Contrast-enhanced Color Research Articles

Contrast‐enhanced colour Doppler‐targeted vs a 10‐core systematic repeat biopsy strategy in patients with previous high‐grade prostatic intraepithelial neoplasia

To compare the results of contrast-enhanced colour Doppler (CECD)-targeted prostate biopsy with a systematic 10-core grey-scale biopsy scheme in patients initially diagnosed with high-grade prostatic intraepithelial neoplasia (HGPIN), as although HGPIN is thought to be a precursor to invasive adenocarcinoma, its diagnosis is no longer considered an indication for repeat prostate biopsy and patients should be followed by prostate-specific antigen levels and a digital rectal examination. In all, 104 patients (aged 45-78 years) diagnosed with HGPIN on initial prostate needle biopsy were referred for a repeat biopsy within 6 months. Two independent examiners evaluated each patient; one used CECD-targeted biopsy (up to five cores) into hypervascular regions in the peripheral zone only, and subsequently the second took a systematic 10-core grey-scale biopsy. Cancer detection rates of both techniques were compared. Overall, 26 of the 104 men (25%) had prostate cancer in the repeated biopsy. Using the CECD technique cancer was detected in 21% (22 of 104). The positive re-biopsy rate using the systematic technique was 9.6% (10 of 104; P < 0.001). The total incidence of HGPIN with no evidence of tumour on re-biopsy was 8.7% (nine of 104). The Gleason score in all 22 cancers detected with the CECD technique varied between 6 and 8. The systematic technique detected cancers with Gleason scores of 6 or 7. There were no adverse events or complications. CECD increased the detection rate of prostate cancer, and using fewer biopsy cores than the systematic biopsy technique in patients previously diagnosed with HGPIN.

Contrast‐enhanced colour Doppler‐targeted prostate biopsy: correlation of a subjective blood‐flow rating scale with the histopathological outcome of the biopsy

To correlate a subjective blood-flow rating scale from contrast-enhanced colour Doppler (CECD) transrectal ultrasonography-targeted prostate biopsy with the histopathological outcome of the biopsy. In all, 760 men with a serum total prostate-specific antigen (PSA) level of ≥ 1.25 ng/mL and a free-to-total PSA ratio of < 18% were included. CECD-targeted biopsies with five cores were taken only in hypervascular areas of the peripheral zone using a second-generation ultrasonography contrast agent, followed by a 10-core systematic biopsy. Prostate blood flow was scored using a subjective 5-point scale in which 1 indicated 'benign', 2 'probably benign', 3 'indeterminate', 4 'probably malignant' and 5 'malignant'. Overall 37% (283 of 760) patients had prostate cancer in the biopsy. All 100 patients with a score of 5 had cancer; 153 had a score of 4, of whom 130 (85%) had cancer and 23 had benign histology (15%); 131 had a score of 3, of whom 34 (26%) had cancer and 97 (74%) had benign histology; 284 had a score of 2, of whom 17 (6%) had cancer and 267 (94%) had benign histology; 92 had a score of 1, of whom two (2%) had cancer and 90 (98%) had benign tissue. Statistical evaluation showed that the subjective blood-flow rating scale correlated strongly and significantly (r = 0.75, P < 0.01) with the histopathological outcome of the biopsy. The present study shows that a subjective CECD blood-flow rating scale is a reliable tool to predict the pathological outcome of biopsy cores.

Ultrasound of the prostate

Ultrasound is a widely used imaging modality for evaluation of the prostate. The main topic of diagnostic imaging is an improvement of prostate cancer diagnosis. The current available systematic prostate biopsy is performed only under ultrasound guidance, but new imaging techniques allow prostate cancer visualization and therefore improved detection. Evolving methods such as contrast-enhanced colour Doppler imaging, contrast-specific ultrasound techniques and elastography may dramatically change the role of ultrasound for prostate cancer diagnosis. The purpose of this review is to provide an overview of ultrasound and its different techniques for imaging of the prostate and to discuss current trends and future directions.

Contrast‐Enhanced Power and Color Doppler Ultrasonography of the Pancreas in Healthy and Diseased Cats

The diagnosis of feline pancreatic disease is difficult, because clinical abnormalities and routine noninvasive diagnostic tests are unreliable. The purpose of this study was to investigate by Doppler ultrasonography if vascularity and blood volume differs in the otherwise ultrasonographically normal and diseased feline pancreas. Thirty-six client owned cats. The pancreas was examined with B-mode and contrast-enhanced color and power Doppler ultrasonography. Doppler images were analyzed with a computer program: parameter fractional area represents a vascularity index and color-weighted fractional area assesses blood volume. Based on the B-mode findings, the pancreas was considered normal in 11 clinically healthy cats and diseased in 25 cats of which 4 were clinically healthy and 21 had clinical signs consistent with pancreatic disease. Histologic or cytologic samples were taken in all diseased pancreata. Fifteen samples were of diagnostic quality: purulent or mixed cellular inflammation (8), nodular hyperplasia (4), and neoplasia (3) were identified. Vascularity and blood volume for all Doppler methods was significantly higher in cats with pancreatic disease. Significantly higher Doppler values were detected with power Doppler than with color Doppler, and with postcontrast color and power Doppler than with precontrast Doppler technologies. Contrast-enhanced Doppler ultrasonography appears feasible in the feline pancreas. Significant differences were found between normal cats and those with evidence of pancreatic pathology. Further studies are needed to evaluate its use for the differentiation of pancreatic disorders and in cats suspected to have pancreatic disease but without B-mode ultrasonographic changes of the pancreas.

Ablation of High Intensity Focused Ultrasound Combined with SonoVue on Rabbit VX2 Liver Tumors: Assessment with Conventional Gray-Scale US, Conventional Color/Power Doppler US, Contrast-Enhanced Color Doppler US, and Contrast-Enhanced Pulse-Inversion Harmonic US

We investigated effects of high intensity focused ultrasound (HIFU) combined with contrast agent SonoVue on rabbit VX2 liver tumors by using conventional gray-scale ultrasonography (US), color/power Doppler (CD/PD) US, contrast-enhanced color Doppler (CE CD) US, and contrast-enhanced pulse-inversion harmonic (CE PIH) US. Fourteen days after implantation of VX2 tumors in livers of 50 rabbits, animals were randomly separated into two groups. Based on principles of HIFU, the volume of the tumor was divided into several parallel "planes" to be ablated. Before ablation on each "plane," 0.2 mL SonoVue was injected in bolus via ear veins of rabbits in group II and normal saline solution was administrated in group I. Conventional gray-scale US, CD US, PD US, CE CD US, and CE PIH US were performed before and after ablation. Twenty-three surviving rabbits in each group underwent HIFU ablation. Conventional gray-scale US showed ablated areas diffusely hyperechoic. On CE PIH US, coagulated areas presented perfusion defect. Both conventional gray-scale US and CE PIH US showed the ablated volume in group II was larger than that in group I. CD US and PD US demonstrated residual vessels in periphery ablated areas in group I, but no residual vessels in group II. CE CD US and CE PIH US depicted less residual vessels in periphery ablated areas in group II than that in group I. By enlarging ablated volume of tissue and reducing residual vessels, effects of HIFU ablation on rabbit VX2 liver tumors were enhanced by contrast agent SonoVue.

Bildgebende Verfahren in der Frühphase des Morbus Bechterew

Diagnosis of ankylosing spondylitis (AS) is still delayed for several years in some patients. The correct diagnosis of early disease has always been a challenge, which has become even more important as with the introduction of TNF-alpha inhibitors, very effective new treatments have become available. For diagnosis of AS imaging methods such as conventional radiography and computer tomography are well established. Functional imaging modalities including magnetic resonance imaging and contrast-enhanced colour Doppler ultrasound provide additional information on the presence of active inflammatory changes in the sacroiliac joints and may help to diagnose AS before radiographic changes become visible. Magnetic resonance imaging and sonography also identifiy other non-sacroiliac axial manifestations of AS and peripheral involvement such as enthesitis and synovitis of peripheral joints.

Comparing Contrast-Enhanced Color Flow Imaging and Pathological Measures of Breast Lesion Vascularity

This study was conducted to compare quantifiable measures of vascularity obtained from contrast-enhanced color flow images of breast lesions to pathologic vascularity measurements. Nineteen patients with solid breast masses received Levovist® Injection (10 mL at 300 mg/mL; Berlex Laboratories, Montville, NJ, USA). Color flow images of the mass pre and post contrast were obtained using an HDI 3000 scanner (Philips Medical Systems, Bothell, WA, USA) optimized for clinical scanning on an individual basis. After surgical removal, specimens were sectioned in the same planes as the ultrasound images and stained with an endothelial cell marker (CD31). Microvessel area (MVA) and intratumoral microvessel density (MVD) were determined for vessels 10–19 μm, 20–29 μm, 30–39 μm, 40–49 μm and ≥50 μm in diameter using a microscope and image processing software. From the ultrasound images, the number of color pixels before and after contrast administration relative to the total area of the breast mass was calculated as a first-order measure of fractional tumor vascularity. Vascularity measures were compared using reverse stepwise multiple linear regression analysis. In total, 58 pathology slides (with 8,106 frames) and 185 ultrasound images were analyzed. There was a significant increase in flow visualization pre to post Levovist injection ( p = 0.001), but no differences were found between the 11 benign and the eight malignant lesions ( p > 0.35). Ultrasound vascularity measurements post contrast correlated significantly with pathology (0.15 ≤ r 2 ≤ 0.46; p < 0.03). The 30–39 μm vessel range contributed most significantly to the MVD relationship ( p < 0.001), whereas the MVA was mainly influenced by vessels 20–29 μm ( p < 0.004). Precontrast ultrasound only correlated with pathology for relative MVA ( r 2 = 0.16; p = 0.01). In conclusion, contrast-enhanced color flow imaging provides a noninvasive measure of breast tumor neovascularity, corresponding mainly to vessels 20–39 μm in diameter, when used in a typical clinical setting.

EVALUATION OF INVESTIGATOR DEPENDENCY IN TRANSRECTAL CONTRAST ENHANCED COLOR DOPPLER TARGETED BIOPSY

1974 EVALUATION OF INVESTIGATOR DEPENDENCY IN TRANSRECTAL CONTRAST ENHANCED COLOR DOPPLER TARGETED BIOPSY Michael Mitterberger*, Daniela Colleselli, Alexandre E Pelzer, Wolfgang Horninger, Georg Bartsch, Hannes Strasser, Leo Pallwein, Johannes Gradl, Ferdinand Frauscher. Innsbruck, Austria. INTRODUCTION AND OBJECTIVE: Although transrectal contrast enhanced targeted prostate biopsy is increasingly proposed for prostate cancer detection, its investigator dependency has yet not been addressed. We compared the different user results of transrectal contrast enhanced targeted prostate biopsy for the prostate cancer detection. METHODS: Ten different investigators performed in 1763 PSA screening volunteers transrectal contrast enhanced color Doppler targeted prostate biopsy. Inclusion criteria were a serum total prostate

Acute renal failure with severe loin pain after anaerobic exercise (ALPE): detection of patchy renal ischaemia by contrast-enhanced colour Doppler.

An 18-year-old Japanese boy developed a severe loin pain 6 h after performing a 200 m dash three times in a baseball training, and was admitted to our hospital. He had a history of acute renal failure with severe loin pain after anaerobic exercise (ALPE) following the same kind of exercise 2 years before. On admission, his serum creatinine (Cr) level was 292 μmol/l (3.3 mg/dl) without accompanying findings of rhabdomyolysis-like elevation of creatine phosphokinase or myoglobinuria. Renal stones were not detected either by plain abdominal X-ray or by sonography. Accordingly, a diagnosis of ALPE was made. We started hydration and pain control by pentazocine without using non-steroidal anti-inflammatory drugs (NSAIDs). ALPE [1] is an uncommon syndrome, which mainly occurs in Asians possibly because of the relatively high prevalence (0.15–0.6%) of renal hypouricaemia [2,3,4]. The pathogenesis of ALPE is not clearly understood, but is considered to be a severe arterial vasoconstriction in the kidney. ALPE is known to demonstrate patchy wedge-shaped defects by contrast media-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) in delayed phase, which are considered to reflect renal ischaemia caused by vasospasm [5]. 99mTc-methylene diphosphonate (MDP) bone scintigraphy is also helpful to diagnose ALPE and to detect its ischaemic regions [6]. However, it requires time to start and to perform these imaging tests, and besides, contrast media for CT or MRI may cause harm, especially to patients with impaired renal function. Thus, we attempted to detect ischaemic regions caused by ALPE with colour Doppler imaging, which is non-invasive and can be implemented at any time and at the patients’ bedside. The use of micro-bubble contrast agent

Editorial Comment on: Comparison of Contrast-Enhanced Color Doppler Imaging (CDI), Computerized Tomography (CT), and Magnetic Resonance Imaging (MRI) for the Detection of Crossing Vessels in Patients with Ureteropelvic Junction Obstruction (UPJO)

Editorial Comment on: Comparison of Contrast-Enhanced Color Doppler Imaging (CDI), Computerized Tomography (CT), and Magnetic Resonance Imaging (MRI) for the Detection of Crossing Vessels in Patients with Ureteropelvic Junction Obstruction (UPJO)

Editorial Comment on: Comparison of Contrast-Enhanced Color Doppler Imaging (CDI), Computerized Tomography (CT), and Magnetic Resonance Imaging (MRI) for the Detection of Crossing Vessels in Patients with Ureteropelvic Junction Obstruction (UPJO)

Objective: To assess the use of contrast-enhanced color Doppler imaging (CDI), computed tomography (CT), and magnetic resonance imaging (MRI) for the detection of crossing vessels at the ureteropelvic junction (UPJ) in patients with ureteropelvic junction obstruction (UPJO). Materials and methods: Forty-eight patients aged 18-69 yr (mean age, 52) who had been diagnosed with an UPJO on intravenous pyelography and diuretic renography were included. Contrast-enhanced CDI was performed by using both color Doppler frequency and color Doppler amplitude (Power) modes. Spiral CT was performed by using a three-phase CT (arterial, venous, and excretory phases) allowing for CT angiography. MRI technique included dual-phase magnetic resonance angiography (arterial, venous) for the assessment of respective arteries and veins. The type (ie, arterial or venous) and position of the vessel relative to the UPJ (ie, anterior or posterior) were assessed. The CDI, CT, and MRI findings were correlated with the surgical findings at laparoscopic pyeloplasty. Results: Forty-four of 48 patients (92%) demonstrated crossing vessels at subsequent laparoscopy. Altogether a total of 60 vessels were detected. Contrast-enhanced CDI and MRI correctly detected all crossing vessels (accuracy, 100%), whereas CT missed four posterior crossing veins (accuracy, 93%). Conclusion: Contrast-enhanced CDI is recommended as first-line imaging modality for the detection of crossing vessels in patients with UPJO.

Comparison of Contrast-Enhanced Color Doppler Imaging (CDI), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) for the Detection of Crossing Vessels in Patients with Ureteropelvic Junction Obstruction (UPJO)

ObjectiveTo assess the use of contrast-enhanced color Doppler imaging (CDI), computed tomography (CT), and magnetic resonance imaging (MRI) for the detection of crossing vessels at the ureteropelvic junction (UPJ) in patients with ureteropelvic junction obstruction (UPJO). Materials and methodsForty-eight patients aged 18–69 yr (mean age, 52) who had been diagnosed with an UPJO on intravenous pyelography and diuretic renography were included. Contrast-enhanced CDI was performed by using both color Doppler frequency and color Doppler amplitude (“Power”) modes. Spiral CT was performed by using a three-phase CT (arterial, venous, and excretory phases) allowing for CT angiography. MRI technique included dual-phase magnetic resonance angiography (arterial, venous) for the assessment of respective arteries and veins. The type (ie, arterial or venous) and position of the vessel relative to the UPJ (ie, anterior or posterior) were assessed. The CDI, CT, and MRI findings were correlated with the surgical findings at laparoscopic pyeloplasty. ResultsForty-four of 48 patients (92%) demonstrated crossing vessels at subsequent laparoscopy. Altogether a total of 60 vessels were detected. Contrast-enhanced CDI and MRI correctly detected all crossing vessels (accuracy, 100%), whereas CT missed four posterior crossing veins (accuracy, 93%). ConclusionContrast-enhanced CDI is recommended as first-line imaging modality for the detection of crossing vessels in patients with UPJO.

Ultrasound of prostate cancer: recent advances

Prostate cancer is the most common cancer in men. In the future, a significant further increase in the incidence of prostate cancer is expected. Therefore, improvement of prostate cancer diagnosis is a main topic of diagnostic imaging. The systematic prostate biopsy ("ten-core biopsy") is now the "gold standard" of prostate cancer diagnosis but may miss prostate cancer. Contrast-enhanced colour Doppler ultrasound (US) and elastography are evolving methods that may dramatically change the role of US for prostate cancer diagnosis. Contrast-enhanced colour Doppler US allows for investigations of the prostate blood flow and consequently for prostate cancer visualization and therefore for targeted biopsies. Comparisons between systematic and contrast-enhanced targeted biopsies have shown that the targeted approach detects more cancers and cancers with higher Gleason scores with a reduced number of biopsy cores. Furthermore, elastography, a new US technique for the assessment of tissue elasticity has been demonstrated to be useful for the detection of prostate cancer, and may further improve prostate cancer staging. Therefore, contrast-enhanced colour Doppler US and elastography may have the potential to improve prostate cancer detection, grading and staging. However, further clinical trials will be needed to determine the promise of these new US advances.

A prospective randomized trial comparing contrast‐enhanced targeted versus systematic ultrasound guided biopsies: Impact on prostate cancer detection

We performed a prospective randomized trial comparing 5 contrast-enhanced color Doppler (CECD) ultrasound (US) targeted biopsy cores to 10 gray-scale US guided systematic biopsy (SB) cores to determine the impact on the cancer detection rate. We prospectively randomized 100 prostate specific antigen (PSA) screening volunteers with an elevated PSA (> or =1.25 ng/ml and free-to-total PSA < 18%) to undergo contrast-enhanced targeted or SB. Contrast-enhanced targeted biopsies with a limited number of five cores were performed into hypervascular areas of the peripheral zone (PZ) during administration of the US contrast agent SonoVue (Bracco, Italy). A subjective grading of the vascularity from 0 to 3 was used: grade 0, no color signal; 1, low density; 2, medium density; and 3, high density of color signals. Ten SBs were obtained in a standard spatial distribution. Cancer detection rates were compared in the groups. Cancer was detected in 16/50 subjects (32%) by targeted biopsy, and in 13/50 patients (26%) with SB. The cancer detection rate was significantly better for the targeted approach (P < 0.04, McNemar). The detection rate for targeted biopsy cores (15.6% or 39/250 cores) was significantly better than for SB cores (6.8% or 34/500 cores, P < 0.001, McNemar). CECD targeted biopsy detected more cancers than SB with a reduced number of biopsy cores.

752: Assessment of Perifocal Vascularisation in Plaques in IPP Patients by T1-MRI and Contrast-Enhanced Color Doppler Ultrasound (CE-US)

You have accessJournal of UrologyPodium 26, Monday, May 21, 2007, 8:00 - 10:00 am1 Apr 2007752: Assessment of Perifocal Vascularisation in Plaques in IPP Patients by T1-MRI and Contrast-Enhanced Color Doppler Ultrasound (CE-US) Germar M. Pinggera, Leo Pallwein, Fritz Aigner, Michael Mitterberger, Hannes Strasser, Nicolai Leonhartsberger, Ferdinand Frauscher, and Georg Bartsch Germar M. PinggeraGermar M. Pinggera More articles by this author , Leo PallweinLeo Pallwein More articles by this author , Fritz AignerFritz Aigner More articles by this author , Michael MitterbergerMichael Mitterberger More articles by this author , Hannes StrasserHannes Strasser More articles by this author , Nicolai LeonhartsbergerNicolai Leonhartsberger More articles by this author , Ferdinand FrauscherFerdinand Frauscher More articles by this author , and Georg BartschGeorg Bartsch More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(18)30992-3AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "752: Assessment of Perifocal Vascularisation in Plaques in IPP Patients by T1-MRI and Contrast-Enhanced Color Doppler Ultrasound (CE-US)." The Journal of Urology, 177(4S), p. 252 © 2016 by American Urological AssociationFiguresReferencesRelatedDetails Volume 177Issue 4SApril 2007Page: 252 Advertisement Copyright & Permissions© 2016 by American Urological AssociationMetricsAuthor Information Germar M. Pinggera More articles by this author Leo Pallwein More articles by this author Fritz Aigner More articles by this author Michael Mitterberger More articles by this author Hannes Strasser More articles by this author Nicolai Leonhartsberger More articles by this author Ferdinand Frauscher More articles by this author Georg Bartsch More articles by this author Expand All Advertisement PDF downloadLoading ...

Dutasteride Prior to Contrast-Enhanced Colour Doppler Ultrasound Prostate Biopsy Increases Prostate Cancer Detection

ObjectivesThis study assessed the effect of premedication with dutasteride, a dual 5α-reductase inhibitor, on prostatic blood flow prior to prostate biopsy and its impact on prostate cancer detection. MethodsThirty-six patients, aged 52–74 yr, with elevated prostate-specific antigen (PSA) levels (≥1.25ng/ml and free-to-total ratio of <18%) were treated with dutasteride 14 d prior to prostate biopsy. Contrast-enhanced colour Doppler (CECD) ultrasound was performed before and 7 and 14 d after dutasteride treatment. Contrast-enhanced targeted biopsies (≤5) were performed into hypervascular areas of the peripheral zone only. Subsequently, a second investigator performed 10 systematic biopsies of the prostate in a standard spatial distribution guided by conventional grey-scale ultrasonography on a Combison 530MT unit. ResultsDutasteride reduced prostatic blood flow in benign prostatic tissue, whereas in prostate cancer areas blood flow was still observed after a 14-d course of dutasteride intake. A reduction of blood flow was observed even after 7 d. Maximum flow reduction was observed after 14 d. Twelve patients (33%) of our cohort were found to have suspicious blood flow and prostate cancer and six cancers (17%) were detected solely by targeted contrast-enhanced biopsy. ConclusionPremedication with dutasteride seems promising to improve prostate cancer detection by using CECD ultrasound.

Contrast-Enhanced Color Duplex Sonography (CDS): an Alternative for the Evaluation of Therapy-Relevant Tumor Oxygenation?

To evaluate the predictive value of radiotherapeutically relevant tumor hypoxia by contrast-enhanced color duplex sonography (CDS). The objectification was based on pO2 histography. 25 patients with metastatic neck lymph node from a primary squamous carcinoma of the head and neck were examined. To visualize as many vessels as possible, a contrast enhancer (Levovist®, Schering Corp., Germany) was administered. Horizontal and longitudinal sonographic scans with a thickness of 5 mm were performed on the metastatic neck lymph node. Color pixel density (CPD) was defined as the ratio of colored to gray pixels in a region of interest. It represents the extent of vascularization in the investigated slice. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO2 readings ≤2.5, 5.0, and 10.0 mmHg, as well as mean and median pO2, were documented. In order to investigate the degree of linear association, the Pearson correlation coefficient was calculated. Moderate (|r| > 0.5) to high (|r| > 0.7) correlation was found between the CPD and the parameters of hypoxic fraction (pO2 readings with values ≤5.0 and 10.0 mmHg, as well as mean and median). There was only a slight correlation between CPD and the fraction of pO2 values ≤2.5 mmHg (r = −0.479). CPD represents the mean degree of vascularization. As a noninvasive measurement, this method seems feasible for evaluating the state of global oxygenation in superficial tumors. Nevertheless, this method is limited through its deficiency in describing the vascular heterogeneity of tumors.

Contrast-Enhanced Color Duplex Sonography (CDS): an Alternative for the Evaluation of Therapy-Relevant Tumor Oxygenation?

To evaluate the predictive value of radiotherapeutically relevant tumor hypoxia by contrast-enhanced color duplex sonography (CDS). The objectification was based on pO(2) histography. 25 patients with metastatic neck lymph node from a primary squamous carcinoma of the head and neck were examined. To visualize as many vessels as possible, a contrast enhancer (Levovist), Schering Corp., Germany) was administered. Horizontal and longitudinal sonographic scans with a thickness of 5 mm were performed on the metastatic neck lymph node. Color pixel density (CPD) was defined as the ratio of colored to gray pixels in a region of interest. It represents the extent of vascularization in the investigated slice. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO(2) readings < or = 2.5, 5.0, and 10.0 mmHg, as well as mean and median pO(2), were documented. In order to investigate the degree of linear association, the Pearson correlation coefficient was calculated. Moderate (/r/ > 0.5) to high (/r/ > 0.7) correlation was found between the CPD and the parameters of hypoxic fraction (pO(2) readings with values < or = 5.0 and 10.0 mmHg, as well as mean and median). There was only a slight correlation between CPD and the fraction of pO(2) values < or = 2.5 mmHg (r = -0.479). CPD represents the mean degree of vascularization. As a noninvasive measurement, this method seems feasible for evaluating the state of global oxygenation in superficial tumors. Nevertheless, this method is limited through its deficiency in describing the vascular heterogeneity of tumors.

3594: The experimental study of the contrast-enhanced sonography in the assessment of arterial Stenosis

Objectives: To evaluate the ability of contrast-enhanced color Doppler ultrasound (US) and contrast-enhanced real-time harmonic gray scale imaging in the diagnosis of arterial stenosis and the assessment of stenosis degree.

Contrast-enhanced Duplex surveillance after endovascular abdominal aortic aneurysm repair: Improved efficacy using a continuous infusion technique

Currently, postoperative endoleak surveillance after endovascular aortic aneurysm repair (EVAR) is primarily done by computed tomography (CT). The purpose of this study was to determine the efficacy of contrast-enhanced ultrasonography scans to detect endoleaks by using a novel infusion method and compare these findings with those of CT angiography (CTA). Twenty male patients (mean age, 70.4 years) underwent surveillance utilizing both CTA and contrast-enhanced color Duplex imaging. One 3-mL vial of Optison (Perfluten Protein A microspheres for injection) and 57 mL normal saline, for a total of 60 mL, were administered to each patient as a continuous infusion at 4 mL/min via a peripheral vein. Each study was optimized with harmonic imaging, and a reduced mechanical index of 0.4 to 0.5, compression of 1 to 3, and a focal zone below the aorta to minimize microsphere rupture. One minute was allowed from the time of infusion to the appearance of contrast in the endograft. Flow was evaluated within the lumen of the graft and its components, as was the presence or absence of endoleaks. Findings were compared with standard color-flow Duplex imaging and CT utilizing CTA reconstruction protocols. All patients evaluated had modular endografts implanted for elective aneurysm repair. Contrast-enhanced duplex scans identified nine endoleaks: one type I and eight type II. No additional endoleaks were seen on CTA. However, CTA failed to recognize three type II endoleaks seen by contrast-enhanced ultrasound. The continuous infusion method allowed for longer and more detailed imaging. An average of 46.8 mL of the contrast infusion solution was used per patient. Contrast enhanced Duplex ultrasonography accurately demonstrates endoleaks after EVAR and may be considered as a primary surveillance modality. Continuous infusion permits longer imaging time.