A technique for MRI-guided transrectal deep pelvic abscess drainage

OBJECTIVE: The purpose of this article is to introduce a technique for transrectal drainage of deep pelvic abscesses performed under interactive MRI guidance. CONCLUSION: A new method for triorthogonal image plane MRI guidance was developed and used to interactively monitor the puncture needle on continuously updated sets of adjustable three-plane images. The merits and limitations of the technique are highlighted and the patient population that is likely to benefit from this approach is suggested.     

Determinants of complications after multiple transrectal core biopsies of the prostate

Transrectal ultrasound-guided biopsies of the prostate were performed on 347 consecutive men. All patients were given prophylactic antibiotics. The first 199 patients received 400 mg norfloxacin immediately after the biopsies were performed and 400 mg the same evening. The second group of 148 patients received 400 mg of norfloxacin 1 h before the examination followed by five doses administered twice daily. A total of 15 major complications were noted. In the first group the complication rate was 6.5% and in the second group 1.4%. The different regimes of prophylactic antibiotic treatment were the only parameters shown to have a statistically significant impact on the complication rate. The number of complications decreased, but were not eliminated, when prophylactic treatment with norfloxacin was given before the biopsies were taken and continued for a total of 3 days. Correspondence to: M. Norberg     

Inter-reader agreement of the ESUR score for prostate MRI using in-bore MRI-guided biopsies as the reference standard

Objectives

The recent European Society of Urogenital Radiology (ESUR) guidelines for evaluation and reporting of prostate multiparametric magnetic resonance imaging (mp-MRI) include the Prostate Imaging Reporting and Data System (PI-RADS). The aim of this study was to investigate the inter-reader agreement of this scoring system.

Methods

One hundred and sixty-four lesions in 67 consecutive patients with elevated prostate-specific antigen and previously negative trans-rectal ultrasound (TRUS)-guided biopsy were scored retrospectively by three blinded readers using PI-RADS. Mp-MRI was performed at 3 T using T2-weighted, diffusion-weighted and dynamic contrast-enhanced imagings (T2WI, DWI, DCE-MRI). Histology of all lesions was obtained by in-bore MRI-guided biopsy. Cohen’s kappa statistics were calculated for all readers.

Results

Inter-reader agreement for all lesions was good to moderate (T2WI, κ?=?0.55; DWI, κ?=?0.64; DCE-MRI, κ?=?0.65). For tumour lesions it was good (T2WI, κ?=?0.66; DWI, κ?=?0.80; DCE-MRI, κ?=?0.63) and for benign lesions moderate to good (T2WI, κ?=?0.46; DWI, κ?=?0.52; DCE-MRI, κ?=?0.67). Using an overall PI-RADS score with a threshold of ≥10, we achieved a sensitivity of 85.7 %, and negative predictive value of 90.1 % for biopsied lesions.

Conclusion

PI-RADS score shows good to moderate inter-reader agreement and enables standardised evaluation of prostate mp-MRI, with high sensitivity and negative predictive value.

Key Points

? The European Society of Urogenital Radiology recently published guidelines for prostate MRI. ? We have evaluated inter-reader agreement of ESUR scoring for multiparametric prostate MRI. ? PI-RADS shows good to moderate inter-reader agreement and is clinically applicable. ? PI-RADS achieves in our series high sensitivity and negative predictive value for biopsied lesions. ? PI-RADS can be used as standardised scoring system in prostate cancer detection.     

Transnasal and transsphenoidal MRI-guided biopsies of petroclival tumors

Magnetic resonance imaging (MRI) allows excellent tissue characterization in the area of the petroclival region and can depict lesions not visualized with ultrasound or computed tomography (CT). The aim of this study was to demonstrate the clinical feasibility and utility of an interactive MR-guidance system to target and biopsy tumors in the petroclival region. MRI-guided biopsies of 10 patients with tumors in the clivus and petrous apex were performed in an open 0.5-T MR system. Lesions were targeted through a transsphenoidal or transnasal approach. Imaging during biopsies was achieved by a combination of standard and interactive mode. T1-weighted spin-echo, T2-weighted fast spin-echo (FSE), and three-dimensional T1-weighted gradient-echo (GRE) scans (standard mode) were selected to provide optimal tissue characterization for both the lesion and surrounding structures and varied according to the anatomic site. For interactive imaging, T1-weighted GRE and T2-weighted FSE sequences were used. We performed MRI-guided transsphenoidal biopsies in 10 patients who had lesions identified by CT (n = 5) and/or MRI (n = 10). The indications for biopsies were to differentiate between suspected malignant processes (n = 4 ) and benign processes (n = 6). Lesions adjacent to structures like the internal carotid artery were accurately targeted in particular. All biopsies were performed successfully and were the basis for selection of further treatment. No complications occurred during the procedures. An open MR system allows interactive control of biopsies in the area of the petroclival region, providing maximum patient safety and diagnostic accuracy not possible in other systems. The advantages of MRI tissue characterization are combined with an interactive, one-step method of localization and targeting, as well as tissue sampling. J. Magn. Reson. Imaging 2001;13:3-11.     

Image registration for targeted MRI-guided transperineal prostate biopsy

Purpose:

To develop and evaluate image registration methodology for automated re‐identification of tumor‐suspicious foci from preprocedural MR exams during MR‐guided transperineal prostate core biopsy.

Materials and Methods:

A hierarchical approach for automated registration between planning and intra‐procedural T2‐weighted prostate MRI was developed and evaluated on the images acquired during 10 consecutive MR‐guided biopsies. Registration accuracy was quantified at image‐based landmarks and by evaluating spatial overlap for the manually segmented prostate and sub‐structures. Registration reliability was evaluated by simulating initial mis‐registration and analyzing the convergence behavior. Registration precision was characterized at the planned biopsy targets.

Results:

The total computation time was compatible with a clinical setting, being at most 2 min. Deformable registration led to a significant improvement in spatial overlap of the prostate and peripheral zone contours compared with both rigid and affine registration. Average in‐slice landmark registration error was 1.3 ± 0.5 mm. Experiments simulating initial mis‐registration resulted in an estimated average capture range of 6 mm and an average in‐slice registration precision of ±0.3 mm.

Conclusion:

Our registration approach requires minimum user interaction and is compatible with the time constraints of our interventional clinical workflow. The initial evaluation shows acceptable accuracy, reliability and consistency of the method. J. Magn. Reson. Imaging 2012;36:987–992. © 2012 Wiley Periodicals, Inc.     

Are transition zone biopsies necessary in transrectal ultrasound-guided transperineal prostate biopsy protocol? Results of a Chinese population-based study

PurposeThe purpose of this study was to determine the utility of routine transperineal transition zone (TZ) biopsies.Materials and MethodsA total of 1028 consecutive patients underwent transrectal ultrasound-guided prostate biopsies for the first time. Sextant biopsies and additional two-core TZ biopsies were performed.ResultsProstate cancer detection rate was increased by sampling two additional cores from TZ.ConclusionsTransition zone biopsies might be reserved to improve the detection rate of prostate cancer in transperineal biopsy protocol.     

Evaluation of localised prostate cancer: a comparative study of transrectal ultrasonography versus histopathology

Thirty-seven patients with prostate cancer were examined with transrectal ultrasound (TRUS) prior to radical prostatectomy, to assess the capacity of this method to detect, stage and determine the size of clinically localised prostate cancers. Hypoechoic lesions were interpreted as tumours. Prominent bulging of the prostate margin adjacent to a hypoechoic lesion was interpreted as extracapsular extension (ECE). Thirty-four patients underwent radical prostatectomy, while 3 patients with lymph node involvement were offered alternative treatment. Following formalin fixation, the specimens were whole-organ mounted. The tumours were measured for size and evaluated for grade, for ECE and for positive surgical margins. Tumour was demonstrated histologically in all 34 specimens. Of the 26 tumours detected by ultrasound, the largest tumour diameter was underestimated in 20 cases. A total of 18 tumours had a positive surgical margin and 9 others had complete ECE though the surgical margins were negative. Only 1 of the 27 ECEs was detected by TRUS. We conclude that a negative TRUS finding does not preclude the presence of a tumour. In this study, TRUS underestimated the size of the tumour and proved unreliable in detecting ECE, and is therefore considered to be of little use for preoperative staging.Correspondence to: M. Norberg     

Navigated MRI-guided liver biopsies in a closed-bore scanner: experience in 52 patients

Objectives

To evaluate clinical effectiveness and diagnostic efficiency of a navigation device for MR-guided biopsies of focal liver lesions in a closed-bore scanner.

Methods

In 52 patients, 55 biopsies were performed. An add-on MR navigation system with optical instrument tracking was used for image guidance and biopsy device insertion outside the bore. Fast control imaging allowed visualization of the true needle position at any time. The biopsy workflow and procedure duration were recorded. Histological analysis and clinical course/outcome were used to calculate sensitivity, specificity and diagnostic accuracy.

Results

Fifty-four of 55 liver biopsies were performed successfully with the system. No major and four minor complications occurred. Mean tumour size was 23?±?14 mm and the skin-to-target length ranged from 22 to 177 mm. In 39 cases, access path was double oblique. Sensitivity, specificity and diagnostic accuracy were 88 %, 100 % and 92 %, respectively. The mean procedure time was 51?±?12 min, whereas the puncture itself lasted 16?±?6 min. On average, four control scans were taken.

Conclusions

Using this navigation device, biopsies of poorly visible and difficult accessible liver lesions could be performed safely and reliably in a closed-bore MRI scanner. The system can be easily implemented in clinical routine workflow.

Key Points

? Targeted liver biopsies could be reliably performed in a closed-bore MRI. ? The navigation system allows for image guidance outside of the scanner bore. ? Assisted MRI-guided biopsies are helpful for focal lesions with a difficult access. ? Successful integration of the method in clinical workflow was shown. ? Subsequent system installation in an existing MRI environment is feasible.

     

经直肠和经会阴活检对前列腺癌诊断价值的Meta分析

 目的 系统性比较了经直肠(transrectal, TR)和经会阴(transperineal, TP)前列腺活检对于前列腺癌的诊断价值。方法 通过检索Pubmed、Embase、Web of science、知网和百度学术等数据库,筛选出直到2018-10的可用研究,并对纳入本研究的5篇文献进行Meta分析,计算95%的置信区间内合并的比值比,用来评估TR和TP在前列腺癌检出率方面的差异。本文共纳入了1561例患者,随机分为TR和TP组。结果 Meta分析显示,接受TP前列腺活检的患者与TR组比较,前列腺癌检出率没有显著改善 (OR=1.09, 95% CI 0.95~1.25)。对于血清前列腺特异性抗原(PSA)水平,两组之间也没有统计学差异 (OR=-0.13, 95% CI -0.71~0.45)。对于前列腺体积,两组之间存在统计学差异(OR=-3.28, 95% CI -6.40~-0.6)。结论 meta分析显示TR和经TP活检对前列腺癌的检出率没有统计学差异。     

Calcifications of the prostate: a transrectal echographic study

Prostatic lithiasis is a well know phenomenon. It has little clinical significance and is not easily shown by conventional radiography, which has poor sensitivity and specificity. The authors have studied 612 patients with both suprapubic and transrectal US in order to 1) assess US sensitivity and specificity and 2) report the frequency, spatial distribution, number and features of prostatic calcifications with special emphasis on differential diagnosis between prostatic neoplasms and chronic prostatitis. The authors have also studied the relationship between morphology and symptoms and the results agree with those reported in the scanty literature. The authors conclude that the parameters studied are directly related to age, except for a younger group with clear evidence of genital inflammation. The authors emphasize the impossibility to correlate morphology of prostatic calcifications with pathologic conditions: there are no specific symptoms clearly connected with calcification even though the inflammation is often associated with calcifications.     

MR兼容性气动驱动设备作为经直肠前列腺活检导航的可行性研究

目的评估使用一种与MR兼容的遥控气动驱动机械装置在实时动态3TMR影像引导下进行经直肠前列腺活检的可行性。材料与方法本前瞻性研究经伦理审查委员会     

Identification of pubic arch interference in prostate brachytherapy: simplifying the transrectal ultrasound technique

PURPOSE: We report a simplified technique allowing identification of pubic arch interference (PAI) using transrectal ultrasound (TRUS). METHODS AND MATERIALS: Fifty consecutive brachytherapy patients implanted using a two-stage technique were studied. The pubic arch was outlined using a marker pen on the ultrasound monitor screen during the dose planning ultrasound. Where pubic arch interference (PAI) was identified attempted needle passage was used to confirm PAI (n = 3). RESULTS: Mean time to perform PAI assessment was 90 s. Three of 50 patients had PAI, which was confirmed by attempted needle passage. No patients required modification to the implant plan during the implant procedure. CONCLUSIONS: TRUS reliably identifies PAI. This simple technique may be used with any TRUS scanner and avoids the need for CT scanning or specific software to identify PAI. Our low incidence of PAI may be related to lower prostate volumes at implantation due to patient selection, neoadjuvant androgen deprivation, or improved patient positioning.     

Multiple transrectal ultrasound-guided biopsies for the detection of prostate cancer and determination of tumor volume,grade, and seminal vesicle invasion

A total of 251 men with suspected prostate cancer were examined by transrectal ultrasound (TRUS) in order to evaluate the usefulness of TRUS and core biopsies for the detection of prostate cancer and determination of tumor volume, grade, and seminal vesicle invasion (SVI). Biopsies targeting hypoechoic lesions were taken in combination with systematic biopsies obtained from six standardized locations. Bilateral seminal vesicle biopsies were obtained from 168 of the men. A total of 26 patients underwent surgery and a comparison between the results of the histopathological evaluation of core biopsies and the prostatectomy specimen was performed. A total of 137 cancers were detected. In 34 patients (25%) the tumors were diagnosed by systematic biopsies alone. Tumor volume as estimated by TRUS underestimated the volume when compared to a planimetric technique. Correlation between the two methods was not found by regression analysis. Systematic biopsies did not improve grading compared to the grading of prostatectomy specimens. A total of 24 SVIs were detected. Valuable information was obtained for the diagnosis of prostate cancer by taking systematic biopsies.     

Value of random US-guided transrectal prostate biopsy

One hundred sixty-four men underwent ultrasound-guided transrectal biopsy of a hypoechoic prostatic nodule suspicious for malignancy, and random biopsy of normal-appearing areas of the gland. The contribution of random biopsy to diagnosis, staging, and management of prostatic carcinoma was evaluated. A diagnosis of carcinoma was made in 71 patients (43.3%). Carcinoma was diagnosed at biopsy of only the nodule in 56 of these patients (79%), at both the nodule and random biopsy site in 10 (14%), and only at the random biopsy site in five (7%). Random biopsy did not result in significant alteration of clinical staging. However, management was altered in five patients with positive results at random biopsy only, four of whom underwent surgery. The additional yield from random prostatic biopsy was small but distinct and had clinical relevance. The authors conclude that random biopsy is a useful procedure in the evaluation of patients with prostatic nodules.     

FluoroCT guided biopsies: a simplified technique

We report the use of a specific handle we designed for interventional procedures guided by fluoro-CT. This handle, easy to use and low cost, improves the procedures reducing dramatically the procedure time.