement of fibrosis in chronic kidney disease (CKD) would be advantageous diagnostically and therapeutically but standard radiologic imaging is too variable for clinical usage. Using MRE, by applying a vibratory force, shear waves are generated that can measure kidney parenchymal shear stiffness that may correlate with tissue fibrosis.
Methods
We used novel 3-dimensional MRE with ASL kidney blood flow rates to study 30 diabetic patients with stage 0 to 5 CKD compared to 13 control individuals without CKD.
Results
MRE cortical shear stiffness at 90 Hz was surprisingly decreased significantly below normal in diabetic nephropathy (DN) of stages 3-5 CKD. Likewise, cortical ASL blood flow decreased progressively from 480±136 ml/min/100g tissue in controls to 152±32 ml/min/100g in stage 5 CKD. Calculation of a surrogate filtration fraction (sFF = eGFR/ASL) decreased progressively from 0.21±0.07 in controls to 0.10±0.02 in Stage 4-5 CKD. To account for the effect of decreased blood flow which has been shown to decrease MRE kidney shear stiffness, we calculated a novel shear stiffness index normalized to blood flow (SSI = MR shear stiffness/ASL blood flow, Pa/ml/min/100g cortical tissue). The SSI increased progressively from 12±3 in the controls to 26±4 in stage 5 CKD. This significant increase of the SSI also correlated with the grade II-V interstitial fibrosis in DN graded ‘blindly’ by biopsy in 5 patients.
Conclusion
MRE coupled with ASL blood flow rates can noninvasively measure kidney tissue perfusion, quantitate a sFF proportional to measured filtration fractions, and calculate a novel shear stiffness index that correlates with the degree of kidney fibrosis in worsening diabetic nephropathy.
| Controls | DM, No Neph | DN, CKD1 | DN, CKD2 | DN, CKD3 | DN, CKD4 | DN, CKD5 | |
| ASL (ml/min/100g) | 480±136 | 593±12 | 446±161 | 392±123 | 302±95*** | 229±7** | 152±32*** |
| sFF (eGFR/ASL) | 0.21±0.07 | 0.18 | 0.31±0.10* | 0.19±0.07 | 0.16±0.04* | 0.10±0.02* | 0.10±0.02* |
| Shear Stiffness, Pa | 5592±693 | 5892±623 | 4876±589* | 4978±447* | 4829±1023** | 4786±703** | 3968±942** |
| SSI (Pa/ml/min/100g) | 12.1±3.2 | 10.8±1.1 | 12.5±3.7 | 14.1±5.2 | 17.2±5.6** | 21.2±2.1*** | 26.4±4.4*** |
Funding
- NIDDK Support