Contrast-enhanced Color Research Articles

A hue preservation lossless contrast enhancement method with RDH for color images

The contrast enhancement with reversible data hiding (CERDH) has become a hot topic in many fields. At present, most schemes applying CERDH methods to color images have the problem of color distortion. To solve this problem, this paper proposes a CERDH method for color images based on constant hue plane. It firstly separates the color images into min, mid and max channels. Then, a novel preprocessing is proposed to maintain the distribution of histogram for original image while vacate room for data hiding. After that, the mid channel is used for data hiding, and min and max channels are hue-preserved to avoid color distortion. Finally, the three channels compose a contrast-enhanced color image. The experimental results show that the proposed method achieves the best enhanced results based on CIEDE2000 compared with the state-of-the-art methods, and color distortion is also greatly reduced.

Color Doppler imaging characteristics of RPE neoplasms: A study of 17 cases.

To report the color Doppler imaging (CDI) features of 17 patients with retinal pigment epithelium (RPE) neoplasms. Retrospective, observational case series. Seventeen patients with RPE adenoma/adenocarcinoma. Contrast-enhanced color Doppler ultrasonography (CDU) was performed in 16 patients with RPE adenoma and in one patient with adenocarcinoma. All 17 RPE neoplasms showed well-defined margins. An oval mass was observed in 11 tumors, a lenticular-shaped mass in four tumors, and a flat mass in two tumors. On CDI, RPE lesions showed homogeneous reflectivity of moderate intensity with no choroidal excavation. After the contrast-enhanced administration of sulfur hexafluoride, mild enhancement was identified in six tumors and moderate enhancement in 11 tumors. In all 17 RPE neoplasms, contrast-enhanced CDU time-intensity curves (TICs) exhibited fast fill-in and slow washout-shaped curves with the dominant vessel within RPE lesions. A "black-linear" sign (defined as a low signal intensity-linear zone located between the tumor and enhanced choroid on CDI) was noted in all 17 patients with RPE neoplasms. This preliminary study noted a "black-linear" sign on CDI of RPE lesions for the first time. The novel sign may be a diagnostic characteristic of RPE neoplasms and may help to distinguish this rare entity from uveal melanomas (UMs).

Contrast-enhanced ultrasound and color doppler ultrasound as guidance for transhepatic artery chemoembolization following three-dimensional conformal radiotherapy

Contrast-enhanced ultrasound and color doppler ultrasound as guidance for transhepatic artery chemoembolization following three-dimensional conformal radiotherapy

Usefulness of intraoperative contrast-enhanced color Doppler ultrasonography for selective renal artery clamping in robot-assisted partial nephrectomy.

Usefulness of intraoperative contrast-enhanced color Doppler ultrasonography for selective renal artery clamping in robot-assisted partial nephrectomy.

Sensitivity of voiding urosonography as afunction of the number of the cyclic bladder fillings

Vesicoureteral reflux (VUR) can occur intermittently. Cyclic testing of VUR (observation of multiple phases of filling and micturition) increases the detection rate of VUR, as has been shown in studies which have generally used a two-cycle test period. How large is the dependence of the sensitivity in voiding urosonography (VUS) on the number of observed cycles when more than two cycles are observed in alarger number of patients? How many cycles should be observed in order to achieve sufficient sensitivity? The study population consisted of 302patients (225 female, average age 2.5years [range 1month-17years]; 77male, average age 6months [range 1month-2.5years]) with 607 kidney-ureter units (KUU), examined in apediatrican practice from 05January2016 to 31December2019. The examinations were performed by contrast-enhanced color Doppler voiding urosonography using the ultrasound contrast agent SonoVue® (Bracco Imaging, Milan, Italy) for an average of 3.14cycles and, in the case of undetectable VUR, for an average of 3.5cycles (range 1-6cycles). In all, 118 of 302patients were found to have VUR. In terms of KUU, 163 of 607 KUU exhibited reflux. VUR occurred intermittently in 32.5% of KUU. Depending on the number of cycles observed, there was asignificant increase in sensitivity of the VUS. Using the observation of five cycles as areference for the sensitivity, the following values are obtained: 1cycle = 82.2%, 2cycles = 87.7%, 3cycles = 96.3%, 4cycles = 98.8%, 5cycles = 100%. To achieve asensitivity of 96% in detecting VUR, three cycles must be observed. If less than three cycles are observed, the sensitivity shows amarked decrease.

Deep CNN and geometric features-based gastrointestinal tract diseases detection and classification from wireless capsule endoscopy images

ABSTRACT Gastrointestinal tract (GIT) infections such as ulcers, bleeding, polyps, Crohn’s disease and cancer are quite familiar today worldwide. Wireless capsule endoscopy (WCE) is an efficient means of investigation of GIT diseases. However, still several challenges exist in this domain, such as lesion shape, colour, texture, size and irregularity. To deal with these problems, several computer-based methods are introduced in computer vision domain but they used only hand-crafted features which produced wrong predictions several times. In this research, a new technique is applied based on the fusion of deep convolutional (CNN) and geometric features. Initially, disease regions are extracted from given WCE images using a new approach named contrast-enhanced colour features . Geometric features are extracted from segmented disease region. Thereafter, unique VGG16 and VGG19 deep CNN features fusion are performed based on Euclidean Fisher Vector . The unique features are fused with geometric features which are later fed to conditional entropy approach for best features selection. The selected features are finally classified by K-Nearest Neighbour . A privately collected database which consists of 5500 WCE images is utilised for the evaluation of the proposed method and achieved best classification accuracy of 99.42% and precision rate of 99.51%. The classification accuracy proves the authenticity of the proposed approach.

Contrast-Enhanced Color Doppler Ultrasonography for Preoperative Evaluation of Sentinel Lymph Node in Breast Cancer Patients

Background: Sentinel lymph node (SLN) biopsy is the standard of care for breast cancer patients with non-palpable axillary lymph nodes. We evaluated the usefulness of contrast-enhanced ultrasonography in preoperative detection of malignant SLNs. Methods: 50 patients with breast cancer (median age: 60 years) underwent a color power Doppler ultrasonography with intravenous contrast (Sonovue®) preoperatively, and findings suggestive of metastatic disease to the SLN were documented. The final histopathological report and the radiological preoperative record were compared. Finally, the sensitivity, specificity and diagnostic accuracy of this evolving diagnostic modality were calculated. Results: Contrast-enhanced ultrasound scan identified a negative SLN in the axilla of 27 patients and final histopathology was negative for 30 cases in total, so negative predictive value was calculated as 90% and positive predictive value was 75%. Overall sensitivity was 83.33% and specificity was 84.38%. Moreover, the ability of contrast-enhanced ultrasound to differentiate between SLN status was only statistically significantly correlated with the actual final histopathological report (p < 0.001), while successful ultrasound prediction was not correlated with any factor. Conclusions: SLN status can be evaluated preoperatively using contrast-enhanced color Doppler ultrasonography with high accuracy.

Contrast-enhanced color Doppler ultrasonography increases diagnostic accuracy for soft tissue tumors.

Resolution of ultrasonography (US) has undergone marked development. Additionally, a new-generation contrast medium (Sonazoid) used for US is newly available. Contrast-enhanced US has been widely used for evaluating several types of cancer. In the present study, we evaluated the ability of color Doppler US (CDUS) and Sonazoid to differentiate between benign and malignant soft tissue tumors. A total of 180 patients (87 male, 93 female) were enrolled in the present study. The patient ages ranged from 1 to 91 years (mean 58.1±20.0years). The maximum size, depth, tumor margins, shape, echogenicity and textural pattern were measured on gray-scale images. CDUS was used to evaluate the intratumoral blood flow with and without Sonazoid. Peak systolic flow velocity (Vp), mean flow velocity (Vm), resistivity index (RI) and pulsatility index (PI) of each detected intratumoral artery were automatically calculated with power Doppler US (PDUS). The present study included 118 benign and 62 malignant tumors. Statistical significances were found in size, depth, tumor margin and textural pattern but not in shape or echogenicity on gray-scale images. Before Sonazoid injection, CDUS findings showed 55% sensitivity, 77% specificity and 69% accuracy, whereas contrast-enhanced CDUS showed 87% sensitivity, 68% specificity and 74% accuracy. There were no statistically significant differences between malignant and benign tumors regarding the mean Vp, Vm, RI and PI values determined on PDUS. In conclusion, contrast-enhanced CDUS proved to be a reliable diagnostic tool for detecting malignant potential in soft tissue tumors.

Sa1004 Measurement of Liver and Spleen Stiffness by ARFI Elastography: Intra-and Inter-Observer Variability and Predictors of Variability

Staging hepatocellular carcinoma (HCC) is an esential step in the decision regarding treatment options. Malignant portal vein thrombosis is a contraindication for all curative treatment, thus establishing the nature (benign or malignant) of PVT is mandatory for staging the disease. The AIM of this paper was to assess the role of contrast enhanced ultrasound (CEUS) for the staging of HCC in patients with liver cirrhosis. METHODS: We evaluated 86 consecutive patients with liver cirrhosis and known HCC, who were discovered with PVT located in different parts of the portal system. Before CEUS we performed a standard ultrasound and a Doppler examination. We used 2.4 ml of second generation contrast agent (SonoVue) for every examination. During the CEUS examination we followed the arterial, portal and late phases as defined in the EFSUMB Guidelines (1) and also the enhancement pattern as described by Rossi et al. (Type 1: thrombus enhancement is absent in all three phasesbenign thrombus; and for malign thrombus-Type 2: diffuse thrombus enhancement that is visible only during the early arterial phase; Type 3: linear or punctate enhancement; Type 4: multilinear or multipunctate enhancement)(2). RESULTS: PVT was located in the proximity of HCC in 63 of the 86 cases (73.2 %). 11 cases (12.7%) were Type 1 Rossi (benign thrombus), 44 cases (51.1%) were Type 2, 14 cases (16.2%) were Type 3 and 17 cases (19.7%) were Type 4 Rossi. Using CEUS we could characterise and obtain a conclusive diagnosis in 85 of the 86 patients (98.8%). CONCLUSIONS CEUS is a method with a good sensibility for the characterisation of PVT in patients with HCC, that allows the staging of the disease for a good therapeutic decision. BIBLIOGRAPHY: 1. M. Claudon, C. F. Dietrich, B. I. Choi, D. O. Cosgrove, M. Kudo, C. P. Nolsoe, F. Piscaglia, S. R. Wilson, R. G. Barr, M. C. Chammas, N. G. Chaubal, M.-H. Chen, D. A. Clevert, J. M. Correas, H. Ding, F. Forsberg, J. B. Fowlkes, R. N. Gibson, B. B. Goldberg, N. Lassau, E. L. S. Leen, R. F. Mattrey, F. Moriyasu, L. Solbiati, H.-P. Weskott, H.-X. Xu. Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver-Update 2012. Published online: 2012 Ultraschall in Med. 2. Rossi S. et al. Contrast-Enhanced Versus Conventional and Color Doppler Sonography for the Detection of Thrombosis of the Portal and Hepatic Venous Systems. AJR 2006; 186:763-773.

Sa1003 Diagnosis of Benign and Malignant Portal Vein Thrombosis in Cirrhotic Patients With Hepatocellular Carcinoma Using Contrast-Enhanced Ultrasound (CEUS)

Staging hepatocellular carcinoma (HCC) is an esential step in the decision regarding treatment options. Malignant portal vein thrombosis is a contraindication for all curative treatment, thus establishing the nature (benign or malignant) of PVT is mandatory for staging the disease. The AIM of this paper was to assess the role of contrast enhanced ultrasound (CEUS) for the staging of HCC in patients with liver cirrhosis. METHODS: We evaluated 86 consecutive patients with liver cirrhosis and known HCC, who were discovered with PVT located in different parts of the portal system. Before CEUS we performed a standard ultrasound and a Doppler examination. We used 2.4 ml of second generation contrast agent (SonoVue) for every examination. During the CEUS examination we followed the arterial, portal and late phases as defined in the EFSUMB Guidelines (1) and also the enhancement pattern as described by Rossi et al. (Type 1: thrombus enhancement is absent in all three phasesbenign thrombus; and for malign thrombus-Type 2: diffuse thrombus enhancement that is visible only during the early arterial phase; Type 3: linear or punctate enhancement; Type 4: multilinear or multipunctate enhancement)(2). RESULTS: PVT was located in the proximity of HCC in 63 of the 86 cases (73.2 %). 11 cases (12.7%) were Type 1 Rossi (benign thrombus), 44 cases (51.1%) were Type 2, 14 cases (16.2%) were Type 3 and 17 cases (19.7%) were Type 4 Rossi. Using CEUS we could characterise and obtain a conclusive diagnosis in 85 of the 86 patients (98.8%). CONCLUSIONS CEUS is a method with a good sensibility for the characterisation of PVT in patients with HCC, that allows the staging of the disease for a good therapeutic decision. BIBLIOGRAPHY: 1. M. Claudon, C. F. Dietrich, B. I. Choi, D. O. Cosgrove, M. Kudo, C. P. Nolsoe, F. Piscaglia, S. R. Wilson, R. G. Barr, M. C. Chammas, N. G. Chaubal, M.-H. Chen, D. A. Clevert, J. M. Correas, H. Ding, F. Forsberg, J. B. Fowlkes, R. N. Gibson, B. B. Goldberg, N. Lassau, E. L. S. Leen, R. F. Mattrey, F. Moriyasu, L. Solbiati, H.-P. Weskott, H.-X. Xu. Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver-Update 2012. Published online: 2012 Ultraschall in Med. 2. Rossi S. et al. Contrast-Enhanced Versus Conventional and Color Doppler Sonography for the Detection of Thrombosis of the Portal and Hepatic Venous Systems. AJR 2006; 186:763-773.

造影カラードプラ超音波内視鏡検査により診断しえた膵十二指腸動脈瘤の1例

造影カラードプラ超音波内視鏡検査により診断しえた膵十二指腸動脈瘤の1例

Contrast Enhanced Transrectal Ultrasound for the Detection of Prostate Cancer: A Randomized, Double-Blind Trial of Dutasteride Pretreatment

The identification of clinically significant disease is crucial for optimal treatment of prostate cancer. Selective detection of prostate cancer with increased microvessel density is possible with contrast enhanced ultrasound. Preliminary studies suggest that pretreatment with a 5α-reductase inhibitor may improve the efficiency of contrast enhanced ultrasound targeted biopsy. This study was designed to quantify prostate cancer detection with contrast enhanced ultrasound with or without short-term pretreatment with dutasteride. In this randomized, double-blind, placebo controlled trial of oral dutasteride pretreatment, contrast enhanced ultrasound findings were graded and used to direct targeted biopsy (up to 6 cores per prostate). A blinded 12-core systematic biopsy was subsequently performed on every subject based on standard medial and lateral sampling of each sextant. Of 311 subjects who underwent randomization, 272 completed participation. Positive biopsies were obtained in 276 of 3,264 (8.5%) systematic cores and 203 of 1,237 (16.4%) targeted cores (OR 2.1, 95% CI 1.7-2.6, p <0.001). ROC analysis for the detection of all prostate cancers demonstrated an increase in diagnostic accuracy from pre-contrast imaging to contrast enhanced ultrasound (A(z) 0.60 vs 0.64, p = 0.005). For the detection of high grade cancer (Gleason score 7 or greater) ROC analysis demonstrated improved accuracy for pre-contrast imaging (A(z) 0.74) and contrast enhanced ultrasound (A(z) 0.80, p = 0.0005). For the detection of high grade cancer with greater than 50% biopsy core involvement, excellent accuracy was demonstrated with pre-contrast and contrast enhanced ultrasound, A(z) 0.83 and 0.90, respectively (p = 0.001). Pretreatment with dutasteride had no significant impact on the detection of prostate cancer (p = 0.97). Contrast enhanced ultrasound targeted biopsy provides a significant benefit for the detection of high grade/high volume prostate cancer.

Analysis of bladder vascular resistance before and after prostatic surgery in patients with lower urinary tract symptoms suggestive of benign prostatic obstruction

To evaluate bladder vascular resistance before and after transurethral resection of the prostate (TURP). Thirty-three patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction were prospectively studied. We analyzed correlations of bladder vascular resistance with various factors including age, vascular risk factors, symptom score, prostate volume (PV), and urodynamic parameters before and 3 months after TURP. Using contrast-enhanced color Doppler ultrasonography for measuring bladder vascular resistance, resistive index (RI) of vesical arteries was calculated. Compared with healthy young male (n = 10) and age-matched controls (n = 10), the study patients had a higher preoperative RI (0.403 ± 0.100, 0.436 ± 0.042, and 0.561 ± 0.089, respectively; P < 0.01). Preoperative RI was significantly higher in patients with PV ≥ 60 ml versus <60 ml (0.604 ± 0.078 vs. 0.525 ± 0.082; P < 0.01), and in patients with severe obstruction versus mild/moderate obstruction (0.615 ± 0.087 vs. 0.534 ± 0.078; P = 0.017). Overall RI decreased significantly after TURP (from 0.561 ± 0.089 to 0.450 ± 0.086; P < 0.001). In patients with persistent urgency after TURP, RI was less improved than in those without urgency after TURP (change of RI 0.068 ± 0.098 vs. 0.135 ± 0.090; P < 0.05). This study was limited by a small sample size. Bladder vascular resistance in patients with LUTS was elevated in correlation with PV and severity of obstruction. Although bladder vascular resistance decreased significantly after TURP in overall patients, less reduction of vascular resistance was related to persistent urgency after TURP, implying that persistent urgency after TURP might be caused by persistent bladder ischemia.

Metronomic doxifluridine chemotherapy combined with the anti-angiogenic agent TNP-470 inhibits the growth of human uterine carcinosarcoma xenografts

Uterine carcinosarcoma is a highly aggressive gynecological neoplasm that responds poorly to conventional chemotherapy and radiotherapy. Metronomic chemotherapy is accepted as a new approach for cancer treatment, and its underlying mechanism seems to involve the suppression of angiogenesis. However, the efficacy of metronomic and anti-angiogenic therapies against uterine carcinosarcoma is unknown. The anti-angiogenic effect of doxifluridine was assessed in vitro using human umbilical vein endothelial cells (HUVEC) co-cultured with FU-MMT-1 human uterine carcinosarcoma cells. The antitumor and anti-angiogenic effects of metronomic doxifluridine (delivered via oral gavage) in combination with TNP-470 were evaluated in vivo. Tumor vascularity was assessed by contrast-enhanced color Doppler ultrasound, laser Doppler and microvessel density staining. Doxifluridine suppressed tube formation of HUVEC and vascular endothelial growth factor production by FU-MMT-1 cells. Metronomic doxifluridine alone significantly suppressed tumor growth compared with the untreated (control) group, while metronomic doxifluridine in combination with TNP-470 significantly inhibited tumor growth compared with each treatment alone. A significant reduction of intratumoral vascularity was observed in FU-MMT-1 xenografts following treatment with metronomic doxifluridine in combination with TNP-470, as compared with each treatment alone. Intestinal bleeding was only observed when the maximum tolerated dose of doxifluridine was administered in combination with TNP-470. Metronomic doxifluridine chemotherapy in combination with TNP-470 might be effective for uterine carcinosarcoma without marked toxicity, possibly acting via its potent anti-angiogenic effects. Clinical studies are needed to evaluate the safety and efficacy of this treatment in humans.

‘Reverse S’ coronary sign

A 64-year-old man presented to stress echocardiography because of recurrent episodes of angina evoked by exercise. Exercise electrocardiogram was positive for mild ST-segment depression. Contrast-enhanced colour Doppler of the left anterior descending coronary artery (LAD) flow revealed a …

Comparative study of contrast-enhanced ultrasound and color Doppler flow imaging in quantitative evaluation of chronic kidney dysfunction

Objective To evaluate the value of contrast-enhanced ultrasonography (CEUS) in quantitative diagnosis of chronic kidney dysfunction(CKD) by comparing it with color Doppler imaging (CDFI). Methods Tirty-three cases (15 males and 18 females) of clinical confirmed CKD (stage Ⅲ～Ⅴ)were included. Forty-five healthy volunteers were performed as control group. CEUS and CDFI were performed on each patient. After intravenous bolus injection of 1ml SonoVue each side,CEUS of renal cortex blood perfusion was collected successively,and a time-intensity curve(TIC) was created with Philips iU22 system's QLAB software. Resistance index(RI) and peak systolic velocity(PSV) of renal partial arteries were also tested. Results Compared with normal kidney,CKD patients had delayed perfusion and decreased intensity. Changes of area under curve(AUC), derived peak intensity(DPI), slope rate of ascending curve(A)and time to peak(TTP) were statistically significant ( P ＜0. 05). Sensitivities of AUC,DPI,A and TTP in diagnosis of CKD (stage Ⅲ～Ⅴ ) were 91.2% ,84. 9% ,90.9% and 85.3%, their specificities were 95.4%,88.9% ,93.3% and 90.9%, their accuracies were 93.6%, 87. 2%, 92.3% and 88. 5%, respectively. The results of CEUS were better than RI in CDFI (sensitivity 70.4%, specificity 37. 8%, accuracy 52.2%).Conclusions CEUS can precisely display the hemodynamic change in CKD ( stage Ⅲ～Ⅴ ), and is more sensitive than CDFI. Key words: Ultrasonography; Microbubbles; Renal insufficiency,chronic

Metronomic irinotecan chemotherapy combined with ultrasound irradiation for a human uterine sarcoma xenograft

Metronomic chemotherapy is the frequent administration of low doses of chemotherapeutic agents targeting tumor-associated endothelial cells. We examined the efficacy of metronomic irinotecan combined with low-intensity ultrasound (US) in human uterine sarcoma and evaluated its antiangiogenesis mechanism by measuring the circulating endothelial progenitor cells (CEP), a surrogate marker of angiogenesis. A human uterine sarcoma cell line, FU-MMT-3, was used in the present study because this tumor is one of the most malignant neoplasms of human solid tumors and it also has a high angiogenesis property. The combination of low-dose irinotecan and US irradiation significantly inhibited the tube formation of HUVEC and vascular endothelial growth factor expression of tumor cells in vitro. The FU-MMT-3 xenografts in nude mice were treated using US at a low intensity (2.0 w/cm(2), 1 MHz) for 4 min three times per week each after the intraperitoneal administration of irinotecan; this treatment was continued for 5 weeks. The tumor vascularity was assessed by contrast-enhanced color Doppler US in real time. The combination treatment significantly inhibited the mobilization of CEP and intratumoral vascularity compared with the control. This combination therapy showed a significant reduction in tumor volume, resulting in a significant prolongation of survival, in comparison with each treatment alone. These results suggest that the effect of metronomic chemotherapy for human uterine sarcoma was accelerated by US irradiation in vivo and this combination might therefore be potentially effective for new cancer therapy.

CONTRAST-ENHANCED HARMONIC ULTRASONOGRAPHY OF MEDIAL ILIAC LYMPH NODES IN HEALTHY DOGS

Herein, we describe the normal contrast-enhanced harmonic, color, and power Doppler ultrasonographic characteristics of the medial iliac lymph nodes in healthy dogs. Contrast-enhanced harmonic ultrasonography of the medial iliac lymph nodes was performed on 14 healthy dogs after intravenous administration of the lipoprotein-bound inert gas-filled microbubble contrast media Definity. Time-pixel intensity curves were generated for 1-min postinjection. Quantification of these curves was performed using Philips QLab software. Non-contrast-enhanced power and color Doppler examinations were performed in each node to assess vascular patterns subjectively. Normal lymph nodes exhibited a mean contrast wash-in phase beginning at 6.3 s from the time of injection with mean peak pixel intensity at 12.1s. Angioarchitecture was best visualized with contrast-enhanced harmonic ultrasound compared with power and color Doppler. Normal lymph nodes in dogs have a central artery with a centrifugal and uniform branching pattern. Contrast-enhanced harmonic ultrasonography is a noninvasive examination that demonstrates improved visibility of the intranodal architecture of healthy medial iliac lymph nodes in dogs compared with conventional, non-contrast-enhanced Doppler methods that may have future clinical applications.

Prostate cancer imaging: what the next decade holds

Prostate carcinoma is the most commonly diagnosed malignancy and the second most common cause of male cancer death in the USA [1]. Autopsy and early observational studies have shown that approximately one out of three men above the age of 50 years has histologic evidence of prostate carcinoma. While a portion of these tumors may be very aggressive and lethal, others are possibly clinically insignificant [2]. Identifying the lethal form of this tumor remains a challenge in this heterogeneous malignancy. The clinical presentation of prostate cancer may range from an asymptomatic condition to a rapidly progressive systemic illness. Prostate specific antigen (PSA) screening has resulted in earlier detection and a downstaging of prostate cancer at diagnosis. At the same time, the commonly used PSA cutoff of 2.5 ng/ml, used by urologists for biopsy, also leads to a significant number of unnecessary biopsies, leading to over diagnosis and overtreatment of indolent disease [3]. Thus far, imaging has only played a relatively small role in the management of localized prostate cancer. The current standard imaging techniques, such as transrectal ultrasound (TRUS), MRI, computed tomography (CT) and nuclear medicine studies, are not able to detect early disease, and only provide limited information for tumor, node, metastasis staging [4]. However, the role of imaging in patients with prostate cancer is evolving. New techniques are under investigation, either alone or combined with standard imaging techniques. TRUS is usually used to guide biopsies and to place brachytherapy seeds, but it does not reliably differentiate healthy from malignant prostate gland tissue. Contrast-enhanced color Doppler imaging, intermittent harmonic imaging and contrast-enhanced flash-replenishment imaging are now combined with standard TRUS. Contrast-enhanced ultrasound takes advantage of an increased density of micro vasculature in cancerous tissue compared with benign prostate tissue. Using micro bubble contrast agents, which diffuse into microvessels, this technique selectively enhances areas with increased vascularity. However, because of the relatively large size of microbubbles (~5–10 μm), leakage into the tumor cannot be well visualized and enhancement can also be due to benign conditions, such as prostatitis [5]. In a recent study of 114 patients with elevated PSA levels and previous negative biopsy contrast-enhanced advanced dynamic flow, Tina Islam

Comparative efficiency of contrast-enhanced colour Doppler ultrasound targeted versus systematic biopsy for prostate cancer detection

To compare the efficiency of contrast-enhanced colour Doppler ultrasound (CECD-US) targeted biopsy versus systematic biopsy (SB) for PCa detection in 1,776 men. Retrospective, single-centre, diagnostic accuracy study from 2002 until 2006 in 1,776 male volunteers with a serum total PSA of 1.25 ng/ml or greater. In each patient five CECD-US targeted biopsies were performed in hypervascular areas in the peripheral zone during intravenous injection of a second-generation microbubble US contrast agent. Subsequently, another examiner performed ten SBs. The PCa detection rates for the two techniques were compared. Of 1,776 patients, cancer was detected in 559 patients (31%), including 476 of the 1,776 patients (27%) with CECD-US and 410 (23%) with SB (p < 0.001). The detection rate for CECD-US targeted biopsy cores (10.8% or 961 of 8,880 cores) was significantly better than for SB cores (5.1% or 910 of 17,760 cores, p < 0.001). Among patients with a positive biopsy for PCa, cancer was detected by CECD-US alone in 149 patients (27%) and by SB alone in 83 (15%) (p < 0.001). This study represents the largest clinical trial to date, demonstrating a significant benefit of CECD-US targeted biopsy relative to SB.