Non-invasive vascular imaging of peripheral vessels

The purpose of this review is to describe recent advances in non-invasive vascular imaging techniques and to discuss their current clinical applications for imaging of peripheral vessels. Principles for applying ultrasound, CT angiography (CTA), and magnetic resonance angiography (MRA) for non-invasive imaging of peripheral arteries and veins are presented. Clinical applications are reviewed for different vascular diseases, therapy planning, and follow-up studies. Conventional Doppler and color duplex sonography are the most cost-effective procedures to detect or rule out peripheral arterial occlusive disease (PAOD) and to provide specific recommendations for therapy. In the near future, contrast-enhanced MRA (CE MRA) with additional axial two-dimensional time-of-flight studies to search for non-anatomic runoff will replace diagnostic intra-arterial digital subtraction angiography (DSA) for planning of reconstructive surgery with acquisition slabs displaying projections similar to intra-arterial DSA. Color duplex sonography should also be the first non-invasive technique applied for the detection of peripheral aneurysms. Preoperative or preinterventional therapy planning of aneurysms may be performed by CTA or CE MRA. Compression ultrasound is the imaging procedure of choice in deep venous thrombosis (DVT). In the preoperative assessment of venous incompetence, color duplex sonography is the imaging technique which is sufficient in most cases.     

Duplex scanning and light reflection rheography in the assessment of the severity of short saphenous vein incompetence

BACKGROUND: Duplex ultrasound assessment of veins in the popliteal fossa is an accepted alternative to venography. Light reflection rheography provides additional quantitative information on venous reflux in chronic venous insufficiency. OBJECTIVE: To use duplex ultrasound and light reflection rheography to study the venous reflux patterns in the popliteal fossa in a group of patients. METHODS: Duplex ultrasound examination and light reflection rheography were used in the assessment of the severity of short saphenous vein incompetence. RESULTS: The study revealed that any associated deep venous reflux which was detectable beyond the saphenopopliteal junction represented a more advanced stage of superficial venous insufficiency. CONCLUSIONS: Light reflection rheography, as a semiquantitative test, provided useful additional information to duplex scan findings in assessing venous reflux of the popliteal fossa. Short saphenous vein reflux with functional deep venous incompetence was associated with shorter venous refilling times and clinically represented a more advanced stage of primary varicose vein disease.     

Traumatic brain injury care path

INTRODUCTION: We report the results of our experience with venography in patients with postoperative recurrent varicocele. The study was carried out to detect the causes of this condition. MATERIAL AND METHODS: Forty-four patients with postoperative recurrent varicocele, examined in our department from June, 1993, to June, 1996, were submitted to selective spermatic venography after clinical examination and color Doppler sonography. Thirty-six patients had been treated with high surgical ligation of the spermatic vein and 8 with inguinal ligation. Thirty-two patients were treated percutaneously, after diagnostic angiography, with coils and/or sclerotizing agents. RESULTS: In our study, the persistence of patent collateral veins, missed at surgical ligation, was the main cause of recurrence (68%): this was due either to a double or triple spermatic vein, mostly in the pelvic tract (50%), venous bridges crossing the surgical ligation (11%), or to retroperitoneal anastomoses (7%). A smaller group of patients showed ineffective ligation of the vein (27%); in the remaining 5% of cases incompetence of the extrafunicular plexus was detected. DISCUSSION AND CONCLUSIONS: Our experience, supported by a literature review, demonstrates that the anatomic variants, not detected preoperatively because phlebography had not been performed, were the most frequent causes of recurrence. Spermatic venography is the most accurate imaging modality for vascular mapping in postoperative recurrences; it often allows to treat the patients simultaneously by a percutaneous approach.     

Color duplex ultrasound in the assessment of primary venous leg ulceration

METHODS: To determine the extent and severelity of venous reflux, color duplex ultrasound was used in 370 limbs of 303 patients with primary varicose veins. The clinical findings were classified according to the CEAP (clinical, etiologic, anatomic, pathophysiologic) clinical classification. RESULTS: Of 370 limbs, 32 showed previously healed ulcer (Class 5) and active ulcer (Class 6). Overall reflux in the superficial venous system was seen in 28 limbs (87.5%), and solitary superficial vein incompetence was detected in 13 (40.6%). Reflux was detected throughout the length of the superficial vein system, and the retrograde peak velocity was greater than 30 cm/second in these limbs. Reflux in the perforating veins was detected in 14 limbs (43.8%), but isolated perforating vein incompetence was seen in only one limb (3.1%). Deep vein incompetence was detected in 12 limbs (37.5%). Concomitant superficial and perforating vein reflux was evident in 4 limbs (12.5%) and 2 limbs (6.3%), respectively, but isolated deep vein incompetence was detected in only one limb (3.1%). The operations indicated were selective stripping of the long saphenous vein in the thigh, high ligation of the short saphenous vein, subfascial ligation of perforating veins, and compression sclerotherapy for varicose tributary veins. Healing of the ulcers was achieved within 1 month after surgery, and the postoperative color duplex scanning revealed correction of deep vein incompetence. CONCLUSIONS: These data suggest that ablation of the superficial vein system and the perforating veins is an appropriate method for the management of patients with primary venous leg ulceration.     

Colour duplex ultrasonography in the rational management of chronic venous leg ulcers

Colour duplex ultrasonographic imaging has largely replaced venography in the assessment of lower-limb venous disorders. This is a study of the use of duplex in the management of patients with chronic venous ulceration in community ulcer clinics. Patients with chronic leg ulceration and an ankle: brachial pressure index of 0.85 or greater were studied. Assessment of venous competence in both the deep and superficial systems of the affected and unaffected legs was performed using colour venous duplex imaging. Reflux was defined as reverse flow for greater than 1 s after manual calf compression. One hundred consecutive patients were assessed over 15 months. Of 111 ulcerated legs, 96 had active ulceration, while 15 had been ulcerated within the previous 6 months. Fifty-seven (51 per cent) of the 111 ulcerated legs had superficial incompetence alone (88 per cent long saphenous system or its perforators, 12 per cent short saphenous system). Six legs (5 per cent) had isolated deep venous incompetence. Forty-two legs had mixed superficial and deep venous reflux; 22 of these had undergone previous venous surgery. Colour venous duplex assessment demonstrated superficial venous disease in approximately half of limbs with chronic leg ulceration. Venous dysfunction in these patients is potentially curable by surgery.     

The value of color-coded duplex ultrasound as standard assessment in erectile dysfunction

Erectile dysfunction has taken on increasing importance in urologic practice. Still open is the question of which tests are mandatory for adequate clinical assessment of erectile dysfunction. One accepted standard modality is the intracavernous pharmacotest with vasoactive agents. In contrast, color duplex sonography is not considered mandatory although it reveals detailed information about penile vessels and functional implications. The question remains whether the information gained by color duplex sonography is relevant for therapy, making it an indispensable standard procedure. Patients with erectile dysfunction were evaluated, without preselection, by extensive history, clinical evaluation, laboratory tests, tumescence and rigidity measurements, intracavernous administration of vasoactive drugs and color duplex sonography. Seventy-nine patients were available for final analysis. Color duplex sonography revealed 39 normal tests, 16 arterial impairments. 19 venous leakages and 5 arteriovenous fistulae. Intracavernous vasoactive agents (pharmacotest) revealed 44 reactions sufficient for intercourse and 35 insufficient responses. In 89% of patients, the diagnoses on color duplex sonography and intracavernous pharmaco-testing were similar. The accuracy of the two methods in diagnosing erectile dysfunction was not statistically different (McNemar's test). In contrast to intracavernous pharmaco-testing, color duplex sonography permitted further etiologic subdivision into arterial disease, venous leakage, arteriovenous fistula and normal result. This was made possible by measuring significantly (P < 0.01) different arterial peak flow velocities, end-diastolic velocities and calculated resistance index. These data did not imply direct clinical consequences. Color duplex sonography and intracavernous pharmacotesting reveal comparable results concerning the diagnosis of an erectile dysfunction. In contrast to pharmacotesting, color duplex sonography reveals details of the nature of the erectile dysfunction. Because this information has no profound implications for the choice of therapeutic procedure, color duplex sonography can not be recommended as a standard procedure in the evaluation of erectile dysfunction.     

Hand-held Doppler as a screening test in primary varicose veins

BACKGROUND: Hand-held Doppler is in common use for evaluating varicose veins, but its accuracy in identifying the exact sites of venous reflux is inferior to that of duplex scanning. It has been suggested that duplex should be used to investigate all varicose veins, but this is currently impractical, and should be unnecessary if hand-held Doppler examination were shown to be an adequate screening test. METHODS: Eighty-five patients (122 legs) with primary varicose veins were evaluated using a hand-held Doppler in the outpatient clinic, according to a protocol. Patients then had venous duplex imaging. RESULTS: Different methods of assessing the long saphenous vein (LSV) (tourniquet and tapping tests, and examination at and below the groin) had similar sensitivities for detecting reflux (75-86 per cent), and together detected 91 per cent of cases. Six of the nine missed had a competent saphenofemoral junction, and five had low-velocity reflux. Hand-held Doppler assessment missed 11 cases of popliteal fossa reflux; only four involved the short saphenous vein (SSV), and most had low-velocity popliteal vein reflux. CONCLUSION: Hand-held Doppler examination missed LSV or SSV incompetence in 11 per cent of legs, but these included cases with short-duration and low-velocity reflux of dubious clinical importance.     

A rational approach to detection of significant reflux with duplex Doppler scanning and air plethysmography

PURPOSE: Several techniques are currently available for the detection of venous reflux. We have attempted to determine the relative value and accuracy of available techniques to develop a logical strategy of investigation in reflux venous insufficiency. METHODS: The morphologic distribution of venous incompetence (erect duplex and descending venography); the results of ambulatory venous pressure measurement, venous refilling time, the Valsalva test, and air-plethysmography (venous refilling index, VFI); and the clinical severity were described in 118 consecutive limbs. In an attempt to validate the tests, results were correlated with the clinical severity classification (class 0, n = 34; class 1, n = 42; class 2, n = 11; class 3, n = 31) and with a standardized quantification of reflux (multisegment score) as seen on standing duplex Doppler scanning with rapid deflation cuffs. RESULTS: Twenty-nine percent of limbs with severe venous disease (class 2/3) had pure deep insufficiency, only 6% had pure superficial disease, and the remainder had a combination. A history of previous thrombosis and the presence of posterior tibial vein incompetence were markedly common with ulcer disease (84% and 42%, respectively). The duplex Doppler multisegment score correlated strongly with clinical severity classification (r = 0.97). The venous refilling time and VFI had the highest sensitivity in identifying severe venous disease (class 2/3), and the ambulatory venous pressure had excellent specificity. CONCLUSIONS: For noninvasive determination of reflux, the combination of VFI and duplex scanning not only localized reflux but also separated severe clinical vein disease from mild, with high sensitivity and specificity. Air plethysmography may also provide valuable information regarding calf muscle pump and outflow obstruction.     

Preoperative assessment of primary varicose veins

The first step in the evaluation of a patient with primary varicose veins is a careful personal history and clinical examination. The individual advice should be based on the disturbance suffered due to the actual varicose veins, "heaviness of the legs" and the advantages and disadvantages of various therapies. The aim of an examination in any type of varicose veins is to determine their relationship to the deep and the surrounding superficial venous system. The continuous-wave Doppler method is often sufficient to examine the trunk of the long saphenous vein. Colour-coded duplex sonography is the chosen method for evaluation of the deep venous system with respect to flow feasibility and valve competence, as well as localization of deficient perforants and anatomic variations at the saphenouspopliteal junction. Phlebography is reserved for cases with inconclusive duplex-sonography results or if no duplex is available. The purpose of this exhaustive preoperative evaluation is to indicate in detail the haemodynamic and anatomic situation in the groin and in the popliteal fossa and to detect the relevant insufficient perforators. Such accurate haemodynamic assessment is the basis for an individualized operation with excellent cosmetic and functional results. Whether a reduced recurrence rate after varicose vein surgery can be shown with this extensive examination scheme has not yet been investigated in a prospective study.     

Ultrasonographic diagnosis of varicoceles

OBJECTIVE: To assess the ability of color duplex scrotal ultrasonography to detect subclinical varicoceles and confirm the diagnosis of clinical varicoceles. DESIGN: Physical examination, color duplex scrotal ultrasonography and internal spermatic venography was performed on 64 testicular units in 33 men. SETTING: Male fertility center. PATIENTS: Two hundred sixty-two consecutive men being evaluated for male factor infertility of whom 33 agreed to undergo venography. MAIN OUTCOME MEASURES: Ultrasonographic measurement of scrotal vein diameter of patients in the supine and upright position, before and during valsalva maneuver, and scrotal vein blood flow reversal with valsalva maneuver was compared with the findings of varicocele by physical examination and venography. RESULTS: The best predictor of a varicocele was internal spermatic vein diameter, and the best overall performance of ultrasonography was achieved with the patient at rest in the supine position. The best cutoff point for venous diameter for a clinical varicocele was 3.6 mm and 2.7 mm for a subclinical varicocele, but the overall accuracy was only 63%. CONCLUSIONS: Confirmatory studies are needed to support the ultrasonographic diagnosis of varicoceles before considering surgical repair.     

Investigation and significance of short saphenous vein incompetence

In this study, 186 limbs with varicose veins or venous skin changes were examined using duplex ultrasonography. Limbs were classified on the basis of short saphenous or popliteal venous incompetence and the number of limbs with venous ulceration (active or healed) recorded. Short saphenous incompetence did not produce a significant increase in the incidence of ulceration, whereas popliteal reflux produced an increase in the risk of ulceration which was statistically significant when compared with limbs without reflux in these two veins (chi 2 = 4.55, P = 0.003). There was no significant difference in the proportion of limbs with concomitant long saphenous reflux between these two groups. Short saphenous reflux is not important in the pathogenesis of venous ulceration. Popliteal reflux is an important factor in the pathogenesis of venous ulceration. More attention should be paid to the surgical correction of popliteal reflux when present in limbs with venous ulceration that fail to heal by conservative measures.     

Ultrasound surveillance for asymptomatic deep venous thrombosis after total joint replacement

Prospective data on 202 consecutive patients who had a total of 123 total hip and ninety-four total knee arthroplasties were collected from two university medical centers. The findings of routine surveillance for deep venous thrombosis performed with ascending contrast venography were compared with those of surveillance with duplex ultrasonography complemented with color-flow Doppler imaging. All of the studies were performed between the third and seventh postoperative days. Of the 202 patients (342 extremities) who were examined, fifty-five (27 per cent) were found to have deep venous thrombosis; fifty-two (95 per cent) of the thrombi were in the calf and three (5 per cent) were in the proximal veins. All of the thrombi were clinically asymptomatic and all were nonocclusive, allowing passage of contrast medium around an intraluminal filling defect. Duplex ultrasonography with color-flow Doppler imaging correctly identified two of the three proximal thrombi and five of the fifty-two thrombi in the calf (sensitivity, 10 per cent). The sensitivity for the detection of thrombi in the calf was zero of sixteen at one of the institutions involved in the study and 14 per cent (five of thirty-six) at the other. There were two false-positive findings on ultrasonographic examination; one involved a proximal thrombus and one, a distal thrombus. We believe that the interinstitutional variability and insensitivity of duplex ultrasonography with color-flow Doppler imaging for the detection of asymptomatic deep venous thrombi in the calf after total joint replacement make it unreliable as a routine surveillance tool after total hip or knee arthroplasty.     

Transtemporal power- and frequency-based color-coded duplex sonography of cerebral veins and sinuses

PURPOSE: To determine the ability of transtemporal power- and frequency-based transcranial color-coded duplex sonography to aid in the assessment of cerebral veins and sinuses, as well as to provide reference data for flow direction and velocity. METHODS: Using a color duplex device equipped with a 2.0/2.5-MHz sector scan, we insonated 120 healthy volunteers and three patients with cerebral venous thrombosis. RESULTS: In subjects 20 to 59 years old, deep middle cerebral veins were identified in 88%, basal veins in 97%, straight sinuses in 60%, and transverse sinuses in 42%. The corresponding values for subjects 60 to 79 years old were 53%, 86%, 23%, and 20%, respectively. Velocities were highest in transverse and straight sinuses, slower in basal veins, and slowest in deep middle cerebral veins. Flow was directed lateromedially in the deep middle cerebral vein, rostrocaudally in the basal vein and straight sinus, and mediolaterally in the transverse sinus. Two patients with straight sinus thromboses showed reversed flow direction in the basal veins, and one patient with superior sagittal sinus thrombosis showed elevated velocities in a deep middle cerebral vein. CONCLUSION: Transtemporal power- and frequency-based color-coded duplex sonography enabled imaging and velocity measurements in deep cerebral veins in subjects 20 to 59 years old, but detection of the straight and transverse sinuses was low. In older subjects, only the basal vein was regularly assessed.     

Clinical usefulness of transrectal sonography and transperineal color Doppler flow imaging in the diagnosis of intrapelvic venous congestion syndrome

BACKGROUND: The present study was designed to reveal the possible use of transrectal sonography (TRS) and transperineal color Doppler flow imaging in predicting intrapelvic venous congestion syndrome (IVCS), as evaluated by three dimensional magnetic resonance venography (3D-MRV). METHODS: Thirty-one patients with prostatodynia and eleven control men were enrolled in this study. The diagnosis of IVCS was made based on the findings by 3D-MRV, such as the dilation of the prostatic capsular vein, the dilation of the pudendal plexus, the interruption of the internal pudendal vein and the dilation of the plexus behind the bladder. The prostatic capsular vein was observed ultrasonically as "sonolucent zone (SZ)", and the maximum width of SZ was measured on sonograms. Transperineal color Doppler flow imaging was used to detect blood flow images of the prostatic capsular vein. The maximum velocity of it was also measured on sound spectrogram. RESULTS: IVCS was confirmed in 29 cases (IVCS group) and the other 13 cases were regarded as non-IVCS group. IVCS was recognized much more frequently in patients with prostatodynia than in controls (87% vs 18%, p < 0.0001). The maximum width of SZ was 2.4 mm (mean) in non-IVCS group, compared to 4.4 mm in IVCS group (p < 0.0001). The cutoff value of 3.0 mm for the maximum width of SZ showed as high as 86% of sensitivity for the detection of IVCS. The maximum velocity of retrograde venous flow during Valsalva's maneuver in IVCS group (mean 14.4 cm/s) was faster than non-IVCS group (mean 7.1 cm/s, p < 0.05). The cutoff value of 10 cm/s for the maximum retrograde venous flow velocity showed as high as 69% of sensitivity for the detection of IVCS. CONCLUSIONS: Both TRS and transperineal color Doppler flow imaging were usefull as a predictor for IVCS.     

Ultrasonography of veins

PURPOSE: The high incidence of acute and chronic diseases of the venous system requires the application of reliable, non-invasive, low-cost methods in diagnosis and follow-up after therapy. MATERIAL AND METHODS: Current technology, principles of examination, and results of ultrasonography of the peripheral venous systems are reviewed. RESULTS: Since the mid 1980s, compression ultrasonography (US) has been introduced in the diagnosis of deep venous thrombosis. Doppler-US methods reach the hallmarks of venous imaging, particularly since the advent of color duplex US. In thrombosis, postthrombotic syndrome, and primary varicosis, color duplex US increasingly replaces the "gold standard" of phlebography as the imaging method of choice. Venous diseases of the neck, and of the upper and lower extremities are reliably recognized by color duplex US. New areas of application of Doppler and duplex-US include examinations of the venous system in patients in intensive care units, evaluation of transplanted organs, and the demonstration of blood flow in hemodialysis shunts. CONCLUSIONS: Color duplex US is useful in most imaging investigations of the peripheral veins. In view of cost development in the medical imaging sector, however, in which ultrasonography takes a major part, critical indication for the application of Doppler- and duplex-US in the diagnosis and follow-up of venous disease is out most importance.     

Preoperative duplex imaging is required before all operations for primary varicose veins

BACKGROUND: Physical examination is unreliable in the detection of sources of reflux in varicose veins. Hand-held Doppler (HHD) ultrasonography has been recommended as an accurate adjunct to physical examination. The aim of this study was to evaluate the accuracy of HHD imaging in comparison with duplex ultrasonography. METHODS: Eighty-nine legs in 61 patients with primary varicose veins were examined with an HHD probe to detect reflux at the saphenofemoral junction (SFJ), the saphenopopliteal junction (SPJ) and in thigh perforators (TPs). Patients then underwent duplex imaging and the results of the tests were compared. RESULTS: The sensitivity of the HHD technique was 73 per cent at the SFJ, 77 per cent at the SPJ and 51 per cent for TPs. In primary varicose veins the surgery planned using HHD imaging alone would have left residual sites of reflux in 24 per cent. CONCLUSION: Examination with HHD ultrasonography is not sufficiently accurate to plan varicose vein surgery. Duplex imaging is recommended before all operations for primary varicose veins.     

Diagnosis of acute lower limb deep venous thrombosis with ultrasound: trends and controversies

Acute deep venous thrombosis of the lower limb is a common and threatening condition whose clinical diagnosis is known to be unreliable. Sonography has gradually superseded venography as the primary diagnostic procedure. A review of the medical literature shows that sonography offers a high level of sensitivity and specificity in symptomatic patients but suffers from a lack of sensitivity at the calf level and in asymptomatic patients. Technologic progress, as well as increased operator experience, may improve sensitivity. Nevertheless, several critical issues remain unresolved, such as the significance of free-floating thrombi, the usefulness of calf and bilateral examination, the criteria that are essential to the diagnosis, the risk of compression sonography, and sonography's role in the direct detection of venous emboli.     

Ultrasound screening for deep venous thrombosis after total knee arthroplasty. 2-year reassessment

The efficacy of ultrasound compared with ascending venography for the detection of deep venous thrombosis immediately after total knee arthroplasty was assessed after a 2-year interval. One hundred thirty-seven patients were eligible for the study; however, 31 patients received only one of the screening methods and a color Doppler examination was inconclusive in six patients. Therefore, 100 patients had a Doppler examination and a venogram. Overall, the sensitivity of ultrasound was 85%, the specificity 97%, the positive predictive value 85%, the negative predictive value 97%, and the accuracy 95%. The sensitivity in the calf was 83%, in the popliteal vein 86%, and in the femoral vein 100%. Two years ago, the initial assessment of ultrasound for the detection of deep venous thrombosis after surgery in patients who had total joint arthroplasty revealed a 75% sensitivity, 99% specificity, 91% positive predictive value, 97% negative predictive value, and 97% accuracy. The sensitivity in the calf was 83%; the sensitivity in the popliteal vein was 40%; and the sensitivity in the femoral vein was 50%. After 2 years of using this screening test with one technician and one radiologist, an improvement with this noninvasive technique was shown. However, it was found that Doppler imaging is not as sensitive as venography for detecting calf thrombi. Any imaging technique should be validated by each institution to determine the validity of the instrument and the learning curve of the technician administering the examination.     

Patterns of venous reflux in limbs with skin changes associated with chronic venous insufficiency

The distribution of venous reflux in patients with skin changes associated with chronic venous insufficiency presenting to a specialist clinic was assessed. A total of 300 limbs in 153 patients were examined by Doppler ultrasonography with colour-flow imaging for the presence of venous reflux in superficial veins, deep veins and medial perforating veins, both above and below the knee. Ninety-eight limbs had skin changes, which included hyperpigmentation, lipodermatosclerosis, atrophie blanche and ulceration. Of this group, 2 per cent had no evidence of venous reflux on duplex scanning, 39 per cent had deep vein incompetence, 57 per cent had superficial vein incompetence and 2 per cent had isolated medial perforating vein reflux. Of 25 limbs with ulceration, 13 had superficial and 12 deep vein reflux. A total of 202 legs, which included 20 normal control limbs, had no skin changes; 22.3 per cent of these had no venous reflux, 8.4 per cent had deep vein incompetence, 65.3 per cent had superficial incompetence and 4.0 per cent had isolated medial calf perforating vein incompetence.     

Value of echo-enhanced Doppler sonography in evaluation of transjugular intrahepatic portosystemic shunts

OBJECTIVE: The value of echo-enhanced color and power Doppler sonography in the evaluation of transjugular intrahepatic portosystemic shunts (TIPS) was assessed and compared with that of unenhanced Doppler sonography and portal angiography. SUBJECTS AND METHODS: In a prospective randomized trial, 31 shunts in 30 patients underwent unenhanced conventional color and power Doppler sonography and portal venography including pressure measurements. The patients were allocated to either echo-enhanced conventional color Doppler sonography or echo-enhanced power Doppler sonography. For echo enhancement, a galactose-based suspension was administered IV. Shunt stenoses, if present, were quantified by percentage of stenosis and correlated with angiography, which was the gold standard. The diagnostic confidence of unenhanced and echo-enhanced Doppler sonography was assessed using a visual analog scale. RESULTS: In the diagnosis of shunt occlusion, echo-enhanced Doppler sonography yielded a sensitivity and a specificity of 100% and 100%, respectively, compared with 100% and 89%, respectively, for unenhanced Doppler sonography. Our evaluation of hemodynamically significant stenoses (portosystemic gradient > or = 15 mm Hg) found echo-enhanced Doppler sonography to be superior to unenhanced Doppler sonography (sensitivity and specificity of 82% and 83%, respectively, compared with 64% and 80%, respectively). In the detection of a shunt stenosis based on morphologic criteria only, echo-enhanced Doppler sonography yielded a sensitivity and a specificity of 78% and 100%, respectively, compared with 47% and 50%, respectively, for unenhanced Doppler sonography. Power Doppler imaging did not improve diagnostic accuracy but did increase diagnostic confidence for unenhanced Doppler sonography compared with conventional color Doppler sonography. The diagnostic confidence for sonographic evaluation of TIPS was significantly (p < .001) increased and the variability of hemodynamic measurements was markedly decreased with echo-enhanced sonography. CONCLUSION: Echo-enhanced Doppler sonography provides images of TIPS like those of angiography and allows morphologic assessment of the shunts, complementary to the essential pulsed Doppler waveform analysis that would be performed in a more guided manner. Also, echo-enhanced Doppler sonography significantly increases the sensitivity and specificity in the diagnosis of shunt dysfunction. The high diagnostic confidence and the diminished variability of spectral Doppler measurements may improve acceptance of sonographic evaluation of TIPS. Echo-enhanced Doppler sonography is safe and effective and may reduce the instances in which TIPS sonographic surveillance is nondiagnostic, in which case angiographic assessment is required.