Vascular 25 & 32 Flashcards
What percent of patients of HYPERtension have underlying renal disease
6%, test will say hypo and that is wrong
Renal artery stenosis should be suspected with (4)
sudden onset or worsening chronic HYPERtension, azotemia, unexplained renal insufficiency/pulmonary edema, hypertensive children
What is azotemia
high nitrogen compounds in the blood
What is the average kidney length
8-13cm (BE ABLE TO IDENTIFY A # WITHIN THIS RANGE)
Renal arteries are _____ to the _____ renal vein
inferior, left (KNOW THAT IT IS INFERIOR TO THE LEFT RENAL VEIN)
Renal arteries have ______ segmental branches ____ to the hilum
2-5, proximal
Duplicate renal arteries often arise from
aortic wall below main renal artery
Duplicate renal arteries usually occur on the
left side
Medial FMD and non-atherosclerotic disease affects
mid-to -distal segment of artery (MAY SAY SOMETHING ELSE ON TEST, KNOW THIS SEGMENT)
What produces “string of beads” appearance on ultrasound or angiogram
medial FMD (FMD ALWAYS MEANS STRING OF BEADS)
What is the sonographic appearance of FMD
string of beads, MULTIPLE segmental concentric narrowing and dilations
Renal arteries lie
INFERIOR TO LEFT RENAL VEIN
Normal renal length
9-13cm
Renal length >cm compared to contralateral kidney indeicates
compromised flow in smaller kidney
PSV of normal renal artery
90-120 cm/s
In normal renal artery, normal range for distal renal artery is
70-90cm/s
Flow0Reducing Renal Artery stensosis, PSV increases significantly above
180 cm/s (MORE THAN 180, VELOCITY INCREASES)
Characteristics of flow reducing renal artery stenosis are (3):
elevated velocity, post stenotic turbulence, dampened distal waveforms
Dampening parvus tardus signal distally showing greater than
60% renal artery stenosis
In renal artery occlusion, low velocity doppler signals are usually noted in the
renal medullary signals (ABSENCE OF FLOW)
PSV ______ and length _____ consistent with CHRONIC renal artery occlusion
<10cm/s, <9cm
Normal renal parenchymal signals demonstrate
continuous high diastolic flow
Normal renal parenchymal is ______ of systolic velocity
40-50%
Elevated renovascular resistance is
not a consideration (WITH 40-50% HIGH DIASTOLIC FLOW)
Parenchymal disease results in impedance to arterial inflow, diastolic-to-systolic velocity ration ____ or resistive index ______ indicates increased ____
<0.3, >0.8, renovascular resistance/medical renal disease
Acceleration index (AI) of ____ indicates proximal flow limiting lesion
<3.78
Acceleration time (AT) of ____ indicates proximal renal artery disease
> 100ms (ACCEL TIME IS WHEN FLOW STARTS TO WHEN FLOW PEAKS–HOW LONG)
Renal-Aortic ration (RAR) of ____ is consistent with ____
> 3,5, >60% stenosis
In renal vein thrombosis, what is the “nutcracker syndrome”
left renal vein compressed by mesentary or SMA (COMPRESSION OF LEFT RENAL VEIN)
With renal stents, slight velocity increase is expected due to
reduction in ARTERIAL COMPLIANCE
What resistive index is predictive of unsuccessful renal revascularization
0.9
What is an RI of 0.9 predictive of? Is it useful?
unsuccessful renal revascularization, no
What should you do first to saline for it to be used
agitate
Microbubbles are (3)
nonuniform in size, relatively small, unstable (HOW WOULD YOU DESCRIBE MICROBUBBLES CAUSED BY AGITATION)
What is a patent foramen ovale (PFO) also called
intracardiac shunt (RULLIGN OUT CARDIAC SHUNT)
What size should the microbubbles be
less than 8 microns
What are microbubble shells made of
human serum albumin, lipid, phosolipid
Why is IV infusion also used
prolongedenhancement times
What is a method that can prolong enhancement times
IV infusion
To be clinically effective, tissue-specific agents must
affinity for target tissues, ability to alter tissue appearance
What changes the signal impedance of normal or abnormal tissues
tissue specific agents
Thrombus-specific agents (2):
attach to fibrin, enhance thrombus detection
What type of agent helps with thrombus detection
tissue specific
Ability to enhance the lysis of thrombus using targeting ultrasound contrast agents and ultrasound energy
sonothrombolysis (KNOW THIS DEFINITION)
Harmonic imaging is ____ and also called ____
twice the transmit frequency (second harmonic)
Harmonics is sending out ___ and receiving ____
1,2
Harmonic imaging have a ____ signal-to-noise ration
higher
What will improve with harmonics
better signal/resolution
What is a contrast-specific equipment modification
low mechanical index (MI)
What minimizes destruction of microbubbles
low MI
Top two uses for contrast are
echocardiography, liver evaluation
Contrast agents can be used to differentiate ____ from _____
stenosis, occlusion
Contrast agents increase visualization of
iliac arteries with bowel gas
How does contrast aid in peripheral arteries
poor visualization of deeply located or small vessels, low veloctiy flow, low volume blood flow
Contrast agents can be used to increase the diagnostic accuracy in identifying thrombus at what percent
26%
Evaluation of carotid artery vasa vasorum and plaque neovascularity may prove to be useful to identify _____ and determine _____
vulnerable plaques, risk of cardiovascular events
Hepatic applications can be used to
enhance detection and characterization of hepatic masses, assess flow through transjugular intrahepatic portosystemic shunt (TIPS)
Hepatic applications improve detection of ____ both in ____ and those with ____
intra and extrahepatic blood flow, normal subjects, portal hypertension
In renal artery stenosis, evaluation of main renal and intrarenal vesses limited by what anatomical variants
duplicate or accessory renal arteries
Contrast agents are useful in exams and have
reduced exam times
For organ transplants, contrast agents improve assessment of blood flow leading to the transplant as well as within
the parenchyma of the transplanted organ
Contrast agents improves ability to detect what in native and transplant organs
ischemic regions
Contrast has the ability to _____ in real time using CES improves _____ and ______
assess blood flow, detection, characteristics of endoleaks
Contrast has the ability to _____ in real time using CES improves _____ and ______
assess blood flow, detection, characteristics of endoleaks
Peripheral arterial applications (3):
differentiate stenosis from occlusion, increase visualization of iliac arteries with bowel gas, degree of arterial collateralization
