Expert answer:sonogram vascular

Solved by verified expert:Question # 1 (open the ZIP File)Answer all the questions from the attached files. I’ve not enough time to do it myself. Please don’t use online sources.1)Discuss the physiologic process behind blood flow in the human body. What makes it possible? 2)Name and describe the two types of laminar flow. How are they related to friction?3)Define helical flow and give an example of where it can be frequently found.4)Describe the components that contribute to turbulent flow. How are they related to friction?5)Define Poiseuille’s Law. What does it tell us about flow?6)Define Bernoulli’s Law. What does it tell us about flow?7)How does Ohm’s Law relate to ultrasound?8)Review arterial anatomy down to the capillary bed. Review arterial resistance in the lower extremity; Include normal at rest, normal in exercise and abnormal Doppler waveforms.9)What is the difference in the capillary bed between exercise and chronic disease?10)Define Atherosclerosis and how it contributes to Peripheral Arterial Disease (PAD)11)List and describe the different severity levels of PAD and the expected clinical findings and sonographic findings associated with them.12)How is AT (acceleration time) helpful in evaluating disease? Where?13)Explain the mapping of a hemodynamic Stenosis in the lower extremity exam. 14)How is the systolic velocity ratio helpful in quantifying % Stenosis in the lower extremity? 15)Describe the sonographic findings of a total arterial occlusion in the lower extremity. Question # 2open the attached file ( Patters and Distribution) and write down a brief summary ( one & half page) with the atticle
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Scientific Articles
The Journal for Vascular Ultrasound 39(2):71–77, 2015
Patterns and Distribution of Deep Vein Thrombus
in the Lower Extremity
Brian Sapp, RVT, RPhS; Garnet Craddock, Jr., MD; James Sapp, BS, RVT
ABSTRACT Introduction.—Practices vary widely among sonography laboratories in the
imaging and evaluation of calf thrombus, contributing to diagnostic and treatment uncertainty.
Our goal was to isolate and determine patterns of deep vein thrombus to question the level of
sonography required for best diagnosis.
Materials and Methods.—We retrospectively evaluated all patients that had a positive venous
duplex exam from 2004 to 2013. Our lab performed 11,503 venous studies during the 8-year period,
with 382 showing, via symptom review and reporting, acute first-time thrombus.
Results.—Mean age 62 years 8 months old, 209 females (54.71%), 171 male (44.76%), 221 left
sided (57.85%), 161 right sided (42.15%). Percentages for the following segments: above the knee
(139, 36.39%), calf (375, 98.17%), superficial (54, 14.14%), IVC (14, 3.66%), iliac (36, 9.42%), CFV (67,
17.54%), PFV (7, 1.83%), FV (114, 29.84%), popliteal AK (123, 32.20%), popliteal fossa (142, 37.17%),
popliteal BK (148, 38.74%), gastrocnemius veins (141, 36.91%), peroneal (243, 63.61%), posterior
tibial vein (191, 50.00%), soleal (109, 28.53%), anterior tibial veins (3, 0.79%), great saphenous vein
(38, 10%), small saphenous vein (18, 5%), and varicosities (8, 2%).
Conclusion.—Calf vein thrombus is found with above the knee thrombus (98.17%). Peroneal
(63.61%), posterior tibial (50%), gastrocnemius (36.91%), and soleal (28.53%) veins should be
routinely imaged. Binomial logistic regression was conducted with eleven-predictor variables
significantly predicted proximal thrombus (above the knee). A test with all eleven-predictor
variables, compared with the null model, was significant (x2 [14] = 288.511, p < 0.001), showing that these variables predict above-the-knee thrombus better than without them (or by chance). We have developed a tool that shows the potential trajectories or tracks of a given patient’s DVT (with associated probabilities), based on aggregated patient data. Introduction Collectively deep vein thrombosis (DVT) and pulmonary embolism (PE) are known as venous thromboembolism (VTE).1 Although the exact incidence of VTE is unknown, it is believed that there are approximately 1 million cases in the United States each year, many of which represent recurrent disease.2 It is estimated that anywhere from 200,000 up to 600,000 Americans will suffer from DVT and PE. Additionally, some estimates suggest 300,000 of these patients die3; however, more From 1Southern Vein Care, Fayetteville, Georgia; 2Piedmont Healthcare, Atlanta, Georgia. Accreditation Statement: This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of the University of Cincinnati and the Society for Vascular Ultrasound. The University of Cincinnati is accredited by the ACCME to provide continuing medical education for physicians. The University of Cincinnati designates this journal activity for a maximum of 1 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credits commensurate with the extent of their participation in the activity. Address correspondence to: Brian Sapp, RVT, RPhS, Lead Vascular Lab Technologist, Southern Vein Care, 1975 Highway 54 West, Suite 110, Fayetteville, GA 30214. E-mail: Brian.Sapp@ piedmont.org recent data from CDC estimates the number of deaths in the US at 60,000–100,000. In the United States, more people die each year from PE than motor vehicle accidents, breast cancer, and AIDS combined.3–7 Practices vary widely among sonography laboratories in the imaging and evaluation of calf thrombus, contributing to diagnostic and treatment uncertainty. Our goal was to determine the distribution of deep vein thrombus in the lower extremity to assist in answering the following question. What level of sonography is required for best practice and diagnosis when evaluating the lower extremity for DVT? It has been our collective experience performing and interpreting venous color flow duplex ultrasound that the location of thrombus presents primarily in the calf and progresses up the lower extremity. Initially in our vascular careers, evaluation of tibial and peroneal vein was performed, however the muscular calf veins (MCV) (soleal and gastrocnemius) were not included in the routine protocol. Approximately 12 years ago, the MCV were added to the venous protocol for imaging of the lower extremity for DVT and in the evaluation for venous insufficiency. The incidence of thrombus identified after making the change was significant. The realization that we had missed or potentially missed a significant amount of thrombus before 72 JVU 39(2) SAPP ET AL. Figure 1 Input observed DVT in DVTrax 2.0 and the diagnostic vectors and probabilities. making the change in protocol was of great concern and the impetus for this study. Providing venous training across the United States, we have witnessed wide variations between facilities, service lines and protocols in the evaluation of the lower extremity for DVT. We have found that in environments in which calf vein thrombus is not deemed important, scanning techniques to evaluate the calf veins often have not been developed and/or taught. In facilities that calf vein thrombus is considered significant the skill of the sonographer has been developed and testing is considered very accurate and reliable. It became apparent that the discrepancy in testing leads to subsequent treatment uncertainty and in many cases the lack of treatment in regard to calf vein thrombus. Our goal was to quantify the amount of thrombus found in each named vein of the lower extremity and to determine the relationship between calf vein thrombus and above the knee thrombus if any. Conflicting clinical results have resulted in differing opinions on the need to test for calf deep vein thrombus (CDVT) as well as to treatment when identified. During our review of the literature we determined that there are three prevailing views on how diagnostic imaging of the lower leg is and should be performed. Review of Literature The first view is that compression ultrasound (CUS) is sensitive for proximal DVT and that proximal DVT has traditionally been associated with a higher risk for PE than CDVT.8 From this perspective, imaging of the calf veins is of limited importance as DVT below the knee often resolves spontaneously and rarely is associated with PE or adverse outcomes.8 In March of 2010, The American Institute of Ultrasound in Medicine (AIUM) drafted and published the Practice Guideline for the Performance of Peripheral Venous Ultrasound Examination. This guideline suggests that for normal examinations, grey scale images should be recorded without and with compression of the common femoral, saphenous–femoral junction, femoral and popliteal veins, and Doppler of the common femoral and popliteal veins. Symptomatic areas such as the calf generally require additional evaluation and additional imaging; however, this is left up to the user and/ or organization to define.8,9 The ACR Appropriateness Guide states, “DVT that is limited to the infra-popliteal calf veins (i.e., below-the-knee or distal DVT) often resolves spontaneously and is rarely associated with PE or other adverse outcomes.”10–13 Investigators in 2015 PATTERNS AND DISTRIBUTION OF DVT IN THE LOWER EXTREMITY 73 Figure 2 Input observed DVT in DVTrax 2.0 and the diagnostic vectors and probabilities. Clinical Outcomes of Untreated Symptomatic Patients with Negative Findings on Sonography of the Thigh for DVT stated the following, “We find that most evaluation of the calf to exclude a DVT have indeterminate findings because the deep veins of the calf cannot be completely assessed due to their small size relative to thigh veins.”9 The article goes on to say that high rates of indeterminate studies for DVT have been reported.9,14,15 The authors of the study found that only 15% of their calf evaluations were diagnostic and 84.2% were considered indeterminate. The two studies referenced in regard to imaging of the calf veins were published in 199015 and 1995,16 respectively. Both of these finding supports the long held view that DVT below the knee is not significant or important. Close examination of the studies used to come to this conclusion shows that the investigators found that most evaluations of the calf to exclude DVT have indeterminate findings because of the small size.9 The study also used references from studies from 1989 and 1995 both authored by Polak16,17 when stating that 84% of calf vein examinations are indeterminate.9 Polak in 1996 came back and published and stated that recent studies showed estimated sensitivity of 93%.18 He further states that almost a third of patients with calf vein DVT have a recurrence of thromboembolic events when not treated with Coumadin.18,19 Although Gottlieb et al. published his finding in 1999 and referenced Polak’s work, he did not include the most recent data at that time that would have contradicted his original findings.9 As we looked further into the Practice Guidelines it became apparent that references are either of older guidelines or of studies that also did not routinely image the calf veins or had poor success imaging calf veins. The ACR guideline does recognize that DVT typically starts distally below the knee but can extend proximally above the knee and potentially result in life-threatening PE. PE can occur in 50–60% of patients with untreated DVT, with an associated mortality rate of 25–30%.8,9 Interestingly, the Gottlieb et al. study also showed a very low rate of PE (0.7%) compared with studies of isolated calf vein thrombus that showed a PE rate of 7.9% for isolated infra-popliteal DVT’s alone.9,20 The rate of PE was 11.4% for femoral– popliteal deep vein thrombus in the same study and a PE rate of 18.1% in multilevel DVT’s involving both segments.20 The study by Alhalbouni et al.20 published in 2011, included 4035 patients, of which 3146 were of hospital patients. They concluded that there was no statistical difference (p = 0.27) in the risk for PE 74 SAPP ET AL. JVU 39(2) Figure 3 Input observed DVT in DVTrax 2.0 and the diagnostic vectors and probabilities. between isolated femoral–popliteal and isolated infrapopliteal DVT. It was noted that a significant number of those with isolated MCV (soleal and gastrocnemius) developed PE. They concluded that scans should include infra-popliteal veins to include the soleal and gastrocnemius.20 The Gottlieb et al. study only involved 120 direct patients and only 13 patients underwent a second examination because of persistent symptoms. Because of the small sample size, the study then pulled from four other literary studies involving 1797 patients; however, three of the studies did not include dedicated examination of the calf. Only 12.5% of the patients in the combined analysis (15 out of 120) had a DVT upon reexamination due to high clinical suspicion of DVT. Three studies were performed in 1990,21 1989,22 and 199323 that demonstrated these statistics. Gottlieb et al. did acknowledge that there are three prevailing views in the imaging community, one that demands a high level of accuracy in evaluation of the calf and others who accept follow-up ultrasound or venography after calf exams with indeterminate findings in patients with persistent symptoms.9 He also acknowledges that some physicians do not consider calf thrombus to have any risk of embolization to the lungs and do not require any further evaluation after the initial sonogram. Gottlieb and Widjaja also acknowledge that differing rates of pulmonary emboli could result from the various approaches to surveying the calves for DVT and suggest that a uniform approach, to the examination of the symptomatic patient with suspected lower extremity DVT, would be valuable in reducing practice variation.9 The second view emerging from the literature is that the imaging of the calf veins (posterior tibial and peroneal veins) should be routine and that the soleal and gastrocnemius veins (known as the muscular calf veins, or MCV) are to be imaged when indicated or if included in the facilities protocol. This view is reflected in the current IAC Standards and Guidelines for Vascular Accreditation Section in section 4B: Peripheral Venous Testing.25 The guideline requires imaging of the common femoral, femoral (proximal, mid, and distal), popliteal, posterior tibial, and peroneal veins. The guideline further states that imaging of the MCV may be required by laboratory protocol or when indicated along with the common iliac, external iliac, great saphenous, small saphenous, proximal deep femoral, anterior tibial, perforating veins, and inferior vena cava.25 Although this is the predominate protocol used in dedicated vascular laboratories, it allows for imaging of the MCV based on the choice of the facility and/or end user. This is the primary protocol that was used by the researchers prior to adding routine imaging of the MCV. It is our experience that many labs with this protocol 2015 75 PATTERNS AND DISTRIBUTION OF DVT IN THE LOWER EXTREMITY often have intradepartment variation in regard to imaging of the gastrocnemius and soleal veins. The third prevailing view requires imaging of all the lower extremity veins to include the deep calf and MCV (PTV, Peroneal, Gastrocnemius and Soleal).4–6,8,10 Espousing this view are mostly vascular laboratories that are ICAVL accredited or adhere to their standards but have identified the need to image the MCV.24 Those studies which included imaging of all of the calf veins showed an appreciative amount and increase in distal DVT when compared with studies that did not perform imaging of the deep and MCV. It is estimated that approximately 40% of the patients with acute isolated calf DVT would be judged to have normal color flow duplex scan (CFDS) examination results if muscular veins of the calf were not imaged.27 In studies where MCV alone were imaged, distal DVT was greatly appreciated over proximal DVT.27 Studies, in which laboratories looked at all the deep and MCV, show that DVT is not only present at a higher rate but that the thrombus also propagates at a higher rate.20,24,26–33 The frequency of distal involvement greatly exceeds that of a proximal involvement in patients with DVT.28 Materials and Methods We retrospectively evaluated all patients that had a positive venous duplex exam from 2004 to 2013. Our lab performed 11,503 venous studies during the 8-year period, with 382 showing, via symptom review and reporting, acute first-time thrombus. Our lab performed 11,503 venous studies during the 8-year period, with 3469 positive exams (for DVT and/or venous insufficiency), the studies included 1227 patients, with 382 showing, via symptom review and reporting, acute and first-time thrombus. For the purpose of this study, patients with chronic DVT or indeterminate thrombus were excluded, as recanalization in such patients may occur in different vein segments at differing rates. All of the patients were tested in an ambulatory outpatient setting and were symptomatic at the time of evaluation; no serial monitoring for nonsymptomatic patients was performed. Scanning included color-flow duplex scanning with CUS used as the primary indicator of thrombus. Imaging was performed on of all of the named veins of the lower extremity including the common femoral, femoral, popliteal, gastrocnemius, peroneal, posterior tibial, soleal, and when indicated, on the anterior tibial, iliac veins (common and external), and IVC. Experienced Registered Vascular Technologists within a dedicated vascular lab setting performed all tests. Our reporting segmented the popliteal vein into three categories: popliteal above the knee, popliteal fossa, and popliteal below the knee. For analysis and continuity with other studies that only studied above the knee DVT, we consider the above knee popliteal vein as the indication of thigh DVT. Results During the retrospective analysis of the acute DVT in our study, we found a total of 1227 studies from 2004 to 2013 were surveyed with a total of 382 fitting inclusion criteria. The mean age 62 years 8 months old, 209 females (54.71%), 171 male (44.76%), 221 left sided (57.85%), and 161 right sided (42.15%). Percentages for the following segments: above the knee (139, 36.39%), calf (375, 98.17%), superficial (54, 14.14%), IVC (14, 3.66%), iliac (36, 9.42%), CFV (67, 17.54%), PFV (7, 1.83%), FV (114, 29.84%), popliteal AK (123, 32.20%), popliteal fossa (142, 37.17%), popliteal BK (148, 38.74%), gastrocnemius veins (141, 36.91%), peroneal (243, 63.61%), posterior tibial vein (191, 50.00%), soleal (109, 28.53%), anterior tibial veins (3, 0.79%), great saphenous vein (38, 10%), small saphenous vein (18, 5%), and varicosities (8, 2%). The analysis showed a strong association with the calf (98.17%) of all cases and thigh DVT was only seen without calf involvement 1.83% of the time. It was also apparent during the collection of data that visual patterns of thrombus were present. Binomial logistic regression was conducted to assess whether the 11 predictor variables significantly predicted proximal thrombus (above the knee). Three predictors were derived from demographic variables: age (with four groups: 10–49, 50–64, 65–79, 80+), sex (male/ female), and which leg the thrombus was observed in (left/right). Eight predictor variables were taken from observation of distal thrombus (below the knee) in the popliteal fossa (POP FOSSA), popliteal below knee (POP BK), gastrocnemius vein (GASTROC), peroneal vein (PERO), posterior tibial vein (PTV), soleal vein (SOLEAL), anterior tibial vein (ATV), and small saphenous vein (SSV). Data from 382 cases were included in the analysis. A test with all 11 predictor variables, compared with the null model, was significant (x2 [14] = 288.511, p < 0.001), showing that these variables predict above-theknee thrombus better than without them (or by chance). Moreover, the model correctly predicted 90.8% of those cases where proximal thrombus had not been observed, and 89.5% of those cases where it had been; overall, the model predicted 90.3% of observed cases. Table 1 summarizes the raw binary logistic regression coefficients, as well as Wald statistics and odds Table 1 Binomial Logistic Regressing Predicting Proximal Thrombus Age Sex Leg POPFOSSA POPBK GASTROC PERO PTV SOLEAL ATV SSV B S.E. Wald Sig. Exp (B) −0.905 −2.025 0.923 −3.534 −2.06 0.068 0.862 0.634 0.823 −19.778 −1.166 0.593 3.955 0.384 0.577 0.787 0.401 0.575 0.562 0.446 22391.805 0.736 2.331 0.262 5.763 37.469 6.844 0.029 2.245 1.273 3.399 0 2.507 0.127 0.609 0.016 0 0.009 0.865 0.134 0.259 0.065 0.999 0.113 0.404 0.132 2.517 0.029 0.128 1.07 2.368 1.886 2.278 0 0.312 76 JVU 39(2) SAPP ET AL. ratios (Exp [B]) for each of the 11 predictor variables. The table shows that POP FOSSA thrombus is a statistically significant predictor of above-the-knee thrombus (Exp [B] = 0.029, x2 [1] = 37.469, p < 0.001). Similarly, POP BK thrombus is a statistically significant predictor of above-the-knee thrombus, as well (Exp [B] = 0.128, x2 [1] = 6.844, p = 0.009). Additionally, the LEG variable was a good predictor of above-the-knee thrombus (Exp [B] = 2.517, x2 [1] = 5.763, p = 0.016). Interestingly, SOLEAL thrombus is approaching statistical significance (Exp [B] = 2.278, x2 [1] = 3.399, p = 0. 065). All of the other Wald chi-square tests were not significant. Discussion Currently in the United States, the American College of Radiology does not require that calf veins be imaged, that sym ... Purchase answer to see full attachment

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