Congenital cholesteatoma: what radiologists need to know.

Congenital cholesteatoma is a rare, non-neoplastic lesion that causes conductive hearing loss in children. It is underrecognized and often diagnosed only when there is an established hearing deficit. In the pediatric population, hearing deficiency is particularly detrimental because it can impede speech and language development and, in turn, the social and academic well-being of affected children. Delayed diagnosis leads to advanced disease that requires more extensive surgery and a greater chance of recurrence. A need to promote awareness and recognition of this condition has been advocated by clinicians and surgeons, but no comprehensive imaging review dedicated to this entity has been performed. This review aims to discuss the diagnostic utility of high-resolution computed tomography and magnetic resonance imaging in preoperative and postoperative settings in congenital cholesteatoma. Detailed emphasis is placed on the essential preoperative computed tomography findings that facilitate individualized surgical management and prognosis in the pediatric population.

Imaging spectrum and complications of otogenic infections: insights into delayed diagnosis.

Skull base osteomyelitis (SBO) is a late manifestation of complicated otogenic infections that presents a diagnostic challenge. Delayed or missed diagnoses lead to high morbidity and mortality and can be attributed to non-specific symptoms, subtle early radiologic findings, radiologic mimicry of nasopharyngeal carcinoma (NPC), and under-recognition from clinician and radiologists. This pictorial review aims to emphasize on early imaging recognition and distinction between SBO and NPC.

Demystifying the challenging diagnosis of post-radiation nasopharyngeal necrosis on multimodality imaging.

Post-radiation nasopharyngeal necrosis (PRNN) is a rare but life-threatening condition that often poses a diagnostic challenge in imaging studies owing to its overlapping features with recurrent nasopharyngeal tumours. We herein describe the characteristic imaging appearance of PRNN on post-contrast T1-weighted magnetic resonance imaging, diffusion-weighted imaging (DWI) and fluorodeoxyglucose (FDG)-PET/CT which may provide insights into its pathological findings.

Acute traumatic subtalar dislocation: A rare but important clinical entity with 15-year retrospective radiological analysis of 23 cases.

Objectives: The objectives of this study were to contribute to the limited existing knowledge about subtalar dislocations, analyze the computed tomography (CT) findings and advantages over radiography, and report the rate and potential risk factors of post-traumatic peri-talar osteoarthritis (OA). Material and Methods: A total of 23 cases of traumatic subtalar dislocation during a 15-year period at three regional hospitals were retrospectively reviewed. Results: All 23 cases were closed dislocations. Successful close reduction was performed in 17 patients (73.9%) and 6 patients (26.1%) required open reduction and internal fixation. Twenty patients (87%) had associated foot and ankle fractures. Fractures of calcaneal medial tubercle were the most common (75%), followed by talar head (30%), sinus tarsi (25%), and medial malleolus (25%). The radiograph's sensitivity for identifying fractures was 48.1%. The mean follow-up period is 30 months. Symptomatic OA affected 8 patients (36.4%). No post-trauatic talar avascular necrosis was noted. Fractures were present in all of those patients with post-traumatic OA (100%). Three out of five patients who sustained high-energy mechanism injury developed radiographic OA (66.7%). Three out of six patients (50%) treated with open reduction and internal fixation also developed radiographic OA. Conclusion: Subtalar dislocation remains a rare injury. It is strongly associated with foot and ankle fractures. Fractures of the calcaneal medial tubercle were the most common. The risk of post-traumatic symptomatic peritalar OA is high. CT is useful in detecting occult fractures and injured bony subregions. We postulated potential risk factors of post-traumatic OA (fracture, high-energy mechanism of injury, open reduction, and internal fixation); however, this requires further study.

Basilar artery diameter as neuroimaging biomarker in Chinese Fabry disease patients.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disease resulting from mutations of α-galactosidase A gene, and has been emphasized as one of the etiologies of young stroke and leukoencephalopathy. Vertebrobasilar dolichoectasia (VBD) is a highlighted finding in FD. We aim to examine the utility of VBD in Chinese FD by comparing the differences in basilar artery (BA) diameter of Chinese FD patients against age-matched controls with and without stroke. METHODS: This was a matched case-control study involving 37 Chinese FD patients. The BA diameters were evaluated on axial T2-weighted magnetic resonance imaging and compared to two age-and-gender matched control groups, one with stroke and one without. The association between BA diameter and stroke occurrences and white matter hyperintensities (WMH) were analyzed among all FD patients. RESULTS: Patients with FD had significantly increased BA diameter compared to controls with and without stroke (p < 0.001). A BA diameter of 4.16 mm could distinguish FD from controls in the stroke subgroup (ROC AUC 0.870, p = 0.001, sensitivity 80% specificity 100%), and with a cut-off of 3.21 mm in the non-stroke subgroup (ROC AUC 0.846, p < 0.001, sensitivity 77.8% specificity 88.9%). Larger BA diameter had more stroke occurrences and was moderately associated with heavier WMH load in terms of higher total FAZEKAS scores. (Spearman's rho = 0.423, p = 0.011). CONCLUSION: VBD was also present in Chinese FD patients. BA diameter has high diagnostic utility in identifying FD from a mixed cohort of stroke and normal controls, and carried predictive value in evaluating neurological complications of FD.

Different facets of intracranial central nervous system lymphoma and its imaging mimics.

Lymphomas of the central nervous system (CNS) are broadly classified into primary CNS lymphoma (PCNSL) and secondary CNS lymphoma (SCNSL). PCNSL refers to lymphoma restricted to the brain, leptomeninges, spinal cord, or eyes without evidence of it outside the CNS at primary diagnosis, while SCNSL refers to secondary CNS involvement by systemic lymphoma. The brain is the most common site of involvement and intracranial CNS lymphoma has a highly variable imaging appearance and varies according to the patient's clinical profile and immunity. This pictorial essay aims to illustrate the different facets of intracranial CNS lymphomas on neuroimaging. This enables radiologists to be familiarized with their key diagnostic features and differentiate from their differential diagnoses, leading to early diagnosis, and treatment.

Computed Tomography for Calcaneal Fractures: Adding Value to the Radiology Report.

Computed tomography (CT) is nowadays the cornerstone for fracture pattern delineation in calcaneal fracture, and for operative planning. It is often challenging for radiologists in generating clinically oriented and meaningful CT reports to the orthopedic surgeon. The article aims to review the commonly encountered calcaneal injuries and highlight the key points in the description of these injuries and implications of the underlying classification system with respect to the surgeon's perspective. A thorough understanding of the pathoanatomy and potential complications of calcaneal fractures also helps radiologists in tailoring the radiology report in contribution to overall patient's management and prognostication. By doing so, we suggest ways in which the radiologists can add value to the radiology report.

Gallium-67 Scan with Single Photon Emission Computed Tomography for the Evaluation and Monitoring of Infected Abdominal Aortic Aneurysms: A 10-Year Case Series.

PURPOSE: This study aimed to evaluate the role of gallium-67 single photon emission computed tomography (SPECT) with contrast computed tomography (CT) in the evaluation and monitoring of infected abdominal aortic aneurysms (IAAA). MATERIALS AND METHODS: A retrospective cohort analysis was performed using prospectively collected data of consecutive patients with IAAA in Princess Margaret Hospital in Hong Kong between January 2010 and December 2020. The patients were identified using the Radiology Information System. RESULTS: All five patients had proven IAAA on CT and/or metabolic imaging. Among them, three were further supported by positive blood culture results. Gallium- 67 SPECT with contrast CT was useful in the detection of residual disease, monitoring, and detection of recurrence. CONCLUSION: Gallium-67 SPECT with contrast CT is helpful for evaluating IAAA. It serves an important role in guiding management, especially during long-term follow-up.