Semiautomated MRI-Based Method for Orbital Volume and Contour Analysis.

OBJECTIVE: The architecture of the orbital cavity is intricate, and precise measurement of its growth is essential for managing ocular and orbital pathologies. Most methods for those measurements are by CT imaging, although MRI for soft tissue assessment is indicated in many cases, specifically pediatric patients. This study introduces a novel semiautomated MRI-based approach for depicting orbital shape and dimensions. DESIGN: A retrospective cohort study. PARTICIPANTS: Patients with at least 1 normal orbit who underwent both CT and MRI imaging at a single center from 2015 to 2023. METHODS: Orbital dimensions included volume, horizontal and vertical lengths, and depth. These were determined by manual segmentation followed by 3-dimensional image processing software. MAIN OUTCOME MEASURES: Differences in orbital measurements between MRI and CT scans. RESULTS: Thirty-one patients (mean age 47.7 ± 23.8 years, 21 [67.7%]) females, were included. The mean differences in delta values between orbital measurements on CT versus MRI were: volume 0.03 ± 2.01 ml, horizontal length 0.53 ± 2.12 mm, vertical length, 0.36 ± 2.53 mm, and depth 0.97 ± 3.90 mm. The CT and. MRI orbital measurements were strongly correlated: volume (r = 0.92, p < 0.001), horizontal length (r = 0.65, p < 0.001), vertical length (r = 0.57, p = 0.001), and depth (r = 0.46, p = 0.009). The mean values of all measurements were similar on the paired-samples t test: p = 0.9 for volume (30.86 ± 5.04 ml on CT and 30.88 ± 4.92 ml on MRI), p = 0.2 for horizontal length, p = 0.4 for vertical length, and p = 0.2 for depth. CONCLUSIONS: We present an innovative semiautomated method capable of calculating orbital volume and demonstrating orbital contour by MRI validated against the gold standard CT-based measurements. This method can serve as a valuable tool for evaluating diverse orbital processes.

Effect of General Anesthesia on MR Optic Nerve Sheath Diameter in the Pediatric Population.

BACKGROUND: Papilledema is thought to be the hallmark sign of increased intracranial pressure (ICP). Distension of the subarachnoid space within the optic nerve sheath is also commonly reported in MR studies as an indirect sign of increased ICP. HYPOTHESIS: General anesthesia and positive pressure ventilation might result in changes in optic sheath diameter (OSD) observed on clinical brain MRI. STUDY TYPE: Retrospective. POPULATION: One hundred forty-five  patients (154 MRI scans, 7.3 years ± 5.1); 97 studies in the anesthesia group (4.4 years ± 3.4) of which 22 had papilledema, and 57 in the non-anesthesia group (12.3 years ± 3.2), of which 28 had papilledema. FIELD STRENGTH/SEQUENCE: 1.5T or 3.0T volumetric T2 images. T2 images were obtained from different vendors. ASSESSMENT: OSD, optic nerve diameter (OND), and peri-optic cerebrospinal fluid (CSF) were measured manually on T2-weighted MR images for various population subgroups (with and without anesthesia; with or without papilledema). The correlation between these measurements and the clinical diagnosis of papilledema was evaluated via receiver operating characteristic (ROC) analysis. STATISTICAL TESTS: Chi-square test; Mann-Whitney Test; Spearman's test and ROCs; Interclass correlation coefficient, P = 0.05. RESULTS: General anesthesia resulted in significantly larger mean OSD in patients with or without papilledema (7.3 ± 1.0 mm vs. 6.1 ± 1.1 mm and 6.7 ± 1.0 mm vs. 5.4 ± 0.9 mm, respectively). In the non-anesthesia group, the average OSD values (6.1 ± 1.1 mm) were significantly higher in papilledema patients compared to non-papilledema patients (5.4 ± 0.9 mm), with larger peri-optic CSF rim (1.6 ± 0.4 mm vs. 1.3 ± 0.3 mm). In the anesthesia group, OND was significantly larger in papilledema patients (3.4 ± 0.4 mm vs. 3.1 ± 0.5 mm), though the average peri-optic CSF rim did not reach a significance in papilledema compared with non-papilledema patients (2.0 ± 0.3 mm vs. 1.8 ± 0.4 mm, P = 0.06). In patients with general anesthesia, peri-optic CSF rim had a limited correlation with increased ICP. DATA CONCLUSION: In the pediatric population, imaging findings of increased OSD on brain MRI might be related to general anesthesia rather than increased ICP. The interpretation of optic nerve sheath distention should be reported cautiously in conjunction with anesthesia status, especially in the pediatric population. EVIDENCE LEVEL: 4 Technical Efficacy: 5.

Integrity of the tectorial membrane is a favorable prognostic factor in atlanto-occipital dislocation.

Objective: Atlanto-occipital dislocation is usually considered to be a fatal injury or one that leaves the victim with serious neurological deficits. The aim of this study is to illustrate a novel positive prognostic factor for atlanto-occipital dislocation, based on cervical MRI studies of patients who suffered this injury.Methods: Over the course of the past year, the authors have treated three consecutive patients with atlanto-occipital dislocation who attained an excellent clinical outcome. We retrospectively evaluated clinical, surgical and radiographic parameters in search of a common denominator to explain the excellent outcome of these patients.Results: All patients presented with severe polytrauma that required urgent surgical intervention including two laparotomies and a thoracotomy. The patients were subsequently treated with an occipitocervical fusion. No patient developed neurological deficits on long-term follow-up. The cervical MRI studies of all patients were notable for a having a preserved tectorial membrane, while other primary stabilizers of the craniocervical junction such as the apical, alar and cruciate ligaments were shown to be severely disrupted. We consider this anatomical distinction to account for their benign clinical course.Conclusion: A preserved tectorial membrane appears to be an important favorable prognostic factor in atlanto-occipital dislocation and may serve to mitigate neurological outcome in such injuries. To determine the integrity of the ligament and consequently affect clinical management, expeditious MRI of the cranio-cervical junction should be considered routinely in such injuries in addition to cervical CT scans.

Successful treatment of invasive mucormycosis with isavuconazole in pediatric patients.

BACKGROUND: Invasive mold infections (IMIs) are a leading cause of mortality among immunocompromised patients. Isavuconazole is a new drug that shows promise in the adult population for the treatment of IMIs. No data regarding the use of isavuconazole in pediatric patients have been published. METHODS: Patients with a diagnosis of IMI from our pediatric hemato-oncology division, treated with isavuconazole between 2010 and 2016, were identified using the hospital's computerized database. Data including demographics, clinical course, and outcome were collected. Pharmacokinetic samples were obtained from two younger patients to guide dosing. RESULTS: In total, three patients (4.5, 5, and 19 years of age) with invasive mucormycosis who were treated with isavuconazole were identified. All patients were treated with isavuconazole as a second line therapy and experienced improvement following the initiation of this treatment. CONCLUSIONS: Based on our limited clinical experience, isavuconazole may be a safe and effective treatment option for children and adolescents afflicted by IMI. Prospective clinical trials should be performed in order to evaluate the pharmakokinetics and safety of isavuconazole in the pediatric population.

Detection of cavernous malformations after whole-brain radiotherapy in primitive neuroectodermal tumor patients-comparing susceptibility-weighted imaging and T2 gradient-echo sequences.

PURPOSE: The aim of this retrospective study is to investigate the value of the susceptibility-weighted imaging (SWI) sequence compared to gradient echo (GRE) in the detection and follow-up of cavernous malformations in patients who underwent whole-brain irradiation as part of their medulloblastoma treatment. METHODS: We retrospectively examined MRI studies of 28 subjects (16 males, 12 females) who received whole-brain irradiation as part of their treatment. Ages at irradiation ranged from 2 to 38 years. All patients were periodically followed up with MR imaging (ranging from 9 to 336 months). Two neuroradiologists reviewed studies of the same patients, comparing the number of suspected cavernomas detected on GRE and SWI sequences performed at different times (median time between studies, 10 months). RESULTS: Hypointense lesions were detected in 24 subjects on SWI sequences and in 19 subjects on GRE sequences. More lesions were seen on SWI than on GRE (p = 0.006). Four patients had no detectable lesions. The minimal period from irradiation to first lesion detection was 14 months. Cavernomas larger than 3 mm were detected in 14 subjects by both GRE and SWI. None of the subjects had symptoms related to cavernomas. CONCLUSIONS: The sensitivity of SWI in the detection of hypointense lesions in patients after whole-brain irradiation is significantly higher than that of the GRE sequence. It appears that almost all subjects eventually develop small hypointense lesions after radiotherapy, and some of them progress to cavernous malformations. The clinical significance of the increased sensitivity of SWI in this group of patients is not entirely certain.

Region-specific changes in brain diffusivity in fetal isolated mild ventriculomegaly.

OBJECTIVES: To evaluate the impact of symmetric and asymmetric isolated mild ventriculomegaly (IMVM, atrial width 10-15 mm) on apparent diffusion coefficient (ADC) values in fetal brain areas. METHODS: Sixty-seven sequential fetal head magnetic resonance imaging scans (feMRI) of VM cases performed between 2009 and 2014 were compared to 38 normal feMRI scans matched for gestational age (controls). Ultrasound- and MRI-proven IMVM cases were divided into asymmetrical (AVM, ≥2 mm difference in atrial width), symmetrical (SVM, <2 mm difference in atrial width), and asymmetrical IMVM with one normal-sized ventricle (AV1norm). RESULTS: ADC values were significantly elevated in the basal ganglia (BG) of the SVM and AV1norm groups compared to controls (p < 0.004 and p < 0.013, respectively). High diffusivity was constantly detected in the BG ipsilateral to the enlarged atria relative to the normal-sized atria in the AV1norm group (p < 0.03). Frontal lobe ADC values were significantly reduced in the AVM and SVM groups (p < 0.003 and p < 0.003 vs. controls). Temporal lobe ADC values were significantly reduced in the AVM group (p < 0.001 vs. controls). CONCLUSION: Isolated mild ventriculomegaly is associated with distinct ADC value changes in different brain regions. This phenomenon could reflect the pathophysiology associated with different IMVM patterns. KEY POINTS: Various ventriculomegaly patterns are associated with distinct diffusional changes. Frontal and temporal lobe ADC values are altered bilaterally, even in asymmetric ventriculomegaly. Basal ganglia ADC values are elevated ipsilateral to the enlarged ventricle.

A biological tissue adhesive and dissolvent system for intraocular tumor plaque radiotherapy: an in vivo animal model experiment.

PURPOSE: To examine a novel biological adhesive and dissolvent system for plaque placement and removal using fibrin glue and urokinase, respectively, in an in vivo animal model. METHODS: The study was performed on 23 rabbit eyes. Of these, eight underwent a technical feasibility study and ultrasonographic plaque displacement measurements, nine were examined clinically and by magnetic resonance imaging and histopathology for tissue reaction to the biological substances used, and in six the impact of fibrin glue as an orbital space occupier on intraocular pressure was assessed. In an additional ex vivo experiment, the glue's radiation attenuating properties were tested using an oncology EDR2 film. RESULTS: Plaque horizontal movement throughout follow-up (7-10 days) was negligible (0.5 ± 0.2 mm), and there was no tilting whatsoever. In the tissue response experiment, no adverse effects were recorded after application of fibrin or urokinase throughout the 21-day follow-up period. Interestingly, a circumscribed local inflammatory response was noted in tissue surrounding the fibrin glue, and persisted at 21 days. In the orbital space-occupying experiment, application of 1 cc fibrin glue did not cause a significant elevation in intraocular pressure (IOP) (P = 0.06), and in the ex vivo experiment, there was no significant difference between radiation readings with and without glue separation of the radioactive sources and film (P = 0.065). CONCLUSIONS: The adhesive and dissolvent system was feasible and safe for plaque placement and removal. It may be superior to conventional surgical plaque placement methods in eliminating the relatively common risk of plaque tilting and complications due to scleral suturing.

Imaging prior to endoscopic ear surgery: clinical note.

Cholesteatoma is an epidermoid cyst that is characterized by independent and progressive growth with destruction of adjacent tissues, especially the bone tissue, and tendency to recurrence. Treatment of cholesteatoma is essentially surgical. The choice of surgical technique depends on the extension of the disease, and preoperative otoscopic and radiological findings can be decisive in planning the optimal surgical approach. Cholesteatoma confined to the middle ear cavity and its extensions can be eradicated by use of the minimally invasive transmeatal endoscopic approach. Computerized tomography of the temporal bones fails to distinguish a cholesteatoma from the inflammatory tissue, granulations, fibrosis or mucoid secretions in 20-70% of cases showing opacification of the middle ear and mastoid. Using the turbo-spin echo (TSE), also known as non-echo planar imaging (non-EPI) diffusion-weighted (DW) magnetic resonance imaging, cholesteatoma can be distinguished from other tissues and from mucosal reactions in the middle ear and mastoid. Current MRI sequences can support the clinical diagnosis of cholesteatoma and ascertain the extent of the disease more readily than CT scans. The size determined by the TSE/HASTE (half-Fourier acquisition single-shot turbo-spin echo) DW sequences correlated well with intraoperative findings, with error margins lying within 1 mm. Our experience with more than 150 endoscopic surgeries showed that lesions smaller than 8 mm confined to the middle ear and its extension, as depicted by the non-EPI images, can be managed with transmeatal endoscopic approach solely. We call upon our otolaryngologist and radiologist colleagues to use the newest MRI modalities in the preoperative evaluation of candidates for cholesteatoma surgery.

[Blindness and symmetrical neurological deficit in a patient with colon cancer receiving adjuvant chemotherapy: is it always cancer?].

Posterior reversible leukoencephalopathy syndrome [PRES] is characterized by a symmetrical brain edema. It is rarely caused by chemotheraphy. While steroids can lead to deterioration in the condition of a PRES patient, they are still the drug of choice for the more common condition of brain edema secondary to metastases. We describe the case of a colon cancer patient who underwent adjuvant treatment with capecitabine and oxaliplatin and was admitted to the hospital with seizures and brain edema. On admission, the condition was attributed to brain metastases and hence a high dose steroid treatment was initiated. Later on, as the patient became comatose, the CT was revised and PRES was suggested as an alternative diagnosis. After tapering the steroids the patient gradually recovered. This report emphasizes the need to be alert and not to confuse PRES with brain metastasis in cancer patients.

Orbital Fat Density as a Diagnostic Tool in Pre-Septal and Orbital Cellulitis.

PURPOSE: To evaluate the usefulness of measuring orbital fat density in identifying post-septal involvement when initial differential diagnosis between orbital and periorbital cellulitis (OC and POC) is unclear. MATERIALS AND METHODS: Retrospective study of patients with clinical diagnosis of OC or POC who underwent contrast-enhanced computerized tomographic scans over a span of 10 years. Intraconal orbital fat density was measured with Hounsfield units (HU) in six areas on axial scans consisting of nasal and temporal intraconal sites. These measurements correlated with the initial and final diagnoses. Main outcome measures were HU values at the initial and final diagnoses. RESULTS: Fifty-seven patients were included. Mean HU measurement was -52 ± 18 HU for the involved side vs. -63 ± 13 for the uninvolved side (P < .001). The values were higher in cases of a final diagnosis of OC in the involved side (P < .001). The HU values were significantly higher in the nasal vs. the temporal locations of each orbit bilaterally (P < .001). The initial POC diagnosis of 20 patients (35%) was revised to OC. CONCLUSION: Intraconal fat density measurements can assist in the primary assessment of orbital involvement in patients with an uncertain initial diagnosis, with a HU value higher than -50 is suggestive of orbital involvement.

Orbital Development in Children with Retinoblastoma: An Imaging-Based Study.

PURPOSE: To examine whether children treated for Retinoblastoma (Rb) have impaired orbital development. METHODS: A retrospective case series was performed among children with Rb treated at a single medical center from 2004 to 2020. Orbital volumes and measurements were assessed by 3-dimensional image processing software. The main outcome measures were differences in orbital growth between Rb and non-Rb eyes assessed at last follow-up. RESULTS: Among 44 patients included (mean age 16.09 ± 18.01 months), a positive correlation between age and orbital volume was observed only in the uninvolved, healthy eyes (p = .03). In unilateral cases, orbital growth in the horizontal, vertical, and depth planes was smaller on the affected side compared to the healthy eyes (p < .05). Orbits that underwent enucleation showed decreased growth over time compared to those treated conservatively (p = .017). CONCLUSIONS: Orbital growth rate is slower in the orbits of children treated for Rb compared to healthy orbits. Enucleation negatively affects orbital growth.

Neoadjuvant BRAF-targeted therapy for ameloblastoma of the mandible: an organ preservation approach.

BACKGROUND: Ameloblastoma is a rare odontogenic neoplasm frequently located in the mandible. Standard treatment involves radical bone resection and immediate reconstruction, causing functional, aesthetic, and psychological impairments. The BRAF V600E mutation is present in approximately 80% of mandible ameloblastomas, and BRAF inhibitors have demonstrated sustained responses in unresectable cases. METHODS: We identified ameloblastoma patients planned for ablative surgery and screened them for BRAF V600E mutation. Neoadjuvant BRAF inhibitors were offered to facilitate jaw preservation surgery. Retrospective data collection encompassed treatment regimens, tolerability, tumor response, and conversion to mandible preservation surgery. RESULTS: Between 2017 and 2022, a total of 11 patients received dabrafenib (n = 6) or dabrafenib with trametinib (n = 5). The median age was 19 (range = 10-83) years. Median treatment duration was 10 (range = 3-20) months. All (100%) patients achieved a radiological response. Ten (91%) patients successfully converted to mandible preservation surgery with residual tumor enucleation. One patient attained complete radiological response, and surgery was not performed. Among the 10 surgically treated patients, all exhibited a pathological response, with 4 achieving near complete response and 6 partial response. At a median follow-up of 14 (range = 7-37) months after surgery, 1 case of recurrence was observed. Grade 1-2 adverse effects were reported in 8 (73%) patients, with a single case of grade 3 (hepatitis). Dose modification was necessary for 3 patients, and 4 experienced treatment interruptions, while 1 patient permanently discontinued therapy. CONCLUSIONS: Neoadjuvant BRAF inhibition may offer a safe and effective strategy for organ preservation in mandible ameloblastoma treatment.

Central nervous system involvement in systemic lupus erythematosus: an imaging challenge.

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder involving multiple organs. One of the main sites of SLE morbidity is the central nervous system (CNS), specifically the brain. In this article we review several imaging modalities used for CNS examination in SLE patients. These modalities are categorized as morphological and functional. Special attention is given to magnetic resonance imaging (MRI) and its specific sequences such as diffusion-weighted imaging (DWI), diffuse tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). These modalities allow us to better understand CNS involvement in SLE patients, its pathophysiology and consequences.

Common sites and etiologies of residents' misinterpretation of head CT scans in the emergency department of a level I trauma center.

BACKGROUND: Misinterpretation of head computerized tomographic (CT) scans by radiology residents in the emergency department (ED) can result in delayed and even erroneous radiology diagnoses. Better knowledge of pitfalls and environmental factors may decrease the occurrence of these errors. OBJECTIVES: To evaluate common misinterpretations of head CT scans by radiology residents in a level I trauma center ED. METHODS: We studied 955 head CT scans of patients admitted to our ED from January 2010 to May 2011. They were reviewed separately by two senior neuroradiologists and graded as being unimportant (score of 1), important but not requiring emergent treatment (score of 2), and important requiring urgent treatment (score of 3). We recorded the time of day the examination was performed, the year of residency, the site, subsite and side of the lesion, the pathology, the anatomical mistake, false-positive findings, and the attending neuroradiologists' score. RESULTS: A total of 955 examinations were interpreted of which 398 had misinterpreted findings that were entered into the database, with the possibility of multiple errors per examination. The overall misinterpretation rate was 41%. The most commonly missed pathologies were chronic infarcts, hypodense lesions, and mucosal thickening in the paranasal sinuses. The most common sites for misdiagnosis were brain lobes, sinuses and deep brain structures. The highest percentage of misinterpretation occurred between 2.30 p.m. and 8 p.m. and the lowest between midnight and 8 a.m. (P < 0.05). The overall percentage of errors involving pathologies with a score of 3 by at least one of the neuroradiologists was 4.7%. Third-year residents had an overall higher error rate and first-year residents had significantly more false-positive misinterpretations compared to the other residents. CONCLUSIONS: The percentage of errors made by our residents in cases that required urgent treatment was comparable to the published data. We believe that the intense workload of radiology residents contributes to their misinterpretation of head CT findings.

[Congenital orbital teratoma].

Congenital orbital teratoma is a rare benign tumor, composed of all three germ cell layers. The Lesion presents clinically as uniLateral proptosis in the newborn. In order to diagnose the tumor correctly a multidisciplinary approach is needed, including ophthalmologists, neurosurgeons, pediatrics, radiologists, and pathologists to eventually diagnose the lesion. Early detection and treatment is needed in order to prevent mechanical destruction of adjacent tissues, and blindness from mechanical pressure on the optic nerve. Surgical excision is the treatment of choice. We present a case report of a newborn, diagnosed with congenital orbital teratoma, and discuss the clinical and histological characteristics of the tumor.

Upfront rational therapy in BRAF V600E mutated pediatric ameloblastoma promotes ad integrum mandibular regeneration.

Ameloblastoma is a neoplasm arising in the craniofacial skeleton. Proliferating odontogenic epithelial cells comprise this benign, yet locally invasive tumor, often causing severe disfiguration. High recurrence rate entails ablative surgical resection, which is the current standard of care, resulting in subsequent critical size osteocutaneous defects. The high incidence of BRAF mutations in ameloblastoma, most notably the BRAF V600E mutation, enabled the use of BRAF inhibiting agent in a neoadjuvant setting. In this investigator-initiated, open-label study, three consecutive pediatric patients, with confirmed BRAF V600E ameloblastoma deemed marginally resectable, were treated with BRAF inhibiting agents, prior to undergoing surgery. The use of upfront BRAF inhibitor treatment resulted in substantial tumor regression, allowing for non-mutilating complete surgical removal, ad integrum bone regeneration and organ preservation. All patients showed a marked radiologic and clinical response to medical treatment, enabling successful conservative surgery. Microscopically, all patients showed evidence of minimal residual tumor with extensive tumor necrosis, fibrosis and generation of new bone. At a median follow-up of 31 months, all patients remained free of disease. Face preservation therapy was achieved in pediatric patients presenting with BRAF V600E mutated ameloblastoma. Our study demonstrates the translational potential of targeted therapy as a neoadjuvant agent. Patient-specific organ preservation therapy should be considered as the new standard of care in ameloblastoma, mainly for children and adolescents.