AI-Supported Autonomous Uterus Reconstructions: First Application in MRI Using 3D SPACE with Iterative Denoising.

RATIONALE AND OBJECTIVES: T2-weighted imaging in at least two orthogonal planes is recommended for assessment of the uterus. To determine whether a convolutional neural network-based algorithm could be used for the re-constructions of uterus axes derived from a 3D SPACE with iterative denoising. MATERIALS AND METHODS: 50 patients aged 18-81 (mean: 42) years who underwent an MRI examination of the uterus participated voluntarily in this prospective study after informed consent. In addition to a standard MRI pelvis protocol, a 3D SPACE research application sequence was acquired in sagittal orientation. Reconstructions for both the cervix and the cavum in the short and long axes were performed by a research trainee (T), an experienced radiologist (E), and the prototype software (P). In the next step, the reconstructions were evaluated anonymously by two experienced readers according to 5-point-Likert-Scales. In addition, the length of the cervical canal, the length of the cavum and the distance between the tube angles were measured on all reconstructions. Interobserver agreement was assessed for all ratings. RESULTS: For all axes, significant differences were found between the scores of the reconstructions by research T, E and P. P received higher scores and was preferred significantly more often with the exception of the comparison of the reconstruction Cervix short of E (Cervix short: P vs. T: p = 0.02; P vs. E: p = 0.26; Cervix long: P vs. T: p = 0.01; P vs. E: p < 0.01; Cavum short: P vs. T: p = 0.01; P vs. E: p = 0.02; Cavum long: P vs. T: p < 0.01; P vs. E: p < 0.01). Regarding the measured diameters, (length of cervical canal/cavum/distance between tube angles) significantly larger diameters were recorded for P compared to E and T (Cervix long (mm): T: 25.43; E: 25.65; P: 26.65; Cavum short (mm): T: 26.24; E: 25.04; P: 27.33; Cavum long (mm): T: 31.98; E: 32.91; P: 34.41; P vs. T: p < 0.01); P vs. E: p = 0.04). Moderate to substantial agreement was found between Reader 1 and Reader 2 (range: 0.39-0.67). CONCLUSION: P was able to reconstruct the axes at least as well as or better than E and T. P could thereby lead to workflow facilitation and enable more efficient reporting of uterine MRI.

Evaluation of Image Quality of Overweight and Obese Patients in CT Using High Data Rate Detectors.

BACKGROUND/AIM: To evaluate the impact of high data rate and sampling frequency detector technology compared to standard scan equipment on the image quality in abdominal computed tomography (CT) of overweight and obese patients. PATIENTS AND METHODS: A total of 173 patients were retrospectively included in this study. Objective image quality in abdominal CT was evaluated using comparative analysis with new detector technology prior to market launch and standard CT equipment. Contrast noise ratio (CNR), image noise, volumetric computed tomography dose index (CTDIVol), and figures of merit (Q and Q1) were assessed for all patients. RESULTS: Image quality was superior in the new detector technology for all parameters evaluated. The dose dependent parameters Q and Q1 showed a significant difference (p<0.001). CONCLUSION: A significant increase in objective image quality could be demonstrated using a new generation detector setup with increased frequency transfer in abdominal CT of overweight patients.

Advanced Diffusion-Weighted Imaging Sequences for Breast MRI: Comprehensive Comparison of Improved Sequences and Ultra-High B-Values to Identify the Optimal Combination.

This study investigated the image quality and choice of ultra-high b-value of two DWI breast-MRI research applications. The study cohort comprised 40 patients (20 malignant lesions). In addition to s-DWI with two m-b-values (b50 and b800) and three e-b-values (e-b1500, e-b2000, and e-b2500), z-DWI and IR m-b1500 DWI were applied. z-DWI was acquired with the same measured b-values and e-b-values as the standard sequence. For IR m-b1500 DWI, b50 and b1500 were measured, and e-b2000 and e-b2500 were mathematically extrapolated. Three readers used Likert scales to independently analyze all ultra-high b-values (b1500-b2500) for each DWI with regards to scan preference and image quality. ADC values were measured in all 20 lesions. z-DWI was the most preferred (54%), followed by IR m-b1500 DWI (46%). b1500 was significantly preferred over b2000 for z-DWI and IR m-b1500 DWI (p = 0.001 and p = 0.002, respectively). Lesion detection was not significantly different among sequences or b-values (p = 0.174). There were no significant differences in measured ADC values within lesions between s-DWI (ADC: 0.97 [±0.09] × 10-3 mm2/s) and z-DWI (ADC: 0.99 [±0.11] × 10-3 mm2/s; p = 1.000). However, there was a trend toward lower values in IR m-b1500 DWI (ADC: 0.80 [±0.06] × 10-3 mm2/s) than in s-DWI (p = 0.090) and z-DWI (p = 0.110). Overall, image quality was superior and there were fewer image artifacts when using the advanced sequences (z-DWI + IR m-b1500 DWI) compared with s-DWI. Considering scan preferences, we found that the optimal combination was z-DWI with a calculated b1500, especially regarding examination time.

Quantitative Assessment of Iteratively Denoised 3D SPACE with Inner-Volume Excitation and Simultaneous Multi-Slice BLADE for Optimizing Female Pelvis Magnetic Resonance Imaging at 1.5 T.

RATIONALE AND OBJECTIVES: High-resolution T2-weighted magnetic resonance imaging (MRI) of the pelvis is the main technique used for diagnosing benign and malignant uterine diseases. However, the procedure may be time-consuming and requires training and experience. Therefore, this study was performed to compare the image quality of standard clinical BLADE (stBLADE) with a prototypical accelerated simultaneous multi-slice (SMS) BLADE procedure with either improved temporal resolution (tr) at the same slice thickness (SL) or improved spatial resolution (sr) with the same examination time and a prototypical isotropic 3D SPACE procedure with inner-volume excitation and iterative denoising. MATERIALS AND METHODS: Patients who underwent clinically indicated MRI of the uterus were included in this prospective study and underwent stBLADE (acquisition time, 2 min 59 s; SL, 4 mm) and SMS BLADE (tr) with the same SL (4 mm) but reduced examination time (1 min 20 s) as well as SMS BLADE (sr) with thinner slices (3 mm) and comparable examination time (3 min 16 s). In addition, 3D SPACE was acquired in a sagittal orientation (5 min 36 s). The short axis of the cervix and the long axis of the corpus uteri were reconstructed in 1-mm and 3-mm SLs, retrospectively. Subjective overall image impression, delineation of anatomy/organs, lesion demarcation, and motion artifacts were assessed using a 5-point Likert scale and compared among the different techniques. The preferred sequence was then selected by three independent assessors. RESULTS: The analysis was based on 38 women (mean age, 44 ± 15 years). The overall image impression was similar for stBLADE, SMS BLADE (sr), and SMS BLADE (tr) but was significantly lower for 3D SPACE than stBLADE (p = 0.01). SMS BLADE (sr) was considered the preferred sequence because of slightly better performance in terms of overall image impression, organ delineation, and lesion demarcation, but without statistical significance. Both SMS BLADE (tr) and (sr) produced significantly fewer motion artifacts than stBLADE (p < 0.01 and p = 0.01), with no significant difference between SMS BLADE (tr) and (sr), while 3D SPACE had a significantly lower rating than stBLADE (p < 0.01). Image quality was rated as the least diagnostic criterion in all sequences and all cases. CONCLUSION: SMS BLADE (sr) was the preferred sequence for MRI of the female pelvis, with higher sr than stBLADE. SMS BLADE (tr) may also be used to reduce the acquisition time without compromising image quality. Despite its lower image quality, 3D SPACE can also reduce the examination time and improve the workflow because of the possibility of retrospective multiplanar reconstructions.

Infiltrative growth pattern of prostate cancer is associated with lower uptake on PSMA PET and reduced diffusion restriction on mpMRI.

PURPOSE: Recently, a significant association was shown between novel growth patterns on histopathology of prostate cancer (PCa) and prostate-specific membrane antigen (PSMA) uptake on [68Ga]PSMA-PET. It is the aim of this study to evaluate the association between these growth patterns and ADC (mm2/1000 s) values in comparison to [68Ga]PSMA uptake on PET/MRI. METHODS: We retrospectively evaluated patients who underwent [68Ga]PSMA PET/MRI for staging or biopsy guidance, followed by radical prostatectomy at our institution between 07/2016 and 01/2020. The dominant lesion per patient was selected based on histopathology and correlated to PET/MRI in a multidisciplinary meeting, and quantified using SUVmax for PSMA uptake and ADCmean for diffusion restriction. PCa growth pattern was classified as expansive (EXP) or infiltrative (INF) according to its properties of forming a tumoral mass or infiltrating diffusely between benign glands by two independent pathologists. Furthermore, the corresponding WHO2016 ISUP tumor grade was evaluated. The t test was used to compare means, Pearson's test for categorical correlation, Cohen's kappa test for interrater agreement, and ROC curve to determine the best cutoff. RESULTS: Sixty-two patients were included (mean PSA 11.7 ± 12.5). The interrater agreement between both pathologists was almost perfect with κ = 0.81. While 25 lesions had an EXP-growth with an ADCmean of 0.777 ± 0.109, 37 showed an INF-growth with a significantly higher ADCmean of 1.079 ± 0.262 (p < 0.001). We also observed a significant difference regarding PSMA SUVmax for the EXP-growth (19.2 ± 10.9) versus the INF-growth (9.4 ± 6.2, p < 0.001). Within the lesions encompassing the EXP- or the INF-growth, no significant correlation between the ISUP groups and ADCmean could be observed (p = 0.982 and p = 0.861, respectively). CONCLUSION: PCa with INF-growth showed significantly lower SUVmax and higher ADCmean values compared to PCa with EXP-growth. Within the growth groups, ADCmean values were independent from ISUP grading.

Can Dynamic Contrast-enhanced MRI Contribute to Improved Assessment of Rectosigmoid Involvement in Deep Infiltrating Endometriosis?

BACKGROUND/AIM: To determine whether a prototypical compressed-sensing volume-interpolated breath-hold (csVIBE) provides diagnostic value in detecting rectosigmoid infiltration in deep infiltrating endometriosis (DIE). PATIENTS AND METHODS: csVIBE was employed in 151 women undergoing pelvic magnetic resonance imaging, of whom 43 had undergone surgery for suspected endometriosis. The accuracy of T2-weighted BLADE and BLADE/csVIBE, additional diagnostic value of csVIBE, and diagnostic confidence were rated by two readers. Additionally, the presence of the "mushroom cap sign" was assessed on BLADE and csVIBE. RESULTS: The diagnostic accuracy, sensitivity, and specificity of BLADE and BLADE/csVIBE were not significantly different between Readers A and B. For both readers, the confidence in the diagnosis increased with csVIBE, but this increase in the odds ratio was not significant for both readers. Both readers preferred csVIBE over BLADE with regard to detection of the "mushroom cap sign." CONCLUSION: csVIBE may provide a diagnostic benefit for surgical strategy selection through better delineation of the "mushroom cap sign."

Impact of Chronic Prostatitis on the PI-RADS Score 3: Proposal for the Addition of a Novel Binary Suffix.

We examined the impact of chronic prostatitis on the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI). In this retrospective study, 63 men underwent 3T mpMRI followed by MRI/ultrasound fusion biopsy to exclude/confirm clinically significant prostate cancer (csPCa). A total of 93 lesions were included for evaluation. Images were assessed by two radiologists. Prostatitis was graded visually on T2-weighted and contrast-enhanced sequences. The correlation of prostatitis features with the assigned Prostate Imaging Reporting and Data System (PI-RADS) and the presence of csPCa were assessed, and the clinical and functional imaging parameters for differentiating between prostatitis and significant tumors were examined. Histopathological analysis was used as the reference standard. The rate of PI-RADS 3 scores tended to be higher in the presence of radiologically severe prostatitis compared with no/discrete prostatitis (n = 52 vs. n = 9; p = 0.225). In severe prostatitis, csPCa was determined in only 7.7% (4/52) of PI-RADS 3 lesions. In severe chronic prostatitis, a binary prostatitis suffix (e.g., PI-RADS 3 i+ versus i-) within the radiological report may help assess the limitations of mpMRI interpretability because of severe prostatitis and avoid unnecessary biopsies. Mean apparent diffusion coefficient (ADCmean) was the best marker (cutoff 0.93 × 10-3 mm2/s) to differentiate between csPCa/non csPCa in severe prostatitis.

Morphological and functional assessment of the uterus: "one-stop shop imaging" using a compressed-sensing accelerated, free-breathing T1-VIBE sequence.

BACKGROUND: The combination of motion-insensitive, high-temporal, and spatial resolution imaging with evaluation of quantitative perfusion has the potential to increase the diagnostic capabilities of magnetic resonance imaging (MRI) in the female pelvis. PURPOSE: To compare a free-breathing compressed-sensing VIBE (fbVIBE) with flexible temporal resolution (range = 4.6-13.8 s) with breath-hold VIBE (bhVIBE) and to evaluate the potential value of quantifying uterine perfusion. MATERIAL AND METHODS: A total of 70 datasets from 60 patients (bhVIBE: n = 30; fbVIBE: n = 40) were evaluated by two radiologists. Only temporally resolved reconstruction (fbVIBE) was performed on 30 of the fbVIBE datasets. For a subset (n = 10) of the fbVIBE acquisitions, a time- and motion-resolved reconstruction (mrVIBE) was evaluated. Image quality (IQ), artifacts, diagnostic confidence (DC), and delineation of uterine structures (DoS) were graded on Likert scales (IQ/DC/DoS: 1 (non-diagnostic) to 5 (perfect); artifacts: 1 (no artifacts) to 5 (severe artifacts)). A Tofts model was applied for perfusion analysis. Ktrans was obtained in the myometrium (Mm), junctional zone (Jz), and cervix (Cx). RESULTS: The median IQ/DoS/DC scores of fbVIBE (4/5/5 κ >0.7-0.9) and bhVIBE (4/4/4; κ = 0.5-0.7; P > 0.05) were high, but Artifacts were graded low (fbVIBE/bhVIBE: 2/2; κ = 0.6/0.5; P > 0.05). Artifacts were only slightly improved by the additional motion-resolved reconstruction (fbVIBE/mrVIBE: 2/1.5; P = 0.08); fbVIBE was preferred in most cases (7/10). Significant differences of Ktrans values were found between Cx, Jz, and Mm (0.12/0.21/0.19; P < 0.05). CONCLUSION: The fbVIBE sequence allows functional and morphological assessment of the uterus at comparable IQ to bhVIBE.

Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society. / Stellenwert und qualitative Voraussetzungen der Magnetresonanztomografie (MRT) für die Therapieplanung beim Rektumkarzinom ­ Interdisziplinäre Empfehlungen der AIO, ARO, ACO und der Deutschen Röntgengesellschaft.

Due to its excellent intrinsic soft tissue contrast, magnetic resonance imaging allows excellent visualization and anatomical separation of therapy-relevant risk structures such as the mesorectal fascia, local lymph nodes, and vascular structures in patients with rectal carcinoma. This makes magnetic resonance imaging (MRI) a valuable evaluation method for further therapeutic stratification. In particular, MRI is indispensable for the decision to refrain from neoadjuvant therapy and to choose a primary surgical approach. In addition to the oncologically generally relevant T-, N-, and M-criteria, two further parameters are included: the extramural vascular infiltration and the circumferential resection margin. Due to the significant impact of MRI on further therapeutic decision-making, standardized MR image quality is considered essential. KEY POINTS:: · Magnetic resonance imaging is a valuable evaluation method for further therapeutic stratification.. · Critical anatomic landmarks for evaluation are circumferential resection margins.. CITATION FORMAT: · Attenberger UI, Clasen S, Ghadimi M et al. Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society. Fortschr Röntgenstr 2021; 193: 513 - 520.

Editorial for "Qualitative and Quantitative Reporting of a Unique Biparametric MRI: Towards Biparametric MRI-Based Nomograms for Prediction of Prostate Biopsy Outcome in Men With a Clinical Suspicion of Prostate Cancer (IMPROD and MULTI-IMPROD Trials)".

LEVEL OF EVIDENCE: 5 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:1568-1569.

Free-Breathing Dynamic Contrast-Enhanced Imaging of the Upper Abdomen Using a Cartesian Compressed-Sensing Sequence With Hard-Gated and Motion-State-Resolved Reconstruction.

OBJECTIVES: The aim of this study was to compare a compressed-sensing free-breathing VIBE (fbVIBE) with a conventional breath-hold VIBE (bhVIBE) for dynamic contrast-enhanced imaging of the upper abdomen. MATERIALS AND METHODS: In total, 70 datasets (bhVIBE, n = 30; fbVIBE n = 40; hard-gated [hg] reconstruction, n = 30; motion-state-resolved [mr] reconstruction, n = 10) were assessed by 2 experienced readers. Both sequences were performed on 1.5-T magnetic resonance imaging scanners. The prototypical fbVIBE sequence acquired a navigation signal along with the imaging data and supported 2 different reconstructions: an hg reconstruction that either accepted or rejected an echo train based on the navigation signal and an mr reconstruction that assigned echo trains to their determined motion states. The hg reconstruction to reduce respiratory motion artifacts was carried out inline on the scanner (duration: approximately 8 minutes on the scanner-integrated CPU). The mr reconstruction delivered better results, but the reconstruction time is multiplied by the number of selected motion states (6 in the current study). Comparable reconstruction times to hg reconstruction can only be achieved on GPU-supported scanners. Therefore, the acquired raw data were selectively reconstructed at a later timepoint (duration: approximately 45 minutes). Welch analysis of variance tests were applied to compare image quality (IQ), delineation of structures, artifacts, and diagnostic confidence, which were rated on Likert-type scales (IQ/delineation of structures/diagnostic confidence: 1 [nondiagnostic] to 5 [perfect]; artifacts: 1 [no artifacts] to 5 [severe artifacts]). Mann-Whitney U tests and Kruskal-Wallis H tests were used to compare the extent of artifacts in older (aged ≥70 years) and younger (aged <70 years) patients. Interobserver agreement was assessed using Cohen κ. RESULTS: Mean ratings for IQ/delineation of structures/diagnostic confidence of fb(hg)VIBE (4.2 ± 0.7/4.3 ± 0.8/4.3 ± 0.7; κ = 0.8/0.7/0.6) and fb(mr)VIBE (4.9 ± 0.3/4.9 ± 0.3/4.9 ± 0.3; κ = 0.3/1/0.9) were higher compared with those of bhVIBE (3.7 ± 0.8/3.8 ± 0.8/3.9 ± 0.9; κ = 0.9/0.9/0.9), whereas artifacts of fb(hg)VIBE/fb(mr)VIBE were rated lower (fb[hg]VIBE/fb[mr]VIBE/bhVIBE = 2.2 ± 0.9/1.3 ± 0.5/2.4 ± 0.9; κ = 0.6/0.6/0.9). The IQ of fb(hg)VIBE was rated significantly higher compared with that of bhVIBE (P = 0.03). All parameters were significantly improved by mr reconstruction compared with fb(hg)VIBE and bhVIBE (P < 0.001). In the fb(hg)VIBE cohort, an insignificant trend toward lower artifacts in the younger age group (≥70 years: 2.5 ± 0.9 vs <70 years: 1.9 ± 0.8) was found, whereas significant differences emerged in the bhVIBE cohort (≥70 years: 3 ± 0.9 vs <70 years: 2.1 ± 0.9; P = 0.02). CONCLUSIONS: Fast fbVIBE using hg and mr reconstructions is technically feasible with improved IQ compared with that of bhVIBE. Free-breathing VIBE may be useful for dynamic contrast-enhanced of the upper abdomen, particularly in older and/or severely ill patients with impaired breath-hold capabilities.

Sensitivity for multimorbidity: The role of diagnostic uncertainty of physicians when evaluating multimorbid video case-based vignettes.

BACKGROUND: Multimorbidity can be defined as the co-occurrence of two or more chronic medical conditions in one person. Within the diagnostic process, accurately detecting a multimorbid disease pattern still poses a major challenge for most physicians, and is known as a source of diagnostic uncertainty. OBJECTIVE: We investigated, how sensitive, confident, and accurate physicians are in diagnosing multimorbid versus monomorbid patients. METHODS: We created eight video case-based vignettes, which differed in type of morbidity (multimorbid versus monomorbid), field of medical specialization (somatic versus mental), and relatedness of underlying diseases (causally related versus unrelated). In total, 74 physicians (GPs, residents in an emergency department and psychiatrists) watched three to five randomly allocated video cases and had to generate suspected diagnoses at the end of each of three video sequences. Additionally, participating physicians rated subjective confidence for all mentioned diagnoses and for three sequences per case with the help of confidence profiles. RESULTS: Altogether, physicians made a large number of accurate diagnoses (69%). Nevertheless, the overall number of underdiagnosed multimorbid cases (misses) was significantly higher (71%) than over-diagnosed monomorbid cases (false alarms) (7%). DISCUSSION: According to Signal Detection Theory, GPs and psychiatrists both showed lower detection performance for medical cases that lay beyond their own field of specialization. Remarkably, residents show the highest sensitivity for multimorbid cases with an approximately identically detection performance d' slightly over 1 for both field of medical specialization (somatic and mental). Furthermore, higher uncertainty in diagnosing multimorbid cases is related to lower confidence especially at the beginning of a diagnostic process, as well as to unrelated and therefore probably rare disease pattern. Several limitations of the study and the video case-based vignettes are described within the discussion section. CONCLUSIONS: Physicians have to be sensitized for multimorbidity even more, and have to be taught in the prevalence of existing disease combinations. Communicating uncertainty with other specialists could be helpful when faced with a sometimes "fuzzy" pattern of symptoms.

Prostate cancer treatment by the latest focal HIFU device with MRI/TRUS-fusion control biopsies: A prospective evaluation.

OBJECTIVES: Magnetic resonance imaging/transrectal ultrasound (MRI/TRUS) fusion-guided focal high intensity focused ultrasound (HIFU) therapy of the prostate has recently been developed as a selective HIFU-therapy technique to enable targeted ablation of prostate cancer. Here we report a series of patients treated with focal HIFU therapy, discuss its potential pitfalls, and address controversies concerning the indications. MATERIALS AND METHODS: This single-center prospective study reports outcomes of patients treated from September 2014 to March 2016. Follow-up was a minimum of 12 months. MRI/TRUS-fusion-guided HIFU was performed under general anesthesia using the Focal One® device (EDAP, France). A control biopsy at 12 months was taken using the MRI/TRUS-fusion biopsy platform Artemis™ (Eigen, California) combining targeted and systematic cores. Prostate-specific antigen (PSA) changes from baseline, patient-reported outcome measures, and complications using the Clavien-Dindo classification system are also reported. RESULTS: Twenty-four patients (PSA < 10 ng/ml, n = 17 Gleason 3+3, n = 7 Gleason 3+4) with either unifocal or bifocal prostate imaging reporting and data system (PI-RADS) 3-5 lesions (n = 19) or without a PI-RADS lesion (n = 5) were treated. Nineteen patients underwent focal HIFU, five patients zonal HIFU. Of the 20 patients that had biopsies at 12 months, 8 patients had a positive biopsy within the ablation zone (overall cancer free rate: 60%). Using different definitions of clinically significant cancer, the cancer-free rate for the ablation zone varies between 75% and 95%. Four of the eight patients (all persistent Gleason 3+4 or upgrading to 4+3) underwent a radical whole gland salvage therapy. Patient-reported outcome measures showed no significant decrease in urinary continence (expanded prostate cancer index composite -26 urinary incontinence: P = 0.080), but there was a reduction in potency (International index of erectile function in preoperatively potent patients: median decrease of 2 points to a median of 19 points at 12 months; 95% confidence interval: 15.79-22.21; P = 0.044). Only one complication > grade II occurred. CONCLUSIONS: Targeted MRI/TRUS fusion-guided focal HIFU allows local tumor ablation, but is not free from limitations. The procedure has good functional outcomes and a quick recovery. Multicenter trials with more patients are required to determine the procedure´s role in the prostate cancer therapy algorithm.

Image Quality Assessment of 2D versus 3D T2WI and Evaluation of Ultra-high b-Value (b=2,000 mm/s2) DWI for Response Assessment in Rectal Cancer.

AIM: The purpose of this IRB-approved, retrospective study was to compare image quality between 2D and high-resolution 3D, T2-weighted (T2WI) magnetic resonance imaging (MRI) sequences and to investigate the additional value of ultra-high b-value diffusion-weighted imaging (DWI; b=2,000 mm/s2) for both rectal cancer staging and evaluating treatment response. MATERIALS AND METHODS: From 12 February to 24 August 2016, 26 consecutive patients (22 males, four females; mean age: 61.9±14.0 years) with histologically-proven rectal cancer. In total 31 examinations [12 prior to and 19 after chemoradiation (CRT)] were included. The patients underwent pelvic MRI on a 3.0-T scanner (Magnetom Skyra, Erlangen, Germany). Three radiologists (3, 4, and 5 years of experience in MRI, respectively) independently assessed all images and rated the image quality of DWI (b=800 mm/s2), apparent diffusion coefficient map, DWI (b=2,000 mm/s2), 3D sagittal T2WI, 3D axial T2WI, 2D sagittal T2WI, and 2D axial T2WI of each patient, respectively. In addition, signal intensity ratios (SIR) were calculated between rectal cancer and obturator internus muscle (background) in all patients after CRT on DWI (b=2,000 mm/s2) and correlated with histopathological regression grade (RG). RESULTS: Tumor delineation was significantly better by 2D T2WI than 3D T2WI both before and after CRT (before CRT: Z=-3.2, p=0.02; after CRT: Z=-4.408, p<0.001; all: Z=-5.192; p<0.001) and was the preferred method, although image quality ratings were not significantly different (3D sagittal: 4.00±0.48; 2D sagittal: 4.03±0.34, p=0.713; 3D axial: 3.85±0.61, 2D axial: 3.78±0.64, p=0.537). Independent t-test showed significantly higher SIR between those with RG 1 or 2 (moderate response: mean score=2.02) and those with RG 3+4 (good response: mean score=0.8) (t=3.044, p=0.011). In those with RG 4 (complete response), SIR of b2000 was 0.946 compared to a 1.41 average of the whole cohort. In two patients, tumor was invisible on b2000 following CRT (RG 3 and 4, respectively). Interobserver agreement was mostly good (κ≥0.6) regarding image quality assessment, except for poor agreement (κ=0.4) in DWI (b2000) between the two less-experienced readers. CONCLUSION: In conclusion, 3D T2WI might be useful for evaluating response to neoadjuvant therapy in a comprehensive, cost-effective protocol, where 2D imaging seems to be preferable. In addition, DWI (b2000) may be beneficial in assessing both the primary and the residual tumor after CRT in rectal cancer and SIR may be helpful in assessing response to CRT.

Is There a Role for Functional MRI for the Assessment of Extracapsular Extension in Prostate Cancer?

BACKGROUND/AIM: Exctracapsular extension (ECE) in prostate cancer has a high impact on treatment decision. MRI might predict presence of ECE non-invasively. PATIENTS AND METHODS: Triplanar T2w-sequences, DWI (diffusion weighted imaging) and DCE (dynamic contrast-enhanced imaging) of 34 patients with PCa were analyzed to prior prostatectomy. Sensitivity (SS) and specificity (SP) of T2w, apparent diffusion coefficient (ADC), plasma flow (PF) and mean transit time (MTT) normalized by PCa/normal tissue ratio for prediction of CI (capsular infiltration)/ECE were determined by area-under-the-receiver-operating-characteristics analysis. RESULTS: SS/SP for detecting ECE was 29/85. AUC (area under the curve) of ECE cases was 0.98/0.92/0.69 (cut-off-ratios 3.2/0.51/0.46), SS 93/100/86% and SP 95/80/50% for PF-/MTT-/ADC-ratios, respectively. PF- and MTT-ratios between CI and without CI/ECE differed significantly (PF, p<0.0001; MTT, p=0.0134) with SS/SP 84/89% for PF and SS/SP 52/100% for MTT-ratios. No significant differences regarding ADC-ratios were identified. CONCLUSION: ECE/CI can be assessed by quantitative DCE analysis with great diagnostic confidence and higher specificity than ADC.

Quantitative Perfusion Analysis of the Rectum Using Golden-Angle Radial Sparse Parallel Magnetic Resonance Imaging: Initial Experience and Comparison to Time-Resolved Angiography With Interleaved Stochastic Trajectories.

OBJECTIVES: Purpose of this study was to compare the quality of perfusion maps obtained from prototypical free-breathing magnetic resonance imaging (MRI) with continuous golden-angle radial sampling and iterative reconstruction (GRASP) to conventional acquisition using time-resolved angiography with interleaved stochastic trajectories (TWIST) in patients with rectal cancer. MATERIAL AND METHODS: Forty cases were included for retrospective analysis. Twenty of the patients received routine multiparametric MRI at 3 T for rectal cancer staging, including perfusion measurement with GRASP or TWIST (10 patients for each technique, including 5 prechemoradiation and 5 postchemoradiation). Twenty patients without history of rectal disease served as control group (10 GRASP, 10 TWIST). GRASP images were reconstructed at temporal resolution of 3.45 seconds (21 spokes/frame). A voxel-by-voxel deconvolution approach was used to determine rectal plasma flow (mL/100 mL per minute). Regions of interest were placed at 3 levels within the tumor and normal rectum (lower, middle, and upper part). The quality of morphologic images, perfusion maps, and arterial input function were scored by 2 blinded radiologists. Independent t tests were applied. RESULTS: Three patients of the TWIST control group had to be excluded due to technical failure of the sequence. Significantly higher scores for the perfusion maps and arterial input functions (total cohort) were obtained using GRASP (P < 0.05). Artifacts in the perfusion maps were rated significantly lower than for TWIST (P < 0.05). In the healthy rectum cohort, the average plasma flow of normal rectal wall was 31.78 ± 7.39 mL/100 mL per minute with GRASP, compared with 77.62 ± 34.08 mL/100 mL per minute with TWIST, indicating much lower variance for GRASP. Plasma flow values obtained with both methods enabled distinguishing between normal rectal wall and rectal cancer, both before and after chemoradiation. Morphologic image quality was generally higher with GRASP (P < 0.01). CONCLUSIONS: GRASP perfusion imaging can distinguish between normal rectum and rectal cancers with higher image quality and less variance than TWIST. Additional morphologic assessment with high spatial resolution from the GRASP acquisition may increase the accuracy and diagnostic confidence of the examination.

The linguistic validation of the gut feelings questionnaire in three European languages.

BACKGROUND: Physicians' clinical decision-making may be influenced by non-analytical thinking, especially when perceiving uncertainty. Incidental gut feelings in general practice have been described, namely, as "a sense of alarm" and "a sense of reassurance". A Dutch Gut Feelings Questionnaire (GFQ) was developed, validated and afterwards translated into English following a linguistic validation procedure. The aims were to translate the GFQ from English into French, German and Polish; to describe uniform elements as well as differences and difficulties in the linguistic validation processes; to propose a procedural scheme for future GFQ translations into other languages. METHODS: We followed a structured, similar and equivalent procedure. Forward and backward-translations, repeated consensus procedures and cultural validations performed in six steps. Exchanges between the several research teams, the authors of the Dutch GFQ, and the translators involved continued throughout the procedure. RESULTS: 12 translators, 52 GPs and 8 researchers in the field participated to the study in France, Germany, Switzerland and Poland. The collaborating research teams created three versions of the 10-item GFQ. Each research team found and agreed on compromises between comparability and similarity on one hand, and linguistic and cultural specificities on the other. CONCLUSIONS: The gut feeling questionnaire is now available in five European languages: Dutch, English, French, German and Polish. The uniform procedural validation scheme presented, and agreed upon by the teams, can be used for the translation of the GFQ into other languages. Comparing results of research into the predictive value of gut feelings and into the significance of the main determinants in five European countries is now possible.

Rapid Cartesian versus radial acquisition: comparison of two sequences for hepatobiliary phase MRI at 3 tesla in patients with impaired breath-hold capabilities.

BACKGROUND: Hepatocyte-specific gadolinium based contrast agents (HSCA) provide substantial information for the classification of liver lesions in magnetic resonance imaging (MRI). However, breathing artifacts which reduce image quality and diagnostic confidence of hepatobiliary phase acquisitions are regularly observed in clinical routine. The aim of this study was to evaluate two approaches to reduce breathing artifacts for hepatobiliary phase imaging. METHODS: Twenty minutes after administration of a HSCA (gadoxetic acid), a T1-weighted VIBE sequence with radial k-space sampling (radialVIBE, 180 s acquisition time in free breathing) and a highly accelerated Cartesian VIBE with Dixon fat separation (CD-VIBE, CAIPIRINHA acceleration with r = 2 × 2, breath-hold 8-10 s) were acquired in 35 patients (12 female, 57 ± 13 years), who showed breath-holding difficulties in early phases of the examinations. Image quality (image sharpness, noise, artifacts, homogeneity of fat saturation, bile duct delineation and overall image quality) as well as conspicuity and liver-to-lesion signal intensity (SI) ratios of focal liver lesions were assessed for both radial- and CD-VIBE. RESULTS: Overall image quality was rated good to excellent for both sequences, while CD-VIBE was preferred in most cases. Though radialVIBE received better results regarding image noise and artifacts, both sequences were rated equally regarding bile duct delineation and sharpness. Focal liver lesion (n = 42) conspicuity was rated significantly better and SI-ratios were significantly higher on CD-VIBE (2.45 ± 1.44 vs. 1.61 ± 0.70 in radialVIBE, p = 0.0001). In three patients, CD-VIBE was rated non-diagnostic due to severe breathing artifacts, while radialVIBE was diagnostic in those patients. CONCLUSION: Both highly accelerated Cartesian as well as radial acquisition techniques provide good to excellent image quality in hepatobiliary phase MRI. In comparison, CD-VIBE offered better overall image quality and liver lesion conspicuity. However, radialVIBE was a valuable alternative in patients unable to sustain even short breath-hold intervals. Further studies including lager patient cohorts are desirable to allow a transfer of these results to a general patient population.

Reconstruction for renal artery aneurysms using the tailoring technique.

OBJECTIVE: Renal artery (RA) aneurysm (RAA) is a rare and complex disease. Treatment options for a RAA include endovascular surgery and open surgery with ex vivo repair or in situ reconstruction. This study evaluated the long-term outcome after vascular reconstruction of RAAs using the tailoring technique. Tailoring or aneurysmorrhaphy means a partial resection of the aneurysm with direct suture of the remaining arterial wall. METHODS: A single-center retrospective study was conducted between January 1990 and December 2015. The tailoring technique was used to surgically repair 88 RAAs in 80 patients (52 women) with a mean age of 52.9 years. Patients' demographic data, vascular therapy, and renal function during follow-up were retrospectively evaluated. RESULTS: The localization of the RAA was at the right kidney in 58 patients. The mean size of the aneurysm was 21.4 ± 9.7 mm (range, 8-67 mm). Hypertension was diagnosed in 56 patients, and 23 were asymptomatic. One RAA was ruptured. The overall morbidity rate was 16.3%, including bleeding (n = 4), RA stenosis (n = 3), RA occlusion (n = 4), RA dissection (n = 1), and myocardial infarction (n = 1). One patient died of myocardial infarction for a 30-day mortality rate of 1.3%. The 30-day primary patency rate was 90.0%. The 30-day secondary patency rate was 95.0%. Follow-up data were obtained from 71 patients who underwent tailoring in 78 RAAs. The mean follow-up period was 60.7 months (range 2-229 months). In 76.4% of patients with RAA and hypertension, RAA reconstruction contributed to the cure or improvement of hypertension. The long-term patency after RAA reconstruction was demonstrated in a Kaplan-Meier curve, with cumulative patency rates of 98.7%, 97.4%, 94.8%, and 92.3% after 18, 24, 36, and 48 months, respectively. Estimated survival rates were 98.8%, 97.5%, and 96.3% after 12, 48, and 60 months, with an estimated mean time of 216.5 ± 7.2 months. CONCLUSIONS: The tailoring technique is a safe and effective procedure with good long-term outcomes. RAA reconstruction contributed to the cure or improvement of renovascular hypertension.

mMRI at 3.0 T as an Evaluation Tool of Therapeutic Response to Neoadjuvant CRT in Patients with Advanced-stage Rectal Cancer.

AIM: To assess whether multiparametric MRI (mMRI) can serve as a tool for evaluating response to chemoradiation therapy (CRT) in advanced-stage rectal cancer. PATIENTS AND METHODS: Twenty-one patients underwent a mMRI protocol at 3T before and after CRT. Two experienced radiologists evaluated the MRI measurements and inter-reader correlation was assessed. Changes in functional parameters in relation to regression, as well as pT stage were analyzed. The perfusion parameters plasma flow (PF) and mean transit time (MTT) were calculated offline using the established UMM Perfusion tool. RESULTS: Apparent diffusion coefficient values were significantly different among the different tumor RGs before CRT (p=0.041). Changes of dynamic contrast enhanced (DCE) MRI values did not reflect treatment response (PF: p=0.5; MTT: p=0.74). CONCLUSION: The results of our study population indicate that a high initial apparent diffusion coefficient value may be predictive of response to therapy following CRT.