X Liver MRI in 30 minutes SCBT/MR Annual Meeting Salt Lake City September 18, 2016 Scott B. Reeder, MD, PhD Department of Radiology University of Wisconsin Madison, WI
Disclosures University of Wisconsin-Madison receives research support from GE Healthcare, and Bracco Diagnostics Founder Calimetrix, LLC Shareholder Elucent Medical Consulting - Parexel International
Overview: Standard Abdominal Protocol Coronal T2w SSFSE (1-2 BH) T1w In/Out Phase (1-2 BH) Injection Pre-contrast 3D-T1w (1 BH) Late Arterial 3D-T1w (1 BH) Portal Venous 3D-T1w (1 BH) Axial T2w FSE (3-4 min) Equilibrium 3D-T1w (1 BH) DWI (2-3 BH) Dynamic T1w Imaging (5-7 min) b=0-50 b=500-800 ADC
Localizers Three plane localizers Perform during same breath-holding maneuver Practice for patient, more accurate prescription Help determine how long patient can hold breath Check coil position to ensure well positioned SSFSE (HASTE) SSFP (FIESTA, true-fisp, BFFE) Contain a great deal of diagnostic information Don t forget to review Corner shots!
Signal T2 Weighted Imaging Fluid Tumor Liver Echo Time (TE)
Coronal SSFSE: 1-2 breath-holds High resolution Rapid, robust overview of anatomy and pathology Surgeons like the coronal view Coronal useful to prescribe axial volumes Should it replace conventional T2w-FSE?? Altered contrast Extended echo train = mix of spin-echoes & stimulated echoes Metastatic disease difficult to visualize Great for cysts and hemangiomas
Examples Hemangioma and Renal Cyst Patient 1 Patient 2 Patient 3 Biliary cystadenoma Caroli s disease
Case: Metastatic Adenocarcinoma T2w FSE with FS T2w SSFSE DWI (b=500) Metastases Inconspicuous On T2w SSFSE Is this a problem??
Hepatic metastasis, rectal CA Precontrast Arterial Delayed T2 FS DWI Case, courtesy Bobby Kalb, MD, University of Arizona
21 yo F, intrahepatic cholangioca Precontrast Arterial Delayed T2 Ax MRCP Case, courtesy Bobby Kalb, MD, University of Arizona
Fat-Iron Sensitive Sequences In-phase and opposed-phase Liver Detection (qualitative) of hepatic steatosis Mass-mimicking steatosis Focal fat Focal sparing Mass characterization HCC Hepatic adenoma Angiomyolipoma Adrenal masses Renal masses (AML, RCC)
Detection of Fat with MRI: In and Opposed Phase (2-point Dixon) Opposed-Phase (W-F) In-Phase (W+F)
Case : Renal Mass Histology: Clear Cell Renal Cell Carcinoma
Case: Hemosiderosis Axial out-of-phase Axial in-phase Axial T2w FSE Coronal T2w SSFSE
Enhancement Phases of Enhancement: Extracellular Contrast Agents HA PV Liver Tumor Time inject
Enhancement Phases of Enhancement: Extracellular Contrast Agents Arterial Late Phase Arterial Phase Portal Venous HA PV Liver Tumor Time Pre inject Late HAP PVP Equilibrium
Patient 3 Patient 2 Patient 1 Cases: Contrast Enhanced T1w Normal Focal Nodular Hyperplasia Renal Cell Carcinoma
Diffusion Weighted Imaging Unrestricted (fluid) Larger ADC (more signal loss) Restricted (cells) Smaller ADC (less signal loss)
DWI: Optional Sequence Suppresses tissues with freely diffusing water Increased conspicuity: lesions with high cellularity Applications Detection and characterization of malignancy helpful for metastatic disease in the liver Not helpful for HCC Pearls: b = 0 is just T2-weighted S=S o e -TE/T2 b > 0 is both T2- & diffusion-weighted S=S o e -TE/T2 e -badc
DWI: Optional Sequence Image quality insufficiently reliable Used with echo planar imaging Distortion, signal dropout (left lobe of liver) Failed fat suppression Problem on all vendors Cannot rely on this sequence alone for detection Pearl: important, but least reliable. Perform last!
Cases: 58yo M with Colorectal Cancer 2x10-3 mm 2 /s Restricted diffusion: high cellularity Axial DWI (b=500) ADC Map (mm 2 /s) 0 mm 2 /s
Abdominal MRI: Current Protocol Dynamic T1w CE-MRI - Detect lesions - Characterize - Vascular T2w MRI - Detect lesions - Characterize - Biliary, renal T1w Fat/Iron Sensitive - liver - pancreas - adrenal glands DWI - Detect lesions - Characterize - Diffuse liver dz Neuroendocrine Mets MRCP - Biliary dz - Pancreas - Surgical Cx s Pancreatic AdenoCA
Enhancement Phases of Enhancement: Extracellular Contrast Agents Late Arterial Phase Portal Venous HA PV Liver Tumor Equilibrium Time inject 3-4 minutes
Time Resolved MRI: Interleaved Variable Density Injection 24s Pre-Contrast T1 # 1 # 2 # 3 # 4 # 5 Portal Venous Phase Equilibrium Phase Dynamic IVD k y k z
Time Resolved MRI: Interleaved Variable Density 4s temporal resolution Focal Nodular Hyperplasia x 4
Data Acquisition: 3D Cartesian High Temporal & Spatial Resolution 2.0 mm isotropic 40 (L/R) x 32 (A/P) x 20 (S/I) cm 3 4.0 sec/frame 3x 20s breath-holds 3T, GE Discovery MR 750 32-channel Torso Phase 5, end of 1 st BH Phase 6, start of 2 nd BH Wang et al ISMRM 2012, 3867
Basic Liver MRI: Current Protocol Contrast Localizers (1 min) T1w IOP (1 min) T2W (1 min) DWI (3-5min) 3D T1w (3-4 min) ~20-25 minutes
Basic Liver MRI: Suggested Approach DWI (b=0) T2 weighted Contrast image! Localizers (1 min) Dual Echo (Dixon) T1w IOP 3D T1w DCE-MRI (1 min) (3 minutes) T2W (1 min) Advanced DWI (b=500) T2w + DWI DWI (1 breath-hold) (3-5min) 3D T1w (3-4 min) Water Fat < 5 minutes Combine In-phase Dixon Opposed fat-water Phase imaging with 3D CE-MRI Combine DWI with T2 weighted imaging** Eliminate localizers**
Thank you! Alex Frydrychowicz, MD Scott Nagle, MD, PhD Jeff Weinreb, MD Claude Sirlin, MD Grant Support WARF Accelerator NIH: R01 DK083380 R01 DK088925 R01 DK096169 RC1 EB010384