Conventional Transrectal Ultrasound Research Articles

Automatic search for photoacoustic marker using automated transrectal ultrasound.

Real-time transrectal ultrasound (TRUS) image guidance during robot-assisted laparoscopic radical prostatectomy has the potential to enhance surgery outcomes. Whether conventional or photoacoustic TRUS is used, the robotic system and the TRUS must be registered to each other. Accurate registration can be performed using photoacoustic (PA markers). However, this requires a manual search by an assistant [IEEE Robot. Autom. Lett8, 1287 (2023).10.1109/LRA.2022.3191788]. This paper introduces the first automatic search for PA markers using a transrectal ultrasound robot. This effectively reduces the challenges associated with the da Vinci-TRUS registration. This paper investigated the performance of three search algorithms in simulation and experiment: Weighted Average (WA), Golden Section Search (GSS), and Ternary Search (TS). For validation, a surgical prostate scenario was mimicked and various ex vivo tissues were tested. As a result, the WA algorithm can achieve 0.53°±0.30° average error after 9 data acquisitions, while the TS and GSS algorithm can achieve and 0.48°±0.32° average errors after 28 data acquisitions.

Comparison of the Diagnostic Accuracy of Percutaneous Fistula Contrast-Enhanced Ultrasound Combined with Transrectal 360° 3-D Imaging and Conventional Transrectal Ultrasound in Complex Anal Fistula.

This study compared the diagnostic accuracy of percutaneous fistula contrast-enhanced ultrasound (CEUS) combined with 360° 3-D transrectal ultrasound (TRUS) imaging (CEUS+360°-TRUS) with that of conventional transrectal ultrasound in the diagnosis of complex anal fistulas. A total of 156 patients clinically diagnosed with complex anal fistula from January 2020 to December 2021 were studied and randomly divided into an experimental group (n=82) and a control group (n=74). Patients in the experimental group were examined by percutaneous fistula CEUS combined with CEUS+360°-TRUS, while patients in the control group were examined using TRUS. The detection of fistulas (main tract, branch and internal orifice) and the accuracy of Parks classification were compared between the two groups. Recurrences were followed up at 1, 3 and 6 mo after the surgery. A total of 156 patients were included, aged 23-68 y (average: 37.7 ± 18.2 y). In both groups, the course of disease was <1 mo in 128 cases, 1-2 mo in 22 cases and >3 mo in 6 cases. A total of 474 fistulas were confirmed by surgery in the aforementioned patients, including 224 main fistulas, 250 branch pipes and 254 internal orifices. The CEUS+360°-TRUS group had 96.87%, 90.41% and 90.14% diagnostic accuracy for the main tract, branch and internal orifice, which was statistically significant (p < 0.001) compared with the 85.00%, 70.00% and 72.46% for the TRUS group, respectively. The overall accuracy of Parks classification of anal fistula in the CEUS+360°-TRUS group was significantly higher than that in the TRUS group (90.24% vs. 78.38%, p < 0.001). After 6 mo of follow-up, the recurrence rate in the CEUS+360°-TRUS group was 4.87%, and the recurrence rate in the TRUS group was 18.91%. Percutaneous fistula CEUS combined with transrectal 360° 3-D imaging has significantly higher accuracy than conventional TRUS in the diagnosis of complex anal fistula, especially for anal fistula branches, internal openings and Parks classification and is beneficial in reducing post-operative occurrence of complex anal fistulas.

The value of multiparametric MRI and transrectal ultrasound fusion guided biopsy in the detection of clinical significant prostate cancer

Objective To evaluate the application of multiparametric MRI (mpMRI)-transrectal ultrasound (TRUS) fusion guided biopsy in the diagnosis of clinical significant prostate cancer (PCa). Methods A prospective analysis was performed in 168 patients with suspected PCa from September 2015 to June 2017 in the First Affiliated Hospital of Soochow University. Suspicious areas on mpMRl were defined and graded using prostate imaging reporting and data system version 2 (PI-RADS V2) score. All the patients had the TRUS-guided systematic biopsy, 108 patients with PI-RAD V2 scores ≥ 3 had additional MRI-TRUS targeted biopsies. Taking pathologic results as golden standard, the detection rates were compared between the 2 methods using χ2 test. Results Initially, all of the 168 patients underwent TRUS biopsy. PCa was detected in 86 (101 niduses) of 168 patients (51.19%, 86/168), 82 (91 niduses) (48.81%, 82/168) were not prostate cancer. Seventy eight (46.43%, 78/168) cases of PCa were detected by TRUS biopsy, and 63 (58.33%, 63/168) cases of PCa were detected by MRI-TRUS fusion guided biopsy, the difference was statistically significant between TRUS biopsy and MRI-TRUS fusion guided biopsy (χ2=3.73, P=0.035). The 168 patients were biopsied with a total of 2 300 cores, including TRUS biopsy 2 016 cores and MRI-TRUS fusion targeted biopsy 284 cores. Additionally, the detection rate for per cores for MRI-TRUS fusion targeted biopsy (51.76%, 147/284) was significantly higher than that for TRUS biopsy cores (19.64%, 396/2 016) (χ2=142.38,P<0.05). Among patients with a positive biopsy for PCa, the biopsy cores for conventional TRUS biopsy was 1 032 comparing to 214 cores for MRI-TRUS biopsy. The suspicious MRI-TRUS fusion targeted biopsy (68.69%, 147/214) detected more PCa compared with TRUS biopsy (38.37%, 396/1 032) (χ2=66.27, P<0.05). Among patients with a positive biopsy for PCa, MRI-TRUS fusion targeted biopsy [69.74% (106/152)] detected more significant cancer cores than TRUS biopsy [54.50% (351/644) ] (χ2=11.67, P<0.05). Conclusion MRI-TRUS fusion biopsy combined with PI-RADS V2 increases positive rate markedly and improves the detection rate of clinical significant PCa. Key words: Prostate neoplasms; Magnetic resonance imaging; Transrectal ultrasound

Application Value of Transrectal Shear Wave Elastography Mode Combined with Elastic Modulus in the Diagnosis of Prostate Cancer

Objective To explore the value of trans-rectal shear wave elastic mode combined with elastic modulus in the diagnosis of prostate cancer and establish a new method for the evaluation of prostate with trans-rectal shear wave elastography(SWE). Methods The typical findings of trans-rectal ultrasound(US)and SWE in 79 patients with prostate cancer(n=41)and benign prostatic hyperplasia(BPH)(n=38)confirmed by surgery or US-guided biopsy were analyzed retrospectively.Their diagnostic value were evaluated with the pathological results as the golden standards. Results Three or more malignant features detected by conventional trans-rectal US(χ 2=42.5,P<0.001)and asymmetrical SWE mode(χ 2=54.2,P<0.001)showed statistically significant difference in prostate cancer and BPH groups.The elastic modulus of Emean and Emax in the prostate cancer group were(92.8±21.5)and(114.2±29.8)kPa,which were significantly higher than those in the BPH group [(56.7±14.0)(t=-8.8,P<0.001)and(68.4±17.2)kPa(t=-8.3,P<0.001)].The receiver-operating characteristic(ROC)curve with Logistic regression showed that the elastic model combined elastic modulus had the largest area under ROC curve and the highest diagnosis efficiency of prostate cancer,with the cutoff value of 0.45.The diagnosis sensitivity,specificity,positive predictive value,negative predictive value,and accuracy of the combination were 95.1%,89.5%,90.7%,94.4%,and 92.4%,respectively. Conclusion Combination of SWE mode and elastic modulus is more valuable than elastic modulus alone in the diagnosis of prostate cancer.

Use of MRI-ultrasound Fusion to Achieve Targeted Prostate Biopsy.

Here, we present a protocol to perform targeted prostate biopsy using a magnetic resonance imaging-ultrasound (MRI/US) fusion system. Prostate cancer has traditionally been diagnosed via transrectal ultrasound (TRUS) biopsy. Though considered the gold standard, TRUS is unable to visualize most prostate cancer lesions and therefore requires sampling of the entire prostate. This biopsy method often undergrades prostate cancer and fails to detect up to 35% of cancers on initial biopsy. Prostate MRI has been shown to have excellent sensitivity in the detection of cancerous lesions, and advancements in MRI technology during the last decade have led to the development of targeted biopsy. In targeted biopsy, a software platform overlays MRI data onto live TRUS images to create a fused MRI/US three-dimensional model of the prostate. Regions suspicious for malignancy on MRI are contoured by a radiologist, uploaded into the fusion system, and then displayed within the live MRI/US fused model. The urologist is then able to directly biopsy these targets. When compared to conventional TRUS biopsy, MRI/US fusion technology has been demonstrated to improve the detection of clinically significant cancer while reducing insignificant cancer detection. This technology, therefore, has the potential to diagnose prostate cancer primarily in men who would benefit from treatment.

The utility and limitations of contrast-enhanced transrectal ultrasound scanning for the detection of prostate cancer in different area of prostate.

To evaluate the ability of contrast-enhanced transrectal ultrasound (CETRUS) scanning for prostate cancer detection in different area, compared with conventional transrectal ultrasound (TRUS). 228 patients underwent TRUS-guided prostate biopsy after examinations of TRUS and CETRUS scanning. Cancer detection between CETRUS and TRUS were compared by patient and by site in different areas (right, left; base, mid-gland, apex). The receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic performance of CETRUS. 89 patients were malignant and 48 patients were significant cancer. Compared with TRUS, CETRUS could increase the detection rates of overall and significant cancer (P = 0.008; P = 0.031). CETRUS had higher sensitivity, specificity (except right lobe), accuracy, positive predictive value (PPV) and negative predictive value (NPV) in total, right and left lobe (P < 0.05). The sensitivity were greater for CETRUS in all areas except left base and right apex (P < 0.05). The accuracy were greater for CETRUS in all areas except left mid-gland and right apex (P < 0.05). ROC analysis showed CETRUS totally got the AUC of 0.816. The AUC was higher in left lobe than right lobe (0.837 vs. 0.793). It was most accurate at the base (0.833), then mid-gland (0.826), and lowest in apex (0.772). CETRUS had a significant advantage over conventional TRUS for prostate cancer detection in different areas. CETRUS much more easily missed the cancer in apex, we must focus more on apex and may add other imaging modalities to improve the visualization and detection of prostate cancer.

Control analysis of fusion images of dynamic contrast-enhanced MRI with transrectal ultrasound and conventional transcrectal ultrasound in prostate biopsy for prostate cancer

Objective To evaluation the value of fusion images of dynamic contrast enhanced MRI (DCE MRI) with transrectal ultrasound(TRUS) and conventional TRUS in prostate biopsy for prostate cancer.Methods The clinical data of 127 patients suspected as early-stage prostate cancer were retrospectively analyzed.79 patients underwent prostate biopsy guided by conventional TRUS(group A).48 patients underwent prostate biopsy guided by fusion images of DCE MRI with TRUS(group B).Then the diagnostic rates,puncture times and complications in the two groups were compared.Results The cases with confirmed prostate cancer were 31 in group A and 22 in group B.The first time diagnostic rates of biopsy were 20.2％(16/79) in group A,and 39.3％ (19/48) in group B respectively(P ＜0.05).The first time sensivity,specifity,positive predictive value and negative predictive value of biopsy were 51.6 ％,100 ％,100％,77.4％ in group A and 86.3％,100％,100％,89.6％ in group B.Puncture times was 15.40 ± 4.67 and 13.01 ± 3.87 respectively.The Gleason score was 6.21 ± 0.91 and 6.35 ± 0.81 respectively.The complication rates were 19.0％(15/79) in group A and 12.5％(6/48)in group B.Conclusions For patients with earlystage prostate cancer,the combination of DCE-MRI and TRUS to guide transrectal prostate biopsy was recommended.It showed an increase in the first time diagnostic rate of biopsy while a reduction in the times and complications of prostated biopsy. Key words: Endosonography; Magnestic resonance imaging ; Prostatic neoplasm ; Biopsy, needle

Innovations in diagnostic imaging of localized prostate cancer

In recent years, various imaging modalities have been developed to improve diagnosis, staging, and localization of early-stage prostate cancer (PCa). A MEDLINE literature search of the time frame between 01/2007 and 06/2013 was performed on imaging of localized PCa. Conventional transrectal ultrasound (TRUS) is mainly used to guide prostate biopsy. Contrast-enhanced ultrasound is based on the assumption that PCa tissue is hypervascularized and might be better identified after intravenous injection of a microbubble contrast agent. However, results on its additional value for cancer detection are controversial. Computer-based analysis of the transrectal ultrasound signal (C-TRUS) appears to detect cancer in a high rate of patients with previous biopsies. Real-time elastography seems to have higher sensitivity, specificity, and positive predictive value than conventional TRUS. However, the method still awaits prospective validation. The same is true for prostate histoscanning, an ultrasound-based method for tissue characterization. Currently, multiparametric MRI provides improved tissue visualization of the prostate, which may be helpful in the diagnosis and targeting of prostate lesions. However, most published series are small and suffer from variations in indication, methodology, quality, interpretation, and reporting. Among ultrasound-based techniques, real-time elastography and C-TRUS seem the most promising techniques. Multiparametric MRI appears to have advantages over conventional T2-weighted MRI in the detection of PCa. Despite these promising results, currently, no recommendation for the routine use of these novel imaging techniques can be made. Prospective studies defining the value of various imaging modalities are urgently needed.

Die Wertigkeit der Echtzeitelastographie in der Diagnostik des Prostatakarzinoms

Randomized biopsy sampling under transrectal ultrasound (TRUS) guidance is the gold standard for the diagnosis of prostate cancer. In addition improvements in the quality of conventional ultrasound, new methods that complement conventional TRUS are opening the door to earlier and better targeted diagnosis of prostate cancer. One of these new methods is sonoelastography. Its impact on prostate cancer diagnostics has not yet been fully investigated, but the number of publications on this new technique indicate increasing interest in it.

New Technical Improvements for TRUS in the Diagnosis of Prostate Cancer

Objectives: Together with the aging population the incidence of prostate cancer (Pca) is still increasing. For the detection of Pca the PSA blood test, digital rectal examination (DRE), and transrectal ultrasound (TRUS) are frequently used methods. TRUS has an important role in diagnosing Pca. However, the low specificity and sensitivity of conventional grayscale TRUS have made it into a volume measuring and biopsy-guiding tool. Methods: A Medline literature search on transrectal ultrasound was performed and relevant articles were reviewed. Results: New ultrasound techniques were introduced to overcome the limitations of conventional grayscale TRUS. In this paper, an overview of developments in TRUS with 3D, Doppler, contrast, intermittent, harmonic, and pulse inversion techniques along with possibilities for future development are discussed. Conclusions: The underlying principles and methods are discussed briefly and clinical results published in recent literature are presented.

Contrast-enhanced three-dimensional power doppler angiography of the human prostate: correlation with biopsy outcome

Objectives. To determine the feasibility of contrast-enhanced three-dimensional (3D) imaging of the prostatic vasculature using power Doppler imaging and to analyze whether semiquantitative judgments of 3D images with respect to symmetry and distribution of vascular structures correlated with biopsy outcome. Methods. 3D power Doppler images were obtained before and after intravenous administration of 2.5 g Levovist. Subsequently, random and/or directed transrectal ultrasound (TRUS)-guided biopsies were performed. Vascular images were analyzed by two experts. Prostate vasculature was judged with respect to symmetry and vessel distribution using a (scale) grading system. Results. Eighteen patients with a suspicion of prostate cancer either because of an elevated prostate-specific antigen (greater than 4.0 ng/mL; Tandem-R-assay) or an abnormal digital rectal examination were included in the study. Prostate cancer was detected in 13 patients. Vascular anatomy was judged abnormal in unenhanced images in 6 cases, of which 5 proved malignant. Enhanced images were considered suspicious for malignancy in 12 cases, including 1 benign and 11 malignant biopsy results. Sensitivity of enhanced images was 85% (specificity 80%) compared with 38% for unenhanced images (specificity 80%) and 77% for conventional gray-scale TRUS (specificity 60%). Of 6 patients who showed no B-mode abnormalities, vascular patterns were judged abnormal in 4 cases, of which 3 were malignant. Conclusions. Contrast-enhanced 3D power Doppler angiography is feasible in patients with suspicion of prostate cancer who are scheduled for prostate biopsies. The sensitivity of power Doppler 3D imaging for the detection of prostate malignancy increased from 38% (5 of 13) to 85% (11 of 13) after administration of intravascular microbubble contrast (Levovist), and specificity was found to be 80% (4 of 5) for both imaging modalities. Thus, the use of Levovist when combined with the power Doppler display mode and 3D image reconstruction offers a promising new research area that might prove useful in prostate cancer detection in the future.

Artificial neural network analysis (ANNA) of prostatic transrectal ultrasound.

Our purpose was to determine the diagnostic potential of a new, computerized method of interpreting transrectal ultrasound (TRUS) information by artificial neural network analysis (ANNA). This method was developed to resolve the current dilemma of visual differentiation between benign and malignant tissue on TRUS. To train and objectively evaluate ANNA, a new precise method of computerized virtual correlation of preoperative ultrasound findings and radical prostatectomy histopathology was devised. After training with this pathologically confirmed digitized TRUS information, ANNA was tested in a blinded study. Following radical prostatectomy, 289 pathology whole-mount sections of 61 patients were correlated digitally with the corresponding TRUS slices. Specific selection of TRUS areas unequivocally identified on the correlated digitized pathohistology resulted in 553 pathology-confirmed representations (samples). Of these, 53 were used for training and 500 were subjected to blind analysis by ANNA. ANNA classified 378 (99%) of the 381 benign pathology-confirmed samples correctly as benign. The false-positive rate was 1% (n = 3). Of the 119 pathology-confirmed malignant samples, 94 (79%) were classified correctly; 25 (21%) were falsely classified as normal. Out of all 119 cancers, ANNA classified 60 (71%) of the hypoechoic cancers as malignant and 24 (29%) as benign. Surprisingly, 34 (97%) of the isoechoic cancers were correctly classified by ANNA, missing only one sample. The introduction of ANNA enhanced the accuracy of TRUS prostate cancer identification. Although not all malignant areas were detected, cancer was detected in each patient. The ability to detect isoechoic cancerous lesions appears to be the essential innovation over conventional TRUS interpretation.

Three‐dimensional ultrasound imaging of the prostate

Prostate cancer is the most commonly diagnosed cancer in men in North America. Since its introduction in 1971, transrectal ultrasound (TRUS) has evolved into one of the primary tools for the evaluation of prostate disease. However, with conventional TRUS, diagnosticians must mentally integrate a series of 2D images in order to develop an impression of the 3D anatomy, and the accurate and precise estimation of prostate volume is difficult. Moreover, an examination takes 10–20 min, often resulting in patient discomfort. We propose using 3D TRUS to overcome these problems. In this thesis, we describe a 3D ultrasound imaging system, analyze the distortion in its images due to miscalibration, and study its performance in estimating prostate volume. Our system consists of three elements: (i) a conventional ultrasound machine and TRUS probe; (ii) a custom‐built assembly for rotating the probe under microcomputer control; and (iii) a microcomputer with an 8‐bit video frame grabber. A typical scan of 200 2D B‐mode images takes 13 s, so that the entire examination takes under 5 min. These images can then be rapidly reconstructed into a 3D image using an algorithm we describe, and interactively displayed using standard software. Also, we describe procedures for accurately calibrating the reconstruction parameters, so that distortions in the shape, length, area, and volume of the 3D image of an object are all less than 1%. We also show that manual planimetry of 3D TRUS images can be used to estimate prostate volumes in vitro with 2.6% accuracy and 2.5% precision, and in vivo with 5.1% intra‐observer variability and 11.4% inter‐observer variability. By comparison, with the height‐width‐length method (Volume=π/6HWL) with conventional 2D TRUS images, in vivo estimates had 11.5% intra‐observer variability and 13.5% inter‐observer variability. Thus 3D TRUS overcomes some of the limitations of 2D TRUS, and has great potential as a tool for the diagnosis, study, and management of prostate disease.