Avinash K. Nehra

Dysphagia is defined as a subjective sensation of difficulty swallowing and can result from oropharyngeal or esophageal etiologies based upon patient symptoms. Dysphagia affects approximately 16% of adults in the general population, with prevalence increasing with age. Esophagogastroduodenuoscopy (EGD) is initially performed to assess for structural abnormalities resulting in esophageal dysphagia. However, if EGD reveals no pathologic abnormalities, high-resolution manometry (HRM) and barium esophagography are performed in order to assess for underlying causes of dysmotility. Esophageal motility disorders (EMDs) are an underrecognized cause of dysphagia and can be characterized by impaired esophageal peristalsis or lower esophageal sphincter dysfunction. High-resolution manometry (HRM) measures key metrics such as integrated relaxation pressure (IRP), which is the deglutitive relaxation across the LES, and metrics of esophageal body peristalsis based on distal contractile integral (DCI) and distal latency (DL). The Chicago Classification version 4 (CCv4.0), published in 2021, provides a standardized classification scheme for differentiating EMDs using metrics from HRM. Additionally, barium esophagography has remained an important adjunctive diagnostic modality, as this may identify strictures, neoplasms, or hiatal hernias, but can also identify major motility disorders such as achalasia and distal esophageal spasm. The combined use of HRM with timed barium esophagram can enhance the diagnostic accuracy of EMDs, particularly when HRM demonstrates inconclusive findings. Therefore, radiologists should be familiar with how imaging findings from barium esophagram integrate with findings noted on HRM. The aim of this review is to highlight the findings of EMDs noted on HRM in conjunction with barium esophagography, thereby illustrating characteristic patterns of primary and secondary EMDs.

Precise and accurate staging of rectal cancer is critical for formulating an appropriate treatment plan, including determining the necessity for neoadjuvant therapy and establishing an adequate surgical approach. MRI is the gold standard for locoregional tumor staging, also playing a central role for patients selected for watchful waiting surveillance after total neoadjuvant therapy. Nevertheless, challenges exist from acquisition to interpretation of rectal MRI examinations and, despite societal guidelines, practices vary across institutions. In this paper, we review the optimal technique for acquisition of diagnostic quality rectal MRI and address its existing challenges and unmet needs, encompassing both acquisition and image interpretation.

Achalasia, a primary esophageal motility disorder, can progress to an end-stage requiring interventions beyond standard therapies. The fluoroscopic findings of end-stage achalasia can be characterized by a dilated, redundant, sigmoidal esophagus with distal esophageal sump formation. Peroral Plication of the Esophagus (POPE) is a novel endoscopic procedure for patients with end-stage achalasia and prominent distal esophageal sump formation. Similar findings can also be seen in some patients after esophagectomy with gastric conduit reconstruction. POPE is indicated when esophageal redundancy rather than lower esophageal sphincter dysfunction is the primary concern. While initial studies show POPE’s technical feasibility, safety, and symptomatic improvement, to our knowledge there is no literature on the imaging findings and evaluation pre and post POPE. This pictorial essay aims to illustrate and describe the important components of a pre-POPE imaging evaluation, expected post-POPE anatomy, and short-term complications.

Objectives Radiologist participation in multidisciplinary tumor board can be time-consuming and demanding, requiring substantial preparation. Anecdotally radiologist participation is felt to help identify discrepancies in previous interpretations; however, there are limited data assessing the actual impact of their tumor board review on patient management. This prospective study aims to evaluate how the reinterpretation of outside imaging and review at hepatobiliary tumor board (HBTB) affects the diagnosis and management of patients with hepatobiliary neoplasms. Methods This prospective analysis included all patients presented at the weekly HBTB between 6/13/2023—6/25/2024. One radiologist reviewed the available reports of outside imaging, the local reinterpretation of outside imaging, the updated local imaging, and documented conclusions from discussion of the case at HBTB. HBTB included 4 radiologists who had reviewed each case. Discrepancies (presence/absence, number, and reasons for) were recorded. When discrepancies occurred, the impact on patient management (5-point Likert scale) was determined by two of the radiologists present at the HBTB in consensus, with input from clinicians if needed. A six-month follow-up was performed to confirm suspected diagnoses. Results 208 cases (128 males, 104 chronic liver disease patients) were presented at HBTB. Disagreements in the detection or characterization of lesions were found in 59/208 (28.4%) of cases. A change in management occurred in 38/59 (64.6%) of these discrepant cases. In cases with recorded discrepancies in which follow-up confirmation was available, the final interpretation was confirmed in 34/41 (82.9%) of cases. Conclusion Our study found a discrepant interpretation in nearly one-third of cases presented at a weekly HBTB and a resultant change in management in 65% of those cases. These findings highlight the importance of reinterpretation of prior imaging studies and the presence of radiologists at HBTB to guide optimal patient management. Key message Patient care is substantially impacted by reinterpretation of prior imaging and participation of radiologists at hepatobiliary tumor board. Graphical abstract

Photon-counting detector (PCD) CT is an emerging technology that has led to continued innovation and progress in diagnostic imaging after it was approved by the U.S. Food and Drug Administration for clinical use in September 2021. Conventional energy-integrating detector (EID) CT measures the total energy of x-rays by converting photons to visible light and subsequently using photodiodes to convert visible light to digital signals. In comparison, PCD CT directly records x-ray photons as electric signals, without intermediate conversion to visible light. The benefits of PCD CT systems include improved spatial resolution due to smaller detector pixels, higher iodine image contrast, increased geometric dose efficiency to allow high-resolution imaging, reduced radiation dose for all body parts, multienergy imaging capabilities, and reduced artifacts. To recognize these benefits, diagnostic applications of PCD CT in musculoskeletal, thoracic, neuroradiologic, cardiovascular, and abdominal imaging must be optimized and adapted for specific diagnostic tasks. The diagnostic benefits and clinical applications resulting from PCD CT in early studies have allowed improved visualization of key anatomic structures and radiologist confidence for some diagnostic tasks, which will continue as PCD CT evolves and clinical use and applications grow. ^©RSNA, 2023 Quiz questions for this article are available in the supplemental material. See the invited commentary by Ananthakrishnan in this issue.

Advances in imaging and quantification techniques have allowed improved diagnosis and assessment of gastrointestinal motility disorders, but radiologists must understand the underlying pathophysiol... The motor function of the gastrointestinal tract relies on the enteric nervous system, which includes neurons spanning from the esophagus to the internal anal sphincter. Disorders of gastrointestin...