radiology for the first year gi fellow - nysge › files › kagen_nysge fellows summer cours… ·...

ACR Overview MRCP Liver Gadoxetate sMRCP MRE MRD

NYSGE Summer Fellows Course

Radiology for the First Year GI Fellow

Alexander C. Kagen, M.D.

Department of Radiology, Site Chair

Mount Sinai West

Mount Sinai St. Luke’s

Associate Professor of Radiology

Icahn School of Medicine at Mount Sinai



Goals & Objectives

1. ACR Appropriateness Criteria

2. Radiology Overview

3. MRI

4. MRCP

5. Liver

6. Gadoxetate Disodium (EOVIST®)

7. Secretin MRCP

8. MR Enterography

9. MR Defacography



Disclosures

1. Speaker’s Bureau

• Lantheus Medical Imaging

• Bayer Healthcare

2. Off Label Discussion:

• Gadoxetate Disodium (Biliary Imaging)



American College of RadiologyAppropriateness Criteria(www.acr.org)

Good resource for Attendings & Fellows

Evidence-Based

Clinical Variants/Vignettes

Ties in Radiation Levels



I. Radiography:I. X-rayII. Fluoroscopy

I. SwallowII. UGIIII. SBSIV. BEV. SinogramVI. Tube Check



II. UltrasoundI. Abdomen/RUQII. LiverIII. AppendixIV. Abscess/DrainageV. EUS



III. CTI. RoutineII. Pancreas- Solid massIII. CT EnterographyIV. CT Colonography

Positive Oral Contrast

Negative Oral Contrast



III. CTI. RoutineII. CT EnterographyIII. CT Colonography



IV. MRII. MRCPII. LiverIII. Gadodexate DisodiumIV. Enhanced MRCPV. Pancreas- cysticVI. MR EnterographyVII. MR Defacography



MRCP

•Exploit High Soft Tissue Contrast

•Display Biliary System

•Exploit Functional/Biological Properties



MRCP Protocol

•Fluid Sensitive MRCP (wait for all the other tissue signal to subside)

T2 MRCP

2D

Thick Slab (40mm)

Thinner Slices (5mm)

3D

VERY Thin 0.8mm slices

Jhaveri, ISMRM 2011



CHD- Common Hepatic Duct

CBD- Common Bile Duct

PD- Pancreatic Duct

CHD

CBD

PD

Duodenum

Cystic Duct

2D Thick Slab MRCP



•Contraction atSphincter of Oddi

•Acquire Multiple Dynamic MRCP Images to Check for Spasm vs Filling Defect

MRCP Protocol

•2D Thick Slab MRCP

Mortele, Radiographics 2006



2D Thick Slab MRCP- SSFSE

1-Straight Coronal x 10

2-15 Degree Oblique x 10


x10






3-15 Degree Oblique x 10x10







x10



MRCP Protocol


T2 MRCP

2D

Thick Slab (40mm)


3D


Jhaveri, ISMRM 2011



MRCP Protocol

2D Thinner Axial T2 weighted images (5mm)

Outline pancreatico-biliary system and plan for 3D sequence



MRCP Protocol


T2 MRCP

2D

Thick Slab (40mm)


3D


Jhaveri, ISMRM 2011



•Behind Aorta

•Anterior to pancreas

MRCP Protocol



MRCP Protocol:

Choledocholithiasis:-2mm or larger-T2 hypointense-T1 hyperintense-Gravity dependent-Sens 81-100%, Spec 85-100%

Guiband L, Radiology 1995

Becker, Radiology 1997

Fulcher, Radiographics, 1999

Soto, AJR 2000

Jhaveri, ISMRM 2011



MRCP Protocol:

Filling Defect Differential Diagnosis:-Pneumobilia (Air) >> will rise-Flow artifact >> central & crossing vessel-Stent or Clip (metal artifact)-Neoplasm, Blood clot

Jhaveri, ISMRM 2011



Liver MRI:

Diffuse Disease:NAFLDIron DepositionFibrosis/Elastography

Focal Disease:Primary

Benign (Cyst, Hemangioma, Infection)Malignant (HCC, CCC, Mixed)

SecondaryMetastasis

Vascular (Shunts)Transplant Evaluation



NAFLD

Opposed Phase In Phase2.2 ms 4.4 ms

% Signal Loss: SI (IP) – SI (OP) x 100SI (IP)

> 10% = Fatty Liver



IN & Opposed Phase Imaging- Fat Fraction



Dixon technique for Fat SaturationObtain 4 sequences in 1 Breath-Hold:

-Fat Only-Water Only-In phase-Opposed phase

“Fat Only” Image



Iron Deposition

•Moderate Liver (LIC = 120umol/g)

•Major Overload (LIC = 350umol/g)



MR Elastography

•Acoustic pressure waves (at 60 Hz) are generated by an active audio driver outside MRI suite

•Transmitted via a flexible tubing to a passive pneumatic driver placed over the anterior body wall

Yin et al. Clin GI & Hep 2007;5:1207-1213



MR Elastography

•Fibrotic Liver has higher mean shear stiffness

Yin et al. Clin GI & Hep 2007;5:1207-1213



MR Elastography▶Correlation with Histology: F0/1/2 vs. F3/4

▶Limitations: inflammation

Yin et al. Clin GI & Hep 2007;5:1207-1213Yin et al. Radiology 2016;278:114-124



Functional Evaluation with MRI

▶MR Elastography: Assess liver stiffness through pressure waves– MRI > FibroScan® (Transient Elastography)– MRI > ARFI (Acoustic Radiation Force Impluse)

▶Diffusion Weighted Imaging (DWI): Assess liver stiffness through water motion restriction

▶ T1ρ: assessing slow molecular motion and thus predicting hepatic fibrosis

Yin et al. Clin GI & Hep 2007;5:1207-1213Taouli B AJR 2007; 189(4):799–806

Sirlin, C. Radiology; 259:3, June 2011Cui J. Hepatology Nov 2015

Sporea I. Medical Ultrasonography; 12:1 2010



Fibroscan (1D Transient Elastography)

VTouch (Point shear wave Elastography)

Shear Wave Elastography

MR Elastography

Tang et al, AJR:205, July 2015



Gadoxetate disodium

Applications: Focal liver lesion characterization

Off label use:•Biliary Leak•Cystic Duct Patency•Biliary Stenosis•Biliary Stent Patency•*Delayed Biliary Transit•Congenital Variants (i.e. Choledochal cysts)

Gupta, AJR 2010



Bile

Cann

alicul

us

Sinusoid

Goodwin, RadioGraphics 2011

Dual Elimination:•50% Renal•50% Hepatic

Signal Intensity to due presence of contrast in bile ducts & hepatocytes

Mechanism of action

Hepatocyte

OATP8 cMOAT



-Hypervascular Lesions-Do NOT retain Eovist on Hepatocyte phase

Hepatic Art Phase

Hepatocyte PhaseHepatocyte Phase



Biliary Excretion



CN LGDN HGDNEarly

HCC

Small &

progressed

HCC

Large &

progressed

HCC

Tumor HA

Normal HA

PV

Intra-nodular blood supply

Organic anion

transporting

polypeptide

(OATP)

expression

Some LGDN, many HGDNs, many early

HCCS, and most progressed HCCs have

reduced OATP expression

Only progressed HCCs have

arterial hypervascularity

Courtesy of Claude Sirlin, MD



Vascular Shunts and Early HCC

▶Benign pseudolesions (arrows)

▶Hypovascular HBP hypointense eHCC (arrowhead)



62 y/o female, Elevated LFTsMRI with Extracellular Agent

MRI with Gadoxetate Disodium

Hepatobiliary Phase (20 min post injection



MRI with Gadoxetate Disodium: Additional Lesions



-Remote history of partial hepatic transplantation-Suspected anterior abdominal wall biloma

-Excreted contrast in fluid collection after 15 minutes confirms biloma. Location of bile leak (arrow) identified

Gupta et al, AJR. (2010) 195:405-413.



-Evaluate stent patency.

-Excreted contrast in stent at 15 minutes confirms stent patencyGupta et al, AJR. (2010) 195:405-413.

5 min

15 minT2 MRC

Stent



PRE POST

sMRCP



sMRCP:

-Stimulates Pancreatic Secretion-Potentially assist Cyst vs IPMN

-Screening for Cystic Pancreatic neoplasms(>2 relatives with a history of pancreatic cancer)

-Store at -20ºC-0.2 mcg/kg SLOWLY over 1 min-Start with 1/10th the dose to test for allergy



GI Anatomy on MR Enterography (MRE)

T2-WI T1-Post Contrast



GI Anatomy on MR Enterography (MRE)



MRE Protocol

•Combination of functional imaging (dynamic imaging, contrast enhancement) and anatomic imaging (T1-and T2-weighted sequences) are needed for pathology detection and characterization



MRE Protocol

•FUNCTIONAL IMAGING

•Cine Sequences•“Movies” of the small bowel can survey motility and strictures

•Contrast enhanced sequences•Can detect areas of inflammation



MRE vs CTE

MRI:•Lack of ionizing radiation•Superior tissue contrast

Repeatability: assessing disease progression disease, detecting complications, monitoring response to therapy

CTE:•Faster•Less Artifacts•Baseline Study



MRE Indications

Crohn Disease (Baseline study is usually CTE)

Postoperative adhesionsCeliac diseaseRadiation enteritisSclerodermaSmall bowel malignancyPolyposis syndromesChronic Abdominal Pain of unknown cause

Tolan et al. RadioGraphics 2010; 30:367–384Lee et al. Radiology:251, June 2009



MRE Findings

Wall ThickeningFold ThickeningUlcerationStrictureAcute Wall EdemaWall FatWall EnhancementPseudosacculation-PseudodiverticulumExtra-enteric Assessment

Tolan et al. RadioGraphics 2010; 30:367–384Lee et al. Radiology:251, June 2009



MRE Findings



MRE Findings

Masselli et al. Abdom Imaging 2004;29(3): 326–334Punwani et al. Radiology 2009;252(3):712–720

Tolan et al. RadioGraphics 2010; 30:367–384



MRE Findings



36 y/o female with long standing crohn's ileitis (approximately 5cm) on Cimzia with progressively worsening inflammatory markers and obstructive symptoms

Initial Study 2-year Follow Up



20122012

T1+Gad: Active InflammationT2WI: Relatively Little Edema

Path•Relatively low level of wall edema•Ulceration, Fissuring, Transmural chronic inflammation



* *

MRE Findings: •Pseudo-sacculation•Short and long segment strictures (3-4)•Prominent mesenteric fat (fat wrapping)



MRE Findings: Long segment active stricture



MRE: Abscess



Common Pelvic Floor Disease: 300,000 – 400,000 Women undergo Surgery1/3 recur

Vaginal Birth: 8-Fold Increase in prolapse

Major Levator Ani Injury is caused by vaginal Delivery in 10-12% of women

Incontinence: Urinary or Fecal

Prolapse: Imaging for Organ Descent, Levator Ani Muscles

MR Defacography (MRD)



Pelvic Compartments:

Anterior- Cystocele, Urethrocele

Middle- Uterus/Vaginal Prolapse, Enterocele, Sigmoidocele

Posterior- Rectocele (>3cm Descent OR 2-3cm bulge anterior to anterior anal line)

Pubococcygeal Line (PCL):Inferior Pubis to Last Coccygeal Joint

MR Defacography (MRD)



Cystocele,Urethral HypermobilityEnterocele,Rectocele & Prolapse



Poor Evacuation Good Evacuation



Summary

•Evidence based guidelines for image utilization of the GI Tract (ACR Appropriateness Criteria)

•Dynamic and high resolution imaging possible of the biliary tree and GI tract leading to better characterization of pathology

•Molecular Imaging with Gadoxetate Disodium (EOVIST®) for better detection and characterization of Hepatic lesions



Thank You

[email protected]

radiology for the first year gi fellow - nysge › files › kagen_nysge fellows summer cours… ·...

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