Indications of renal doppler ultrasound 3

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


Perivascular artifact in inferior pole

“confetti phenomenon”

Color Doppler US / High PRF

Low resistance arterial flow

Arterialized venous flow

Feeding artery & draining vein







Nutcracker syndrome

Renal mass


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







Nutcracker syndrome

Renal mass


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



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


Color Doppler US

Localization of upper extremityof thrombus

Power Doppler US

Tumoral vascularizationof thrombus







Nutcracker syndrome

Renal mass


• Nephropathies

• Kidney stones

• Hydronephrosis

• Uretero-pelvic junction obstruction

• Fraley syndrome (Upper calix syndrome)


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


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%


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


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


EFSUMB – 2011

Education

Indications of renal doppler ultrasound 3