Abstract:The assessment of the renal arteries is particularly important in the detection of a renovascular cause of the arterial hypertension. The purpose of the present study was twofold: to evaluate the accuracy of duplex scanning in non-invasively diagnosing renal artery stenoses in hypertensive patients, and to determine the results of transluminal angioplasty of renal artery stenoses as assessed by duplex scanning. In 76 patients with arterial hyertension, 170 renal arteries (18 kidneys supplied by two renal arter… Show more
“…2 ). It should be noted here that older studies [ 2 , 11 , 16 , 38 ] tended to set lower peak velocities (below 150 cm/s). These studies were not carried out using CCDS but using a combination of B-mode and Doppler sonography.…”
Section: Significance Of Color-coded Duplex Sonography In the Detectimentioning
confidence: 62%
“… Fig. 1 a Sketch of ultrasound visualization of the renal arteries, epigastric and flanking views [ 38 ] ( Ao aorta, GB gall bladder, k kidney, MPS ileopsoas muscle, WS spine). b Sonoanatomy with visualization of both renal artery branches ( ARR and ARL ) originating from the aorta ( A ).…”
Section: Examination Proceduresmentioning
confidence: 99%
“…b Sonoanatomy with visualization of both renal artery branches ( ARR and ARL ) originating from the aorta ( A ). Retrocaval ( VC ) course of the right renal artery ( ARR ) [ 38 ]. c Visualization of the entire course of the right renal artery ( AR ) from the renal hilum ( K ), along a retrocaval course ( VC ) to the aorta ( A ) in the left image ; right image , the course of the right renal vein ( VR ) ventral to the artery ( AR ) [ 38 ] …”
Section: Examination Proceduresmentioning
confidence: 99%
“… Fig. 2 Left-sided renal artery stenosis (> 70 %) adjacent to the ostium (predilection site for atherosclerotic stenosis) with a PSV of 278 cm/s [ 38 ] Fig. 3 Difficulty associated with angle adjustment parallel to the flow vectors (vascular wall) in the case of a tortuous course of the renal artery at the origin of the artery (predilection site for atherosclerotic stenosis).…”
Section: Significance Of Color-coded Duplex Sonography In the Detectimentioning
Background and purposeAs a non-invasive, side effect-free and cost-effective method, ultrasonography represents the method of choice for the diagnosis of renal artery stenosis. Four different criteria in total, including two direct criteria in peak systolic velocity (PSV) and renal aortic ratio (RAR) and two indirect criteria in resistance index (RI) and acceleration time (AT) for the measurement of relevant renal artery stenosis are described, each demonstrating highly variable accuracy in studies. Furthermore, there is controversy over the degree beyond which stenosis becomes therapeutically relevant and which ultrasound PSV is diagnostically relevant in terms of stenosis grading.Material and methodsThis article gives a critical review based on a selective literature search on measurement methodology and the validity of ultrasound in renal artery stenosis. A critical evaluation of methods and a presentation of measurement principles to establish the most precise measurement method possible compared with the gold standard angiography, as well as an evaluation of the importance of computed tomography angiography (CTA) and magnetic resonance angiography (MRA).Results and conclusionsThe PSV provides high sensitivity and specificity as a direct measurement method in stenosis detection and grading. Most studies found sensitivities and specificities of 85–90 % for > 50 % stenosis at a PSV > 180–200 cm/s in ROC curve analysis. Other methods, such as the ratio of the PSV in the aorta to the PSV in the renal artery (RAR) or indirect criteria, such as side to side differences in RI (dRI) or AT can be additionally used to improve accuracy. Contrast-enhanced ultrasound improves accuracy by means of echo contrast enhancement. Although in the past only high-grade stenosis was considered relevant for treatment, a drop in pressure of > 20 mmHg in > 50 % stenosis (PSV 180 cm/s) is classified as relevant for increased renin secretion. Stenosis in fibromuscular dysplasia can be reliably graded according to the continuity equation. Although the available studies on the grading of in-stent restenosis are the subject of controversy, there is a tendency to assume higher cut-off values for PSV and RAR. Whilst MRA and CTA demonstrate an accuracy of > 90 %, this is at the cost of possible side effects for patients, particularly in the case of pre-existing renal parenchymal damage.Additional online materialThis article includes two additional video sequences on visualizing renal artery stenosis. This supplemental material can be found under: dx.doi.org/10.1007/s00772-015-0060-3
“…2 ). It should be noted here that older studies [ 2 , 11 , 16 , 38 ] tended to set lower peak velocities (below 150 cm/s). These studies were not carried out using CCDS but using a combination of B-mode and Doppler sonography.…”
Section: Significance Of Color-coded Duplex Sonography In the Detectimentioning
confidence: 62%
“… Fig. 1 a Sketch of ultrasound visualization of the renal arteries, epigastric and flanking views [ 38 ] ( Ao aorta, GB gall bladder, k kidney, MPS ileopsoas muscle, WS spine). b Sonoanatomy with visualization of both renal artery branches ( ARR and ARL ) originating from the aorta ( A ).…”
Section: Examination Proceduresmentioning
confidence: 99%
“…b Sonoanatomy with visualization of both renal artery branches ( ARR and ARL ) originating from the aorta ( A ). Retrocaval ( VC ) course of the right renal artery ( ARR ) [ 38 ]. c Visualization of the entire course of the right renal artery ( AR ) from the renal hilum ( K ), along a retrocaval course ( VC ) to the aorta ( A ) in the left image ; right image , the course of the right renal vein ( VR ) ventral to the artery ( AR ) [ 38 ] …”
Section: Examination Proceduresmentioning
confidence: 99%
“… Fig. 2 Left-sided renal artery stenosis (> 70 %) adjacent to the ostium (predilection site for atherosclerotic stenosis) with a PSV of 278 cm/s [ 38 ] Fig. 3 Difficulty associated with angle adjustment parallel to the flow vectors (vascular wall) in the case of a tortuous course of the renal artery at the origin of the artery (predilection site for atherosclerotic stenosis).…”
Section: Significance Of Color-coded Duplex Sonography In the Detectimentioning
Background and purposeAs a non-invasive, side effect-free and cost-effective method, ultrasonography represents the method of choice for the diagnosis of renal artery stenosis. Four different criteria in total, including two direct criteria in peak systolic velocity (PSV) and renal aortic ratio (RAR) and two indirect criteria in resistance index (RI) and acceleration time (AT) for the measurement of relevant renal artery stenosis are described, each demonstrating highly variable accuracy in studies. Furthermore, there is controversy over the degree beyond which stenosis becomes therapeutically relevant and which ultrasound PSV is diagnostically relevant in terms of stenosis grading.Material and methodsThis article gives a critical review based on a selective literature search on measurement methodology and the validity of ultrasound in renal artery stenosis. A critical evaluation of methods and a presentation of measurement principles to establish the most precise measurement method possible compared with the gold standard angiography, as well as an evaluation of the importance of computed tomography angiography (CTA) and magnetic resonance angiography (MRA).Results and conclusionsThe PSV provides high sensitivity and specificity as a direct measurement method in stenosis detection and grading. Most studies found sensitivities and specificities of 85–90 % for > 50 % stenosis at a PSV > 180–200 cm/s in ROC curve analysis. Other methods, such as the ratio of the PSV in the aorta to the PSV in the renal artery (RAR) or indirect criteria, such as side to side differences in RI (dRI) or AT can be additionally used to improve accuracy. Contrast-enhanced ultrasound improves accuracy by means of echo contrast enhancement. Although in the past only high-grade stenosis was considered relevant for treatment, a drop in pressure of > 20 mmHg in > 50 % stenosis (PSV 180 cm/s) is classified as relevant for increased renin secretion. Stenosis in fibromuscular dysplasia can be reliably graded according to the continuity equation. Although the available studies on the grading of in-stent restenosis are the subject of controversy, there is a tendency to assume higher cut-off values for PSV and RAR. Whilst MRA and CTA demonstrate an accuracy of > 90 %, this is at the cost of possible side effects for patients, particularly in the case of pre-existing renal parenchymal damage.Additional online materialThis article includes two additional video sequences on visualizing renal artery stenosis. This supplemental material can be found under: dx.doi.org/10.1007/s00772-015-0060-3
“…die Bfutsrrom ung im rena-len Ge faf3system nichtinvasiv zu messen. Wah rend diese Methode be reits bei einigen Erkra nkungen wie der Nierenarterienstenose ( 10,23), der Tran splantatab stotiun g ( I I, 19, 25) und de r Harntraktob struktion (7. 17) etabliert ist, liegen tiber die dopplersonographische Untersuchung von Kindem mit einem HUS nur vereinze lt Beric hte vor (8,18). 1m folgenden werden die sonographischen und dup lexsonographischen Befu nde dieses Krank heit sbildes demonstriert sowie ein Bezug zu klin ischcn und nuklcanncdizin ischcn Umersuc hungscrgebnisscn hcrgcstellt.…”
We conclude that in the acute stage of the HUS either "B-Imaging" or duplex sonography yield pathological parameter values. For the observation of the renal symptoms during the chronic phase of the disease, duplex sonography is clearly superior.
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