Vascular Ultrasound

Videos

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Chapter 1: Aneurysms

Abdominal aortic aneurysm: A large abdominal aortic aneurysm is seen in transverse section. Note the sac contents have a heterogeneous appearance. Play Video opens in new tab/window

Longitudinal view of an aortic aneurysm: A typical view of a fusiform aotic aneurysm. Play Video opens in new tab/window

Abdominal aortic aneurysm with a saccular component: A longitudinal view of an abdominal aortic aneurysm. The posterior wall of the aneurysm to have saccular dilation. The measurement of the aortic diameter is taken in the longitudinal section. Play Video opens in new tab/window

Anteroposterior (AP) diameter measurement of an aortic aneurysm: The AP diameter of a large abdominal aortic aneurysm is shown in this transverse image. It is often more accurate to measure the diameter of the aorta in the longitudinal plane to avoid problems of obliquity (see Ch. 11). Play Video opens in new tab/window

Aortic and iliac artery aneurysms: The cine-loop starts with a transverse view of a small abdominal aortic aneurysm as it is followed to the aortic bifurcation. The proximal segments of the common iliac arteries appear ectatic but, as they are followed distally, two large iliac aneurysms are seen. The movie then shows a longitudinal view. A short segment of relatively normal-diameter common iliac artery is seen between the abdominal aortic aneurysm and the iliac aneurysm. Play Video opens in new tab/window

Pseudo-dissection of abdominal aortic aneurysm: In this example the B-mode suggests that there may be a dissection of the aorta with two flow lumens. However, close inspection shows that this is due to anechoic thrombus. Color flow imaging clearly shows that there is only one flow lumen present. This aneurysm could have been incorrectly diagnosed as a dissection. Play Video opens in new tab/window

Dissection of the aorta: This cine-loop demonstrates a dissection of a normal-caliber abdominal aorta that occurred after an injury. The flap is seen in cross-section towards the posterior aspect of the aorta. It is more clearly seen in longitudinal section towards the end of the clip. Play Video opens in new tab/window

Abdominal aortic aneurysm containing a mobile flap: In this example, a mobile flap is seen on the posterior wall in cross-section. This patient presented with acute ischemia due to an embolus in the lower leg; it is likely that the ischemia resulted from this disruption of the aortic wall. The flap is also shown in longitudinal section. Play Video opens in new tab/window

Popliteal aneurysm: A popliteal aneurysm is shown in cross-section (arrow). From the B-mode appearance it contains a large amount of thrombus. The popliteal vein is seen superficial to the aneurysm and appears moderately compressed due to the aneurysm. The longitudinal view gives a more impressive view of this aneurysm, which contains a large amount of thrombus and is occluded distally. Some flow is seen proximally. Play Video opens in new tab/window

Patent popliteal aneurysm: A large 2.6-cm diameter popliteal aneurysm is seen in this cine-loop. The aneurysm was detected as the patient had a prominent popliteal pulse on palpation. Play Video opens in new tab/window

Pitfalls of abdominal aortic aneurysm scanning: In this cine-loop, the scanning depth has been set too deep in a thin patient and the lumbar spine dominates the image. The abdominal aorta and vena cava are seen adjacent to each other in the upper third of the image. An inexperienced operator could mistake the lumbar spine for an abdominal aortic aneurysm. Play Video opens in new tab/window

Groin seroma misdiagnosed as a false aneurysm: This groin seroma was clinically misdiagnosed as a false aneurysm. The patient had previously had an arteriotomy for arterial access. The scan shows a transverse image of the groin, and the common femoral vein and artery can be seen in the lower part of the image. There is no communication to the seroma. It can be seen that there are flashes of noise in the seroma due to the adjacent pulsations of the femoral artery. Play Video opens in new tab/window

False femoral aneurysm: This movie shows a false femoral aneurysm with B-mode and color flow imaging. Spectral Doppler recordings have been taken from the neck of the false aneurysm. Note the characteristic Doppler signature. (In this example, due to the angle of insonation and high velocities within the neck, aliasing was unavoidable). Play Video opens in new tab/window

Chapter 2: Arm and Vertebral

Proximal subclavian artery stenosis and subclavian steal: A significant stensois of the proximal subclavian artery is indicated by color flow aliasing and high spectral Doppler velocities. Flow distal to the stenosis is turbulent and the waveform shape is abnormal. Towards the end of the movie the common carotid artery is briefly shown (coded red) followed by imaging of the vertebral artery, which demonstrates reverse flow (coded blue) towards the steered box. Play Video opens in new tab/window

Reverse flow in vertebral artery, spectral Doppler: Spectral Doppler recordings from vertebral artery shown in the previous clip indicate significant reverse flow (flow below the baseline indicated by positive numbers and therefore flow towards the steered beam). Play Video opens in new tab/window

Thoracic outlet syndrome: During arm abduction it can be seen that there is significant compression of the subclavian artery in the region of the clavicle. Play Video opens in new tab/window

Thoracic outlet syndrome with Doppler: Spectral Doppler recordings demonstrate abnormally high velocities in the subclavian artery due to compression of the vessel during arm abduction. Many asymptomatic “normal” individuals are able to demonstrate this finding, making the diagnostic accuracy of this test less certain Play Video opens in new tab/window

Flow from an internal mammary coronary artery bypass graft to the heart: In this example, the internal mammary artery has been grafted to the heart during coronary artery bypass surgery. Imaging of the internal mammary artery is possible as it divides from the posterior aspect of the proximal subclavian artery. Note the waveform shape as most flow occurs in diastole. Play Video opens in new tab/window

Chapter 3: Carotids

Carotid scan: A duplex scan of a carotid artery with some mild disease at the origin to the internal carotid artery (<30% narrowing). Doppler waveforms are demonstrated from the common, external, and internal carotid arteries. Note the effect of temporal tapping seen in the external carotid artery waveform. Play Video opens in new tab/window

Mild to moderate disease: Heterogeneous plaque, containing some anechoic areas, is seen at the origin and extending into the ICA. B-mode and color flow imaging suggest a stenosis in the 40% range. The spectral Doppler sample volume has been placed into an area of aliasing seen in the color flow image. The automatic tracking of the peak systolic velocity varies between 120 and 132 cm/sec. Reported measurement should always be taken on a frozen spectrum to allow for accurate placement of the measurement calliper. In this example the velocity was 122 cm/sec indicating a stenosis of <50%. Note that spectral Doppler recordings should also be taken across the lesion within the ICA. Play Video opens in new tab/window

Moderate disease: Atheroma is seen on the posterior wall at the origin to the internal carotid artery. The B-mode and color image suggest narrowing in the region of 50%. An area of aliasing is seen across the stenosis. The plaque is reasonably homogeneous and broadly represents a type 3 plaque. Play Video opens in new tab/window

Carotid disease: A narrowing is seen at the origin to the internal carotid artery. Note the area of flow reversal just distal to the stenosis on the posterior aspect of the artery (blue color) Spectral Doppler flow recordings indicate a peak systolic velocity of 250cm/sec that would be consistent with a 70% stenosis. However, end diastolic velocities of 66-78cm/sec and the color flow appearance suggests narrowing of less than 70%. In this example it would also be important to calculate appropriate velocity ratios between the ICA and CCA and also to ensure that there is not contralateral disease present before drawing final conclusions. This highlights the difficulty of grading disease on a single parameter. Play Video opens in new tab/window

Carotid stenosis: Significant internal carotid artery disease is interrogated with color flow imaging and spectral Doppler. Note that the color box has been steered from the left to right, as the right steer provides a better angle of insonation. The peak systolic velocity is in excess of 400 cm/s, indicating a severe stenosis. Turbulence is also recorded distal to the stenosis and can be heard in the spectral Doppler recording. Play Video opens in new tab/window

Critical stenosis: A critical stenosis is demonstrated at the origin to the ICA. However, in this example the peak velocities are less than 300 cm/sec. This is probably due to the fact that resistance to flow is so high; the peak velocity is now decreasing across the stenosis as shown in Figure 5.4. Note the automatic waveform tracking is unable to accurately follow the real time maximum velocity due a relatively poor spectral trace. The ICA diameter beyond stenosis is small suggesting under-perfusion and the PSV is only 10 cm/sec. This should be reported clearly and highlighted to the surgeon as there may be difficulty in inserting a carotid shunt. It is possible that additional imaging may be needed to examine the ICA distally. Play Video opens in new tab/window

Carotid stenosis: A heterogeneous plaque is seen on the posterior wall at the origin to the internal carotid artery. The stenosis is shown in both cross-section and longitudinal section with color flow imaging. Spectral Doppler velocities demonstrate a peak systolic velocity >240 cm/s consistent with a >=70% stenosis. Note the end-diastolic velocity is just below 100 cm/s, which would suggest narrowing <70%, but in this example it would be sensible to use the peak systolic velocity combined with the color flow and B-mode appearance as the main criteria for grading the stenosis, which would therefore be >70%. Play Video opens in new tab/window

Calcification and color flow imaging: A short area of calcification is causing a loss of color signal but the color flow display beyond the disease appears undisturbed, suggesting that the stenosis is not significant. This should be confirmed with spectral Doppler. Play Video opens in new tab/window

Short stenosis: A short stenosis is demonstrated at the origin to the internal carotid artery, with significant calcification. Doppler measurements indicate a >=70 stenosis. Play Video opens in new tab/window

Calcified stenosis: There is a loss of the color flow signal due to calcification within an internal carotid artery stenosis. However, spectral Doppler recordings demonstrate high peak systolic velocity and end-diastolic velocity constant with a narrowing in the region of 90%. Play Video opens in new tab/window

Gross calcification: In this relatively poor recording of an internal carotid artery stenosis, there is marked calcification obscuring the lumen and no color filling is seen due to the calcification. Despite these limitations, color flow imaging at the distal end of the stenosis indicates aliasing and turbulence and spectral Doppler recording confirms the presence of a severe stenosis. Play Video opens in new tab/window

Subocclusion: There is a subocclusion of the internal carotid artery shown by the small string of flow (arrow). Note a low pulse repetition frequency or color scale has been selected. No diastolic flow is visible. There is the potential to make a serious error and confuse the jugular vein (coded red) seen lying directly over the internal carotid artery as the internal carotid artery itself. Careful inspection of the direction of flow shows that it is towards the right side of the screen, which is towards the base of the neck. Play Video opens in new tab/window

Occlusion of the internal carotid artery: Note that color flow imaging and spectral Doppler demonstrate very little or absent diastolic flow in the common carotid artery. The external carotid artery is shown in the recording and the superior thyroid artery is clearly visible dividing from the posterior aspect of the artery. Play Video opens in new tab/window

Occlusion of the internal carotid artery 2: In the transverse plane the occluded internal carotid artery appears on the right of the screen. The occlusion is probably longstanding as the vessel has collapsed down (see arrow in longitudinal image). The external carotid artery is shown and some branches are visible. Spectral Doppler recordings demonstrate high resistance flow in the common carotid artery with absence of diastolic flow. Play Video opens in new tab/window

Post carotid endarterectomy: The carotid bifurcation following carotid endarterectomy. The artery has been patched and some sutures and the patch material are indicated by the arrow. Note that the bifurcation appears slightly dilated due to use of the patch, which is thought to prevent restenosis. There is evidence of marked intinal hyperplasia in the image, especially in the distal common carotid artery. Play Video opens in new tab/window

Tortuous vessels: A transverse view of the right side of the lower neck demonstrates tortuousity of the common carotid artery and subclavian artery. This patient had a noticeable pulsatile swelling at the base of the neck due to the tortousity and this is often mistakenly diagnosed as an aneurysm. The distal brachiocephalic artery is seen in this image. The origin to the common carotid artery lies superior to the origin of the subclavian artery. Play Video opens in new tab/window

Normal vertebral artery: The movie starts with a quick view of the common carotid artery. Normal forward flow (coded red) is demonstrated in the vertebral artery. Note the vertebral vein is seen, coded blue. The transverse processes of the spine are clearly seen projecting upwards. Examples of reverse flow are shown in the arm menu. Play Video opens in new tab/window

Carotid stent: An example of a carotid stent. The structure of the stent is clearly visible. There is also evidence of atheroma on the posterior wall sitting behind the stent. Play Video opens in new tab/window

Carotid stent with color flow: Color flow imaging across a carotid stent. The movie starts with a view of the origin to the external carotid artery before turning to follow the internal carotid artery. Color flow imaging suggests a wide patent good lumen through the stented region. Play Video opens in new tab/window

Stent stenosis: A stenosis is seen at the proximal end of a carotid stent, demonstrated by color flow aliasing, Spectral Doppler recordings have been taken proximal to the stent and at the stenosis and indicate a doubling in velocity. Note the use of right and left Doppler steering to optimize the angle of insonation to the common artery and the stent respectively. Play Video opens in new tab/window

Flow reversal at the carotid bifurcation: The image of a normal carotid bifurcation clearly shows flow reversal (coded blue) on the posterior wall. This is a common finding and occurs to the geometry of the bifurcation. Play Video opens in new tab/window

Abnormal waveform due to proximal disease: Doppler recordings from a nondiseased carotid bifurcation and internal carotid artery demonstrate abnormal-looking waveforms, this patient had severe braciocephalic artery disease resulting in this appearance. Play Video opens in new tab/window

Carotid tumor B-mode: This transverse B-mode movie shows a large carotid body tumor sitting in between the internal carotid artery and external carotid artery. Play Video opens in new tab/window

Carotid body tumor with color flow imaging: A dramatic view of a carotid body tumor with color flow imaging. Note the flow within the tumor. Play Video opens in new tab/window

Chapter 4: DVT

Ultrasound compression of a normal femoral vein: A normal common femoral vein is seen to collapse fully as compression is applied with the transducer. As further pressure is applied the femoral artery can be seen to distort. Play Video opens in new tab/window

Normal calf veins: Ultrasound compression is used to confirm patency of the posterior tibial (PT) and peroneal veins (Per). The compression was from the medial side of the calf. Towards the end of the cine-loop the probe is positioned on the posterior lateral side of the calf to show another view of the peroneal veins. Note the fibula (Fib) seen from this view. Play Video opens in new tab/window

An extensive DVT is demonstrated in the common femoral, deep femoral, and femoral veins.: Ultrasound compression shows noncollapse of the veins. Echoes are clearly visible in the lumen. The first part of the cine-loop is in cross-section before turning to longitudinal views. Color flow imaging also indicates an absence of flow in the veins. Play Video opens in new tab/window

Bifed femoral vein: This cine-loop starts with a transverse view of the proximal femoral vein. The deep femoral vein is seen in the lower part of the image. As the femoral vein is followed distally it divides into two trunks that rejoin distally. Play Video opens in new tab/window

DVT of the peroneal veins: A thrombus is seen in one trunk of the peroneal veins. The vein is dilated and does not fully compress. The thrombus is also demonstrated on the longitudinal image. Play Video opens in new tab/window

Longitudinal image of a DVT in the femoral vein: In this cine-loop a DVT is seen in the femoral vein. It extends to the confluence of the femoral vein and deep femoral vein and the large color filling defect is clearly seen. The thrombus is relatively anechoic and is therefore likely to have occurred fairly recently. Play Video opens in new tab/window

Thrombus involving one trunk of a bifed femoral vein: In this cine-loop, one trunk of a bifed femoral vein is incompressible. The other trunk, shown by the arrow, is easily compressed. Color flow imaging also demonstrates flow in only one trunk. Play Video opens in new tab/window

Chronic scarring of the common femoral vein: There appears to be fibrosis of the anterior wall of the common femoral vein. The vein is partially compressible. This appearance suggests chronic damage of the vein wall and would be consistent with chronic post thrombotic syndrome. Play Video opens in new tab/window

Abnormal femoral vein: In this example the superficial femoral artery is clearly visible but the adjacent femoral vein is not clearly seen. There is evidence of smaller collateral veins adjacent to the artery. This patient suffers with chronic swelling of the leg, and previously suffered from an extensive DVT involving the femoral vein, which has now retracted to a small fibrous cord. Play Video opens in new tab/window

Thrombus associated with a jugular vein catheter: In this transverse view of the jugular vein, thrombus is clearly seen adherent to a catheter. Play Video opens in new tab/window

Lymph node in groin: Lymph nodes can sometimes be mistaken for occluded veins. In this example, some flow is seen within the node. The nodes can become very prominent, especially if there is infection or ulceration involving the leg. Play Video opens in new tab/window

Lymphoedema: Leg swelling can occur due to lymphoedema. The image often has a ‘grainy’ appearance with increased thickness of the subcutaneous tissues. The B-mode image is often poor and it can be difficult to clearly identify structures or vessels below the muscular fascia. Play Video opens in new tab/window

Slow-moving venous flow and stasis: In this movie, there is little flow in a dilated gastrocnemius vein. Aggregation of the blood leads to the characteristic speckle pattern seen within the vein. Although in this example there is no difficulty in seeing some movement of the speckle, it is easy to see why a cursory examination by an inexperienced operator might report the speckle pattern in the vein as a DVT. Play Video opens in new tab/window

Chapter 5: Endovascular Aneurysm Repair

Normal endovascular aneurysm repair: A transverse view of an endovascular aneurysm repair. Flow is seen in the two graft limbs. Play Video opens in new tab/window

Longitudinal image of an endovascular aneurysm repair: The two graft limbs are seen in this image. In many cases the graft limbs is lie side by side within the sac and therefore would not be seen together in the same plane Play Video opens in new tab/window

Technical tip to improve color imaging: In this transverse view of an endovascular aortic aneurysm repair, there is poor filing of the lower graft limb. This is because the transducer is perpendicular to the sac. This will provide the best B-mode image but for Doppler recordings, some slight tilting of the transducer crates a Doppler angle to the sac and improves the color image, as seen in the second part of the movie. Play Video opens in new tab/window

Small type II endoleak: A very small type II collateral endoleak is seen at the top of the sac. Doppler recordings demonstrate a to-and-fro pattern similar to that seen in a false aneurysm. Play Video opens in new tab/window

Larger type II leak: A type II collateral leak is seen from the inferior mesenteric artery. Play Video opens in new tab/window

Endovascular aortic aneurysm repair leak and the onset of systolic flow: In this movie, type II endoleak is present, as seen on the posterior aspect of the sac, and was found to be from a lumbar artery. On careful inspection it can be seen that the onset of the systolic phase is slightly delayed when compared to the main body of the graft. This probably due to the blood supplying the endoleak having to take a longer route via collateral vessels. Play Video opens in new tab/window

Type II lumbar endoleak: In this example, flow was entering the sac via the IMA (out of plane in this image) and flowing across the sac and leaving by a lumber vessel shown in blue. The Doppler waveform shows net flow in one direction only, unlike the to and fro flow pattern seen in a ‘blind ending leak’. Play Video opens in new tab/window

Graft migration: Although often difficult to detect with ultrasound, this example shows that an endovascular aortic aneurysm repair device has migrated or slipped from the neck towards the top of the sac. The walls of the proximal end of the stent can be directly seen and are level with the start of the aneurysm sac. Play Video opens in new tab/window

Occluded graft limb: In this example one limb of the bifurcating device has occluded. The occluded limb is lying superior to the patent limb in this movie. Play Video opens in new tab/window

Chapter 6: EVLT

Puncture of great saphenous vein: The great saphenous vein is cannulated. This is shown in cross-section but is often easier to see in longitudinal section. Play Video opens in new tab/window

Guide wire across saphenofemoral junction: The guide wire is seen across the saphenofemoral junction. If the wrong plane is used it is possible to lose the image of the guide wire, especially if the guide wire is sitting to one side of the vein. Play Video opens in new tab/window

Guide wire and sheath: The guide wire and predilator are removed from the sheath and the lumen of the sheath is clearly visible at the end of the movie. At this point the sheath tip is at the level of the saphenofemoral junction and will need to be withdrawn as appropriate. Play Video opens in new tab/window

Laser fiber advanced through sheath: The laser fiber has been inserted and can be seen extending beyond the sheath. It is vital to see the laser tip clearly. Note the subtle “step” between the laser fiber and end of the sheath just to the right of the middle of the image. Play Video opens in new tab/window

Laser tip and saphenofemoral junction: The laser tip can be seen just distal to the saphenofemoral junction. It is important to stress that in this example the tip is very close to the junction and at the end of the movie it is being withdrawn to a more acceptable position (see the next movie). Play Video opens in new tab/window

Positioning of laser tip: The laser tip has been positioned approximately 2 cm below the saphenofemoral junction. The clinician in charge is responsible for ensuring that the final positioning is satisfactory. Play Video opens in new tab/window

Injection of tumescence anesthesia: Local anesthetic tumescence is injected. If the vein is in a superficial compartment, it is important to inject the tumescence into the compartment, as shown in this example Play Video opens in new tab/window

Activation of the laser: The blood is being vaporized and this effect can be seen in the image. Play Video opens in new tab/window

Appearance of a successful endovenous treatment: The saphenofemoral junction is patent due to flow from a normal superficial epigastric vein. However the great saphenous vein is seen to be totally occluded beyond this point. Many clinicians position the tip of the laser fiber just distal to the superficial epigastric vein junction as it is thought that preserving this tributary may help to prevent material or thrombus propagating across the saphenofemoral junction Play Video opens in new tab/window

Chapter 7: Bypass grafts

Proximal anastomosis and main body of an insitu vein graft: A cine-loop starting at the origin of an insitu bypass graft. Note some flow separation and disturbance at the graft anastomosis where there is some mild dilation. This is also demonstrated with spectral Doppler. However, recordings just within the graft show established pulsatile flow. The main body of the graft is then followed rapidly with color flow imaging. By setting the color scale so that the peak systolic phase is in the upper region of the color scale, any increase in flow velocity, which could be related to a stenosis will be rapidly identified as an area of aliasing. Play Video opens in new tab/window

Potential graft stenosis: Color flow imaging demonstrates an area of aliasing in the main body of an insitu vein graft. This should be carefully assessed with spectral Doppler, to grade the significance. Play Video opens in new tab/window

Hyperplasia causing a moderate graft stenosis: Visible areas of hyperplasia are seen in an insitu vein graft. Spectral Doppler recordings taken just proximal and across the stenosis indicate a peak systolic ratio of 1.4 times, which is not significant. However, this stenosis would be monitored for evidence of progression Play Video opens in new tab/window

Color flow imaging of a distal graft anastomosis: In this example, the distal end of a femoropopliteal bypass is seen. There is evidence of retrograde flow (left side of image and region of aliasing), filling a patent segment of the distal popliteal artery just above the anastomosis. Play Video opens in new tab/window

Color flow imaging of the distal anastomosis of a tunnelled femoropopliteal bypass graft: As the graft lies deep, the anastomosis is imaged from the popliteal fossa where the distal end of the graft is seen. The scan shows the native artery is occluded above the anastomosis unlike the previous example. Filling of the distal popliteal artery is seen below the anastomosis. Play Video opens in new tab/window

Distal graft aneurysm: The distal end of an insitu vein graft has become aneurysmal and the anastomosis to the distal popliteal artery has also developed an aneurysm. Imaging of the runoff into the tibioperoneal trunk is also shown in this example. Play Video opens in new tab/window

Severe graft stenosis: This cine-loop starts at the origin of the graft. As the graft is followed an area of narrowing and aliasing is seen. Spectral Doppler recordings indicate a peak systolic velocity ratio of >10 times, consistent with a critical graft stenosis. This would require urgent treatment to prevent graft occlusion. Play Video opens in new tab/window

Graft occlusion: This example shows an occluded insitu vein graft. Some low level echoes are seen in the occluded lumen. Note the color gain is increased to detect any flow but only noise is visible as the gain is increased. Play Video opens in new tab/window

Graft aneurysm at a valve site: An aneurysm has formed in the main body of an insitu vein graft at a valve site. Note the area of hyperplasia in the aneurysm. Play Video opens in new tab/window

A synthetic PTFE graft anastomosed to a vein graft: A composite graft of PTFE and vein has been used in this patent. The walls of the PTFE graft are clearly visible at the start of the cine-loop and evidence of ring supports can be seen. Towards the end of the loop the transition between PTFE and vein is seen in the middle of the image of the graft. Play Video opens in new tab/window

False aneurysm of graft anastomosis: A false aneurysm has occurred at the distal anastomosis of an aortobifemoral graft to the common femoral artery. In this transverse image the echogenic anterior wall of the graft is clearly visible. Play Video opens in new tab/window

Graft infection: A cross section of a synthetic graft is shown with suspicious areas associated with the graft which track to the surface. This was confirmed as a graft infection. Play Video opens in new tab/window

Pre-graft occlusion: Doppler recordings from an occluding vein graft indicate high resistance pre-occlusive signals or thump with no net flow. The graft distal to this point of measurement had already thrombosed. Play Video opens in new tab/window

Graft scanning tip: In this example a medium frequency transducer is unable to clearly image the distal end of a graft in a large leg. Switching to a low frequency curvilinear probe provides better visibility of the distal anastomosis Play Video opens in new tab/window

Chapter 8: Lower Limb Artery

The groin: A transverse survey of the major arteries and veins at the level of the groin and upper thigh. It is important to have a sound knowledge of the anatomy in this area for both venous and arterial scanning. The movie starts at the level of the left saphenofemoral junction (SFJ) and shows the common femoral artery (CFA).The common femoral vein is clearly seen medial to the artery. Moving distally, the femoral bifurcation is seen with the superficial femoral artery (SFA) and profunda artery (PA). Finally the confluence of the deep femoral vein (labeled PV) and femoral vein (FV) is seen. Note the level of the SFJ can vary slightly and may be just above the common femoral artery bifurcation or at a similar level. Play Video opens in new tab/window

Longitudinal image of femoral artery bifurcation: The common femoral artery bifurcation is clearly shown in this image. The profunda femoris artery is deep to the superficial femoral artery (SFA). Note the profunda artery often runs lateral to the proximal SFA and in many cases will not be seen in the same plane. Play Video opens in new tab/window

Triphasic flow: Normal triphasic pulsatile flow is demonstrated in the superficial femoral artery Play Video opens in new tab/window

Superficial femoral artery stenosis: Areas of narrowing are indicated by color aliasing in this scan of the superficial femoral artery. The Doppler spectrum is shown proximal, and across the stenosis. The peak systolic velocity ratio (>6 times) indicates severe narrowing. Play Video opens in new tab/window

Occlusion at the origin to the superficial femoral artery: An occlusion of the superficial femoral artery is shown. Note the small stump of flow seen at the origin. Play Video opens in new tab/window

Moderate superficial femoral artery stenosis: Color flow imaging shows an area of flow disturbance and minor aliasing. This is investigated with spectral Doppler and the peak systolic velocity ratio is found be <2 times, indicating that this stenosis is not hemodynamically significant. Play Video opens in new tab/window

Calcified popliteal artery stenosis: Significant calcification is seen in the popliteal artery. Spectral Doppler recordings indicate a significant stenosis with a PSV ratio of nearly 10 times. Play Video opens in new tab/window

Occlusion of mid superficial femoral artery: The mid superficial femoral artery is seen to occlude in longitudinal section with a large collateral leaving the artery at the start of the occlusion. This is then seen in transverse section. The movie clip finishes showing refilling of the superficial femoral artery in longitudinal section from collateral vessels. Play Video opens in new tab/window

Significant stenosis of common iliac artery: Assessment of the inflow arteries can be difficult. This movie shows a typical scan. The iliac artery is followed proximally and an area of color aliasing is seen at the common iliac artery origin. This is assessed with spectral Doppler and high velocities with an abnormal-looking waveform are recorded (marked spectral broadening is present). It is difficult to compare these velocities with a proximal velocity as this would be the aorta, which is a different-caliber vessel. However, a recording is shown from the external iliac artery demonstrating an abnormal-looking waveform with increased systolic rise time and a loss of reverse flow. This would also indicate that the common iliac artery stenosis is hemodynamically significant. Play Video opens in new tab/window

Problems with calcification: Examples of calcification in lower limb arteries. This movie starts by demonstrating marked calcification in the SFA wall giving a ‘beaded’ appearance to the color flow image. The Doppler waveform shows an absence of a reverse flow component. Halfway through the clip, an attempt is made to the image the calf vessels. It is difficult to demonstrate color filling in the runoff vessels although they are known to be patent. The distal calf artery waveform appears monophasic and this is probably due to a loss of vessel compliance. Play Video opens in new tab/window

Calcification of the femoral artery: A very large calcified plaque is seen in the common femoral artery. The plaque has a ‘cauliflower’ appearance. Play Video opens in new tab/window

Acute occlusion of popliteal artery: An embolus has acutely occluded the popliteal artery. The start of the occlusion can be clearly seen in the middle section of the artery. Note that evidence of “pendulum” flow can be seen on the B-mode image just proximal to the occlusion. Play Video opens in new tab/window

14: sample Play Video opens in new tab/window

Chapter 9: Physics

B-mode gain control: This movie clip starts with the B-mode gain set too low and very little information can be seen in the image. The gain is progressively increased: optimum gain is achieved halfway through the clip when there is good contrast throughout the image and the lumen appears black. As too much gain is applied towards the end of the clip, the lumen is filled with noise and speckle, which would make diagnosis very difficult. Although not shown here, the depth gain compensation sliders can also be used to achieve an appropriate gain at discrete depths in the image. Play Video opens in new tab/window

The color box: It is important to understand how the steering of the color box or the direction of a vessel relative to the steering of the color box can affect the color flow display. In this example no steer is applied to the box and the vessel runs in a perpendicular direction through the box (angle of 90°). This results in very poor Doppler shift information. Although a color flow image is displayed, it is very difficult to interpret or use for diagnosis as both red and blue colors are present within the artery at the same time. This indicates opposite directions of flow within the same area of the vessel, which would not be the case in this normal carotid artery where flow is one direction. The next movie shows the same artery imaged with an appropriately steered color box. Play Video opens in new tab/window

Steered color box: This example of the carotid artery, shown in the previous movie, shows that a right color box steer has been applied to the artery, resulting in a much improved color image. Note flow in the jugular vein coded blue, as flow is in the opposite direction to the arterial flow. Play Video opens in new tab/window

Direction of vessels relative to the color box: The movie starts with the same problem displayed in an earlier movie clip, with an artery running in a perpendicular direction through a nonsteered color box. However, heel–toeing or tilting of the transducer in the longitudinal plane results in a better angle being created between the box or Doppler beam and the artery and therefore improved Doppler shift information, which is evident as more tilting is applied. In this example of a carotid artery it would probably be more appropriate to steer the box first rather than tilt the transducer but it is important to understand this principle. In other areas of the body, such the adductor canal in the leg, the artery dives deep and will appear at an angle to a nonsteered color box which normally results in a good color display. Generally steering of the color box decreases the sensitivity of the transducer, so square boxes are useful when vessels run at an angle through the box. Play Video opens in new tab/window

Understanding the direction of flow: One of the most confusing aspects of using color flow imaging and spectral Doppler is working out the direction of flow from the image. In this example from the carotid artery, the head is labeled on the left of the screen so flow must be traveling from right to left in the image. The first thing to note is that the box is steered left and flow will therefore be traveling away from the direction of the box steer or Doppler beam. Looking at the color bar, the color displayed on the lower part of the bar is always away from the transducer, which in this case is red and is the correct direction. The spectral Doppler display is above the spectral Doppler baseline but the numbers on the scale show a minus sign. Any figure with a minus is away from the transducer or Doppler beam, again the correct direction for this example. Halfway through the clip the artery is imaged with a right steer and the head is still to the left of the image. Notice that steering the box the opposite way has resulted in inversion of the color display. On the color bar, red is now on top of blue. The color at the top of the bar indicates flow towards the transducer, which is red and indicates the correct direction. The spectral Doppler display displays numbers without minus signs, indicating positive numbers. Positive numbers represent flow towards the transducer or Doppler beam. Play Video opens in new tab/window

Color aliasing: The following example starts with an appropriate scale or color pulse repetition frequency (PRF) setting. Peak systole is demonstrated towards the higher end of the red color scale. Watch the figures on the left side labeled PRF and those just above and below the color bars labeled in cm/s as the scale is decreased. As the PRF reaches 1000 and then 700, significant aliasing is occurring and it may be possible to miss a localized flow disturbance. The scale is then set too high (PRF 6000) and the end-diastolic flow is not adequately displayed. The scale or PRF should be optimized to the particular flow situation. Play Video opens in new tab/window

Color baseline: An alternative method to remove color aliasing is to alter the color baseline instead of the color scale so that the range of velocities represented in one direction is increased or decreased. This is shown in this example. Watch the color bar and see what happens to the display as the color baseline changes. As the red range is increased, the color hue decreases in the color image of the vessel. As the red range is decreased, aliasing occurs. Play Video opens in new tab/window

Optimizing the Doppler display: In this example, the movie starts with poor color box steering to the carotid artery which is quickly improved by steering to the left. Spectral Doppler recordings initially look very confusing as flow is below the baseline and aliasing is indicated, as the tops of the peaks are missing and can be seen above the baseline. However, the flow is in the correct direction as the lower part of the waveform is shown in the scale with negative numbers indicating flow away from the beam or transducer. To make sense of the spectrum it is first inverted and now the negative numbers appear above the baseline along with the spectrum. The Doppler scale is increased to accommodate the whole spectrum. As the whole scale is not being used, one further improvement is made to obtain better resolution of the spectrum. This is achieved by lowering the baseline and reducing the scale so the whole waveform just fits within the display. Play Video opens in new tab/window

Doppler gain: The active moving part of this clip starts with very low gain and poor discrimination of the waveform. The gain is increased and by the time the trace has reached the right side, the gain is already too high (the third or fourth waveforms in from the right show optimum gain setting). The gain is then increased further and mirroring and noise can be seen in the reverse channel below the baseline. Also look carefully at the height of the peaks as the gain is increased. They get higher and it can be seen that inappropriate gain may result in errors in velocity measurements. Play Video opens in new tab/window

Color priority control: Some scanners have a color write priority control which enables the operator to display color flow information in images with high B-mode gain (see Ch. 4). This movie starts with a normal color flow image of the carotid artery. The B-mode gain is increased and overwrites the color display as the screen pixels in the region of the artery cannot display both gray-scale and color information at the same time. There is therefore a threshold at which the signal intensity will be written as gray-scale. The B-mode gain is then reduced and the image appears normal. Now the B-mode gain is increased again and the color flow information overwritten once again. Look to the middle left of the color bar and a fine green line is visible on the gray-scale bar. Watch as the green line is moved up, increasing the write priority to color. It can be seen that the color flow image reappears in the high-gain B-mode image. The write priority is then set to minimum and the color flow image disappears. Using this control can be helpful when there are strong echoes in a vessel lumen which are difficult to remove and are interfering with the color display. Play Video opens in new tab/window

Color gain and stenoses: This image shows a tight carotid stenosis and anechoic type 1 plaque. At the start of the image the color gain is low and it is difficult to see flow across the stenosis. As the gain is increased the color begins to fill the vessel and the residual flow lumen across the stenosis, demonstrated by the color, becomes larger. This is why measuring the residual flow lumen using the color display can be unreliable. Play Video opens in new tab/window

Pulsatile color flow image: Color flow imaging shows forward (red) and reverse flow (blue) simultaneously in the superficial femoral artery (see Ch. 5). Play Video opens in new tab/window

Reflection: This movie shows an unusual false aneurysm of the temporal artery that developed after an injury. Looking carefully at the image, it can be seen that there is near-perfect B-mode and color reflection of the aneurysm due to the presence of the skull, which is a strongly reflecting interface. Similar problems occur when imaging the subclavian artery due to the chest wall. Play Video opens in new tab/window

8: sample Play Video opens in new tab/window

Chapter 10: Varicose Veins

Venous valve site in popliteal vein: The opening and closing of a normal venous valve during augmentation are shown in this movie. This recording was taken from the below-knee popliteal vein. Play Video opens in new tab/window

Transverse "Mickey Mouse" view of saphenofemoral junction: A cine-loop showing the left saphenofrmoral junction located at the 10 o’clock position with respect to the common femoral vein. Note that the femoral artery lies lateral to the vein (right-hand side of image). The saphenofemoral junction and proximal great saphenous vein may be incompetent in this image as they are fairly large. Play Video opens in new tab/window

Competent saphenofemoral junction shown in longitudinal image: This movie shows a competent junction assessed with color flow imaging and spectral Doppler in a patient with no varicose veins. Note that calf squeezing is being applied in this example to augment flow but there appears to less flow augmentation on the third squeeze as the veins and venous sinuses have not had enough time to refill fully via the arterial and capillary system in between each squeeze. Play Video opens in new tab/window

Incompetent saphenofemoral junction: A large incompetent saphenofemoral junction is demonstrated. Reflux is demonstrated with color flow imaging and spectral Doppler. Note the reflux is coded blue in the color image and appears below the baseline in the spectral display. Play Video opens in new tab/window

Incompetent saphenofemoral junction and anterior accessory saphenous vein: In this example of the right saphenofemoral junction, the GSV and a large anterior accessory saphenous vein (AASV) are seen. As the probe is moved distally it is apparent that the AASV, shown by the arrow is larger than the GSV, which is shown by the arrow towards the last third of the clip. The AASV is also showing some aligbment to the deep arteries and veins on the far left of the image. Play Video opens in new tab/window

Small saphenous vein (SSV) and saphenopopliteal junction: In this example the SSV is clearly seen within a fascial compartment. The arrow shows the SSV being tracked back to the saphenopopliteal junction, which in this case is located towards the anterior lateral aspect of the popliteal vein when viewed from the popliteal fossa. The junction can be located in many different positions with respect to the popliteal vein. Play Video opens in new tab/window

Transverse view of the small saphenous vein (SSV) and popliteal fossa: In this transverse view of the popliteal fossa, the short saphenous vein (SSv), popliteal vein (PV) and popliteal artery (PA) have been labeled partway through the clip to aid identification. Note evidence of gastrocnemius and soleal veins between the level of the SSV and popliteal vein. The SSV should lie within a fascial compartment, resembling an “Egyptian eye.” If in doubt, move the probe just below the popliteal fossa, where it will normally be easier to distinguish. Play Video opens in new tab/window

Varicose veins: A transverse view of tortuous varicose veins. Note the reflux with color flow imaging. The muscular fascia can be clearly seen as an echogenic band just below the varicose veins. Play Video opens in new tab/window

Great saphenous vein (GSV) and saphenous compartment: The GSV is seen in the saphenous compartment. The moving arrow indicates the muscular fascia and the superficial saphenous fascia. During the movie, a large varicose-looking tributary is seen diving from the GSV and running out of the saphenous compartment. The GSV then becomes smaller beyond the varicose tributary and when this was assessed with Doppler, the lower segment of the GSV was competent but the GSV proximal to the tributary was incompetent. (See Figure 13.6). Play Video opens in new tab/window

Great saphenous vein (GSV) trunk with reflux: In this movie the GSV is seen within the saphenous compartment in transverse section. A localized dilation or varix is seen. Turning to longitudinal section, significant reflux is demonstrated in the GSV with color flow imaging and spectral Doppler. Play Video opens in new tab/window

Transverse view of small saphenous vein (SSV), saphenopopliteal junction, and thigh extension (TE) vein: A large varicose SSV is followed in transverse section to the saphenopopliteal junction located at the 9 o’clock position with respect to the popliteal. A TE vein is present and, as the main trunk of the SSV begins to run deep, the TE continues to run up the posterior thigh. Deep muscular veins are also draining to the popliteal vein at the 3 o.clock position. Play Video opens in new tab/window

Small saphenous vein (SSV) confluence with gastrocnemius vein: In this example the SSV drains to the gastrocnemius system rather than the popliteal vein. The loop starts in transverse section and the arrow follows the SSV as it joins a large gastrocnemius trunk. The veins are than shown in longitudinal section, where the SSV is seen superficial before dropping down to join the gastrocnemius vein system. Note the excellent view of the venous valves in the popliteal vein just distal to the junction with the gastrocnemius vein. Play Video opens in new tab/window

Competent popliteal vein: The popliteal vein is assessed for reflux and is found to be competent. Note that good flow augmentation has been achieved with a strong calf squeeze. Play Video opens in new tab/window

Incompetent saphenopopliteal junction: transverse view: At the start of the movie the SSV is seen superficially and is then followed back to the saphenopopliteal junction shown at the 3 o’clock position with respect to the popliteal vein. Color flow imaging indicates significant reflux, coded blue. As there is no audio track to this movie, how could we tell if there was reflux from the spectral Doppler trace alone? The key is to look at the numbers on the Doppler scale. Flow towards an ultrasound transducer or beam is normally shown as a positive number on the Doppler scale (note that the plus sign is not shown on this machine but is inferred, as the negative sign is shown with the numbers on the opposite side of the baseline.) Therefore, flow towards the probe in this example should be positive (below the baseline) and the augmentation with calf squeeze away from the probe negative (above the baseline). This is clearly the case in this example and significant reflux is indicated. By pressing the Doppler invert button the reflux can be shown above the baseline but the negative sign will now appear below the baseline. Play Video opens in new tab/window

Normal spontaneous phasic flow with respiration in the femoral vein: Spectral Doppler recordings have been taken from the proximal femoral vein and demonstrate normal spontaneous phasic flow with respiration. Changes in flow can also be seen due to the cardiac cycle. Towards the end of the clip, the patient stops breathing and the flow temporally ceases. When the patient breathes-out there is a short duration of increased flow. Play Video opens in new tab/window

Valsalva maneuver with color flow imaging: In this example it was difficult to assess reflux in the proximal great saphenous vein and saphenofemoral junction with calf augmentation as the recordings were borderline for reflux and not consistent. Therefore a Valsalva maneuver was performed. Reflux across the saphenofemoral junction was demonstrated with a Valsalva maneuver coded in the red scale towards the beam steer. The vein is also seen to distend slightly during Valsalva. Play Video opens in new tab/window

Valsalva maneuver spectral Doppler: Reflux is demonstrated with spectral Doppler. The patient inspires deeply (flow above the baseline) and after a short pause performs a Valsalva with flow occurring below the baseline (there is some noise above the baseline). As the patient releases and inspires, there is flow back towards the heart (flow above baseline). In this example, definition of the reflux is fairly poor as the position of the vein may have moved slightly relative to the sample volume as the Valsalva maneuver was performed. This highlights the problems of dynamically assessing venous reflux. In extreme cases it is possible for the transducer to “slip” to one side of the vein and therefore no signal is recorded, although reflux may be present. Play Video opens in new tab/window

Trickle reflux across a valve site (leaking valve): In this example, there is evidence of an eccentric leak to one side of the vein following augmentation. It is sometimes difficult to grade this type of reflux as it appears as a trickle on spectral Doppler (see Figure 13.20). It is also possible that assessment early in the day may have shown a competent vein, whereas later in the day, when a person has been standing for long periods, the veins slightly dilate, leading to minor reflux. Play Video opens in new tab/window

Thrombophlebitis: In this longitudinal and transverse view of the great saphenous vein, significant thrombophlebitis is seen within the vein. Play Video opens in new tab/window

Thrombophlebitis and ultrasound compression: The great saphenous vein will not collapse with ultrasound compression and evidence of thrombophlebits is seen. Play Video opens in new tab/window

Large varix involving great saphenous vein: A large localized dilatation is seen in a varicose great saphenous vein in transverse section. If this patient was having endovenous vein therapy, it is possible for guide wires to coil or even knot in these dilated areas. Applying some pressure over the vein at this point can compress it and allow for easier passage of the catheters. Play Video opens in new tab/window

Ligated saphenofemoral junction: In this patient the right saphenofemoral junction has been ligated by previous surgery and the great saphenous vein is not visible. The junction would have been at the 2 o’clock position with respect to the common femoral vein on this image (arrow). There is evidence of some small venous tributaries adjacent to the femoral vein but no direct connection is seen. Play Video opens in new tab/window

Recurrent saphenofemoral junction shown in B-mode: In this cine-loop there is evidence of recurrent saphenofemoral junction supplying a tortuous area of recurrent varicose veins. These then supply a recurrent great saphenous vein trunk seen towards the end of the movie. It is possible that the great saphenous vein was not fully stripped during the original surgery. Play Video opens in new tab/window

B-mode image of calf perforator: Perforators are easiest to identify by sweeping the transducer along the vein in transverse plane. In this example a perforator to the posterior tibial veins is seen. Notice the break in the fascia as the perforator runs from the superficial veins to the posterior tibial veins. Play Video opens in new tab/window

Incompetent mid-thigh perforator: A large incompetent mid-thigh perforator is seen in cross-section supplying recurrent varicose veins. The reflux is coded blue. In the spectral Doppler recording the duration of reflux is less than a second, but in this case it is likely to be significant as the reflux component below the baseline (positive numbers therefore flow towards the transducer or beams) is similar in shape to the augmentation phase. Play Video opens in new tab/window