Term
| A DUPLEX ULTRASOUND EXAMINATION OF THE RENAL ARTERIES MAY BE ORDERED: |
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Definition
| IN THE PATIENT WHO HAS UNCONTROLLED HYPERTENSION, DECREASING RENAL FUNCTION, OR AN ABDOMINAL BRUIT |
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Term
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Definition
| LOW RUMBLING SOUND HEARD WITH AUSCULTATION WHICH MAY INDICATE ANEURYSM OR STENOSIS |
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Term
| RENAL DOPPLER EXAM METHODS |
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Definition
| THE DIRECT METHOD ENTAILS BILATERAL EXAMINATION OF THE ENTIRE RENAL ARTERY FROM THE MOST PROXIMAL POINT (WHERE IT ARISES FROM THE AORTA) TO THE MOST DISTAL POINT (PRIOR TO ENTERING THE KIDNEY).THE INDIRECT METHOD INVOLVES THE EVALUATION OF THE SEGMENTAL RENAL ARTERIES (WITHIN THE RENAL) ONLY. NEXT, LET’S REVIEW THE ANATOMY OF THE VASCULAR SYSTEM OF THE KIDNEYS. |
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Term
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Definition
| THE MAIN RENAL ARTERIES ARISE FROM THE AORTA SLIGHTLY DISTAL TO THE SUPERIOR MESENTERIC ARTERY. THE RIGHT RENAL ARTERY RUNS BEHIND THE IVC AND IS LONGER THAT THE LEFT RENAL ARTERY. THE LEFT RENAL VEIN IS POSTERIOR TO THE SMA AND ANTERIOR TO THE AORTA. THE RIGHT RENAL VEIN IS SHORTER THAN THE LEFT. THE SEGMENTAL RENAL ARTERIES COURSE THROUGH THE HILUM OF THE KIDNEY AND ARE BRANCHES OF THE MAIN RENAL ARTERY. THE INTERLOBAR ARTERIES LIE BETWEEN THE RENAL MEDULLARY PYRAMIDS.THE ARCUATE ARTERIES BRANCH FROM THE INTERLOBAR ARTERIES ,TURN AT THE CORTICO-MEDULLARY JUNCTION AND COURSE PARALLEL TO THE CORTEX.THE INTERLOBULAR ARTERIES IN THE CORTEX BRANCH FROM THE ARCUATE ARTERIES. |
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Term
| NORMAL FINDINGS WITH RENAL VASCULAR STUDY |
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Definition
NORMAL FINDINGS:
High systolic flow velocity (PSV 100 ± 20 cm/s.)
High diastolic flow velocity ( EDV 30 ± 5 cm/s)
Low resistance (RI < 0.75) |
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Term
| ABNORMAL FINDINGS WITH RENAL VASCULAR STUDY |
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Definition
ABNORMAL FINDINGS:
CRITERIA FOR > 60% STENOSIS
Peak systolic velocities exceed 180 cm/sec
Exhibits stenotic profile
Spectral broadening
Post stenotic turbulence
Increased resistance to flow |
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Term
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Definition
| THE RAR IS NORMALLY CALCULATED DURING A RENAL ARTERY EXAMINATION IN ORDER TO COMPARE THE FLOW VELOCITY IN THE RENAL ARTERY WITH THE FLOW VELOCITY IN THE AORTA. REMEMBER THAT THE AORTA DEMONSTRATES A LOWER RESISTANCE FLOW PATTERN SUPERIOR TO THE RENAL ARTERIES. INFERIOR TO THE RENAL ARTERIES, THE FLOW PATTERN BEGINS TO PICK UP THE RESISTANCE PATTERN OF THE LOWER EXTREMITIES. |
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Term
| WHAT IS THE NORMAL AND ABNORMAL VALUES FOR RAR |
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Definition
RENAL TO AORTIC RATIO (RAR)
RAR= renal artery PSV divided by aortic PSV
Normal= less than 3.5
Abnormal= greater than or equal to 3.5 |
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Term
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Definition
| THE EDR IS A RATIO USED TO DETERMINE CHANGES IN FLOW RESISTANCE. |
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Term
| WHAT IS THE NORMAL AND ABNORMAL VALUES FOR EDR |
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Definition
END DIASTOLIC RATIO (EDR)
EDR= end diastolic velocity divided by peak systolic velocity
Used for renal art, interlobar art, arcuate art
Normal = .33 or greater
Abnormal = less than .23 |
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Term
| POURCELOT’S RATIO (RESISTIVITY INDEX) |
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Definition
Used to determine if resistance is increasing
RI = PSV-EDV divided by PSV
Normal = less than .7
Abnormal = greater than or equal to .7 |
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Term
| WHAT IS THE “STRING OF PEARLS” EFFECT |
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Definition
| IT IS A TERM FOR FIBROMUSCULAR DYSPLASIA WHICH MOST OFTEN OCCURS IN THE MID OR DISTAL SEGMENT OF THE RENAL ARTERY. THIS CONDITION IS MOST COMMON IN WOMEN. |
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Term
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Definition
| USING THE INDIRECT METHOD FOR EVALUATION OF THE ARTERIES WITHIN THE KIDNEY, WE ARE ABLE TO INDIRECTLY ASSESS FOR MAIN RENAL ARTERY STENOSIS OR OCCLUSION. Evaluates segmental and interlobar artery waveforms to indirectly assess main renal artery for significant stenosis or occlusion |
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Term
| NL INDIRECT WAVEFORM PARAMETERS |
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Definition
| NORMAL WAVEFORM PATTERNS IN THE SEGMENTAL ARTERIES SHOULD DEMONSTRATE THE PRESENCE OF AN EARLY SYSTOLIC PEAK, AN ACCELERATION TIME OF LESS THAN .07 SECONDS, AND DEMONSTRATE FLOW IN THE DIASTOLIC PORTION OF THE WAVEFORM . |
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Term
| ABNL INDIRECT WAVEFORM PARAMETERS |
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Definition
| ABNORMAL WAVEFORM PATTERNS IN THE SEGMENTAL ARTERIES DEMONSTRATE AN ABSENCE OF THE EARLY SYSTOLIC PEAK, AN ACCELERATION TIME OF GREATER THAN .07 SECONDS, A TARDUS PARVUS WAVEFORM PATTERN, AND AN IPSILATERAL RI OF LESS THAN 0.75. |
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Term
| ANATOMY OF MESENTERIC ARTERIES |
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Definition
| THE CELIAC AXIS (TRUNK) AND ITS BRANCHES (THE LEFT GASTRIC ARTERY, SPLENIC ARTERY, COMMON HEPATIC ARTERY), THE SUPERIOR MESENTERIC ARTERY, AND THE INFERIOR MESENTERIC ARTERY CONSTITUTE THE VESSELS TO BE EXAMINED. |
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Term
| NORMAL MESENTERIC FLOW PATTERNS |
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Definition
| THE CELIAC ARTERY, HEPATIC ARTERY AND SPLENIC ARTERY NORMALLY DEMONSTRATE LOW RESISTANCE WAVEFORM PATTERNS. THE SMA AND IMA BOTH HAVE HIGH RESISTANCE WAVEFORM PATTERNS IF THE PATIENT IS FASTING, AND LOW RESISTANCE PATTERNS IF THE PATIENT IS NOT. |
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Term
| MESENTERIC DOPPLER DIAGNOSTIC PARAMETERS > 70 % STENOSIS |
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Definition
| GREATER THAN 70% STENOSIS IS PRESENT, IF THE PEAK SYSTOLIC VELOCITY IN THE CELIAC ARTERY IS GREATER THAN 200 CM/SEC AND DEMONSTRATES POST STENOTIC TURBULENCE. GREATER THAN 70% STENOSIS IS PRESENT, IF THE PEAK SYSTOLIC VELOCITY IN THE SUPERIOR MESENTERIC ARTERY IS GREATER THAN 275 CM/SEC AND POST STENOTIC TURBULENCE IS PRESENT. |
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Term
| DEFINE ANEURYSM AND IT'S DIFFERENT TYPE |
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Definition
| A TRUE ANEURYSM IS DEFINED AS THE DILATION OF ALL THREE LAYERS OF THE ARTERIAL WALL. FUSIFORM AND SACCULAR REFER TO THE SHAPE OF THE ANEURYSM. FUSIFORM IS THE MOST COMMON OF THE TWO. A FUSIFORM ANEURYSM IS A DIFFUSE CIRCUMFERENTIAL DILATION OF AN ARTERIAL SEGMENT. A SACCULAR ANEURYSM IS THE LOCALIZED OUT POUCHING OF AN ARTERY. A DISSECTING ANEURYSM IS NOT A TRUE ANEURYSM, BUT RATHER A SMALL TEAR IN THE INTIMA. THIS ALLOWS BLOOD TO FORM A CAVITY BETWEEN THE INTIMA AND THE MEDIA, AND A NEW (FALSE) LUMEN IS FORMED. ALL OF THESE TYPES OF ANEURYSMS MAY OCCUR IN THE ABDOMINAL AORTA. |
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Term
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Definition
| A DISSECTING ANEURYSM OCCURS WHEN THERE IS A TEAR BETWEEN THE INTIMA AND MEDIA. A NEW LUMEN IS FORMED AND BLOOD FORMS A CAVITY BETWEEN THE TWO LAYERS. THE CAUSE MAY BE IDIOPATHIC OR BE RELATED TO MARFAN’S SYNDROME (ASSOCIATED WITH A WEAKENED TUNICA MEDIA).A DISSECTING ANEURYSM IS MOST COMMON IN THE THORACIC AORTA. ON ULTRASOUND, A DOUBLE CHANNEL IS VISUALIZED WITH A VIBRANT (MOVING) INTIMAL FLAP. |
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Term
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Definition
| AN ANEURYSM MAY BE CAUSED BY MULTIPLE FACTORS THAT RESULT IN THE BREAKING DOWN OF THE WELL ORGANIZED STRUCTURAL COMPONENTS OF THE AORTIC WALL. THE EXACT CAUSE IS NOT FULLY KNOWN. ATHEROSCLEROSIS IS THOUGHT TO PLAY AN IMPORTANT ROLE IN ANEURYSMAL DISEASE. GENETIC DISORDERS,GIANT CELL ARTERITIS, AND INFECTIONS MAY ALSO PLAY A PART IS THE DEVELOPMENT OF ANEURYSMS. |
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Term
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Definition
| PATIENT SIGNS AND SYMPTOMS THAT ARE ASSOCIATED WITH ABDOMINAL AORTIC ANEURYSM INCLUDE CONSTANT PAIN IN THE ABDOMEN, CHEST, LOWER BACK, OR GROIN. AN ANEURYSM IN THE ABDOMINAL AORTA MAY PRESENT AS A PALPABLE PULSATILE ABDOMINAL MASS. 30 TO 60% OF ANEURYSMS ARE ASYMPTOMATIC AND ARE DISCOVERED INCIDENTALLY. RUPTURE OF AN AORTIC ANEURYSM IS CATASTROPHIC. SURGICAL REPAIR OF AN ANEURYSM IS DONE WHEN THE ANEURYSM IS 5 CM IN DIAMETER OR GREATER, OR SMALLER THAN 5 CM BUT GROWING AT A RATE OF GREATER THAN 1 CM PER YEAR. |
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Term
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Definition
| THE PORTAL VENOUS SYSTEM DELIVERS NUTRIENT BLOOD FROM THE BOWEL AND SPLEEN TO THE LIVER.THERE IS A CAPILLARY BED ON EACH END OF THE SYSTEM. ONE IS IN THE GUT AND THE OTHER WITHIN THE SUBSTANCE OF THE LIVER. THE PORTAL VEIN IS FORMED BY THE SUPERIOR MESENTERIC VEIN AND THE SPLENIC VEIN. AT THE PORTA HEPATIS, THE PORTAL VEIN BIFURCATES INTO THE RIGHT PORTAL VEIN AND THE LEFT PORTAL VEIN. THE RIGHT PORTAL VEIN HAS BOTH ANTERIOR AND POSTERIOR BRANCHES. THE LEFT PORTAL VEIN HAS MEDIAL AND LATERAL BRANCHES.THE PORTAL VEIN COURSES WITHIN THE SEGMENTS OF THE LIVER. PORTAL VEIN WALLS ARE ECHOGENIC.THE NORMAL DIAMETER OF THE PORTAL VEIN IS LESS THAN 13 MM. |
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Term
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Definition
| NORMAL FLOW IN THE PORTAL VEIN IS LOW IN VELOCITY AND CONTINUOUS. NO FILLING DEFECTS ARE SEEN USING COLOR DOPPLER.FLOW IS IN A HEPATOPEDAL DIRECTION.NO VARICES ARE PRESENT.ANY COLLATERALS THAT MAY BE PRESENT DEMONSTRATE NORMAL FLOW. |
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Term
| THE CAUSE OF PORTAL HYPERTENTION |
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Definition
| Elevated pressure in the portal venous system due to increased impedance of flow through the liver |
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Term
| PORTAL HYPERTENSION COMPLICATIONS |
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Definition
| PORTAL HYPERTENSION CAN LEAD TO + ASCITES, SPLENOMEGALY, GI BLEEDING, JAUNDICE, AND HEPATIC FAILURE |
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Term
| LEFT GASTRIC VEIN AS A PORTOSYSTEMIC SHUNT |
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Definition
| WHEN BLOOD IS UNABLE TO REACH THE LIVER THROUGH THE PORTAL VEIN DUE TO PORTAL HYPERTENSION, PRESSURE GRADIENT CHANGES OCCUR THAT CAUSE RETROGRADE FLOW IN THE GASTRIC VEIN IN 80-90% OF CASES OF PORTAL HYPERTENSION.INCREASED PRESSURE IN THE GASTRIC VEIN MAY LEAD TO ESOPHAGEAL VARICES. GASTRIC VARICES MAY OCCUR IN THE AREA OF THE STOMACH, UNDER THE LEFT LOBE OF THE LIVER, AND NEAR THE SPLEEN (SPLENIC VARICES). |
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Term
| TRANSJUGULAR INTRAHEPATIC PORTOSYSTEMIC SHUNTS |
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Definition
| + A TIPS PROCEDURE ENTAILS THE PLACEMENT OF A STENT BETWEEN THE PORTAL VEIN AND THE HEPATIC VEIN. + THE PURPOSE OF THIS PROCEDURE IS THE DECOMPRESSION OF THE PORTAL VENOUS SYSTEM. THIS PROCEDURE DOES NOT REMEDY THE CAUSE OF THE PORTAL HYPERTENSION. |
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Term
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Definition
| THE HEPATIC VEINS DRAIN THE BLOOD FROM THE LIVER INTO THE IVC. THERE ARE THREE HEPATIC VEINS, THE RIGHT, WHICH DIVIDES THE RIGHT LOBE INTO THE ANTERIOR AND POSTERIOR SEGMENTS,THE MIDDLE, WHICH DIVIDES THE LIVER INTO THE RIGHT AND LEFT LOBES, AND THE LEFT HEPATIC VEIN WHICH DIVIDES THE LEFT LOBE INTO MEDIAL AND LATERAL SEGMENTS .THE HEPATIC VEINS BECOME LARGER AS THEY APPROACH THE DIAPHRAGM NEAR THE IVC. THE BEST IMAGING PLANE TO VIEW THESE VESSELS IS SUBCOSTALLY IN A TRANSVERSE - OBLIQUE ORIENTATION. |
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Term
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Definition
| BUDD CHIARI SYNDROME IS SYNONYMOUS WITH HEPATIC VENOUS OUTFLOW OBSTRUCTION. CAUSES ARE IDIOPATHIC, CONGENITAL, DUE TO THROMBUS IN THE HEPATIC VEINS OR IVC, DUE TO INJURY AND INFLAMMATION, LIVER PATHOLOGY , OR CERTAIN MALIGNANT TUMORS. |
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Term
| ULTRASOUND FINDINGS IN BUDD CHIARI SYNDROM |
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Definition
NO VISUALIZATION OF RIGHT HEPATIC VEIN WITH GRAY SCALE OR COLOR DOPPLER
DISCONTINUITY BETWEEN THE MAIN HEPATIC VEIN AND IVC
REVERSED FLOW IN HEPATIC VEINS (BICOLOR)
PRESENCE OF INTRAHEPATIC COLLATERALS
IVC - no flow, slow flow, bidirectional flow, narrowing |
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