Feasibility of diffusion tensor imaging (DTI) with fibre tractography of the normal female pelvic floor

To prospectively determine the feasibility of diffusion tensor imaging (DTI) with fibre tractography as a tool for the three-dimensional (3D) visualisation of normal pelvic floor anatomy. Five young female nulliparous subjects (mean age 28 ± 3 years) underwent DTI at 3.0T. Two-dimensional diffusion-weighted axial spin-echo echo-planar (SP-EPI) pulse sequence of the pelvic floor was performed, with additional T2-TSE multiplanar sequences for anatomical reference. Fibre tractography for visualisation of predefined pelvic floor and pelvic wall muscles was performed offline by two observers, applying a consensus method. Three eigenvalues (λ1, λ2, λ3), fractional anisotropy (FA) and mean diffusivity (MD) were calculated from the fibre trajectories. In all subjects fibre tractography resulted in a satisfactory anatomical representation of the pubovisceral muscle, perineal body, anal - and urethral sphincter complex and internal obturator muscle. Mean FA values ranged from 0.23 ± 0.02 to 0.30 ± 0.04, MD values from 1.30 ± 0.08 to 1.73 ± 0.12 × 10(-)³ mm²/s. Muscular structures in the superficial layer of the pelvic floor could not be satisfactorily identified. This study demonstrates the feasibility of visualising the complex three-dimensional pelvic floor architecture using 3T-DTI with fibre tractography. DTI of the deep female pelvic floor may provide new insights into pelvic floor disorder

The additional value of weight-bearing and gravity stress ankle radiographs in determining stability of isolated type B ankle fractures

Goal The aim of this study is to investigate whether weight-bearing and gravity stress radiographs have additional value in predicting concomitant deep deltoid ligamentous (DDL) injury in case of isolated Weber type B fibular fractures. This may help to make the clinically relevant distinction between unstable fractures and fractures that can be treated conservatively. Methods In this prospective cohort study, 90 patients with an isolated type B ankle fracture, without a medial or posterior fracture, and a medial clear space (MCS) = SCS + 2 mm, the RM view showed 0% sensitivity and 97% specificity in diagnosing a DDL rupture. Both the GS view (with MCS >= SCS + 3 mm as cut-off value) and the WB radiograph (with cut-off value MCS >= SCS + 2 mm) showed 6% sensitivity and 100% specificity. Conclusion The gravity stress and weight-bearing radiograph can accurately exclude DDL injury. They might have extra value in addition to the conventional mortise view in assessing the stability of isolated type B ankle fractures. This helps in deciding whether patients should be selected for operative or safe conservative treatment.Trauma Surger

Reducing the oral contrast dose in CT colonography: evaluation of faecal tagging quality and patient acceptance

AIM: To evaluate the minimal iodine contrast medium load necessary for an optimal computed tomography colonography tagging quality. MATERIALS AND METHODS: Faecal occult blood test positive patients were randomly selected for one of three iodine bowel preparations: (1) 3×50ml meglumine ioxithalamate (45g iodine), (2) 4×25ml meglumine ioxithalamate (30g iodine); or (3) 3×25ml (22.5g iodine) meglumine ioxithalamate. Two experienced readers assessed the tagging quality per colonic segment on a five-point scale and the presence of adherent stool. Also semi-automatic homogeneity measurements were performed. Patient acceptance was assessed with questionnaires. RESULTS: Of 70 eligible patients, 45 patients participated (25 males, mean age 62 years). Each preparation group contained 15 patients. The quality of tagging was insufficient (score 1-2) in 0% of segments in group 1; 4% in group 2 (p <0.01 versus group 1); and 5% in group 3 (p=0.06 versus group 1). In group 1 in 11% of the segments adherent stool was present compared with 49% in group 2 and 41% in group 3 (p <0.01, group 2 and 3 versus group 1). Homogeneity was 85, 102 (p <0.01), and 91 SD HU (p=0.26) in groups 1, 2, and 3, respectively. In group 1 two patients experienced no burden after contrast agent ingestion compared to one patient in group 2 and nine patients in group 3 (p=0.017). CONCLUSION: A dose of 3×50ml meglumine ioxithalamate is advisable for an optimal tagging quality despite beneficial effects on the patient acceptance in patients receiving a lower dos

Dynamic magnetic resonance imaging to quantify pelvic organ prolapse: reliability of assessment and correlation with clinical findings and pelvic floor symptoms

The aim of this study was to assess the interobserver agreement of magnetic resonance imaging (MRI)-based staging of pelvic organ prolapse (POP) and to quantify associations between MRI-based POP staging, findings at pelvic examination, and pelvic floor symptoms. This was a cross-sectional study of ten symptomatic POP patients, ten symptomatic patients without POP, and ten nulliparous asymptomatic women. Three different observers performed MRI-based POP staging using the pubococcygeal line (PCL), midpubic line (MPL), perineal line, and H line as references. The interobserver agreement of MRI-based staging of the anterior and middle compartment was good to excellent. In symptomatic women without prolapse, MRI-based and pelvic-examination-based POP staging were poorly correlated. In none of the women were MRI-based POP Quantification (POP-Q) staging and pelvic floor symptoms strongly associated. The interobserver agreement of MRI-based POP staging is excellent, but the added clinical value of such staging is questionable due to poor association with clinical findings and pelvic floor symptom

Diagnostic performance of radiographers as compared to radiologists in magnetic resonance colonography

To evaluate the diagnostic performance of radiographers compared to radiologists in the detection of colorectal lesions in MR colonography. 159 patients at increased risk of colorectal cancer were included. Four different experienced observers, one MR radiologist, one radiologist in training and two radiographers evaluated all MR colonography examinations. The protocol included T1-weighted and T2-weighted sequences in prone and supine position. Colonoscopy was used as reference standard. Mean sensitivity rates with 95% confidence intervals (CIs) were determined on a per-patient and per-polyp basis, segmented by size (>or= 6mm and >or= 10mm). Specificity was calculated on a per-patient basis. The McNemar and chi-square (chi(2)) test was used to determine significant differences. At colonoscopy 74 patients (47%) had normal findings; 23 patients had 40 polyps with a size > or = 6mm. In 10 patients at least 1 polyp >or= 10mm was found (20 polyps in total). Similar sensitivities for patients with lesions >or= 10mm were found for radiologists and radiographers (65% (95%CI: 44-86%) vs. 50% (95%CI: 28-72%)) (p=n.s.). For lesions >or=10mm combined per-patient specificity for radiologists and radiographers was 96% (95%CI: 94-98%) and 73% (95%CI: 68-79%) (p or=6mm differed significantly between both groups of observers (57% (95%CI: 42-71%) vs. 33% (95%CI: 19-46%)) (p=0.03). Radiographers have comparable sensitivity but lower specificity relative to radiologists in the detection of colorectal lesions >or= 10mm at MR colonography. Adequate training in evaluating MR colonography is necessary, especially for readers with no prior experience with colonograph

Evaluation of the female pelvic floor in pelvic organ prolapse using 3.0-Tesla diffusion tensor imaging and fibre tractography

Objectives To prospectively explore the clinical application of diffusion tensor imaging (DTI) and fibre tractography in evaluating the pelvic floor. Methods Ten patients with pelvic organ prolapse, ten with pelvic floor symptoms and ten asymptomatic women were included. A two-dimensional (2D) spin-echo (SE) echo-planar imaging (EPI) sequence of the pelvic floor was acquired. Offline fibre tractography and morphological analysis of pelvic magnetic resonance imaging (MRI) were performed. Inter-rater agreement for quality assessment of fibre tracking results was evaluated using weighted kappa (kappa). From agreed tracking results, eigen values (lambda 1, lambda 2, lambda 3), mean diffusivity (MD) and fractional anisotropy (FA) were calculated. MD and FA values were compared using ANOVA. Inter-rater reliability of DTI parameters was interpreted using the intra-class correlation coefficient (ICC). Results Substantial inter-rater agreement was found (kappa = 0.71 [95% CI 0.63-0.78]). Four anatomical structures were reliably identified. Substantial inter-rater agreement was found for MD and FA (ICC 0.60-0.91). No significant differences between groups were observed for anal sphincter, perineal body and puboperineal muscle. A significant difference in FA was found for internal obturator muscle between the prolapse group and the asymptomatic group (0.27 +/- 0.05 vs 0.22 +/- 0.03; P = 0.015). Conclusion DTI with fibre tractography permits identification of part of the clinically relevant pelvic structures. Overall, no significant differences in DTI parameters were found between group

A Prospective Multicenter Comparison Study of Risk-adapted Ultrasound-directed and Magnetic Resonance Imaging–directed Diagnostic Pathways for Suspected Prostate Cancer in Biopsy-naïve Men

Background: European Association of Urology guidelines recommend a risk-adjusted biopsy strategy for early detection of prostate cancer in biopsy-naïve men. It remains unclear which strategy is most effective. Therefore, we evaluated two risk assessment pathways commonly used in clinical practice. Objective: To compare the diagnostic performance of a risk-based ultrasound (US)-directed pathway (Rotterdam Prostate Cancer Risk Calculator [RPCRC] #3; US volume assessment) and a magnetic resonance imaging (MRI)-directed pathway. Design, setting, and participants: This was a prospective multicenter study (MR-PROPER) with 1:1 allocation among 21 centers (US arm in 11 centers, MRI arm in ten). Biopsy-naïve men with suspicion of prostate cancer (age ≥50 yr, prostate-specific antigen 3.0–50 ng/ml, ± abnormal digital rectal examination) were included. Intervention: Biopsy-naïve men with elevated risk of prostate cancer, determined using RPCRC#3 in the US arm and Prostate Imaging Reporting and Data System scores of 3–5 in the MRI arm, underwent systematic biopsies (US arm) or targeted biopsies (MRI arm). Outcome measurements and statistical analysis: The primary outcome was the proportion of men with grade group (GG) ≥2 cancer. Secondary outcomes were the proportions of biopsies avoided and GG 1 cancers detected. Categorical (nonparametric) data were assessed using the Mann-Whitney U test and χ2 tests. Results and limitations: A total of 1965 men were included in the intention-to-treat population (US arm n = 950, MRI arm n = 1015). The US and MRI pathways detected GG ≥2 cancers equally well (235/950, 25% vs 239/1015, 24%; difference 1.2%, 95% confidence interval [CI] −2.6% to 5.0%; p = 0.5). The US pathway detected more GG 1 cancers than the MRI pathway (121/950, 13% vs 84/1015, 8.3%; difference 4.5%, 95% CI 1.8–7.2%; p < 0.01). The US pathway avoided fewer biopsies than the MRI pathway (403/950, 42% vs 559/1015, 55%; difference −13%, 95% CI −17% to −8.3%; p < 0.01). Among men with elevated risk, more GG ≥2 cancers were detected in the MRI group than in the US group (52% vs 43%; difference 9.2%, 95% CI 3.0–15%; p < 0.01). Conclusions: Risk-adapted US-directed and MRI-directed pathways detected GG ≥2 cancers equally well. The risk-adapted US-directed pathway performs well for prostate cancer diagnosis if prostate MRI capacity and expertise are not available. If prostate MRI availability is sufficient, risk assessment should preferably be performed using MRI, as this avoids more biopsies and detects fewer cases of GG 1 cancer. Patient summary: Among men with suspected prostate cancer, relevant cancers were equally well detected by risk-based pathways using either ultrasound or magnetic resonance imaging (MRI) to guide biopsy of the prostate. If prostate MRI availability is sufficient, risk assessment should be performed with MRI to reduce unnecessary biopsies and detect fewer irrelevant cancers