US Fusion Research Articles

Automatic rigid image Fusion of preoperative MR and intraoperative US acquired after craniotomy

BackgroundNeuronavigation of preoperative MRI is limited by several errors. Intraoperative ultrasound (iUS) with navigated probes that provide automatic superposition of pre-operative MRI and iUS and three-dimensional iUS reconstruction may overcome some of these limitations. Aim of the present study is to verify the accuracy of an automatic MRI – iUS fusion algorithm to improve MR-based neuronavigation accuracy.MethodsAn algorithm using Linear Correlation of Linear Combination (LC2)-based similarity metric has been retrospectively evaluated for twelve datasets acquired in patients with brain tumor. A series of landmarks were defined both in MRI and iUS scans. The Target Registration Error (TRE) was determined for each pair of landmarks before and after the automatic Rigid Image Fusion (RIF). The algorithm has been tested on two conditions of the initial image alignment: registration-based fusion (RBF), as given by the navigated ultrasound probe, and different simulated course alignments during convergence test.Results Except for one case RIF was successfully applied in all patients considering the RBF as initial alignment. Here, mean TRE after RBF was significantly reduced from 4.03 (± 1.40) mm to (2.08 ± 0.96 mm) (p = 0.002), after RIF. For convergence test, the mean TRE value after initial perturbations was 8.82 (± 0.23) mm which has been reduced to a mean TRE of 2.64 (± 1.20) mm after RIF (p < 0.001).ConclusionsThe integration of an automatic image fusion method for co-registration of pre-operative MRI and iUS data may improve the accuracy in MR-based neuronavigation.

MP55-11 PSMA-GUIDED PROSTATE BIOPSY

You have accessJournal of UrologyCME1 Apr 2023MP55-11 PSMA-GUIDED PROSTATE BIOPSY David Kuppermann, Jeremie Calais, Elizabeth Tran, Samantha Gonzalez, Merdie Delfin, and Leonard Marks David KuppermannDavid Kuppermann More articles by this author , Jeremie CalaisJeremie Calais More articles by this author , Elizabeth TranElizabeth Tran More articles by this author , Samantha GonzalezSamantha Gonzalez More articles by this author , Merdie DelfinMerdie Delfin More articles by this author , and Leonard MarksLeonard Marks More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003308.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PSMA scanning is a most accurate method for detection of metastatic PCa. PSMA scanning may also reveal intra-prostatic cancer (PCa). Since MRI-guided biopsy (MRGB) may miss 15-20% of clinically-significant csPCa (≥GG2), we postulated that biopsy targeting PSMA foci in the prostate (PSMA-guided biopsy, PSMA-GB) might provide PCa detection in cases where MRGB failed. METHODS: 48 men with negative MRI-guided biopsy (MRGB), but continued suspicion of PCa (increased PSA density), underwent PSMA scanning within 6 months of MRGB. In the 23 with focal PSMA uptake in the prostate, a PSMA-GB was performed using PET/CT images instead of MR images for fusion with ultrasound. 4-8 biopsy cores were taken from each PSMA ‘hot spot’(Figure 1). Method of PSMA-GB was identical to MRGB, but employed US fusion with PET/CT instead of MRI, as detailed in the original case report (PMID: 28607878). Method of Ga-PSMA image acquisition via PET/CT scanning has been reported (PMID: 30920593). Contouring of PSMA foci within the prostate was via Profuse software by co-author J.C. Image fusion and trans-rectal targeted biopsy was via Artemis device (LSM). Detection rate of csPCa by PSMA-GB was primary endpoint. RESULTS: Among the 23 study patients, mean age=67 yrs (Range: 53-81); prostate volume=58.5cc (22.7-109.3); PSA=13.8 ng/ml (4.5- 34.8); PSA density=0.245 ng/ml/cc (0.073- 0.57). At first biopsy (MRGB), PIRADS score = 0-2 in 19 men and >3 in 4. PSMA-GB was successfully completed in all 23. Overall detection rate of csPCa was 15/23 (65.22%): GG2 in 6, GG3 in 6, GG4 in 2, and GG5 in 1. Median SUVmax (standardized uptake value) was 12.5 (5.8-28.7) in men whose PSMA hotspot revealed csPCa vs 5.8 (3.2-10.4) in men with negative PSMA-GB. Of 12 men whose PSMA focus was highly suspicious, i.e., Emmett’s Primary Score of 4 or 5 (PMID: 34373749 ), 11 had csPCa. CONCLUSIONS: Prostate biopsy, which targets PSMA ‘hot spots’ via PET/CT-US fusion, often leads to detection of csPCa missed by MRI-guided biopsy. Source of Funding: Jean Perkins Foundation; NCI-R01 CA 195505; and Department of Nuclear Medicine, UCLA. © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e767 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information David Kuppermann More articles by this author Jeremie Calais More articles by this author Elizabeth Tran More articles by this author Samantha Gonzalez More articles by this author Merdie Delfin More articles by this author Leonard Marks More articles by this author Expand All Advertisement PDF downloadLoading ...

Image Fusion Involving Real-Time Transabdominal or Endoscopic Ultrasound for Gastrointestinal Malignancies: Review of Current and Future Applications.

Image fusion of CT, MRI, and PET with endoscopic ultrasound and transabdominal ultrasound can be promising for GI malignancies as it has the potential to allow for a more precise lesion characterization with higher accuracy in tumor detection, staging, and interventional/image guidance. We conducted a literature review to identify the current possibilities of real-time image fusion involving US with a focus on clinical applications in the management of GI malignancies. Liver applications have been the most extensively investigated, either in experimental or commercially available systems. Real-time US fusion imaging of the liver is gaining more acceptance as it enables further diagnosis and interventional therapy of focal liver lesions that are difficult to visualize using conventional B-mode ultrasound. Clinical studies on EUS guided image fusion, to date, are limited. EUS-CT image fusion allowed for easier navigation and profiling of the target tumor and/or surrounding anatomical structure. Image fusion techniques encompassing multiple imaging modalities appear to be feasible and have been observed to increase visualization accuracy during interventional and diagnostic applications.

A duct-dimension-regulation approach for eliminating MHD PbLi flow reversal in buoyancy-opposed poloidal duct relevant for typical liquid breeder blanket designs

Lithium-lead (PbLi) flow plays the major roles: removing nuclear heating, breeding tritium and multiplying neutrons, in the appeared typical liquid breeder blanket designs for magnetically confined fusion reactors. Under the buoyancy effect caused by the volumetric nuclear heating with large gradient in the radial direction, flow reversals can be generated in the magnetohydrodynamic (MHD) PbLi flow in the poloidal downward-flow duct(s) of such blanket designs, which may import negative consequences to the functionality of the breeder blanket. Based on a theory regarding mixed convection in fully developed MHD duct flows developed by Smolentsev et al. (Smolentsev, Moreau & Abdou, Characterization of key magnetohydrodynamic phenomena in PbLi flows for the US DCLL blanket, Fusion Engineering and Design 83, 771-783, 2008), this study attempts to further quantitatively analyze the above-mentioned flow-reversal issues, and in the meantime to develop an approach to eliminate the reverse flow regime by regulation of the duct dimensions. Numerical simulations are performed for buoyancy-opposed MHD duct flows of PbLi in order to demonstrate the effectiveness of the proposed duct-dimension-regulation approach on eliminating the occurrence of reverse flows. It is found that, in the reverse flow regime, the reversal structures travel to the downstream from their onset locations at a speed essentially equal to the mean flow velocity in the bulk; the reverse flow regime can be effectively eliminated by regulating the duct dimensions. Comprehensive discussions about the reverse flow related issues in the DCLL type blanket are then stressed.

HTS Cable Conductor for Compact Fusion Tokamak Solenoids

Significant progress has been made recently in the US fusion community to develop a strategic plan to enable engineering design and construction of a fusion pilot plant (FPP). Princeton Plasma Physics Laboratory (PPPL) is working on developing high current density HTS conductors for next fusion experiments. Partnering with the US industry, we are evaluating feasibility and affordability of Conductor on Round Core (CORC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${}^\circledR$</tex-math></inline-formula> ) developed by Advanced Conductor Technologies (ACT) for the next compact fusion tokamak facility. High current density achieved by a CORC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${}^\circledR$</tex-math></inline-formula> cable based on a four-layer model coil recently tested at National High Magnetic Field Laboratory (NHMFL) motivated its consideration for low cost, reduced size fusion magnet application. This is of interest to PPPL because of its scalability to tokamak central solenoid (CS) coils in terms of required flux swings for plasma startup operations. Partnering with ACT, we designed and built a two-layer model coil solenoid directly wound with CORC to demonstrate its applicability for compact solenoids such as that used in the national spherical torus experiment (NSTX), NSTX-upgrade (NSTX-U) and the US sustained high-power density test facility (SHPD). The ∼160 mm diameter solenoid wound by a two-layer CORC is being tested in early 2022 under electromagnetic cyclic loading at NHMFL in a unique 160 mm bore, 14 T background field magnet facility.

Ultrasound fusion imaging system in neurology practice.

The ultrasound fusion imaging (UFI) system is a new promising imaging modality that combines live ultrasound investigations with preregistered CT, MRI, or PET images. In this study, we want to present our initial experience with the new method that combines the transcranial color-coded sonography (TCCS) in different insonation planes and the 3T-weighted MRI cerebral images. The study validates the diagnostic capabilities of the system to detect different normal cerebral structures in healthy volunteers. In the present paper, we also discuss the advantages of US fusion imaging technology and its clinical applications in Neurology.

Contribution of Dynamic Contrast-enhanced and Diffusion MRI to PI-RADS for Detecting Clinically Significant Prostate Cancer.

Background Prostate Imaging Reporting and Data System (PI-RADS) version 2.0 requires multiparametric MRI of the prostate, including diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) imaging sequences; however, the contribution of DCE imaging remains unclear. Purpose To assess whether DCE imaging in addition to apparent diffusion coefficient (ADC) and normalized T2 values improves PI-RADS version 2.0 for prediction of clinically significant prostate cancer (csPCa). Materials and Methods In this retrospective study, clinically reported PI-RADS lesions in consecutive men who underwent 3-T multiparametric MRI (T2-weighted, DWI, and DCE MRI) from May 2015 to September 2016 were analyzed quantitatively and compared with systematic and targeted MRI-transrectal US fusion biopsy. The normalized T2 signal (nT2), ADC measurement, mean early-phase DCE signal (mDCE), and heuristic DCE parameters were calculated. Logistic regression analysis indicated the most predictive DCE parameters for csPCa (Gleason grade group ≥2). Receiver operating characteristic parameter models were compared using the Obuchowski test. Recursive partitioning analysis determined ADC and mDCE value ranges for combined use with PI-RADS. Results Overall, 260 men (median age, 64 years [IQR, 58-69 years]) with 432 lesions (csPCa [n = 152] and no csPCa [n = 280]) were included. The mDCE parameter was predictive of csPCa when accounting for the ADC and nT2 parameter in the peripheral zone (odds ratio [OR], 1.76; 95% CI: 1.30, 2.44; P = .001) but not the transition zone (OR, 1.17; 95% CI: 0.81, 1.69; P = .41). Recursive partitioning analysis selected an ADC cutoff of 0.897 × 10-3 mm2/sec (P = .04) as a classifier for peripheral zone lesions with a PI-RADS score assessed on the ADC map (hereafter, ADC PI-RADS) of 3. The mDCE parameter did not differentiate ADC PI-RADS 3 lesions (P = .11), but classified lesions with ADC PI-RADS scores greater than 3 with low ADC values (less than 0.903 × 10-3 mm2/sec, P < .001) into groups with csPCa rates of 70% and 97% (P = .008). A lesion size cutoff of 1.5 cm and qualitative DCE parameters were not defined as classifiers according to recursive partitioning (P > .05). Conclusion Quantitative or qualitative dynamic contrast-enhanced MRI was not relevant for Prostate Imaging Reporting and Data System (PI-RADS) 3 lesion risk stratification, while quantitative apparent diffusion coefficient (ADC) values were helpful in upgrading PI-RADS 3 and PI-RADS 4 lesions. Quantitative ADC measurement may be more important for risk stratification than current methods in future versions of PI-RADS. © RSNA, 2022 Online supplemental material is available for this article See also the editorial by Goh in this issue.

MP09-20 PROSTATE BIOPSY TARGETED TO PROSTATE SPECIFIC MEMBRANE ANTIGEN (PSMA) FOCI

You have accessJournal of UrologyCME1 May 2022MP09-20 PROSTATE BIOPSY TARGETED TO PROSTATE SPECIFIC MEMBRANE ANTIGEN (PSMA) FOCI David Kuppermann, Jeremie Calais, Wayne Brisbane, Elizabeth Tran, Lorna Herbert, Matthias Benz, Johannes Czernin, and Leonard Marks David KuppermannDavid Kuppermann More articles by this author , Jeremie CalaisJeremie Calais More articles by this author , Wayne BrisbaneWayne Brisbane More articles by this author , Elizabeth TranElizabeth Tran More articles by this author , Lorna HerbertLorna Herbert More articles by this author , Matthias BenzMatthias Benz More articles by this author , Johannes CzerninJohannes Czernin More articles by this author , and Leonard MarksLeonard Marks More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002531.20AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PSMA PET imaging is the most accurate imaging method known for detection of metastatic PCa. PSMA PET may also reveal intra-prostatic cancer. 68Ga-PSMA scanning was approved by FDA in December 2020 for pre-op staging of PCa and to detect possible recurrence. MRI-guided biopsy (MRGB) is the preferred method for diagnosis of prostate cancer (PCa), but PCa may be MRI-invisible (≈15-20%). Herein we study intra-prostatic PSMA focal uptake as a target for biopsy detection of PCa using PET/CT-US fusion (PSMA-guided biopsy, PSMA-GB). METHODS: In a prospective trial, 13 men underwent PSMA PET/CT imaging prior to fusion biopsy at UCLA. Subjects are men with negative prior biopsy (10 MRGB), but continued clinical suspicion of PCa and focal uptake of PSMA in the prostate. Method of PSMA-GB is identical to MRGB (PMID 26749141) but employs US fusion with PET/CT instead of MRI, as detailed previously (PMID: 28607878). Method of Ga-PSMA image acquisition via PET/CT scanning has been reported (PMID: 30920593). Contouring of intra-prostatic foci of PSMA positivity was via Profuse software by co-author J.C. Image fusion & trans-rectal targeted biopsy was via Artemis device (LSM). Detection rate of csPCa ( >GG2) by PSMA-GB was primary endpoint. RESULTS: To date, 13 men have completed study. Median age=71 yrs.; prostate volume=27.7 cc (IQR 22.1, 38.3); PSA density=0.25 ng/ml/cc (IQR 0.10, 0.45 PSMA-GB was successfully completed in all 13 with no more difficulty than usual MRI-GB. Overall detection rate was 9/13 (70%): GG2 in 1, GG3 in 6, and GG4 in 2. Max Cancer Core Length was 4 mm median (IQR 3, 9). 4 PSMA foci were anterior; all 4 contained csPCa. Median SUVmax (standardized uptake value) was 6 in PSMA lesions returning <GG1 findings vs 8.2 in men with csPCa. Median PSAD (density) was higher in men with csPCa (0.25) than others (0.20). Of 5 men with prior radiation, 4 had csPCa on PSMA-GB. CONCLUSIONS: Prostate biopsy, which targets PSMA “hot spots” via PET/CT-US fusion, may lead to detection of clinically significant cancers missed by MRI-guided biopsy. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e144 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information David Kuppermann More articles by this author Jeremie Calais More articles by this author Wayne Brisbane More articles by this author Elizabeth Tran More articles by this author Lorna Herbert More articles by this author Matthias Benz More articles by this author Johannes Czernin More articles by this author Leonard Marks More articles by this author Expand All Advertisement PDF DownloadLoading ...

Radiofrequency ablation using real-time ultrasonography-computed tomography fusion imaging improves treatment outcomes for T1a renal cell carcinoma: Comparison with laparoscopic partial nephrectomy.

PurposeTo determine whether real-time ultrasonography–computed tomography (US-CT) fusion imaging can improve technical feasibility versus B-mode US and provide comparable outcomes of radiofrequency ablation (RFA) for T1a renal cell carcinoma (RCC) compared with laparoscopic partial nephrectomy (LPN).Materials and MethodsBetween June 2013 and August 2016, biopsy- or pathologically confirmed stage T1a RCCs were retrospectively reviewed. Of these, 39 cases were included in the RFA group, and 46 cases were included in the LPN group. In the RFA group, we evaluated tumor visibility and technical feasibility before RFA on a four-point scale on B-mode US and US-CT fusion images. After RFA, hospital days, creatinine value, complications, and disease-free survival rate were compared between the two groups. All results were analyzed by use of the Mann–Whitney U-test and Kaplan–Meier method.ResultsCompared with B-mode US alone, real-time US-CT fusion significantly improved the tumor visibility score and overall mean technical feasibility grade (p<0.001). The 5-year disease-free survival rate was 97.4% and 97.8% in the RFA and LPN groups, respectively, and there was no statistically significant difference between groups (p=0.1). Mean periprocedural creatinine levels were significantly lower in the RFA group than in the LPN group. The number of hospital days was shorter in the RFA group. Minor complications were present in 5.1% of the RFA group and 13.0% of the LPN group, with no major complications.ConclusionsUS-CT fusion-image-guided RFA improved tumor visibility scores and overall mean technical validity and resulted in a comparable disease-free survival rate to LPN.

Design window for open-surface lithium divertor with helium-cooled substrate

This study for an open-surface flowing lithium (Li) divertor with a thin helium-cooled substrate includes a scaling analysis, numerical computations and an analytical solution to access the design window for a low vaporization divertor option where the maximum temperature at the Li free surface is limited to 450 °C. Three heat removal regimes were identified in the scaling analysis and then accessed in numerical computations: convection-dominated, diffusion-dominated and convection-diffusion. Of them, convection-dominated regime, in which all applied heat flux is removed by a high velocity Li layer, offers the highest heat removal capability. For a generic divertor, a high surface heat flux of 10 MW/m2 can be removed with the Li flowing at 7.3 m/s. Under the conditions of the US Fusion Nuclear Science Facility (FNSF), the required Li velocities are 6.5 m/s for the inner leg, and 15 m/s for the outer leg. The obtained analytical solutions for the diffusion-dominated regime, where the incident heat flux is removed by helium, suggests the lowest of the three regimes heat removal capability in the range of 0.5–1.2 MW/m2.

Systematic biopsy should not be omitted in the era of combined magnetic resonance imaging/ultrasound fusion-guided biopsies of the prostate

To evaluate prostate cancer detection rates with classical trans-rectal ultrasound-guided systematic 10-core biopsies (SB), targeted biopsies (TB) guided by magnetic resonance (MR)/US fusion imaging and their combination in biopsy-naïve and patients with previously negative prostate biopsies. We compared pathology results after radical prostatectomy with biopsy findings. Consecutive patients with prostate imaging-reporting and data system lesions grade ≥ 3 submitted to MRI/US-guided TB and subsequent standard 10-core SB between December 2015 and June 2019 were analyzed. Detection rate (TB- or SB-positive) in 563 included patients (192 naïve, 371 with previous biopsies) was 56.7% (67.7% for the first, 50.9% for repeated biopsies). With TB (disregarding SB), the rates were 41.4%, 52.1% and 35.8%, respectively. With SB (disregarding TB), the rates were 49.1%, 63.0% and 41.8%, respectively. Eventually, 118 patients underwent surgery and clinically significant cancer was found in 111 (94.1%) specimens. Of those, 23 (20.7%) would have been missed had we relied upon a negative TB and 14 (12.6%) would have been missed had we relied upon a negative SB, disregarding a positive finding on the alternative biopsy template. SB should not be omitted since TB and SB combination have higher detection rate of clinically relevant prostate cancer than either procedure alone.

Segmentation of the Prostate Transition Zone and Peripheral Zone on MR Images with Deep Learning.

Purpose To develop a deep learning model to delineate the transition zone (TZ) and peripheral zone (PZ) of the prostate on MR images. Materials and Methods This retrospective study was composed of patients who underwent a multiparametric prostate MRI and an MRI/transrectal US fusion biopsy between January 2013 and May 2016. A board-certified abdominal radiologist manually segmented the prostate, TZ, and PZ on the entire data set. Included accessions were split into 60% training, 20% validation, and 20% test data sets for model development. Three convolutional neural networks with a U-Net architecture were trained for automatic recognition of the prostate organ, TZ, and PZ. Model performance for segmentation was assessed using Dice scores and Pearson correlation coefficients. Results A total of 242 patients were included (242 MR images; 6292 total images). Models for prostate organ segmentation, TZ segmentation, and PZ segmentation were trained and validated. Using the test data set, for prostate organ segmentation, the mean Dice score was 0.940 (interquartile range, 0.930-0.961), and the Pearson correlation coefficient for volume was 0.981 (95% CI: 0.966, 0.989). For TZ segmentation, the mean Dice score was 0.910 (interquartile range, 0.894-0.938), and the Pearson correlation coefficient for volume was 0.992 (95% CI: 0.985, 0.995). For PZ segmentation, the mean Dice score was 0.774 (interquartile range, 0.727-0.832), and the Pearson correlation coefficient for volume was 0.927 (95% CI: 0.870, 0.957). Conclusion Deep learning with an architecture composed of three U-Nets can accurately segment the prostate, TZ, and PZ. Keywords: MRI, Genital/Reproductive, Prostate, Neural Networks Supplemental material is available for this article. © RSNA, 2021.

Gleason Grade Group Concordance between Preoperative Targeted Biopsy and Radical Prostatectomy Histopathologic Analysis: A Comparison Between In-Bore MRI-guided and MRI-Transrectal US Fusion Prostate Biopsies.

To determine and compare rates of grade group (GG) discrepancies between different targeted biopsy techniques (in-bore vs fusion) after propensity score weighting using whole-mount radical prostatectomy (RP) histopathologic analysis as the reference standard. This retrospective study evaluated men who underwent targeted (fusion or in-bore) biopsy between April 2017 and January 2019 followed by prostatectomy. The primary endpoint of the study was a change in GG from biopsy to RP at a patient level. For downgrade and upgrade analysis, men with biopsy GG1 (downgrade not possible) and GG5 (upgrade not possible) were excluded, respectively. GG upgrade, downgrade, and concordance rates of each targeting approach were compared using propensity score weighting and logistic regression with inverse probability of treatment weighting. Significance level was set at .05. Index lesion GG on RP specimen served as the reference standard. A total of 191 men (90 in the in-bore [mean age, 63 years ± 7 (standard deviation)] and 101 in the fusion biopsy group [mean age, 65 years ± 7]) were eligible and included. Fewer GG upgrades were noted in the in-bore biopsy group (14%; 12 of 85) compared with the fusion plus systematic biopsy group (30%; 28 of 93) (P = .012). The incidence of GG downgrade in the in-bore group (25%; 21 of 84) was higher than in the fusion group (17%; 16 of 93); however, the difference was not statistically significant (P = .2). Of the 77 men misclassified by both biopsy techniques, the majority (56%, n = 43) had a change in GG of 2 to 3 or 3 to 2. Superior sampling accuracy with MRI-guided in-bore biopsies offers a lower incidence of GG upgrades compared with MRI-transrectal US fusion biopsies upon RP.Keywords: Biopsy/Needle Aspiration, MR-Imaging, Oncology, Pathology, Prostate Supplemental material is available for this article.© RSNA, 2021.

Quantitative Evaluation of an Automated Cone-Based Breast Ultrasound Scanner for MRI-3D US Image Fusion.

Breast cancer is one of the most diagnosed types of cancer worldwide. Volumetric ultrasound breast imaging, combined with MRI can improve lesion detection rate, reduce examination time, and improve lesion diagnosis. However, to our knowledge, there are no 3D US breast imaging systems available that facilitate 3D US - MRI image fusion. In this paper, a novel Automated Cone-based Breast Ultrasound System (ACBUS) is introduced. The system facilitates volumetric ultrasound acquisition of the breast in a prone position without deforming it by the US transducer. Quality of ACBUS images for reconstructions at different voxel sizes (0.25 and 0.50 mm isotropic) was compared to quality of the Automated Breast Volumetric Scanner (ABVS) (Siemens Ultrasound, Issaquah, WA, USA) in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and resolution using a custom made phantom. The ACBUS image data were registered to MRI image data utilizing surface matching and the registration accuracy was quantified using an internal marker. The technology was also evaluated in vivo. The phantom-based quantitative analysis demonstrated that ACBUS can deliver volumetric breast images with an image quality similar to the images delivered by a currently commercially available Siemens ABVS. We demonstrate on the phantom and in vivo that ACBUS enables adequate MRI-3D US fusion. To our conclusion, ACBUS might be a suitable candidate for a second-look breast US exam, patient follow-up, and US guided biopsy planning.

Additional Diagnostic Value of Fusion Imaging of CEUS and First CEUS of Invisible Hepatic Lesions ≤2 cm.

To explore the clinical value of image fusion of contrast-enhanced ultrasonography (CEUS) and contrast-enhanced computed tomography (CECT) in the diagnosis of invisible lesions with a size ≤2 cm on conventional ultrasound imaging, and compare it with the clinical value of "first CEUS" . A total of 132 patients with 147 lesions with abnormal blood supply with a size ≤2 cm on CECT were included in this study. "first CEUS" was performed for these lesions. Then "fusion CEUS," that is, CEUS administered after fusion of US and CECT images, was carried out. The detection rates of the "first CEUS" and "fusion CEUS" were compared. How "fusion CEUS" corrects the misdiagnosis of liver lesions on CECT was analyzed. One hundred nine lesions considered as HCC and 38 lesions considered as benign lesions on CECT were included. The detection rates for the lesions of "first CEUS" and "fusion CEUS" were 71.4% and 96.6%, respectively (P < 0.001). Among the 147 lesions, 68 were with a diameter ≤ 1 cm. The detection rate of "first CEUS" and "fusion CEUS" were 55.9% and 95.6%, respectively (P < 0.001) for the lesions with a size ≤1 cm. "Fusion CEUS" and "first CEUS" corrected the misdiagnosis in 2 lesions on CECT. The "first CEUS" and "fusion CEUS" can improve the lesion conspicuity. Compared with "first CEUS," "fusion CEUS" has a higher diagnostic ability and hence can detect most of the invisible lesions on the former.

PT430 - Utility of mpMRI/transrectal US fusion confirmatory biopsy in men with a previous diagnosis of prostate cancer amenable to active surveillance

PT430 - Utility of mpMRI/transrectal US fusion confirmatory biopsy in men with a previous diagnosis of prostate cancer amenable to active surveillance

Use of real-world clinical lab data to reveal Asian NTRK fusion test availability patterns.

e15574 Background: The development and launch of first-generation tropomyosin receptor kinase (TRK) inhibitors, such as larotrectinib and entrectinib, has brought targeted treatment options to neurotrophic tropomyosin-related kinase (NTRK) fusion–positive adult and pediatric cancer patients who may have been out of treatment options. Widespread adoption of NTRK fusion testing is needed to support successful selection of patients for these TRK inhibitors as well as other targeted therapies. The objective of this study was to investigate global availability of NTRK fusion testing, with a specific focus on Asia. Methods: For this study, real-world clinical pathology laboratory data, derived from Diaceutics’ proprietary Global Diagnostic Index (GDI) of more than 2500 labs, were investigated to assess the current footprint of NTRK fusion testing in Asia. Availability of clinical routine testing was analyzed in selected cohorts of laboratories across different regions, comparing Asia to the US and Europe. Laboratories were included based on their large volume of testing or on their importance (e.g., large academic and large commercial laboratories). Results: Data on availability of NTRK fusion testing by clinical laboratories reveal different patterns of NTRK fusion test adoption in Asia, depending on the region under study. In China and similarly in the US, Italy, and France clinical NTRK fusion testing is already being performed by the majority of laboratories from the selected cohort. In Japan, physicians have limited access to testing, with only a few laboratories from the selected cohort performing testing for NTRK fusions. Conclusions: NTRK fusion testing is essential for identifying patients eligible for first-generation TRK-inhibitors. Various laboratories across selected cohorts of labs in China and Japan lack the capability to initiate clinical NTRK fusion testing in-house, denying some patients the potential benefit from these breakthrough therapies. Consequently, patient outcomes will be suboptimal due to lack of testing infrastructure. The readiness of Asian markets to support patient selection successfully can affect the rate of testing and the impact of these innovative therapies on patients’ lives. [Table: see text]

Classification of Cancer at Prostate MRI: Deep Learning versus Clinical PI-RADS Assessment.

Background Men suspected of having clinically significant prostate cancer (sPC) increasingly undergo prostate MRI. The potential of deep learning to provide diagnostic support for human interpretation requires further evaluation. Purpose To compare the performance of clinical assessment to a deep learning system optimized for segmentation trained with T2-weighted and diffusion MRI in the task of detection and segmentation of lesions suspicious for sPC. Materials and Methods In this retrospective study, T2-weighted and diffusion prostate MRI sequences from consecutive men examined with a single 3.0-T MRI system between 2015 and 2016 were manually segmented. Ground truth was provided by combined targeted and extended systematic MRI-transrectal US fusion biopsy, with sPC defined as International Society of Urological Pathology Gleason grade group greater than or equal to 2. By using split-sample validation, U-Net was internally validated on the training set (80% of the data) through cross validation and subsequently externally validated on the test set (20% of the data). U-Net-derived sPC probability maps were calibrated by matching sextant-based cross-validation performance to clinical performance of Prostate Imaging Reporting and Data System (PI-RADS). Performance of PI-RADS and U-Net were compared by using sensitivities, specificities, predictive values, and Dice coefficient. Results A total of 312 men (median age, 64 years; interquartile range [IQR], 58-71 years) were evaluated. The training set consisted of 250 men (median age, 64 years; IQR, 58-71 years) and the test set of 62 men (median age, 64 years; IQR, 60-69 years). In the test set, PI-RADS cutoffs greater than or equal to 3 versus cutoffs greater than or equal to 4 on a per-patient basis had sensitivity of 96% (25 of 26) versus 88% (23 of 26) at specificity of 22% (eight of 36) versus 50% (18 of 36). U-Net at probability thresholds of greater than or equal to 0.22 versus greater than or equal to 0.33 had sensitivity of 96% (25 of 26) versus 92% (24 of 26) (both P > .99) with specificity of 31% (11 of 36) versus 47% (17 of 36) (both P > .99), not statistically different from PI-RADS. Dice coefficients were 0.89 for prostate and 0.35 for MRI lesion segmentation. In the test set, coincidence of PI-RADS greater than or equal to 4 with U-Net lesions improved the positive predictive value from 48% (28 of 58) to 67% (24 of 36) for U-Net probability thresholds greater than or equal to 0.33 (P = .01), while the negative predictive value remained unchanged (83% [25 of 30] vs 83% [43 of 52]; P > .99). Conclusion U-Net trained with T2-weighted and diffusion MRI achieves similar performance to clinical Prostate Imaging Reporting and Data System assessment. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Padhani and Turkbey in this issue.

SC41 - Utility of mpMRI/transrectal US fusion confirmatory biopsy in men with a previous diagnosis of prostate cancer amenable to active surveillance

SC41 - Utility of mpMRI/transrectal US fusion confirmatory biopsy in men with a previous diagnosis of prostate cancer amenable to active surveillance

Use of MRI-Guided Biopsy for Selection and Follow-up of Men Undergoing Hemi-gland Cryoablation of Prostate Cancer

To investigate safety, efficacy, and quality of life impact of hemi-gland cryotherapy for clinically-significant prostate cancer (CaP), when patient selection and follow-up includes MRI-guided biopsy. Twenty-nine men with unilateral CaP (all clinically significant with prostate volume <60 cc) were enrolled in a prospective observational trial of hemi-gland cryotherapy. Mean patient age was 68.7 years. Median prostate-specific antigen (PSA) was 6.6 ng/mL. MRI-guided biopsy (3T-MRI, Artemis US fusion) was used for diagnosis and repeated at 6-month follow-up in all men. Treatment was under general anesthesia using the BTG/Galil system. Validated questionnaires were used to determine effects of treatment on urinary and sexual function and quality of life. Cryotherapy was completed satisfactorily in all 29 cases in <60 minutes with no intraoperative complications. Significant decreases in PSA (median decrease 5.6 ng/mL) and PSA density (median decrease 0.14 ng/mL/cc) were observed (P < .01). At 6 months, 23 patients (79%) demonstrated no residual cancer on follow-up MRI-guided biopsy of the treated side. Three patients (10%) revealed micro-residual disease. Three patients (10%) had residual cancer and underwent further treatment. Ipsilateral MRI lesions were present before treatment in 26 patients and after treatment in only 2, reflecting the gross ablative effect; however, MRI showed disappearance of lesions in 4 patients with residual tumor on biopsy. The single complication was 1 case of transient urinary retention; 85% of men who were sexually active continued without change after treatment. Voiding function was unchanged. Hemi-gland cryoablation for clinically-significant CaP is well-tolerated, and when patients are selected and followed by MRI/US fusion biopsy, cancer control appears promising at 6 months.