EDUARDO D CAMPUZANO BS,RT(R,MR,CT) MR UROGRAPHY EDUARDO D CAMPUZANO BS,RT(R,MR,CT)

MR UROGRAPHY MR Urography (MRU)- Have the potential to provide a comprehensive assessment of the urinary system, renal parenchyma, vascular structures, and surrounding tissues

OBJECTIVES INDICATIONS PREPARATIONS PROTOCOL FINDINGS PITFALLS SUMMARY

URINARY SYSTEM Diagnostic modalities: IV Urogram Renal Ultrasound CT Urography MR Urography CT is the imaging of choice for acute symptoms

INDICATIONS Clinical Indications: Hematuria Urolithiasis Stricture/Obstructions Anomalies Neoplasm Renal Insufficiency/Allergy Pregnancy/Pediatrics

MR UROGRAPHY Advantages over CT Urography: Elimination of ionizing radiation Non Ionic Contrast Contrast Resolution Non Contrast imaging (T2 Imaging) Disadvantages vs. CT Urography: Claustro/Implants CT: 15 min vs. MR: 45 min Spatial resolution ( 3-6 mm) Calcifications not seen Cost Uncooperative patient CT is the modality of choice for acute symptoms

PATIENT PREPARATION 250 ml IV normal saline solution Furosemiode/Lasik PO Water (30 minutes prior to MRI) Furosemiode/Lasik Non Dilated Systems Glucagon Minimized Peristalsis Intravenous Contrast (Multihance) Single Dose Lasik and Saline/Water improves urine production, dilutes urine.Furosemiode improves distention and opacification in non dilated system(better for static-fluid Urogram)

MR UROGRAPHY PROTOCOL Pre Contrast T2* SSFP Axial FS T2 SSTSE Axial FS T2 SSTSE Cor Diffusion Axial T2 Axial TSE FS T1 Cor 3D GRE FS T1 Axial 3D GRE (Dixon) T2 3D Cor Nav SSH T2 Cor & Sag Cine T1 3D COR GRE (Pre) Post Contrast T1 3D COR GRE (Arterial) T1 3D COR GRE (60 sec) T1 3D COR GRE (120 sec) T1 3D COR GRE (Delays) T1 3D GRE FS Axial T1 3D GRE FS Cor T2 SSTSE Cor (Post Void)

Comprehensive MR Urogram Static-Fluid 2D/3D Urogram (T2) Independent of renal excretory, uses urine as contrast 2D Cine SSH sequence allows visualization of moving urine 3D sequences best with dilated/obstructed system. Excretory 3D Urogram (T1) Dependent of renal excretory Good for non dilated system. Provides function and morphology MRU/MRI/MRA provides a complete assessment of the Urinary System T2 3D Static Fluid 2D Cine Static Fluid T1 3D Excretory

MR UROGRAPHY Positioning Abd/Pelvis Scout Coronal Positioning Ureters Cover from Above Kidneys to below Bladder for all Axials Cover entire Anatomy (Kidneys,Ureters ,and Bladder)

MR UROGRAPHY Positioning Axial T2 TSE Fat Sat Coronal Positioning Ureters Cover entire Anatomy (Kidneys,Ureters ,and Bladder)

3D UROGRAM Coverage Increase coverage on the 3D volume (cost time) Angle 3D volume to cover entire anatomy (Kidneys,Ureters and Bladder)

Maximum Intensity Projection (MIP) 3D T2 Static-Fluid Maximum Intensity Projection (MIP) Volume Rendering (VR) Place Navigator Box, on your Coronal images. Check box placement in the Axial images.

SSH T2 Coronal Cine Except only 1 slices in multiple measurements Same sequence as a Single Shot MRCP Except only 1 slices in multiple measurements

SSH T2 Coronal Cine Positioning 1- Sagittal Scout SSH T2 (Cine) COR 2D Slab SSFSE ( Red Box) Sat Band (Yellow Box),angle if needed Use 8-12 Dynamics(cine) Wait 5-10 secs between dynamics

SSH T2 Sagittal Cine Positioning 1- Coronal SSH SSH T2 (Cine) Sag Use 8-12 Dynamics(cine) Wait 10 secs between dynamics 2D Slab SSFSE ( Red Box),70-80 cm Angle if needed ,do Both Kidneys.

SSH T2 Sagittal Cine Positioning 1- Coronal SSH SSH T2 (Cine) Sag Ureter must be seen in cine, reposition/repeat if needed

STRICTURE/OBSTRUCTION

STRICTURE/OBSTRUCTION T2 3D Static Fluid 2D Cor Cine Static Fluid 2D Sag Cine Static Fluid

KIDNEY TRANSPLANT 3D Cor T2 Static Fluid T2 Axial TSE 2D Cor Cine

PREGNANCY Pregnancy (Acute): Contrast-enhanced MR urography is generally not recommended in pregnant women. 3D T2-weighted (static-fluid) urography(Navigator) is performed. Cine MR urography(multiple acquisitions ) may be necessary to visualize the entire ureters and exclude fixed narrowing or filling defects. Images copyright of John R. Leyendecker, MD. Department of Radiology, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem

PEDIATRICS Pediatric (Congenital): MR Urography provides imaging(Urinary System) without ionizing radiation. Is performed without iodinated contrast (Renal Impairment). Images copyright of John R. Leyendecker, MD. Department of Radiology, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem

MR UROGRAPHY AT 3T

MR UROGRAPHY @ 3T Limitations: Dielectric Effect Minimized on newer scanners, dialectric pads. Susceptibility Artifacts Due to local distortion(air, metal),use shortest TE available. Motion Artifacts Increases at 3T (Peristalsis, Flow) Specific Absorption Rate (SAR) HASTE, split the acquisitions in order to minimized SAR. Chemical Shift Artifacts Increases at 3T ,Steady State sequence are hampered by this artifact.

RENAL CALCULUS TRUFISP FS AXIAL T1 3D AX VIBE (Pre) T1 3D AXIAL VIBE (Post)

NEOPLASM RENAL CELL CARCINOMA AXIAL T1 3D VIBE CORONAL T1 3D VIBE

RELATED PATHOLOGIES Prostate Enlargement Gonadal Vein Varicose Bladder Thickened Uterine Fibroids Renal Cyst

POST PROCCESSING TECHNIQUES Maximum Intensity Projection (MIP) Volume Rendering (VR) Thin Volume (MIP) Multiple Planar Reconstruction (MPR)

PITFALLS & ARTIFACTS Non Dilated System (3D T2 Static Fluid) Pitfalls: Can mimic stricture/obstruction Artifacts: High concentration of Gadolinium T2* shortening (Single Dose) T2 COR HASTE T1 3D VIBE POST T2 3D Static Fluid

TIPS & TRICKS Prone Position Tips: Minimizes peristalsis motion Coverage Include entire Urinary System Appropriate Delays Continue scanning until ureters are fully filled. Full Bladder Improves visualization of Urinary System. Prone Position Minimizes peristalsis motion Better visualization of Urinary system. Tricks: Use Navigator of Liver or Kidney (Nav within FOV)

CONCLUSION MR Urography: Is a technique that can be useful for assessing patients with a variety of urinary tract disorders. MRU provides a morphological and functional evaluation of the urinary system. Extremely useful on patients with no excretory function (T2). MRU can be combined with MRA/MRV and MRI of the urinary system to provide a complete diagnostic evaluation of the urinary system.