MRI-guided Biopsy Research Articles

Tumour-Targeted Treatment Intensification for Prostate Cancer Using Magnetic Resonance Imaging Guidance

IntroductionLocal control in prostate cancer may be improved with targeted dose escalation to regions with high tumour burden. Multiparametric magnetic resonance imaging (mpMRI) combined with MRI-guided biopsies may aid in defining tumour-dense regions before radiation therapy. Deformable registration techniques may be used to map these tumour regions onto the radiotherapy planning MRI. Radiation therapy delivery techniques such as volumetric modulated arc therapy and high-dose-rate brachytherapy may allow for highly conformal dose escalation, and when coupled with image-guided radiation delivery (ie, cone beam computed technology and fiducial markers), may allow high-precision dose-escalated treatment. MethodsEligible prostate cancer patients were enrolled on a prospective trial of tumour dose escalation. Two strategies were investigated: (1) an integrated boost to external beam radiation for a total tumour dose of 95 Gy in 38 fractions or (2) a focal high-dose-rate boost of 10 Gy before 76 Gy in 38 fractions external beam radiation. Patients underwent MRI-guided biopsy with fiducial marker placement before therapy. mpMRI was acquired and used in conjunction with a non-endorectal coil T2 MRI and computed technology simulation images to define the gross tumour volume via a deformable registration approach for intraprostatic tumour dose escalation. ResultsA case example for each dose escalation strategy illustrates the tumour-targeted approach using MRI guidance. ConclusionsCombining mpMRI sequences with a deformable registration approach may aid in more accurate and reproducible definition of tumour-dense regions. This novel process coupled with daily image guidance may allow high-precision dose-escalated tumour-targeted radiotherapy for prostate cancer.

A survey by the European Society of Breast Imaging on the utilisation of breast MRI in clinical practice

ObjectivesWhile magnetic resonance imaging (MRI) is considered a helpful diagnostic tool in breast imaging, discussions are ongoing about appropriate protocols and indications. The European Society of Breast Imaging (EUSOBI) launched a survey to evaluate the utilisation of breast MRI in clinical practice.MethodsAn online survey reviewed by the EUSOBI board and committees was distributed amongst members. The questions encompassed: training and experience; annual breast MRI and MRI-guided-intervention workload; examination protocols; indications; reporting habits and preferences. Data were summarised and subgroups compared using χ2 test.ResultsOf 647 EUSOBI members, 177 (27.4%) answered the survey. The majority were radiologists (90.5%), half of them based in academic centres (51.9%). Common indications for MRI included cancer staging, treatment monitoring, high-risk screening and problem-solving, and differed significantly between countries (p≤0.03). Structured reporting and BI-RADS were mostly used. Breast radiologists with ≤10 years of experience preferred inclusion of additional techniques, such as T2/STIR (p=0.03) and DWI (p=0.08) in the scan protocol. MRI-guided interventions were performed by a minority of participants (35.4%).ConclusionsThe utilisation of breast MRI in clinical practice is generally in line with international recommendations. There are substantial differences between countries. MRI-guided interventions and functional MRI parameters are not widely available.Key points• MRI is commonly used for the detection and characterisation of breast lesions.• Clinical practice standards are generally in line with current recommendations.• Standardised criteria and diagnostic categories (mainly BI-RADS) are widely adopted.• Younger radiologists value additional techniques, such as T2/STIR and DWI.• MRI-guided breast biopsy is not widely available.

Does magnetic resonance imaging-guided biopsy improve prostate cancer detection? A comparison of systematic, cognitive fusion and ultrasound fusion prostate biopsy.

BackgroundThe increase in the use of multiparametric magnetic resonance imaging for the detection of prostate cancer has led to the rapid adoption of MRI-guided biopsies (MRGBs). To date, there is limited evidence in the use of MRGB and no direct comparisons between the different types of MRGB. We aimed to assess whether multiparametric MRGBs with MRI-US transperineal fusion biopsy (FB) and cognitive biopsy (CB) improved the management of prostate cancer and to assess if there is any difference in prostate cancer detection with FB compared with CB.MethodsPatients who underwent an MRGB and a systematic biopsy (SB) from June 2014 to August 2016 on the Central Coast, NSW, Australia, were included in the study. The results of SB were compared with MRGB. The primary outcome was prostate cancer detection and if MRGB changed patient management.ResultsA total of 121 cases were included with a mean age of 65.5 years and prostate-specific antigen 7.4 ng/mL. Seventy-five cases (62%) had a Prostate Imaging and Reporting Data System 4–5 lesions and 46 (38%) had a Prostate Imaging and Reporting Data System 3 lesions. Fifty-six cases underwent CB and 65 underwent FB.Of the 93 patients with prostate cancer detected, 19 men (20.5%) had their management changed because of the MRGB results. Eight men (9%) had prostate cancer detected on MRGB only and 12 men (13%) underwent radical prostatectomy or radiotherapy based on the MRGB results alone.There was a trend to a higher rate of change in management with FB compared with CB (29% vs. 18%).ConclusionsThis is one of the first Australian studies to assess the utility of MRGB and compare FB with CB. MRGB is a useful adjunct to SB, changing management in over 20% of our cases, with a trend toward FB having a greater impact on patient management compared with CB.

Magnetic resonance imaging of the prostate and targeted biopsy, Comparison of PIRADS and Gleason grading.

Multiparametric magnetic resonance imaging (mpMRI) of the prostate has become integral in the investigation of suspected prostate cancer. Regions of interest are graded using the PIRADS scoring system, and in our institution, lesions graded as PIRADS 3-5 undergo sampling by MRI-guided biopsy. Limited data currently exists on PIRADS grading and biopsy results. Retrospective review of 343 MRI-guided biopsies (MRGB) performed between April 2013 and December 2016 was conducted. This included patients irrespective of whether they were biopsy naïve, biopsy negative or known low-grade malignancy. A Gleason score (G) >= 3+4 was considered to reflect clinically significant disease (CSD). Of the 18 PIRADS 2 cases (at referrer request) who went to biopsy, 16 were negative and two had small volume Gleason 6 cancer. A total of 75 PIRADS 3 cases were biopsied with 88% negative or small volume Gleason 6 cancer, only 12% yielded ≥ G 3+4. Of the 133 PIRADS 4 lesions, 24% were negative, 25% were G6 and 51% were ≥ G 3+4. A total of 117 PIRADS 5 cases were biopsied with 7% negative, 13% Gleason 6 and 80% considered significant (≥ G 3+4). Of all biopsies, 230 (67%) had a positive result (≥G6) with 171 of these (75%) being considered CSD, with overall CSD of 50% (171/343). This paper demonstrates the incidence of CSD for different PIRADS grades. The low incidence of CSD in PIRADS 3 lesions suggests that in low clinical risk men, follow up in priority to biopsy may be an alternative treatment pathway.

Early Adoption of MRI-Guided Prostate Biopsies Rose Rapidly among Men with Private Health Insurance

Early Adoption of MRI-Guided Prostate Biopsies Rose Rapidly among Men with Private Health Insurance

Is breast magnetic resonance imaging (MRI) useful for diagnosis of additional sites of disease in patients recently diagnosed with pure ductal carcinoma in situ (DCIS)?

PurposeTo determine if breast MRI is useful for detecting additional or invasive sites of disease in patients initially diagnosed with pure DCIS. Materials and methodsA retrospective review of women diagnosed with pure DCIS who underwent a breast MRI for evaluation of extent of disease was performed at a single institution from January 2013 to April 2015. Data analysis included imaging (mammography, ultrasound and MRI) and pathology characteristics (histology and biomarker status) of the primary DCIS as well as descriptors for the additional sites of disease incidentally found by breast MRI. ResultsA total of 108 patients were diagnosed with pure DCIS during this time period. A breast MRI for staging was recommended for all patients. 76 patients had an MRI performed, ages ranging from 38 to 79 years old (median, 53 years); sizes ranging from 0.3 to 10cm (mean, 2.2cm). A total of 52 patients (68%) either had suspicious new finding(s) (n=27, 36%) or bigger tumor size than originally visualized on mammography (n=43, 57%). A total of twenty-seven patients (36%) had other MRI findings suspicious for additional sites of disease in either breast (four in the ipsilateral breast and twenty-three in the contralateral breast). From this group of patients, twenty-three (85%) patients underwent MRI-guided biopsy as recommended. The four patients who did not have the recommended MRI guided-biopsy either underwent total mastectomies or refused the biopsy. Six out of the twenty-three patients (26%) were diagnosed with an additional site of cancer (5 DCIS and 1 IDC) (7.9%, CI=3.7%, 16.2%). All of the six patients had contralateral disease (100%) and none had a second site of disease in the ipsilateral breast. The size of the additional sites of disease ranged from 0.4 to 8cm (mean, 3.1cm) and the size of the primary lesion in this selected group ranged from 0.1 to 10.9cm (mean, 5.6cm). Ages ranged from 44 to 63 years old (median, 52.5 years). Five out 6 patients (83%) presented with the first site of disease as pure DCIS with estrogen (ER) and progesterone (PR) receptors positive and one case (17%) was pure DCIS ER/PR- negative. The second incidental lesion found on MRI demonstrated 5 cases of contralateral pure DCIS and 1 case of contralateral invasive disease. From this group, we did not have the data for biomarker analysis for the second site of disease in 2 cases and 3 cases showed concordant biomarker status between the first and second sites of disease. The 1 case that presented with an invasive component in the contralateral side of the initially biopsy-proven pure DCIS had discordant biomarkers compared to the first site of disease: the first site of pure DCIS was ER/PR-negative and the second site of invasive ductal carcinoma (IDC) presented with ER/PR-positive status. ConclusionFrom a total of 76 patients with recent diagnosis of pure DCIS who underwent staging breast MRI examination for diagnosis of additional sites of disease, approximately 8% (95% confidence interval=3.7%, 16.2%) was diagnosed with an additional site of cancer and 1.3% (95% confidence interval=0.2%, 7%) of the total cases had invasive disease in the additional sites with different biomarker status; changing their management and prognosis.

Current Utilization and Acceptance of Multiparametric MRI in the Diagnosis of Prostate Cancer. A Regional Survey.

To assess the current regional acceptance, valuation, and clinical role of multiparametric MRI (mp-MRI) in prostate cancer diagnostics by patients and physicians. Of 482 distributed standardized questionnaires, 328 patient and 31 physician questionnaires (urological and general practitioners in and around Düsseldorf) were analyzed over a period of 11 months. Questions were asked concerning general knowledge about prostate cancer, current diagnostic procedures, and knowledge about mp-MRI and MRI-guided biopsy. 70 % of the patients regarded accurate and exact diagnostics of prostate carcinomas as very important and 68 % considered MP-MRI a useful technique. 28 % of the patients with elevated PSA levels and negative transrectal ultrasound-guided biopsy (TRUS-GB) received MP-MRI as a secondary diagnostic. More than half of the patients estimated their overall knowledge about prostate cancer mediocre or worse and wished for more information about MR diagnostics. The majority of physicians (55 %) ordered MP-MRI studies of the prostate and 68 % saw their basic role in secondary diagnostics. In this regional assessment mp-MRI of the prostate was considered useful by patients and practitioners. Currently, there still is a considerable discrepancy between recommended and the actual number of conducted MP-MRI studies, particularly in patients after previous negative TRUS-GB, although practitioners already see the benefit in this patient collective. Even though the use of prostate MRI is frequently more established than suggested in the current German S3-guideline, its full potential has not yet been exploited. More comprehensive information about the applications and diagnostic benefits of prostate MRI is needed and desired among patients and physicians. · The use of prostate MRI is frequently more established than suggested in the current German S3-guideline (12/2016). · The full potential of mp-MRI of the prostate has not been exploited. · More information about the clinical benefit and potential of prostate MRI is necessary and desired by patients and clinicians. · Ullrich T, Schimmöller L, Oymanns M et al. Current Utilization and Acceptance of Multiparametric MRI in the Diagnosis of Prostate Cancer. A Regional Survey. Fortschr Röntgenstr 2018; 190: 419 - 426.

Lesion characteristics, histopathologic results, and follow-up of breast lesions after MRI-guided biopsy.

We aimed to assess the effectiveness of magnetic resonance imaging (MRI)-guided vacuum-assisted breast biopsy (VABB), evaluate and compare the characteristics and histopathologic findings of lesions, and overview the follow-up results of benign lesions. MRI findings and histopathologic results of breast lesions biopsied by MRI-guided VABB between 2013 and 2016 were retrospectively analyzed. MRI findings closely related with malignancy were investigated in particular. Follow-up results of benign lesions were evaluated. MRI-guided VABB was applied to 116 lesions of 112 women. Of the lesions, 75 (65%) were benign, while 41 (35%) were malignant. Segmental (94%), clustered (89%), and clustered ring (67%) non-mass-like enhancement patterns were found to be more related with malignancy. False-negative rate of MRI-guided VABB was 12%, underestimation rate was 21%. One of the 54 followed-up benign lesions had a malignant result. MRI-guided VABB is a reliable method for the diagnosis of breast lesions that are positive only on MRI. Follow-up results show that cancer detection rate is low for radio-pathologically concordant lesions. Further multicenter studies with larger patient population are needed to elucidate these results.

Retrospective comparison of direct in-bore magnetic resonance imaging (MRI)-guided biopsy and fusion-guided biopsy in patients with MRI lesions which are likely or highly likely to be clinically significant prostate cancer

PurposeTo compare clinically significant prostate cancer (csPCa) detection rates between magnetic resonance imaging (MRI)–transrectal ultrasound (TRUS) fusion-guided prostate biopsy (FGB) and direct in-bore MRI-guided biopsy (MRGB).MethodsWe performed a comparison of csPCa detection rates between FGB and MRGB. Included patients had (1) at least one prior negative TRUS biopsy; (2) a Prostate Imaging Reporting and Data System (PI-RADS) 4 or 5 lesion and (3) a lesion size of ≥8 mm measured in at least one direction. We considered a Gleason score ≥7 being csPCa. Descriptive statistics with 95% confidence intervals (CI) were used to determine any differences.ResultsWe included 51 patients with FGB (59 PI-RADS 4 and 41% PI-RADS 5) and 227 patients with MRGB (34 PI-RADS 4 and 66% PI-RADS 5). Included patients had a median age of 69 years (IQR, 65–72) and a median PSA level of 11.0 ng/ml (IQR, 7.4–15.1) and a median age of 67 years (IQR, 61–70), the median PSA 12.8 ng/ml (IQR, 9.1–19.0) within the FGB and the MRGB group, respectively. Detection rates of csPCA did not differ significantly between FGB and MRGB, 49 vs. 61%, respectively.ConclusionWe did not detect significant differences between FGB and MRGB in the detection of csPCa. The differences in detection ratios between both biopsy techniques are narrow with an increasing lesion size. This study warrants further studies to optimize selection of best biopsy modality.

Where Do Transrectal Ultrasound- and Magnetic Resonance Imaging-guided Biopsies Miss Significant Prostate Cancer?

To identify the location of missed significant prostate cancer (sPCa) lesions by transrectal ultrasound-guided biopsy (TRUSbx) and multiparametric magnetic resonance imaging-guided biopsy (mpMRIbx) in men undergoing repeat biopsies. A total of 289 men with prior negative TRUSbx underwent multiparametric magnetic resonance imaging. The location of any suspicious lesion was registered and scored using Prostate Imaging Reporting and Data System version 1 classification according to the likelihood of being sPCa. All patients underwent repeat transrectal ultrasound-guided biopsy (reTRUSbx) and targeted mpMRIbx (image fusion) of any suspicious lesion. Biopsy results were compared and the locations of missed sPCa lesions were registered. Cancer significance was defined as (1) any core with a Gleason score of >6, (2) cancer core involvement of ≥50% and for reTRUSbx on patient level, and (3) the presence of ≥3 positive cores. Of the 289 patients, prostate cancer was detected in 128 (44%) with 88 (30%) having sPCa. Overall, 165 separate prostate cancer lesions were detected with 100 being sPCa. Of these, mpMRIbx and reTRUSbx detected 90% (90/100) and 68% (68/100), respectively. The majority of sPCa lesions (78%) missed by primary TRUSbx were located either anteriorly or in the apical region. Missed sPCa lesions at repeat biopsy were primarily located anteriorly (84%) for reTRUSbx (n = 27/32) and posterolateral midprostatic (60%) for mpMRIbx (n = 6/10). Both TRUSbx and mpMRIbx missed sPCa lesions in specific segments of the prostate. Missed sPCa lesions at repeat biopsy were primarily located anteriorly for TRUSbx and posterolateral midprostatic for mpMRIbx. Localization of these segments may improve biopsy techniques in men undergoing repeat biopsies.

Comparison of Biopsy Results and Surgical Outcomes of Magnetic Resonance Imaging-Guided and Transrectal Ultrasonography-Guided Repeat Biopsy

Purpose We compared biopsy results and surgical outcomes of magnetic resonance imaging (MRI)-guided biopsy with transrectal ultrasonography (TRUS)-guided biopsy to demonstrate efficacy of MRI-guided biopsy on previous biopsy negative patients. Materials and Methods We retrospectively reviewed data of 120 patients who were categorized into MRI-guided biopsy groups (n=20) and TRUS-guided biopsy groups (n=100). All patients were diagnosed with prostate cancer (PCa) and had undergone radical prostatectomy (RP) after MRI-guided or TRUS-guided repeat biopsy between January 2010 and March 2016. Detection rate of significant cancer and Gleason score upgrading and downgrading were examined, in addition to biopsy results and subsequent RP outcomes. Results Median values for prostate-specific antigen level of the TRUS-guided biopsy group and the MRI-guided biopsy group were 6.67 and 5.86 ng/mL (p=0.303), respectively. Median prostate volume of each group (34.1 mL vs. 23.5 mL, p=0.007), number of positive cores (2.0 vs. 3.0, p=0.001) and maximum cancer/core rate (30.0% vs. 60.0%, p<0.001) were statistically different. Positive core rates of each group were 21.9% and 87.1%, respectively. Pathologic T stage was the only variable that showed difference in surgical outcomes (p=0.002). Most of PCa was confirmed as clinically significant PCa after RP in MRI-guided biopsy group (95%). Conclusions MRI-guided biopsy showed higher positive core rate and detection rate of clinically significant PCa than TRUS-guided biopsy in repeat biopsy setting. Prospective multicenter large-scale study and accumulation of data is expected to further define superiority of the MRI-guided biopsy. Key Words: Prostatic neoplasms; Repeat biopsy; Magnetic resonance imaging; Transrectal ultrasonography; Outcomes.

The Positive Outcome of MRI-Guided Vacuum Assisted Core Needle Breast Biopsies Is Not Influenced by a Prior Negative Targeted Second-Look Ultrasound

PurposeThe study sought to investigate the outcome of breast magnetic resonance–guided biopsies as a function of the indication for magnetic resonance imaging (MRI), the MRI features of the lesions, and the performance or not of a targeted second-look ultrasound (SLUS) prior breast MRI-guided biopsy. MethodsWe identified 158 women with MRI-detected breast lesions scheduled for MRI-guided biopsy (2007-2013). Patient demographics, performance of targeted SLUS, imaging characteristics, and subsequent pathology results were reviewed. ResultsThree biopsies were deferred, and 155 lesions were biopsied under MRI guidance (155 women; median age 55.14 years; range 27-80 years). Ninety-eight women underwent a SLUS prior to the MRI-guided biopsy (63%). Of the 155 biopsied lesions, 23 (15%) were malignant, 106 (68%) were benign, and 26 (17%) were high risk. Four of 15 surgically excised high-risk lesions were upgraded to malignancy (27%). Most of the biopsied lesions corresponded to non–mass-like enhancement (81%, 126 of 155) and most of the biopsies (52%, 81 of 155) were performed in a screening context. No demographic or MRI features were associated with malignancy. No differences were noted between the 2 subgroups (prior SLUS vs no prior SLUS) except for the presence of a synchronous carcinoma associated with a likelihood of targeted SLUS before MRI-guided biopsy (P = .001). ConclusionA negative SLUS does not influence the pathology outcome of a suspicious lesion biopsied under MR guidance.

Pathologic Findings of Breast Lesions Detected on Magnetic Resonance Imaging.

- Breast magnetic resonance imaging (MRI) is now used routinely for high-risk screening and in the evaluation of the extent of disease in newly diagnosed breast cancer patients. Morphologic characteristics and the kinetic pattern largely determine how suspicious a breast lesion is on MRI. Because of its high sensitivity, MRI identifies a large number of suspicious lesions. However, the low to moderate specificity and the additional cost have raised questions regarding its frequent use. - To identify the pathologic entities that frequently present as suspicious enhancing lesions and to identify specific MRI characteristics that may be predictive of malignancy. - One hundred seventy-seven MRI-guided biopsies from 152 patients were included in the study. The indication for MRI, MRI features, pathologic findings, and patient demographics were recorded. The MRI findings and the pathology slides were reviewed by a dedicated breast radiologist and breast pathologists. - Seventy-one percent (126 of 177) of MRI-guided breast biopsies were benign, 11% (20 of 177) showed epithelial atypia, and 18% (31 of 177) showed malignancy. The vast majority (84%; 62 of 74) of MRI lesions with persistent kinetics were benign. However, 57% (17 of 30) of lesions with washout kinetics and 65% (62 of 95) of mass lesions were also benign. - Magnetic resonance imaging detects malignancies undetected by other imaging modalities but also detects a wide variety of benign lesions. Benign and malignant lesions identified by MRI share similar morphologic and kinetic features, necessitating biopsy for histologic confirmation.

Prostate cancer: in-bore magnetic resonance guided biopsies at active surveillance inclusion improve selection of patients for active treatment.

Background Active surveillance (AS) of low-risk prostate cancer (PCa) is an accepted alternative to active treatment. However, the conventional diagnostic trans-rectal ultrasound guided biopsies (TRUS-bx) underestimate PCa aggressiveness in almost half of the cases, when compared with the surgical specimen. Purpose To investigate if additional multi-parametric magnetic resonance imaging (mpMRI) of the prostate and MRI-guided in-bore biopsies (MRGB) at AS inclusion would improve selection of patients for active treatment. Material and Methods All patients enrolled in AS programs at two Danish centers, from October 2014 to January 2016, were offered an mpMRI 8-12 weeks after the initial diagnostic TRUS-bx. Candidates had low-risk disease (PSA < 10 ng/mL, <cT2b, Gleason score [GS] < 7). Prostate lesions were scored on the five-point PIRADS scale (version 1 and 2). MRGB were performed on PIRADS 4 or 5 lesions. Significant cancer was defined as GS > 6 or GS 6 (3 + 3) lesions with ≥ 6 mm maximal cancer core length (MCCL). Results A total of 78 patients were included and in 21 patients a total of 22 PIRADS-score 4 or 5 lesions were detected. MRGB pathology revealed that 17 (81%) of these and 22% of the entire AS population harbored significant cancers at AS inclusion. In eight (38%) cases, the GS was upgraded. Also, nine patients (43%) had GS 6 (3 + 3) foci with MCCL ≥ 6 mm. Conclusion In an AS cohort based on TRUS and TRUS-bx diagnostic strategies, supplemental mpMRI and in-bore MRGB were able to efficiently reclassify a substantial number of patients as candidates for immediate active treatment.

What is the yield of breast MRI in the assessment of palpable breast findings?

To examine the contribution of magnetic resonance imaging (MRI) to characterise palpable breast masses after conventional imaging was found to be non-contributory. The breast MRI database was reviewed for studies performed between January 2010 and December 2015 for the clinical indication of palpable breast finding with negative standard imaging. Medical files were reviewed for demographic data, clinical information, radiology, and pathology reports. Benign versus malignant outcomes were determined at histopathology or a minimum of 12 month follow-up. Investigation of palpable breast finding was the clinical indication for 167 of 7,782 (2%) examinations. Thirty-two (19%) women in the study had positive MRI findings. Most (20, 63%) findings corresponded to the palpable area, resulting in three carcinomas being diagnosed. Only one carcinoma required MRI-guided biopsy for diagnosis. Eighteen women with negative MRI underwent ultrasound-guided biopsy from the palpable area, which resulted in a diagnosis of one carcinoma. One carcinoma was incidentally detected in another location. Within the present population, the sensitivity for detecting malignancy was 80%, specificity 78%, negative predictive value 99%, and positive predictive value 13%. Although cancer was found in four cases in the palpable area, the biopsy was directed using MRI in only one case. A new palpable finding with non-contributory standard imaging should prompt a needle-guided biopsy and not further evaluation using MRI.

MR-guided Percutaneous Biopsy of Focal Hepatic Dome Lesions with Free-hand Combined with MR Fluoroscopy Using 1.0-T Open High-field Scanner.

To prospectively estimate the safety, feasibility and accuracy of 1.0T open-magnetic resonance (MR)-guided percutaneous biopsy in free-hand of focal lesions located in the hepatic dome. All percutaneous MR-guided biopsies of the lesions were performed at the Shandong Medical Imaging Research Institute. Thirty-six patients with focal liver lesions located in the hepatic dome measuring 6-36 mm in the maximum diameter were included in this study. Lesions were divided into two groups on the basis of maximum nodule diameters: ≤1.5 cm (n=14) and >1.5 cm (n=22). Surgical pathology of nodules or clinical and imaging follow-up for at least 12 months were used to establish final diagnosis. Diagnostic accuracy, specificity, sensitivity, average procedure time and complications were recorded and analyzed. All obtained samples were sufficient for diagnosis. Accuracy, sensitivity and specificity of MRI-guided percutaneous liver lesions biopsy in diagnosing malignant tumors were 97.2%, 96.7% and 100%, respectively. Accuracy, sensitivity and specificity were 92.9%, 90.9% and 100% for the lesions that were 1.5 cm or smaller in diameter and 100%, 100% and 100% for lesions larger than 1.5 cm in diameter, respectively. There was no significant difference between the two groups (p>0.05). The average procedure time for each pass of the needle from skin entry to the target lesion was 1.1 min and the total procedural time was 28.5 min. Biopsy-induced complications included peri-hepatic hemorrhage in 8.3% (3/36) of cases. No serious complications occurred. 1.0T open-MR-guided free-hand percutaneous biopsy is a safe, feasible and highly accurate diagnostic method for pathological diagnosis of focal liver lesions located in the hepatic dome.

Safety and Feasibility of Direct Magnetic Resonance Imaging-guided Transperineal Prostate Biopsy Using a Novel Magnetic Resonance Imaging-safe Robotic Device

To evaluate safety and feasibility in a first-in-human trial of a direct magnetic resonance imaging (MRI)-guided prostate biopsy using a novel robotic device. MrBot is an MRI-safe robotic device constructed entirely with nonconductive, nonmetallic, and nonmagnetic materials and developed by our group. A safety and feasibility clinical trial was designed to assess the safety and feasibility of a direct MRI-guided biopsy with MrBot and to determine its targeting accuracy. Men with elevated prostate-specific antigen levels, prior negative prostate biopsies, and cancer-suspicious regions (CSRs) on MRI were enrolled in the study. Biopsies targeting CSRs, in addition to sextant locations, were performed. Five men underwent biopsy with MrBot. Two men required Foley catheter insertion after the procedure, with no other complications or adverse events. Even though this was not a study designed to detect prostate cancer, biopsies confirmed the presence of a clinically significant cancer in 2 patients. On a total of 30 biopsy sites, the robot achieved an MRI-based targeting accuracy of 2.55 mm and a precision of 1.59 mm normal to the needle, with no trajectory corrections and no unsuccessful attempts to target a site. Robot-assisted MRI-guided prostate biopsy appears safe and feasible. This study confirms that a clinically significant prostate cancer (≥5-mm radius, 0.5 cm3) depicted in MRI may be accurately targeted. Direct confirmation of needle placement in the CSR may present an advantage over fusion-based technology and gives more confidence in a negative biopsy result. Additional study is warranted to evaluate the efficacy of this approach.

Revised PROPELLER for T2-weighted imaging of the prostate at 3 Tesla: impact on lesion detection and PI-RADS classification.

To evaluate revised PROPELLER (RevPROP) for T2-weighted imaging (T2WI) of the prostate as a substitute for turbo spin echo (TSE). Three-Tesla MR images of 50 patients with 55 cancer-suspicious lesions were prospectively evaluated. Findings were correlated with histopathology after MRI-guided biopsy. T2 RevPROP, T2 TSE, diffusion-weighted imaging, dynamic contrast enhancement, and MR-spectroscopy were acquired. RevPROP was compared to TSE concerning PI-RADS scores, lesion size, lesion signal-intensity, lesion contrast, artefacts, and image quality. There were 41 carcinomas in 55 cancer-suspicious lesions. RevPROP detected 41 of 41 carcinomas (100%) and 54 of 55 lesions (98.2%). TSE detected 39 of 41 carcinomas (95.1%) and 51 of 55 lesions (92.7%). RevPROP showed fewer artefacts and higher image quality (each p < 0.001). No differences were observed between single and overall PI-RADS scores based on RevPROP or TSE (p = 0.106 and p = 0.107). Lesion size was not different (p = 0.105). T2-signal intensity of lesions was higher and T2-contrast of lesions was lower on RevPROP (each p < 0.001). For prostate cancer detection RevPROP is superior to TSE with respect to motion robustness, image quality and detection rates of lesions. Therefore, RevPROP might be used as a substitute for T2WI. • Revised PROPELLER can be used as a substitute for T2-weighted prostate imaging. • Revised PROPELLER detected more carcinomas and more suspicious lesions than TSE. • Revised PROPELLER showed fewer artefacts and better image quality compared to TSE. • There were no significant differences in PI-RADS scores between revised PROPELLER and TSE. • The lower T2-contrast of revised PROPELLER did not impair its diagnostic quality.

Post-clip placement MRI following second-look US-guided core biopsy for suspicious lesions identified on breast MRI.

To evaluate whether the post-clip placement MRI following second-look ultrasound (US)-guided core biopsy is useful to confirm the adequate sampling of suspicious lesions identified on breast MRI. Between 2014 and 2016, 31 consecutive women with 34 suspicious lesions that had not been identified on previous mammography or US were detected using MRI. Among them, 26 women with 29 lesions (mean size 1.5cm, range 0.5-5.8cm) found by second-look US underwent US-guided biopsy, subsequent clip insertion and post-clip placement MRI. Five women with five lesions that were not found by second-look US underwent MRI-guided biopsy. The technical success rate and lesion characteristics were described. The technical success rate was 96.6% (28/29). One failure case was a benign, 1.1-cm non-mass enhancement. Of the 28 success cases, 23 (82.1%) were masses and 5 (17.9%) were non-mass enhancements; 17 (60.7%) were benign, 4 (14.3%) were high-risk and 7 (25.0%) were malignant lesions. The technical success rate was 100% (28/28) for masses and 83.3% (5/6) for non-mass enhancements. Post-clip placement MRI following US-guided biopsy is useful in confirming the adequate sampling of lesions identified on MRI. This method could be an alternative to MRI-guided biopsy for lesions visible on US. • Post-clip MRI is useful for confirming adequate sampling of US-guided biopsy. • Post-clip MRI following US-guided biopsy revealed a 96.6 % technical success rate. • One technical failure case was a benign, 1.1-cm non-mass enhancement. • The technical success rate of US-guided biopsy for non-mass enhancements was 83.3 %.

Developing a Compact Robotic Needle Driver for MRI-Guided Breast Biopsy in Tight Environments

In this letter, we present the design and development of a new robotic system for MRI-guided breast biopsy. The robot's structure is nonmagnetic, therefore, it can safely operate from within the scanner's magnetic bore; it has a compact Cartesian mechanism that allows it perform needle insertion tasks from both frontal and lateral directions inside an open bore scanner. A combination of piezoelectric and pneumatic actuators drive the motion of the proposed three degrees-of-freedom robot. To control the needle's insertion, we present an adaptive position regulator that uses the feedback from multiple sensors and that is robust to external disturbances. A detailed experimental study is presented to validate the performance and magnetic properties of the new mechanical prototype.