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Rare Pathologies by Renal Doppler
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Indications of renal Doppler ultrasound
Renal artery stenosis
Renal artery thrombosis & emboli
Renal vein thrombosis
Aneurysm & pseudo-aneurysm
Arterio-venous communications
Nutcracker syndrome
Renal mass
Miscellaneous indications
Arterio-venous communicationDirect communication from artery to vein without capillary bed
• Congenital A-V malformation 25% Multiple large arterial feeding vessels
Numerous A-V communications
• Acquired A-V fistula 75% Single communication of artery & vein
0.3 – 4 % after kidney biopsy
Sidhu R et al. Semin Ultrasound CT MRI 2009 ; 30 : 271 – 288.
A-V malformation
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
A-V malformationwith pseudo-aneurismal dilatation
Low resistance arterial flowArterialized venous flow
Hydronephrosis or cystwith calcified wall
Aneurismal dialatation with perivascular artifact
A-V fistulaFirst described in 1962 1
• Cause Iatrogenic (percutaneous procedure) –Trauma
• Clinic Asymptomatic (80%)Gross hematuria – High output cardiac failureThrombo-embolic episodes – RF – HTN
• Evolution Most regress spontaneously in 6 monthsSome progress to life-threatening complication
• Rx Asymptomatic: follow-up by DopplerSymptomatic: embolization
Routine post-biopsy Doppler US & 6 months later1 Fernstrom I et al. J Urol 1962 ; 88 : 709.2 J Clin Ultrasound 2008 ; 36 : 377 – 380.
Arterio-venous fistula
Feeding artery
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
Perivascular artifact in inferior pole
“confetti phenomenon”
Color Doppler US / High PRF
Low resistance arterial flow
Arterialized venous flow
Feeding artery & draining vein
Indications of renal Doppler ultrasound
Renal artery stenosis
Renal artery thrombosis & emboli
Renal vein thrombosis
Aneurysm & pseudo-aneurysm
Arterio-venous communications
Nutcracker syndrome
Renal mass
Miscellaneous indications
Doppler US in nutcracker syndrome
Hilar portion & aorto-mesenteric portionCut-off value in supine position 3.8Cut-off value in upright position5.5
Fitoz S et al. J Ultrasound Med 2007 ; 26 : 573.
Ratio of A-P diameter of LRV
Ratio of peak velocities of LRV
Aorto-mesenteric portion & hilar portionCut-off value in supine position 4.2Cut-off value in upright position5.1
Nutcracker syndrome / Ratio of A-P diameterOblique transverse sonograms
Peker A et al. J Clin Ultrasound 2011 ; 39 : 418 – 421.
Hilar portion: 25 mm Aorto-mesenteric portion: 2mm
Ratio: 12.5
Supine position
Hilar portion: 24 mm Aorto-mesenteric portion: 2mm
Ratio: 12
Upright position
Nutcracker syndrome / Ratio of peak velocities
Cho BS et al. Nephrol Dial Transplant 2001 ; 16 : 1620 – 1625.
Peak velocity ratio: 6
LRV near hilum
Peak velocity: 19.9 cm/sec
LRV between aorta & SMA
Peak velocity: 99.7 cm/sec
Nutcracker syndrome / SMA angle
Peker A et al. J Clin Ultrasound 2011 ; 39 : 418 – 421.
Upright position
14 °
Supine position
33°
Cut-off value 41° in supine position – 21° in upright position
Indications of renal Doppler ultrasound
Renal artery stenosis
Renal artery thrombosis & emboli
Renal vein thrombosis
Aneurysm & pseudo-aneurysm
Arterio-venous communications
Nutcracker syndrome
Renal mass
Miscellaneous indications
Doppler in renal MassLimited role compared to CT
• Pseudo-tumors Prominent column of Bertin Persistent fetal lobulationDromedary hung
• Renal tumors Tumoral vascularizationCEUS: solid or cystic mass
• Venous invasion Renal veinsIVC
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
Normal interlobular arteries
at periphery of PCB
Prominent column of Bertin (PCB)Mistaken for intra-renal tumor
Prominent column of Bertin
or mass
Vascularization of renal tumors
Jinzaki’s classification
Intratumoral focal vessels
Penetrating vessels
Peripheral vessels
Penetrating & peripheral
Angiomyolipoma
Angiomyolipoma
Carcinoma
Carcinoma
Pattern 1
Pattern 2
Pattern 3
Pattern 4
Jinzaki M et al. Radiology 1998 ; 209 : 543 – 550.
Vascularization of renal tumors
Jinzaki M et al. Radiology 1998 ; 209 : 543 – 550.
Pattern 3
Peripheral vessels
Carcinoma
Pattern 4
Penetrating & peripheral vessels
Carcinoma
Solid renal mass / CEUS
Hypervascular lesion
CEUS / 34 sec MSCT / arterial phase
Hypervascular lesion
Gray-scale US
Subtle deformation of renal contour
Clear renal cell tumor at surgery
Setola SV et al. Abdom Imaging 2007 ; 32 : 21 – 28.
Bosniak renal cyst classificationCategory CT features
Significance
I Thin wall, water density & does not enhanced No septa, calcification, or solid component
Benign
Israel GM & Bosniak MA. Urology 2005 ; 66 : 484 – 488.
II Thin septa with “perceived” enhancement Fine or slightly thick calcification High attenuation non-enhancing cyst < 3 cm
Benign
IIF Thick regular septa with “perceived” enhancement Thick regular wall with “perceived” enhancement Thick, nodular, & irregular calcification High attenuation non-enhancing cyst > 3 cm
Likely benignFollow-up
III Thick smooth or irregular septa Thick smooth or irregular wall With measurable enhancement
Some benignSome malignant
IV Criteria of category III Enhancing mass independent of wall or septa
MalignantCystic carcinoma
Cystic renal mass / CEUS
Thin-walled cyst No septa or solid component
Bosniak category I
CECT scan
Enhancing mural nodule within cystBosniak category IV
CEUS
Park BK et al. Eur J Radiol 2007 ; 61 : 310 – 314.
Renal cell carcinoma after partial nephrectomy
Invasion of IVC in RCC
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
Color Doppler US
Localization of upper extremityof thrombus
Power Doppler US
Tumoral vascularizationof thrombus
Indications of renal Doppler ultrasound
Renal artery stenosis
Renal artery thrombosis & emboli
Renal vein thrombosis
Aneurysm & pseudo-aneurysm
Arterio-venous communications
Nutcracker syndrome
Renal mass
Miscellaneous indications
• Nephropathies
• Kidney stones
• Hydronephrosis
• Uretero-pelvic junction obstruction
• Fraley syndrome (Upper calix syndrome)
Miscellaneous indications
Renal Doppler in nephropathies
• Acute tubular necrosis
• Tubulo-interstitial nephropathy
• Micro-angiopathy
• Nephro-angiosclerosis
• Diabetic nephropathy
Glomerulo-nephritis
(↑ RI in end stage disease)
Elevated RI Normal RI
Diabetic nephropathy
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
Increased resistive index: 0.89
Renal insufficiency
Kidney stone / Twinkling artifact
Tchelepi H et al. Am J Roentgenol 2009 ; 192 : 11 – 18.
Twinkling sign from large stone
Presence of small stone
Large stone causing hydronephrosis
Presence of posterior shadowingUseful for evaluation of small kidney stones
High PRF & gain just below artifact limit
Hydronephrosis
RI of LK: 0.45RI of RK: 0.65Hydronephrosis of right UPJ
Δ RI (right – left) > 0.05
Sensibility: 10 – 40%, Specificity > 80%
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
Obstruction without dilatation Indications Dilatation without obstruction
Hydronephrosis in pregnancy
Renal colic in pregnancyPhysiological hydronephrosis or stone?
Retrospective study of 262 patients (2 local hospitals)
Data on clinical presentation, imaging, & interventions
Clinical & laboratory features unhelpful to predict stone
Left-sided colic more likely to indicate stone
Improved accuracy of Doppler in predicting stone (55 – 72%):
Elevated resistive indexAbsence of urinary jet
Andreoiu M et al. Urology 2009 ; 74 : 757 – 761.
Urinary jet
Obstructed ureter if no jet seen after 15 min of observation
Presence of jet do not exclude incomplete obstruction
Tuma J et al. European course book: Genitourinary ultrasound.
European Foundation of Societies of Ultrasound in Medicine & Biology, 2011.
Uretero-pelvic junction obstruction
Most common cause of UT obstruction in children
Multiples proposed factors
Delayed recanalization of fetal ureter
Abnormal development of ureteral muscle
Abnormal ureteral peristalsis
Aberrant vessels or bands
Sivit CJ. Ultrasound Clin 2006 ; 1 : 67 – 75.
Bilateral in 25%
Uretero-pelvic junction obstruction
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.Sidhu R et al. Semin Ultrasound CT MRI 2009 ; 30 : 271 – 288.
Hilar artery seen in 30 – 45% of patients
Crossing vessel usually located anterior to UPJ obstruction
Fraley syndrome / Upper calyx syndromeVascular compression of superior calyx
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
IV pyelography
Superior calyx obstructiondue to extrinsic compression
Color Doppler US
Segmental artery crossingthe dilated calyx
CT Angiography before tt: polar nephrectomy – reimplantation
References
Arnold – 2004 Springer-Verlag – 2011
Hélénon O et al. EMC-Radiologie 2005 ; 2 : 367 – 412.
EFSUMB – 2011