7/10/2015. Deborah J. Rubens, MD RENAL DOPPLER IT MAKES THE DIAGNOSIS! DISCLOSURES. Renal Doppler It Makes the Diagnosis!

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1 Renal Doppler It Makes the Diagnosis! None DISCLOSURES Deborah J. Rubens, M.D. Professor of Imaging Sciences, Oncology and Biomedical Engineering University of Rochester Medical Center Associate Director, Center for Biomedical Ultrasound University of Rochester School of Medicine and Dentistry OBJECTIVES Discuss the different applications of Doppler in renal diagnosis Show the most common abnormal findings Outline some of the pitfalls in renal Doppler imaging. Goals of Renal Doppler Imaging Vascular Abnormalities Stenosis, thrombosis, infarct Fluid from solid masses Stone identification Parenchymal injury/compromise Biopsy Guidance Technique Use coronal to optimize RA angle Follow to hilum Sample MRV Renal Transplant Doppler Peak systolic velocity of main renal artery, anastomosis, and feeding iliac artery Demonstrate patent main renal vein and iliac vein. 1

2 Parenchyma Technique Sample segmental arteries (jx of sinus fat and medulla) Upper, mid, lower pole Resistive Index (RI) -(PSV- EDV/PSV) Normal >.05, < 0.8 Vascular Complications RA Thrombosis, stenosis RV Thrombosis, stenosis Infarcts AVM Parenchymal compromise ATN, compression Renal Artery Thrombosis Immediate post op Patient anuric Rx with thrombectomy or vascular revision 47 yo male with no urine output in recovery One day s/p cadaveric transplant with no urine output. Note wall thump in RA and normal flow in iliac artery No flow in transplant, normal flow in iliac a 30 minutes later after thrombectomy Renal Artery Stenosis Affects 1-5% of population Cause of 5-22% of ESRD Hypertension-especially malignant or in young patients Atherosclerotic (origin) FMD- anywhere along vessel Arteritis (rare) Granata A, Fiorini F, Andrulli S, Logias F, Gallieni M, Romano G, Sicurezza E, Fiore C.D. Doppler ultrasound and renal artery stenosis: An overview J Ultrasound Dec; 12(4): PMCID: PMC US Screening for Renal A. Stenosis Technique critical Must see renal a origins Supine AP or Coronal Decubitis PSV > cm/sec PSV >200 cm/s Sens 97%* **, Spec 72*-79**%, PPV 81%* NPV 95%* RAR >3.5 Sens 91%, Spec 91% ** * Williams G.J., Macaskill P., Chan S.F. Comparative accuracy of renal duplex sonographic parameters in the diagnosis of renal artery stenosis: paired and unpaired analysis. Am J Roentgenol. 2007;188: [PubMed] **Soares G.M., Murphy T.P., Singha M.S., Parada A., Jaff M. Renal artery duplex ultrasonography as a screening and surveillance tool to detect renal artery stenosis: a comparison with current reference standard imaging. J Ultrasound Med. 2006;25:

3 2012 Review of Criteria 313 patients (606 RA s) US vs. angiography Most Accurate Criteria for 60% stenosis PSV > 285 cm/sec- Sens 67%, Spec 90%, Acc 81% RAR >3.7 Sens 69%, Spec 91%, Acc 82% Combined PSV 200 and RAR 3.5 Sens 72%, Spec 83%, Acc 78% (for PSV 180, Sens 72%, Spec 81%, Acc 78%) Critical analysis of renal duplex ultrasound parameters in detecting significant renal artery stenosis.aburahma AF, Srivastava M, Mousa AY, Dearing DD, Hass SM, Campbell JR, Dean LS, Stone PA, Keiffer T. J Vasc Surg Oct; 56(4):1052-9, 1060.e1; discussion Epub 2012 May 15. RAS - Direct Criteria Problems Difficult to examine entire artery Up to 30% accessory arteries* Ultrasound detects half of accessory arteries However, less than 1% of RAS isolated to the accessory artery** Fibromuscular dysplasia * Chain S., Luciardi H., Feldman G., Berman S., Herrera R.N., Ochoa J. Diagnostic role of new Doppler index assessment of renal artery stenosis. Cardiovascular Ultrasound. 2006;25(4):4. [PubMed] **Bude R.O., Forauer A.R., Caoili E.M., Nghiem H.V. Is it necessary to study accessory arteries when screening the renal arteries for renovascular hypertension? Radiology. 2003;226: [PubMed] RAS Indirect Criteria Asymmetric Resistive Indices Loss of Early Systolic Peak Delayed systolic acceleration > 0.07 sec Parvus-tardus Not reliable variable compliance (hypertension), useful for severe stenosis, segmental disease RAS - Elevated Intra-renal RI s Do They Predict Outcome? RI 0.8 in RAS - angioplasty or surgery does not improve: Renal function Blood pressure Kidney survival Independent risk of mortality Radermacher J, Chavan A, Bleck J, Vitzthum A, Stoess B, Gebel MJ, Galanski M, Koch KM, Haller H Use of Doppler ultrasonography to predict the outcome of therapy for renal-artery stenosis. N Engl J Med Feb 8; 344(6): RAS - Elevated Intra-renal RI s RAS? Results subsequently challenged by Garcia- Criado- 36 patients RI > 0.8: Improved renal function in 29% Improved blood pressure in 50% Crutchley evaluated 86 patients post rx: RI > 0.8 assoc with GFR decline no BP response RI strongest predictor of mortality Garcìa-Criado A., Gilabert R., Nicolau C., Real M.I., Muntañá X., Blasco J. Value of Doppler sonography for predicting clinical outcome after renal artery revascularization in atherosclerotic renal artery stenosis. J Ultrasound Med. 2005;24(12): [PubMed] Crutchley T.A., Pearce J.D., Craven T.E., Stafford J.M., Edwards M.S., Hansen K.J. Clinical utility of the resistive index in atherosclerotic renovascular disease. J Vasc Surg. 2009;49: [PubMed] 3

4 Downstream changes? Renal A Stenosis? CT 1 month later Sample at bruit for PSV Post Transplant Complications: Renal Artery Stenosis 1-8% of cases, usually anastomotic Clinical presentation: refractory hypertension and/or progressive renal impairment Immediate (rare) to 2-3 years post txp Screen with US Confirm with MRA or CTA or conventional angiography RENAL ARTERY STENOSIS DOPPLER ULTRASOUND CRITERIA Native Kidney -70% stenosis- PSV>200cm/sec Transplant Kidney-50% stenosis- various PSV (cm/sec) 200 demorais (symptomatic) 250 Baxter (symptomatic) 300 Patel (screening) 19/144 patients, 5 w/stenosis 350 Gottlieb (symptomatic) 15 patients 4 stenoses Baxter G, et al, Clinical radiology 1995 vol Patel, U et al, Clinical Radiology vol 58, #10, Oct 2003 pp Gottlieb, R et al AJR : demorais et al. JCU (3): RENAL ARTERY STENOSIS DOPPLER ULTRASOUND CRITERIA Native kidney: PSV RAR>3.5=70% stenosis Transplant : PSV ratio of renal to iliac a Should we use the same threshold? De Morais >1.8:1 ratio PSV 200cm/sec 12/22 sx patients positive for 50% lesions-sensitive, not specific Gao 3.5:1 ratio-psv 350cm/sec for 80% lesion, p<.01 Baxter G, et al, Clinical radiology 1995 vol Patel, U et al, Clinical Radiology vol 58, #10, Oct 2003 pp Gottlieb, R et al AJR : demorais et al. JCU (3): Gao J et al, Clinical Imaging 2009, Vol33 No 2, RENAL ARTERY STENOSIS DOPPLER ULTRASOUND CRITERIA Intrarenal criteria:tardus Parvus Waveform Acceleration time >.08 (Baxter, Gao) >.1 (Gottlieb, demorais) Variable reliability (Baxter, Patel) Baxter G, et al, Clinical radiology 1995 vol Patel, U et al, Clinical Radiology vol 58, #10, Oct 2003 pp Gottlieb, R et al AJR : demorais et al. JCU (3): Gao J et al, Clinical Imaging 2009, Vol33 No 2,

5 Asymptomatic Patient Importance of the Ratio RAS Technique is Critical Absolute velocity high (>300 cm/sec) Renal to Iliac ratio is 2:1 Not clinically significant Improved angle of insonation velocity now normal ratio to iliac Elevated Velocity RAS? If PSV doesn t work, what about intrarenal waveforms? January 08 July 08 Grayscale should confirm Intrarenal waveforms alone unreliable. No intervention between January and July What about timing? Early elevated velocities (1 st week) can be attributed to edema at anastomosis Velocities may decrease over time 15 patients with elevated velocities ( m/s) at 2 months reduced by.5m/sec on avg 20 months later with no difference in renal fx or BP vs controls Brabrand et al Spontaneous reduction of initially elevated peak systolic velocity in renal transplant artery. Transplant International 2011 Jun; 24(6): The numbers mean nothing without symptoms BP is controlled only medical mgt 5

6 Does Txp RAS Matter? Review of National Txp Data Base % incidence of RAS (823/41867) 17% had angioplasty No difference in BP or renal fx post angioplasty vs those treated with medical rx RAS associated with increased risk of graft loss. Hurst FP, Abbott KC, Neff RT, et al. Incidence, predictors and outcomes of transplant renal artery stenosis after kidney transplantation: analysis of USRDS.Am J Nephrol. 2009;30(5): Intervention vs Conservative Therapy 13 yr Single Center Retrospective Study of 43 patients with RAS ( total 1187 patients) 27 with angioplasty 16 with conservative therapy 5 year follow up showed no difference in egfr deterioration over time, no change in BP or number of antihypertensive meds between the 2 groups. No difference in graft loss or death Geddes CC, McManus SK, Koteeswaran S, Baxter GM. Long-term outcome of transplant renal artery stenosis managed conservatively or by radiological intervention. Clin Transplant Sep-Oct;22(5): Waveforms Make the Diagnosis RAS? Iliac A Stenosis Waveforms tardus-parvus Normal RA to Iliac ratio Day 0 80 yo F; AKI, decreased renal fx s/p AAA repair Very poor flow in the parenchyma with tardus parvus waveforms 3:1 ratio Dx? Arterial compression syndrome Following revision returns to normal 6

7 No urine output post transplant Renal Vein Thrombosis Acute pain, swelling, nonfunctioning graft P/op days 0-8 Salvage with early detection. Diagnostic criteria: Absent venous flow Dilated vein with thrombus Reversed diastolic flow in intrarenal arteries Reversed diastolic flow also seen in severe acute rejection, compression syndrome Sign of renal vein thrombosis until proven otherwise 1 day p/op decreased urine output 56 yo male day 0 post txp RVT? Compressive Hematoma Acute tubular necrosis 4 days later Renal Vein Thrombosis? Renal Vein Compression Patient returned to the OR where transplant was repositioned. Transplant Compartment Syndrome Related to ischemic injury and swelling from reperfusion Doppler findings mimic RVT Surgical pressure relief preserves fx Transplantation: 15 January Volume 89 - Issue 1 - pp

8 15 yo M Proteinuria Assymmetric Gray Scale Normal RI Patent RVs 15 yo M Proteinuria What is missing? MRV in continuity Grayscale confirms Native RVT 19 yo male: gross hematuria/anemia Difficult Doppler Diagnosis RI s usually not affected 4/11 reversed diastolic flow Incomplete Thrombus Look for waveform changes, absent flow in affected veins Visible thrombus grayscale DX: Nutcracker Syndrome Entrapment of LRV between SMA and aorta Clin sx: flank pain, hematuria, proteinuria 4.8:1 ratio between peak RV vel and hilar vel Rx with waiting (children) or stenting, vasc surgery bypass (adult) Renal Color Flow Imaging Stone disease-using the twinkle artifact Indeterminate renal mass Vascular malformations Biopsy guidance Other parenchymal pathology Shin, J. I., Park, J. M., Lee, J. S., & Kim, M. J. (2007). Doppler ultrasonographic indices in diagnosing nutcracker syndrome in children. Pediatr Nephrol, 22(3),

9 TWINKLE ARTIFACT 27 yo M w/ hematuria Renal stones may be extremely difficult to identify. We use color Doppler for quick localization and confirmation of stone disease. TWINKLE ARTIFACT Mosaic of color occurs distal to small strong reflectors. Occurs with color or power Doppler Identified with spectral noise tracing Caused by renal calculi, bladder calcification, cholesterol crystals in the GB (occurs in 83% of renal stones-(lee et al) Due to intrinsic machine noise (phase or clock jitter) and surface irregularity (Kamaya et al) References:Lee JY, Kim SH, Cho JY, et al Twinkling Artifacts from Urinary Stones: clinical observations and phantom studies. AJR 2001:176: Kamaya A. Tuthill T. Rubin JM. Twinkling artifact on color Doppler sonography: dependence on machine parameters and underlying cause..ajr. 180(1):215-22, 2003 Jan. Rahmouni A, Bargoin R, Herment A, et al. Color Doppler twinkling artifact in hyperechoic regions. Radiology 1986: 199: Twinkle Artifact/Stone Detection Prospective vs non-contrast CT (1.2mm) 51 patients- 114 stones 1-9 mm (avg 3mm) Twinkle 92 TP, 6 FP, 22 FN Shadow 74 TP, 8FP, 40 FN PPV of twinkle was 94%, Sensitivity 83% PPV of stone shadow 65%, Sensitivity 80% Combined PPV 96% and Sensitivity 88% JUM Kielar, Shabana, Vakili, Rubin 2012; 31(10): Technique 68 yo F Large stone not seen without color/twinkle LOW Color frequency (1-4MHz) High PRF (Scale)- 9

10 68 yo female 46 yo F with Hx of UTI LOW frequency needed for twinkle Color flow misinterpreted as vascularity, suspected renal tumor. Twinkle is posterior to echo, use spectral TWINKLE ARTIFACT-Spectral Noise 21 yo F rt flank pain 35 year old with microhematuria Indeterminate Renal Mass 84 yo M with abd pain: incidental CT detected renal mass? Cyst? 40 patients with complex cystic masses detected by CT 21 RCCs, 9 complex cysts, 2MCNs, 8 simple cysts CEUS accuracy 80-83%, vs 63-75% CT Non-enhanced US accuracy only 30% May improve with spectral Doppler Quaia E, Bertolotto M, Cioffi V, et al. Comparison of Contrast Enhanced Sonography with Unenhanced Sonography and Contrast Enhanced CT in the Diagnosis of Malignancy in Complex Cystic Renal Masses AJR 2008; 191: Solid Mass: always use spectral Doppler 10

11 ? High density cyst 81yo F CRF Interventional Renal Doppler Biopsy guidance- avoid large vessels Immediate post-bx assessment, bleeding Monitor complications- AVF, compression Use spectral and color Doppler Repeat US lower scale with spectral tracing confirms neoplasm 47 yo male 4 days post txp with delayed graft function: biopsy requested 47 yo male 4 days post txp with delayed graft function: biopsy requested Biopsy planned for the lower pole anteriorly Diagnosis? Biopsy route changed to the mid kidney Post biopsy a new artery has appeared. Arteriovenous Fistula 10% incidence p/bx May present with hematuria Most small, asymptomatic, resolve spontaneously. Focal aliasing Artery high vel, low RI Venous arterialization Pseudoaneurysm Much less common than AVF Appearance/dx same as PSA elsewhere Manage conservatively if possible c/o Dr U. Hamper JHU 11

12 71 yo M Right Renal Bx 65 yo M, Lt flank pain post trauma What to do next? Turn on Color Spectral Doppler Diagnosis? 24 hours later Page Kidney Diagnosis? Acute or Chronic Renal compression Sx: Hypertension or ARF Subcapsular collection (US, CT or MR) Absent diastolic flow on spectral Doppler Chung et al: Acute Page kidney following renal allograft biopsy: a complication requiring early recognition and treatment. Am J Transplant 2008 Jun; 8(6): Extent underestimated by US- MRA was patent Focal Abnormalities: Infarct 20 yo female with LUQ pain, leukocytosis Pyelonephritis Not seen with grayscale Turn down scale to show perfusion Not usually a grayscale diagnosis 12

13 Conclusion: Renal Doppler Imaging Makes the Diagnosis for: Renal Artery Stenosis Renal Vein Stenosis Infarcts Indeterminate Renal Masses Stone Disease Pre and Post biopsy complications Renal Doppler: It makes the diagnosis!. Deborah Rubens, M.D. THANK YOU 13