Study of cavernosal arterial anatomy using color and power Doppler sonography: impact on hemodynamic parameter measurement.

PURPOSE: We report on color and power Doppler ultrasound to study cavernosal arterial anatomy, and evaluate the impact of vascular anatomy on the measurement of hemodynamic parameters. MATERIALS AND METHODS: Cavernosal arterial anatomy of 42 patients with erectile dysfunction was evaluated using color and power Doppler ultrasound. A computerized waveform analysis was used to measure peak systolic velocity, end diastolic velocity and resistive indexes at various sites, including the penile crura, and proximal mid and distal penile shaft. Hemodynamic parameters were measured in each artery in cases of bifurcated or multiple cavernosal arteries. RESULTS: A total of 80 corpora were adequately evaluated. We observed a single artery without major proximal branches in 37 corpora, a single artery with major proximal branches in 17, bifurcated arteries in 15, 2 cavernosal arteries in 4 and marked arterial tortuosity in 1. In 6 corpora the main cavernosal artery arose from the superficial dorsal artery. The peak systolic velocity was highest at the proximal and decreased progressively at the distal site. The peak systolic velocity plus or minus standard deviation at the mid shaft averaged 69.3+/-30.0% of that at the proximal penile shaft. Of the 15 corpora with bifurcated arteries 67% had a 40% or greater difference in peak systolic velocity between the branches. Complete or partial occlusion of the cavernosal artery was identified in 3 corpora, and a dramatic difference in peak systolic velocity proximal and distal to the stenotic area was demonstrated. CONCLUSIONS: Cavernosal arterial anatomy is variable and hemodynamic parameters differ at various sites of measurement. Parameters should be measured at a consistent proximal site to obtain a reliable assessment. Variations in vascular anatomy and cavernosal artery pathology should be considered when interpreting color Doppler sonography and before penile vascular surgery.     

Doppler ultrasound procedures in the diagnosis of occlusive processes of the supra-aortic arteries

Reported in this paper is experience obtained from application of Doppler sonography to more than 2,000 examinations of patients with suspicion of cerebrovascular insufficiency. Indications for Doppler-type investigation are described together with criteria of Doppler sonography for positive detection of occlusive processes in greater brain-feeding arteries and for adequate assessment of results obtained from vascular surgery. The sensitivity of Doppler sonography amounted to 88.8 per cent and its specificity to 92.9 per cent, as recorded from 117 patients who had been angiographically followed up. Doppler ultrasonography for its high productivity in terms of wide-ranging diagnostic information was found to be the optional method for non-invasive diagnosis of occlusion in supra-aortic arteries, provided absence of contraindications.     

Is duplex ultrasonography an effective single modality for the preoperative evaluation of peripheral vascular disease?

The purpose of this study was to determine whether duplex ultrasonography can be used as an effective modality for the preoperative evaluation of lower-extremity arterial occlusive disease. The records of all patients undergoing both color flow duplex scanning and contrast arteriography of the lower extremities during a 13-month period were reviewed. Comparisons between the two modalities were made at the femoral, popliteal, and tibial artery levels. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were calculated for duplex scanning using angiography as the gold standard. Three hundred fifteen arterial segments were evaluated. Color flow imaging overestimated the degree of stenosis in seven vessels and underestimated the degree of stenosis in four vessels. Overall duplex ultrasonography accurately determined lower-extremity arterial anatomy as defined by contrast arteriography with a sensitivity of 96.9 per cent, a specificity of 96.2 per cent, a positive predictive value of 94.6 per cent, a negative predictive value of 97.8 per cent, and an overall accuracy of 96 per cent. The accuracy of duplex ultrasonography must be determined in each individual vascular laboratory. Once this is satisfactorily accomplished color flow scanning may be used as the single imaging modality for lower-extremity arterial occlusive disease in selected patients deemed to be at high risk for contrast angiography.     

Persistierende primitive Hypoglossusarterie (PPHA)

The persistent primitive hypoglossal artery (PPHA) is an embryonal communication between the posterior and anterior circulation of arteries supplying the brain; it is normally obliterated in the early embryonal stages. In a symptom-free patient with arterial occlusive disease, internal carotid artery occlusion was incidentally diagnosed using color duplex ultrasound, whereby the resupply of blood to the distal extracranial internal carotid artery occurred due to retrograde blood flow via the PPHA, resulting in nearly normal blood flow to the distal extra- and intracranial carotid circulation. We describe how color duplex ultrasonography can be used to differentiate therapy-relevant findings, when blood flow is lacking in the proximal internal carotid artery.     

Anatomy and management of upper moiety vascular variation in children with duplex kidney

PurposeTo describe the upper pole vascular anatomy of duplex kidney and provide our experience with laparoscopic upper pole partial nephrectomy (LUPPN).MethodsA retrospective study was performed among patients with duplex kidney who underwent computed tomography angiography at one single institution, some of whom were subsequently treated with LUPPN. According to imaging results and intraoperative findings, the arterial supply to the upper moiety of a duplex system was classified based on number and branching pattern.ResultsA total of 84 children were included in the study. Twenty patients (23.8%) were managed conservatively and LUPPN in lateral position was performed in the others. All laparoscopic procedures were successfully completed as planned without conversion. No major intraoperative complications occurred. Of these patients, 68 cases (73.1%) were supplied with one branch of the renal artery. The vascular anatomy of duplex kidney was classified into three patterns according to the variation of arteries. In 71 cases (76.3%), the renal artery separated into two or more arteries near the renal parenchyma, called perihilar arterial branching. Other branching patterns featured accessory renal arteries and branches of the adrenal artery. Gender was not significantly associated with the vascular number (p = 0.19) and the pattern of variation (p = 0.83).ConclusionsLUPPN is an effective technique for children with duplex kidney. The upper renal moiety is mainly supplied by one branch of the renal artery and the most common pattern is perihilar arterial branching. Determining vascular variation before surgery might be beneficial to avoid intraoperative hemorrhage and accidental vessel injury.Type of studyRetrospective cohort study.Level of evidenceLevel IV.     

髂外-腘动脉人工血管交叉转流术治疗髂股动脉硬化闭塞症

目的 探讨髂外动脉-腘动脉人工血管移植交义转流术治疗单侧髂股动脉硬化广泛性闭塞的疗效.方法 1999年9月至2007年10月39例患者经血管彩超、CT血管造影(CTA)或数字减影血管造影(DSA)检查,证实单侧髂股动脉硬化广泛性闭塞;静息痛25例,14例足趾溃疡或坏疽,平均踝/肱指数0.19;采用健侧髂外动脉-患侧胴动脉人工血管移植交叉转流术,左转至右22例,右转至左17例.结果 围手术期无死亡及截肢患者.踝/肱指数由术前平均0.19术后升至0.94;术前以80 m/min速度行走,跛行距离15～60 m,术后(100～120)m/min行走,距离增至350～500 m或>500 m;术后血管彩超检测胭动脉平均血流速为45 cm/s,胫前(后)动脉术前极少量血流信号,术后平均血流速41 cm/s.35例(89.7%)平均随访3.4年,3年一二期累计通畅率85.7%,其中4例截肢,保肢率88.6%.结论 髂外动脉-腘动脉人工血管移植交叉转流术是治疗单侧髂股动脉闭塞可行有效的方法,尤其适宜全身状态较差,合并有重要器官病变的老年患者.     

Follow-up of renal and mesenteric artery revascularization with duplex ultrasonography

Objective

To evaluate the long-term anatomic results of renal revascularization procedures using duplex ultrasonography.

Design

A case series.

Setting

A university-affiliated hospital.

Patients

Twenty-five patients who had undergone renal percutaneous transluminal angioplasty (PTA) (18 arteries), renal bypass (10 arteries) and mesenteric bypass (6 arteries). The mean follow-up was 22 months (range from 3 to 48 months) for those who underwent renal PTA, 23 months (range from 1.5 to 70 months) for those who underwent renal bypass and 34 months (range from 8 to 144 months) for those who underwent mesenteric bypass.

Main Outcome Measures

Patency rates for the three procedures as assessed by duplex ultrasonography.

Results

Duplex ultrasonography demonstrated patency without stenosis after renal and mesenteric artery revascularization in 14 arteries subjected to renal PTA, 9 arteries subjected to renal bypass and 6 arteries subjected to mesenteric bypass. Three arteries that had renal PTA had recurrent vessel stenosis and one had occlusion. One artery that had renal bypass showed occlusion.

Conclusions

Renal PTA, renal bypass and mesenteric bypass are durable procedures at 2 years of follow-up, and duplex ultrasonography is a valuable method for assessing the patency of arteries after renal and mesenteric revascularization.     

Renal artery stenosis: evaluation with colour duplex ultrasonography

Background: Detection of renal artery stenoses (RAS) by means of duplex Doppler ultrasound with direct scanning of the main renal arteries is subject to numerous limitations. Using semiquantitative analysis of the Doppler curve, which can be recorded from intrarenal arteries, it is possible to detect RAs unaffected by the problems of direct Doppler scanning of the renal arteries. Method: Both angiography of the renal arteries and colour duplex ultrasonography (US) of the intrarenal vessels (interlobar arteries) were performed in 214 patients (53.2±15.1 years) with severe arterial hypertension. Angiography was used as 'gold standard' in the diagnosis of RAS and the Doppler results were compared with the subsequent findings on angiography. At angiography, the reduction of diameter >70% was assessed as haemodynamically effective RAS. For the duplex Doppler diagnosis of RAS the following parameters were calculated: (a) resistive index (RI) of each kidney, and (b) side-to-side differences of the resistive indices (&Dgr;RI) between the right and left kidney. Results: Angiography demonstrated 59 RAS (>70%) in 53 patients, including six with bilateral RAS. By means of duplex US we found a significant difference of RI between kidneys with RAS (0.48±0.11) and without RAS (0.63±0.08; P<0.001). In addition, a significant difference of the &Dgr;RI was noted in patients with RAS (24.4%±12.5%) and the controls without RAS (3.6%±2.7%). Using a combination of both RI and &Dgr;RI, threshold values of RI=0.45 resp. &Dgr;RI=8% yields a sensitivity of 92.5% and a specificity of 95.7% in the detection of haemodynamically effective RAS. Conclusion: Colour duplex US with calculation of the RI and &Dgr;RI of intrarenal arteries is a valuable non-invasive test assessing the haemodynamic effects of RAS. Low costs and safety support the use of the Doppler technique in screening for renovascular disease.     

Accuracy of lower extremity arterial duplex mapping.

We performed lower extremity arterial duplex mapping from the aortic bifurcation to the ankle in 150 consecutive patients evaluated for aortic and lower extremity arterial reconstruction and compared lower extremity arterial duplex mapping in a blinded fashion to angiography. On the basis of history, physical examination, and four-cuff segmental Doppler pressures individual lower extremities were classified as normal, isolated aortoiliac disease, infrainguinal disease, and multilevel inflow and outflow disease. For vessels proximal to the tibial arteries, lower extremity arterial duplex mapping was analyzed for its ability to insonate individual arterial segments, detect a 50% or greater stenosis, and distinguish stenosis from occlusion. In the tibial arteries lower extremity arterial duplex mapping was evaluated for its ability to visualize tibial vessels and to predict interruption of tibial artery patency from origin to ankle. Lower extremity arterial duplex mapping visualized 99% of arterial segments proximal to the tibial vessels, with overall sensitivities for detecting a 50% or greater lesion ranging from 89% in the iliac vessels to 67% at the popliteal artery. Stenosis was successfully distinguished from occlusion in 98% of cases. In the tibial vessels lower extremity arterial duplex mapping was better at visualizing anterior tibial and posterior tibial artery segments (94% and 96%) than peroneal artery segments (83%), (p less than 0.001). Overall sensitivities for predicting interruption of tibial artery patency were 90% for the anterior tibial, 90% for the posterior tibial, and 82% for the peroneal. Clinical disease category did not influence in a major way the accuracy of lower extremity arterial duplex mapping in either above-knee or below-knee vessels.     

Contrast-enhanced duplex scanning of crural arteries by means of continuous infusion of Levovist

OBJECTIVES: To estimate the dosage needed for continuous infusion and to investigate whether continuous infusion of the ultrasound contrast-enhancing agent Levovist (SH U 508A) can improve duplex scanning of crural arteries in patients with peripheral arterial obstructive disease (PAOD) eligible for distal bypass graft surgery. DESIGN, PATIENTS, AND METHODS: The study design consisted of two parts. Part 1 investigated the color and spectral Doppler scan enhancement of three different Levovist dosages (200, 300, and 400 mg/mL) in one arterial segment of a patent lumen of a crural artery in seven patients with PAOD. Part 2 investigated the value of the optimum Levovist dosage in the assessment of 10 crural arteries in 10 consecutive patients with PAOD. Angiography was the reference standard. RESULTS: Part 1: Levovist significantly enhanced color and spectral Doppler scan as compared with baseline ultrasound scan, but no differences were found between the Levovist dosages. Thus, the lowest Levovist dosage sufficed for application in part 2, because of its infusion volume and prolonged enhancement time. Part 2: The agreement between contrast-enhanced duplex scanning and angiography was moderate (kappa = 0.50; 95% confidence interval [CI], 0.03-0.97). Five (50%) of 10 crural arteries that could not adequately be visualized with routine duplex scanning could be visualized with contrast-enhanced duplex scanning. CONCLUSION: Contrast-enhanced duplex scanning by means of continuous infusion of Levovist in patients with PAOD improves the ultrasound scan investigation of crural arteries in case routine duplex scanning is inconclusive and might reduce the need for angiography.     

医源性股动脉假性动脉瘤的超声诊断与治疗

目的评价彩色多普勒超声在医源性股动脉假性动脉瘤诊治中的价值。方法对13例股动脉插管术后穿刺部位触及搏动性肿物、闻及血管杂音的患者,采用Philipsiu22彩色超声诊断仪进行二维、彩色多普勒、频谱多普勒超声检查,观察其大小、形态、内部回声及血流形态、频谱特征,对明确诊断者,在超声引导下进行压迫。结果13例临床上高度怀疑假性动脉瘤形成的患者均通过彩色多普勒超声检查明确诊断,且在超声引导下进行压迫,成功闭合动脉破裂口。结论彩色多普勒超声是医源性股动脉假性动脉瘤的首选诊断、治疗方法。     

Duplex imaging of the renal arteries with contrast enhancement

Duplex ultrasound evaluation of the renal arteries is a technically challenging procedure. Its accuracy is significantly influenced by operator expertise and patient factors, such as overlying bowel gas and obesity. Intravenous microbubble contrast agents enhance vascular reflective acoustic signals and may improve ultrasound diagnostic accuracy. The clinical usefulness of such a contrast agent in the renal vasculature was examined prospectively. A total of 22 patients (16 males and 6 females) with mean age of 63 +/-3 years with suspected abdominal vascular disease were studied prospectively. A complete color flow duplex imaging study of the renal vasculature was performed. This was then followed by an identical examination during which an ultrasound contrast agent (Definity, DuPont Pharmaceutical) was infused intravenously at a rate of 2 to 4 mL/min. In addition to imaging of the vessels, the peak systolic velocity and Doppler waveforms of the aorta and renal arteries were examined. These results were independently compared to results with contrast angiography. A mean of 67 mL of contrast was used per patient. Of the total of 43 renal arteries examined, the accuracy for the detection of occlusions was 75% (3 of 4) for both standard and contrast-enhanced duplex ultrasound. The accuracy for the detection of hemodynamically significant stenosis was 50% (6 of 12) for standard and 75% (9 of 12) for contrast-enhanced duplex ultrasound. Visualization of normal or minimally diseased arteries was 94% (30 of 32) for standard and 97% (31 of 32) for contrast-enhanced ultrasound. Although overall accuracy was not enhanced by the infusion of ultrasound contrast, 5 of 7 arteries not visualized by color flow duplex were detected following the infusion of contrast agent, resulting in an additional 10% (5 of 48) of vessels visualized. Peak systolic velocities were increased by an average of 10% in normal or minimally diseased vessels and 12% in stenotic vessels following contrast administration but these differences were not statistically significant. Contrast-enhanced duplex imaging of the renal arteries is safe but not routinely required when performed by an experienced sonographer. However, it may increase visualization and accuracy in patients with stenoses or when the vessels are not initially visualized. Although increased velocities are seen when contrast agent is used, this does not appear to necessitate different Doppler criteria at this time.     

锁骨下动脉阻塞支架置入50例临床分析

目的探讨腔内支架置入治疗锁骨下动脉闭塞症的临床疗效。方法2001年5月~2006年4月,我院采用腔内支架置入治疗锁骨下动脉闭塞50例53支病变。45例经股动脉顺行,5例经腋动脉逆行支架置入。7例伴有颈动脉或椎动脉严重狭窄同期行支架置入。结果术后患肢血压测定均较术前明显提高,患/健侧血压指数由术前0.69±0.12提高至术后0.98±0.11(t=9.731,P=0.000)。43例随访3~60个月,平均14.5月,锁骨下动脉再狭窄率(>50%)11.6%(5/43)。结论腔内介入支架治疗锁骨下动脉严重狭窄和闭塞是一种安全、有效的方法,为临床首选。     

Screening algorithm for aortoiliac occlusive disease using duplex ultrasonography-acquired velocity spectra from the distal external iliac artery

Aortoiliac duplex scanning can be difficult to perform owing to the deep location of these vessels. We propose a new method to indirectly screen for aortoiliac disease by performing duplex examination of the distal external iliac artery (DEIA). After performing a preliminary study on 21 patients, the parameters of the Doppler waveform that best distinguish normal from diseased arteries were the presence or absence of reverse flow, peak systolic velocity, and resistance index. These values were used in a derived equation, with the value Y > or = 0.78 predicting normal proximal inflow. We then studied 118 aortoiliac segments in 81 consecutive patients with arteriography and DEIA duplex ultrasonography. To predict moderate to severe stenosis, duplex ultrasonography had a sensitivity of 95.7%, a specificity of 84.1%, a positive predictive value of 80%, and a negative predictive value of 96.8%. Our formula thus predicted significant disease in 55 of the 118 aortoiliac segments (47%), with these segments needing further arteriographic evaluation. The other 63 limbs can be safely considered as having normal aortoiliac inflow. Our method accurately screens for aortoiliac disease and is excellent for predicting normal inflow. This information can be used to better plan the intraoperative diagnostic study and intervention.     

Internal thoracic artery-inferior epigastric artery as a collateral pathway in aortoiliac occlusive disease

OBJECTIVE: In patients with aortoiliac occlusion, the internal thoracic artery-inferior epigastric artery (ITA-IEA) collateral is one of the collaterals supplying blood flow to the lower extremity, and the interruption of this collateral may cause severe leg ischemia. The aim of this study was to evaluate by color duplex ultrasonography scans the ITA-IEA pathway and its significance as a collateral in providing lower-extremity perfusion in aortoiliac occlusive disease. METHODS: Color duplex ultrasonography scans were prospectively performed in 64 consecutive patients with aortoiliac occlusion. Blood flow measurement in the ITA, IEA, and common femoral artery was done on both sides. The patients were stratified according to occlusion level (aorta, common iliac artery, external iliac artery), and the data obtained from such groups were compared. RESULTS: In 95% of patients with aortoiliac occlusion, the ITA-IEA pathway was functioning as a collateral, with mean collateral flow of 66 +/- 48 mL/min, and its average contribution to lower-extremity perfusion was 38% +/- 23%. Additionally, a moderately positive correlation was found between flows of ITA and IEA (r = 0.55, P < .0001). Depending on the level of occlusion, the collateral flow and its contribution to perfusion progressively decreased from the proximal to distal aortoiliac occlusion level. Furthermore, the difference in the ITA-IEA flow volume was statistically significant between occlusion levels (P = .009), but the differences in the perfusion contribution were not different among levels (P = .311). There was also no statistical difference between the groups concerning collateral flow volume and contribution to lower-extremity perfusion in relation to unilateral or bilateral occlusion of the iliac artery, the state of distal run-off being good or poor, or the clinical findings being mild or severe. CONCLUSION: In patients with aortoiliac occlusion, the ITA-IEA collateral pathway is an important route providing lower-extremity perfusion. Additionally, Doppler sonographic flow measurements of the contribution of the ITA-IEA route to lower-extremity perfusion may provide beneficial diagnostic information necessary for the pretreatment work-up of patients with aortoiliac occlusion, especially for whom the ITA is planned to be used as a coronary artery graft.     

Noninvasive diagnosis of renal artery stenosis by ultrasonic duplex scanning

We retrospectively studied the results of duplex scanning for evaluation of renal artery disease in 158 patients. Satisfactory examinations were achieved in 144 patients (90%). Arteriograms were available for 43 renal arteries. We used the ratio of the peak velocities in the renal artery and the aorta (RAR) to separate nonstenotic arteries (less than 60% diameter reduction) from stenotic arteries (greater than 60% diameter reduction). With an RAR of greater than 3.5 to indicate stenotic lesions, duplex scanning had a sensitivity of 91% (20 of 22 diseased arteries correctly identified) and specificity of 95% (20 of 21 normal or insignificantly diseased arteries correctly identified). One of four occluded arteries was incorrectly interpreted as patent because of misidentification of a collateral vessel. Prospective studies will be necessary to validate this test and establish other criteria for a more detailed classification of renal artery stenosis. The ratio of the end-diastolic to peak systolic velocities in the renal artery (EDR) tended to decrease with increasing serum creatinine levels, presumably because renal vascular resistance increases with end-stage parenchymal disease. EDR may prove useful in the detection of advanced parenchymal disease before renal artery revascularization is attempted.     

Evaluation of vasculogenic erectile impotence using penile duplex ultrasonography

A total of 140 patients underwent penile vascular evaluation with intracavernous papaverine injection combined with duplex ultrasonography. Of these patients 8 were potent men who were evaluated for reasons other than erectile failure. These potent men were used as controls to obtain normal values. The remaining 132 patients had erectile impotence of various etiologies. Real-time imaging with high resolution, high frequency probes allowed for visualization of the cavernous arteries along the entire length in addition to accurate measurement of the diameter. Simultaneous selectively focused Doppler ultrasonography was used to measure the blood velocity and other vascular parameters in the cavernous and dorsal arteries. Comparison of measurements before and after papaverine injection allowed for objective interpretation of the injection results. The results were analyzed and compared to other data available on the same patients, such as history and physical examination, nocturnal penile tumescence, penile blood pressures, selective arteriography and dynamic cavernosography. In addition to the 8 potent men, there were 35 patients (27% of the impotent patients) whose vascular findings were normal. A total of 78 patients (59% of the impotent patients) had arterial insufficiency; a subgroup of 13 patients had the pelvic arterial steal syndrome. Dynamic cavernosography confirmed venous leak in all 19 patients (14% of the impotent patients) whose penile duplex ultrasonography suggested the possibility of a venous leak. Ten patients (7%) had prolonged erection after papaverine injection and they were managed without consequences. One patient had a small hematoma that resolved uneventfully. Penile duplex ultrasonography was a helpful and objective method to evaluate vasculogenic impotence.     

The limitations of diagnosis of carotid occlusion by Doppler ultrasound.

Duplex scanning has been advocated as an acceptable alternative to angiography in the preoperative evaluation of carotid artery stenosis. To evaluate the accuracy of carotid Doppler in differentiating severe carotid stenosis from occlusion, we compared the results of angiography with duplex scanning in 124 carotid arteries (62 patients) and with continuous-wave Doppler in 662 carotid arteries (331 patients). The specificity was 95-99%, sensitivity was 86-96%, and accuracy was 95-98%. Duplex scanning wrongly identified occlusion in four arteries and failed to detect occlusion in one artery. In making decisions prior to carotid endarterectomy, even infrequent errors are unacceptable. We recommend angiography of all surgical candidates with apparent severe stenosis when the internal carotid artery cannot be clearly identified on duplex, or to distinguish apparent occlusion from undetectably low blood flow.     

Impact of Medicare denials on noninvasive vascular diagnostic testing.

PURPOSE: The purpose of this study was to evaluate the impact of Medicare coverage limitations and claim denials on noninvasive vascular diagnostic testing. METHODS: All Medicare claims for noninvasive vascular diagnostic studies from January 1, 1999, to December 31, 1999, were identified from the hospital billing database according to Current Procedural Terminology codes for carotid artery duplex ultrasound scan, venous duplex ultrasound scan, and lower-extremity arterial Doppler scan. Reasons for Medicare denial of payment for these tests were reviewed and a cost analysis was performed. RESULTS: During the 1-year period, there were 1096 noninvasive vascular diagnostic studies performed on Medicare patients. Of these 1096 tests, 176 (16.1%) were denied by Medicare (19.6% of 408 carotid duplex ultrasound scans, 16.8% of 345 venous duplex ultrasound scans, and 11.1% of 343 lower-extremity arterial Doppler scans). Of the noninvasive vascular tests denied by Medicare, an abnormal result was present in 72.5% of carotid duplex ultrasound scans, 32.8% of venous duplex ultrasound scans, and 78.9% of lower-extremity arterial Doppler scans. Overall, 88.1% of all initially denied claims (N = 176) were ultimately reimbursed by Medicare after resubmission, including 77.1% of the 118 claims denied based on compliance rules for "medical necessity." CONCLUSION: Because of coverage limitations, Medicare denials of noninvasive vascular diagnostic tests can lead to potential uncompensated physician and hospital technical fees if denied claims are unrecognized. Vascular laboratories performing these tests need to review compliance with Medicare guidelines. Improvements may need to be made at both the provider and Medicare carrier levels in obtaining reimbursement for appropriately ordered noninvasive vascular diagnostic studies.     

移植肾术后肾动脉闭塞的彩色多普勒超声表现

目的 探讨彩色多普勒超声对移植肾术后肾动脉闭塞的的诊断价值.方法 回顾分析3例经临床证实的肾移植术后动脉闭塞的彩色多普勒超声表现.结果 1例肾动脉主干及其分支完全闭塞,2例移植肾内多支段动脉及其分支闭塞,仅见一支段动脉充盈.结论 移植肾术后肾动脉闭塞的彩色多普勒超声表现对早期诊断具有重要意义.