Introduction Lorsqu’exposé au froid, l’être humain est capable de maintenir sa température corporelle constante en produisant de la chaleur par deux mécanismes le frisson musculaire et l’activation ...du tissu adipeux brun. Le but de notre recherche est d’étudier les adaptations métaboliques musculaires lors d’une exposition aiguë et chronique au froid. Matériels et méthodes Les participants (hommes sains et jeunes) sont exposés au froid dans une combinaison à refroidissement dont la température peut être ajustée par l’expérimentateur. Lors d’une première session, les participants sont exposés à une température de 4 °C pour 2,5 h L’intensité et le patron de frisson et l’utilisation des substrats énergétiques du corps dans son ensemble (calorimétrie indirecte) sont mesurés pendant toute la période d’exposition. Une biopsie musculaire est prélevée avant et après l’exposition au froid. L’évolution de l’utilisation des substrats énergétiques (glucides et lipides) et du couplage mitochondrial est étudiée sur fibres musculaires perméabilisées (électrode de Clark). Les participants sont ensuite exposés au froid (10 °C) 2 h/jour, 5 jours/semaine pour 4 semaines. Les mêmes tests sont réalisés à la fin de la période d’acclimatation. L’effet de l’exposition chronique au froid sur le typage de fibres ainsi que sur l’expression de gènes musculaires sera étudié. Résultats Les résultats préliminaires ne montrent pas de changements de température de peau (indice de perte de chaleur), de dépense énergétique ou d’intensité de frisson suite à quatre semaines d’acclimatation. Les analyses de typages de fibres, d’expression de gènes musculaires et de respiration mitochondriale sont actuellement en cours. Conclusion Cette étude va permettre de mieux comprendre les adaptations métaboliques suite à une exposition chronique au froid. En raison de l’augmentation de la dépense énergétique lors d’une exposition au froid, cette méthode est vue comme une nouvelle thérapie pour combattre l’obésité. De futures études sont nécessaires afin de prouver que cette méthode serait efficace.
Highlights • Objective IQ for T2WI was at 1.5T under optimized parameters comparable to 3T. • SNR and CNR of DWI were significantly higher at 3T. • Subjective IQ on was significantly better at 3T. • ...PI-RADS v2 scores were similar at 3T and 1.5T.
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.
To flesh out the ESUR guidelines for the standardized interpretation of multiparametric magnetic resonance imaging (mMRI) for the detection of prostate cancer and to present a graphic reporting ...scheme for improved communication of findings to urologists.
The ESUR has recently published a structured reporting system for mMRI of the prostate (PI-RADS). This system involves the use of 5-point Likert scales for grading the findings obtained with different MRI techniques. The mMRI includes T2-weighted MRI, diffusion-weighted imaging, dynamic contrast-enhanced MRI, and MR spectroscopy. In a first step, the fundamentals of technical implementation were determined by consensus, taking into account in particular the German-speaking community. Then, representative images were selected by consensus on the basis of examinations of the three institutions. In addition, scoring intervals for an aggregated PI-RADS score were determined in consensus.
The multiparametric methods were discussed critically with regard to implementation and the current status. Criteria used for grading mMRI findings with the PI-RADS classification were concretized by succinct examples. Using the consensus table for aggregated scoring in a clinical setting, a diagnosis of suspected prostate cancer should be made if the PI-RADS score is 4 or higher (≥ 10 points if 3 techniques are used or ≥ 13 points if 4 techniques are used). Finally, a graphic scheme was developed for communicating mMRI prostate findings.
Structured reporting according to the ESUR guidelines contributes to quality assurance by standardizing prostate mMRI, and it facilities the communication of findings to urologists.
•Re-biopsy of obvious, peripheral, negatively biopsied PI-RADS-4-lesions is recommended.•Negatively biopsied transition zone confined PI-RADS-4-lesions with overlaying signs of severe stromal ...hyperplasia rarely contain csPCa.•Targeted MR/US fusion biopsy alone can miss some csPCa.•In uncertain cases PSAD should be considered for biopsy decision.
To evaluate if subgroups of patients assigned to MRI category PI-RADS 4 regarding clinical and MRI imaging aspects have distinct risks of prostate cancer (PCa) to facilitate adequate clinical management of this population, especially after negative targeted biopsy.
This prospective, IRB approved single center cross-sectional study includes 931 consecutive patients after mp-MRI at 3 T for PCa detection. 193 patients with PI-RADS assessment category 4 received subsequent combined targeted MRI/US fusion-guided and systematic 12-core TRUS-guided biopsy as reference standard and were finally analyzed. The primary endpoint was PCa detection of PI-RADS 4 with MRI subgroup analyses. Secondary endpoints were analyses of clinical data, location of PCa, and detection of targeted biopsy cores.
PCa was detected in 119 of 193 patients (62%) including clinically significant PCa (csPCa; Gleason score ≥3 + 4 = 7) in 92 patients (48%). MRI subgroup analysis revealed 95% PCa (73% csPCa) in unambiguous PI-RADS 4 index lesions without additional, interfering signs of prostatitis in the peripheral zone or overlaying signs of severe stromal hyperplasia in the transition zone according to PI-RADS v2. Transition zone confined PI-RADS-4-lesions with overlaying signs of stromal hyperplasia showed PCa only in 11% (4% csPCa). Targeted biopsy cores missed the csPCa index lesion in 7% of the patients. PSA density (PSAD) was significantly higher in PCa patients.
Small csPCa can reliably be detected with mp-MRI by experienced readers, but can be missed by targeted MR/US fusion biopsy alone. Targeted re-biopsy of unambiguous (peripheral) PI-RADS-4-lesions is recommended; whereas transition zone confined PI-RADS-4-lesions with overlaying signs of stromal hyperplasia might be followed-up by re-MRI primarily.
To evaluate image quality and diagnostic value of multiparametric prostate MRI (mpMRI) in patients with total hip replacement (THR) at 1.5 and 3 Tesla.
In this retrospective multicenter cohort study ...patients with uni- or bilateral THR and 1.5 T or 3 T mpMRI were included. Seventy consecutive, standard-of-care examinations per field strength were evaluated regarding their diagnostic value. The overall diagnostic value and prostate imaging quality score (PI-QUAL) were assessed. Artifact severity in the localizer and mpMRI sequences (T2w, DWI, DCE) was scored on a 3-point scale. Correlation between diagnostic value and artifacts was analysed. Moreover, a subgroup analysis focussed on image quality at different 3 T scanner generations.
140 consecutive patients (mean age 72, median PSA value 8.3 ng/ml) were included. When comparing 1.5 T to 3 T examinations, no significant differences were observed regarding the artifact severity of DWI and the localizer and the overall diagnostic value of the images. There was a strong correlation between the diagnostic value, PI-QUAL score, and artifact severity in the localizer and DWI. T2w and DCE sequences showed overall low artifacts. Significant improvement in image quality for 3 T at the latest scanner generation was observed, especially for DWI (p < 0.03).
MpMRI of patients with THR can be conducted at both field strengths without significant differences in artifacts. The localizer might be useful as an early forecasting feature for diagnostic value and particularly for contrast medium application decision. Patients with THR could benefit from technically advanced scanner generation and rs/ptx-EPI DWI sequences.
This study analyzes the value of dynamic contrast-enhanced MRI (DCE) of the prostate on 1.5 T and 3 T examinations in patients within PI-RADS category 4.
In this retrospective, bi-centric, cohort ...study all consecutive patients classified as PI-RADS 4 in mpMRI with 100 verified prostate cancers (PCa) in subsequent MRI/US-guided fusion biopsy were included for 1.5 T and 3 T, each. PCa detection in index lesions (IL) upgraded to PI-RADS 4 based on positive DCE findings was compared between 1.5 T and 3 T. Secondary objectives are subgroup analysis of PZ lesions and comparison of ISUP grade group distribution between 1.5 T and 3 T.
In total, 293 patients within PI-RADS category 4, including 152 (mean 66 ± 8y; median PSA 6.4 ng/ml;116 PZ IL) in the 1.5 T group and 141 (mean 65 ± 8y; median PSA 7.2 ng/ml;100 PZ IL) in the 3 T group were included. Overall amount of PCa (66 % vs 71 %; p = 0.346) and portion of upgraded IL (28 % vs 21 %; p = 0.126) did not differ significantly. At 1.5 T PCa detection was higher in upgraded PZ lesions compared to 3 T (23 % vs 14 %; p = 0.048). The amount of upgraded PZ lesions with ISUP grade group 2–5 PCa was significantly higher at 1.5 T versus 3 T (13.8 % vs 4.0 %; p = 0.007). 33 % (11/33; 1.5 T) and 32 % (10/31; 3 T) of the ISUP grade group 1 PCa of the PZ lesions were detected in upgraded lesions (10% of all PZ index lesions, respectively).
DCE enabled the detection of a substantial amount of additional clinically significant PCa in prostate mpMRI at 1.5 T. The effect was smaller at 3 T and was accompanied in relation to 1.5 T by higher risk of overdiagnosis due to detection of additional low-risk PCa.
Objectives
To prospectively evaluate the effect of hyoscine butylbromide (HBB) on visualisation of anatomical details and motion-related artefacts in mp-MRI of the prostate at 3.0 Tesla.
Methods
One ...hundred and three consecutive patients (65 ± 10 years) were included in this trial, powered to demonstrate an improvement of image quality after HBB administration, assessed on a 5-point scale by two blinded readers. All patients received high-spatial resolution axial T2-weighted TSE sequences at 3.0 T without spasmolytic agent, repeated after application of 40 mg HBB and followed by routine mp-MRI. Secondary endpoints were (1) susceptibility to side effects, (2) dependence of spasmolytic effect on patients´ weight, and (3) prostate volume.
Results
In 68% of patients, HBB significantly improved the anatomic score (mean 3.4 ± 0.9 before and 4.4 ± 0.7 after HBB for both readers,
p
= <0.001). In 67%, HBB significantly enhanced the artefact score (mean 3.2 ± 1 before and 4.2 ± 0.8 after HBB for reader 1,
p
= <0.001; 3.2 ± 1 and 4.1 ± 0.8 for reader 2,
p
= <0.001). Subgroup analysis revealed no statistically significant difference between patients with different bodyweight or prostate volume. Inter-reader agreement was excellent (k = 0.95–0.98).
Conclusions
Hyoscine butylbromide significantly improves image quality and reduces motion-related artefacts in mp-MRI of the prostate independent of bodyweight or prostate volume. No side effects were reported.
Key Points
•
Hyoscine butylbromide (HBB) improved image quality in over 2/3 of patients.
•
Severe artefacts were reduced after HBB in more than 20%.
•
The number of non-diagnostic MRI was reduced to <1% after HBB.
•
HBB effect was independent of bodyweight and prostate volume.
•
No side effects of HBB were reported in this study population.
Background an aims: Current interferon alfa (IFN) treatment of chronic hepatitis B has limited efficacy. The role of hepatitis B virus (HBV) genotypes for response to IFN was investigated. Patients ...and methods: HBV genotype was determined by direct sequencing of the HBV X gene in 165 consecutive patients with chronic replicative hepatitis B treated with standard IFN. HBV genotype A or D was found in 144 cases. Results: Sustained response (six months after treatment) to standard IFN therapy was higher in HBV genotype A compared with HBV genotype D infected patients (49% v 26%; p<0.005). Sustained response to IFN was 46% versus 24% (p<0.03) in hepatitis B e antigen (HBeAg) positive hepatitis (n = 99) and 59% versus 29% (p<0.05) in HBeAg negative hepatitis (n = 45) for HBV genotype A compared with HBV genotype D. HBeAg status had no negative impact on IFN response. Multivariate logistic regression identified HBV genotype A and high pretreatment alanine aminotransferase levels (>2×upper limit of normal) as independent positive predictive parameters of IFN response. Conclusions: The present study indicates that HBV genotypes A and D are important and independent predictors of IFN responsiveness in chronic hepatitis B. HBV genotype adapted treatment regimens may further improve treatment efficacy in chronic hepatitis B.
Objectives
To evaluate different analgesic techniques in MRI-guided in-bore prostate biopsy (IB-GB) regarding the influence on patient procedural experience of pain.
Methods
Two hundred fifty-two ...consecutive patients who had received an IB-GB either with intrarectal instillation of 2% lidocaine gel (
n
= 126, group A) or with periprostatic nerve block (PPNB) with 2% mepivacaine (
n
= 126, group B) were retrospectively included in this study. Pain scores were measured on a visual analog scale, the operating room time (ORT) was recorded for each biopsy and correlations between the parameters were analysed.
Results
Pain scores for IB-GB were slightly lower in group B compared with group A (2.0 ± 1.9; 2.4 ± 1.7;
p
= 0.02). In group A, significantly more targeted biopsy cores were acquired (group B: 5.2 ± 1.1; group A: 5.6 ± 0.8;
p
< 0.01). ORT was comparable and not significantly different in both groups. There was only a weak correlation between pain scores and ORT in group B (
r
S
= 0.22;
p
= 0.01), but no correlation between pain scores and the number of biopsy cores or the prostate volume.
Conclusions
Pain levels are generally low for MRI-guided in-bore biopsy using either PPNB or intrarectal instillation of lidocaine gel. A statistically significant, slightly lower pain score was documented for PPNB and might be preferred when the focus is analgesia. On the other hand, due to the minor difference and easier administration, intrarectal gel instillation seems to be a reasonable practice for standard analgesia for MRI-guided in-bore biopsy.
Key Points
• Pain levels were low for MRI-guided in-bore biopsy using either PPNB or intrarectal instillation of lidocaine gel as analgesic method.
• PPNB prior to IB-GB resulted in a slightly lower pain score but required a higher effort.
• Intrarectal gel anaesthesia seems to be a reasonable practice for standard analgesia for IB-GB in an outpatient setting.
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