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 morphol- ogy 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

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 ± 8.0 vs. 21.2 ± 3.5 mm, p = 0.089) and the sphincter length longer (19.7 ± 7.3 vs. 16.7 ± 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

Schnelle und bewegungsresistente Abbildung des Halsvolumens mittels Echtzeit-MRT

Hintergrund: Die hohe Bildfrequenz der Echtzeit-MRT wurde in vorherigen Studien zur bewegten Abbildung des Schluckvorganges mit 24 Bildern pro Sekunde genutzt. In der folgenden Studie soll die hohe Bildfrequenz der raschen und bewegungsresistenten Abbildung des Halsvolumens dienen. Eine erste spätere Anwendung soll die Fisteldiagnostik nach Laryngektomie sein.Material und Methoden: Die dynamische Nutzung der Echtzeit-MRT wurde zur schnellen Volumenabdeckung erweitert, indem nach jedem Einzelbild mit einer Messzeit von nur 50 Millisekunden die Position der Schichtebene um 10% (0.4 mm) der Schichtdicke (4 mm) weitergeschoben wurde. Das neuartige Verfahren wurde zunächst an einem normalen und gesunden Hals geprüft. Weil in Folgestudien die Detektion von Halsfisteln untersucht werden soll, wurde zudem der Hals eines vor mehreren Jahren laryngektomierten Patienten in gleicher Weise gemessen.Ergebnisse: Ein 80 mm großes, T1-gewichtetes Volumen im Halsbereich konnte mit 200 überlappenden Schichtbildern in nur 10 Sekunden vermessen werden, wobei die einzelnen Aufnahmen keinerlei Bewegungsartefakte aufweisen. Sowohl beim gesunden Hals als auch beim Hals des laryngektomierten Patienten gelang die schnelle Abbildung des gesamten Halsvolumens in hoher räumlicher Auflösung (0.75x0.75 mm). Insbesondere die bei Fisteldiagnostiken wesentlichen Halsweichteile oberhalb des Stomas waren gut beurteilbar.Diskussion: Das neuartige Echtzeit-MRT wurde bereits bei der Volumendarstellung verschiedener Organe (Leber, Prostata, Hirn, Arteria carotis) eingesetzt. In der aktuellen Studie erfolgte erstmals die schnelle Volumendarstellung der Halsweichteile ohne Bewegungsartefakte. Die erreichte räumliche Auflösung war von hoher Qualität. Dies lässt die zuverlässige Anwendung bei der angestrebten Fisteldiagnostik erwarten.Fazit: Die neuartige Nutzung des Echtzeit-MRT zur schnellen und bewegungsresistenten Volumendarstellung ist auch zur Abbildung der Halsweichteile geeignet und könnte eine Alternative zu radiologischen Durchleuchtungen des Halsvolumens darstellen

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/mm2) 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