[Staging and Diagnostics of Rectal Cancer]. / Modalitäten des Stagings und der Diagnostik bei Rektumkarzinom.

The review titled "Staging and Diagnostics of Rectal Cancer" aims to provide insight to imaging techniques in patients with rectal cancer.Rectal cancer is among the most common malignancies, with one of the highest mortality rates worldwide. Timely diagnosis and therapy of this cancer therefore has important socio-economic implications.Radiological imaging plays a major role in the planning of subsequent therapy. Modern tomographic imaging is used not only for initial diagnosis, but also for staging.The individual role of different imaging techniques in diagnosis of rectal cancer will be explained in detail, and their function in general. Furthermore, we will present relevant radiological research related.The increasing role of MRI-based local staging will be presented in detail in this review. Defined diagnostic criteria, based on common recommendations, will be explained. We will show how MRI-based local staging can support the initial diagnosis and follow-up examinations in collaboration with other medical specialties in therapeutic planning. In particular, we describe how MRI is capable of substantially influencing the determination of surgical procedures in rectal cancer.

Perioperative LiMAx Test Analysis: Impact of Portal Vein Embolisation, Chemotherapy and Major Liver Resection.

BACKGROUND: Postoperative liver failure (PLF) is a severe complication after major liver resection (MLR). To increase the safety of patients, clinical bedside tests are of great importance. However, limitations of their applicability and validity impair their value. METHODS: Preoperative measurements of the liver maximum capacity (LiMAx) were performed in n = 40 patients, who underwent MLR (≥3 segments). Matched postoperative LiMAx was measured in n = 21 patients. Liver function was compared between pretreated patients (n = 11 with portal vein embolisation (PVE) and n = 19 patients with preoperative chemotherapy) and therapy naïve patients. The LiMAx values were compared with liver-specific blood parameters and volumetric analysis. RESULTS: In total, n = 40 patients were enrolled in this study. The majority of patients (n = 33; 82.5%) had high preoperative LiMAx values (>315 µg/kg/h), while only seven patients (17.5%) had medium values (140-315 µg/kg/h), and none of the patients had low values (<140 µg/kg/h). A comparison of pretreated patients (with PVE and/or chemotherapy) and therapy naïve patients showed no significant difference in the preoperative LiMAx values (p > 0.05). The preoperative LiMAx values were significantly higher than the matched postoperative values on postoperative day 1 (p < 0.0001). A comparison between the expected and measured postoperative LiMAx showed a difference (≥10%) in 7 out of 13 patients (53.8%). After an initial postoperative decrease in the LiMAx, the patients without complications (n = 12) showed a continuous increase until 14 days after surgery. In the patients with postoperative complications, a decrease in the LiMAx was associated with a prolonged recovery. CONCLUSIONS: For patients undergoing MLR within the 0.5% rule, which is the clinical gold standard, the LiMAx values do not offer any additional information. Additionally, the LiMAx may have reflected liver function, but it did not deliver additional information regarding postoperative liver recovery. The clinical use of LiMAx might be relevant in selected patients beyond the 0.5% rule.

Visualization of deglutition and gastroesophageal reflux using real-time MRI: a standardized approach to image acquisition and assessment.

This study aims to develop a standardized algorithm for gastroesophageal image acquisition and diagnostic assessment using real-time MRI. Patients with GERD symptoms undergoing real-time MRI of the esophagus and esophagogastric junction between 2015 and 2018 were included. A 10 ml bolus of pineapple juice served as an oral contrast agent. Patients performed Valsalva maneuver to provoke reflux and hiatal hernia. Systematic MRI assessment included visual presence of achalasia, fundoplication failure in patients with previous surgical fundoplication, gastroesophageal reflux, and hiatal hernia. A total of 184 patients (n = 92 female [50%], mean age 52.7 ± 15.8 years) completed MRI studies without adverse events at a mean examination time of 15 min. Gastroesophageal reflux was evident in n = 117 (63.6%), hiatal hernia in n = 95 (52.5%), and achalasia in 4 patients (2.2%). Hiatal hernia was observed more frequently in patients with reflux at rest (n = 67 vs. n = 6, p < 0.01) and during Valsalva maneuver (n = 87 vs. n = 8, p < 0.01). Real-time MRI visualized a morphologic correlate for recurring GERD symptoms in 20/22 patients (90%) after fundoplication procedure. In a large-scale single-center cohort of patients with GERD symptoms undergoing real-time MRI, visual correlates for clinical symptoms were evident in most cases. The proposed assessment algorithm could aid in wider-spread utilization of real-time MRI and provides a comprehensive approach to this novel imaging modality.

T1 mapping of the prostate using Single-Shot T1FLASH and MOLLI MRI Techniques: Comparison of artifact burden and image quality.

PURPOSE: To assess artifact burden and image quality of different MRI T1 mapping techniques of the prostate. METHODS: Participants with suspected prostate cancer (PCa) were prospectively enrolled from June-October 2022 and examined with multiparametric prostate MRI (mpMRI; 3 T scanner; T1wi, T2wi, DWI und DCE). T1 mapping was performed before and after administration of gadolinium-based contrast-agent (GBCA) using (i) a modified Look-Locker inversion (MOLLI) technique and (ii) a novel single-shot T1FLASH inversion recovery technique. T2wi, DWI, T1FLASH and MOLLI sequences were systematically examined regarding prevalence of artifacts and image quality using a 5-point Likert-Scale. RESULTS: A total of n = 100 patients were included (median age: 68 years). T1FLASH maps (pre-and post-GBCA) showed metal artifacts in 7% of cases and susceptibility artifacts in 1%. For MOLLI maps, pre-GBCA metal and susceptibility artifacts were documented in 6.5% of cases each. MOLLI maps post-GBCA showed artifacts in 59% of cases resulting primarily from urinary GBCA excretion and GBCA accumulation at the bladder base (p < 0.01 versus T1FLASH post-GBCA). Image quality for T1FLASH pre-GBCA was rated at a mean 4.9+/-0.4 and for MOLLI at 4.8+/-0.6 (p = 0.14). Post-GBCA image quality was rated at a mean 4.9+/-0.4 for T1FLASH and at 3.7+/-1.1 for MOLLI (p < 0.001). CONCLUSIONS: T1FLASH maps provide a fast and robust method for quantification of T1 relaxation times of the prostate. T1FLASH is suitable for T1 mapping of the prostate following administration of contrast agents, while MOLLI T1 mapping is impaired through GBCA accumulation at the bladder base leading to severe image artifacts and reduced image quality.

T1 Mapping of the Prostate Using Single-Shot T1FLASH: A Clinical Feasibility Study to Optimize Prostate Cancer Assessment.

PURPOSE: The aim of this study was to assess the clinical feasibility of magnetic resonance imaging (MRI) T1 mapping using T1FLASH for assessment of prostate lesions. METHODS: Participants with clinical suspicion for prostate cancer (PCa) were prospectively enrolled between October 2021 and April 2022 with multiparametric prostate MRI (mpMRI) acquired on a 3 T scanner. In addition, T1 mapping was accomplished using a single-shot T1FLASH technique with inversion recovery, radial undersampling, and iterative reconstruction. Regions of interest (ROIs) were manually placed on radiologically identified prostate lesions and representative reference regions of the transitional zone (TZ), benign prostate hyperplasia nodules, and peripheral zone (PZ). Mean T1 relaxation times and apparent diffusion coefficient (ADC) values (b = 50/b = 1400 s/mm 2 ) were measured for each ROI. Participants were included in the study if they underwent ultrasound/MRI fusion-guided prostate biopsy for radiologically or clinically suspected PCa. Histological evaluation of biopsy cores served as reference standard, with grading of PCa according to the International Society of Urological Pathology (ISUP). ISUP grades 2 and above were considered clinically significant PCa for the scope of this study. Histological results of prostate biopsy cores were anatomically mapped to corresponding mpMRI ROIs using biopsy plans. T1 relaxation times and ADC values were compared across prostate regions and ISUP groups. Across different strata, T1 relaxation time, ADC values, and diagnostic accuracy (area under the curve [AUC]) were compared using statistical methods accounting for clustered data. RESULTS: Of 67 eligible participants, a total of 40 participants undergoing ultrasound/MRI fusion-guided prostate biopsy were included. Multislice T1 mapping was successfully performed in all participants at a median acquisition time of 2:10 minutes without evident image artifacts. A total of 71 prostate lesions was radiologically identified (TZ 49; PZ 22). Among those, 22 were histologically diagnosed with PCa (ISUP groups 1/2/3/4 in n = 3/15/3/1 cases, respectively). In the TZ, T1 relaxation time was statistically significantly lower for PCa compared with reference regions ( P = 0.029) and benign prostate hyperplasia nodules ( P < 0.001). Similarly, in the PZ, PCa demonstrated shorter T1 relaxation times versus reference regions ( P < 0.001). PCa also showed a trend toward shorter T1 relaxation times (median, 1.40 seconds) compared with radiologically suspicious lesions with benign histology (median, 1.47 seconds), although statistical significance was not reached ( P = 0.066). For discrimination of PCa from reference regions and benign prostate lesions, T1 relaxation times and ADC values demonstrated AUC = 0.80 and AUC = 0.83, respectively ( P = 0.519). Discriminating PCa from radiologically suspicious lesions with benign histology, T1 relaxation times and ADC values showed AUC = 0.69 and AUC = 0.62, respectively ( P = 0.446). CONCLUSIONS: T1FLASH-based T1 mapping yields robust results for quantification of prostate T1 relaxation time at a short examination time of 2:10 minutes without evident image artifacts. Associated T1 relaxation times could aid in discrimination of significant and nonsignificant PCa. Further studies are warranted to confirm these results in a larger patient cohort, to assess the additional benefit of T1FLASH maps in conjunction with mpMRI sequences in the setting of deep learning, and to evaluate the robustness of T1FLASH maps compared with potentially artifact-prone diffusion-weighted imaging sequences.

Assessment of esophagogastric junction morphology by dynamic real-time MRI: comparison of imaging features to high-resolution manometry.

PURPOSE: To assess the esophagogastric junction (EGJ) on real-time MRI and compare imaging parameters to EGJ morphology on high-resolution manometry (HRM). METHODS: A total of 105 of 117 eligible patients who underwent real-time MRI and high-resolution manometry for GERD-like symptoms between 2015 and 2018 at a single center were retrospectively evaluated (male n = 57; female n = 48; mean age 52.5 ± 15.4 years). Real-time MRI was performed at a median investigation time of 15 min (1 frame/40 ms). On HRM, EGJ morphology was assessed according to the Chicago classification of esophageal motility disorders. Real-time MRI was performed at 3 T using highly undersampled radial fast low-angle shot acquisitions with NLINV image reconstruction. A 10 mL pineapple juice bolus served as oral contrast agent at supine position. Real-time MRI films of the EGJ were acquired during swallowing events and during Valsalva maneuver. Anatomic and functional MRI parameters were compared to EGJ morphology on HRM. RESULTS: On HRM, n = 42 patients presented with EGJ type I (40.0%), n = 33 with EGJ type II (31.4%), and n = 30 with EGJ type III (28.6%). On real-time MRI, hiatal hernia was more common in patients with EGJ type III (66.7%) than in patients with EGJ type I (26.2%) and EGJ type II (30.3%; p < 0.001). Sliding hiatal hernia was more frequent in patients with EGJ type II (33.3%) than in patients with EGJ type III (16.7%) and EGJ type I (7.1%; p = 0.017). The mean esophagus-fundus angle of patients was 85 ± 31° at rest and increased to 101 ± 36° during Valsalva maneuver. CONCLUSION: Real-time MRI is a non-invasive imaging method for assessment of the esophagogastric junction. Real-time MRI can visualize dynamic changes of the EGJ during swallowing events.

Cross-insitutional standardization of imaging protocols - A pilot study within the scope of the Comprehensive Cancer Center Lower Saxony. / Standortübergreifende Standardisierung von Untersuchungsprotokollen ­ eine Pilotstudie im Rahmen des Comprehensive Cancer Centers Niedersachen.

PURPOSE: Cross-institutional establishment of standardized protocols for CT and MR imaging of primary liver and pancreas tumors in an oncological center. MATERIALS AND METHODS: This prospective dual-institution study was approved by the local IRBs. Minimum requirements (phases, sequences, slice thickness) for imaging of primary liver and pancreas tumors were defined and implemented at both sites. Between 06/19 and 08/19 in-house examinations were evaluated in terms of compliance with defined protocols and image quality. In addition, extramural examinations that were demonstrated at interdisciplinary tumor board meetings in the same study period were reviewed. Results were analyzed by means of descriptive statistics, and differences between centers, modalities and organs assessed (Fisher-exact Test, p < 0.05 deemed significant). RESULTS: 480 data sets (397 internal, 83 extramural) were included in this study and analyzed. Overall protocol compliance for in-house examinations was 93.5 % (371/397 datasets), without statistical significant difference between the two institutions (p = 0.0615). External studies met minimum requirements in 48.2 % (40/83 datasets). Regarding in-house imaging, significant differences were observed between CT of the liver and the pancreas (p < 0.05) and between CT and MRI of the pancreas (p < 0.05). CONCLUSION: As demonstrated in this pilot project, cross-institutional establishment of standardized imaging protocols is feasible with a compliance rate of more than 90 %. Standardized imaging protocols may serve as a quality indicator in oncological imaging, and over time, improve cross-institutional patient care. KEY POINTS: · Cross-institutional establishment of standardized imaging protocols is feasible with high compliance.. · Standards may serve as a quality indicator in oncological imaging.. · In perspective, cross-institutional patient care may be improved.. CITATION FORMAT: · Römermann I, Al-Bourini O, Seif Amir Hosseini A et al. Cross-insitutional standardization of imaging protocols - A pilot study within the scope of the Comprehensive Cancer Center Lower Saxony. Fortschr Röntgenstr 2021; 193: 410 - 416.

Assessment of esophageal motility disorders by real-time MRI.

PURPOSE: To investigate imaging findings of esophageal motility disorders on dynamic real-time. MATERIAL AND METHODS: 102 patients with GERD-like symptoms were included in this retrospective study between 2015-2018. Dynamic real-time MRI visualized the transit of a 10 mL pineapple juice bolus through the esophagus and EGJ with a temporal resolution of 40 ms. Dynamic and anatomic parameters were measured by consensus reading. Imaging findings were compared to HRM utilizing the Chicago classification of esophageal motility disorders, v3.0. RESULTS: All 102 patients completed real-time MRI in a median examination time of 15 min. On HRM, 14 patients presented with disorders with EGJ outlet obstruction (EGJOO) (13.7 %), 7 patients with major disorders of peristalsis (6.9 %), and 32 patients with minor disorders of peristalsis (31.4 %). HRM was normal in 49 patients (48.0 %). Incomplete bolus clearance was significantly more frequent in patients with esophageal motility disorders on HRM than in patients with normal HRM (p = 0.0002). In patients with motility disorders with EGJOO and major disorders of peristalsis, the esophageal diameter tended to be wider (23.6 ±â€¯8.0 vs. 21.2 ±â€¯3.5 mm, p = 0.089) and the sphincter length longer (19.7 ±â€¯7.3 vs. 16.7 ±â€¯3.0 mm, p = 0.091) compared to patients with normal HRM. 3/7 patients with achalasia type II were correctly identified by real-time MRI and one further achalasia type II patient was diagnosed with a motility disorder on MRI films. The other 3/7 patients presented no specific imaging features. CONCLUSION: Real-time MRI is an auxiliary diagnostic tool for the assessment of swallowing events. Imaging parameters may assist in the detection of esophageal motility disorders.

Gadolinium-based Contrast Agents for Cardiac MRI: Use of Linear and Macrocyclic Agents with Associated Safety Profile from 154 779 European Patients.

PURPOSE: To assess current use and acute safety profiles of gadolinium-based contrast agents (GBCAs) in cardiac MRI given recent suspensions of GBCA approval. MATERIALS AND METHODS: Patients were retrospectively included from the multinational multicenter European Society of Cardiovascular Radiology (ESCR) MR/CT Registry collected between January 2013 and October 2019. GBCA-associated acute adverse events (AAEs) were classified as mild (self-limiting), moderate (pronounced AAE requiring medical management), and severe (life threatening). Multivariable generalized linear mixed-effect models were used to assess AAE likelihood. RESULTS: A total of 154 779 patients (average age, 53 years ± 19 [standard deviation]; 99 106 men) who underwent cardiac MRI were included, the majority of whom underwent administration of GBCAs (94.2% [n = 145 855]). While linear GBCAs were used in 15.2% of examinations through 2011, their use decreased to less than 1% in 2018 and 2019. Overall, 0.36% (n = 556) of AAEs were documented (mild, 0.12% [n = 178]; moderate, 0.21% [n = 331]; severe, 0.03% [n = 47]). For nonenhanced cardiac MRI, examination-related events were reported in 2.59% (231 of 8924) of cases, the majority of which were anxiety (0.98% [n = 87]) and dyspnea (0.93% [n = 83]). AAE rates varied significantly by pharmacologic stressor, GBCA molecular structure (macrocyclic vs linear GBCA: multivariable odds ratio, 0.634; 95% confidence interval: 0.452, 0.888; P = .008), GBCA subtype, and imaging indication. CONCLUSION: Gadolinium-based contrast agent administration changed according to recent regulatory decisions, with use of macrocyclic agents almost exclusively in 2018 and 2019; these agents also demonstrated a favorable acute safety profile.Supplemental material is available for this article.© RSNA, 2020.