Role of Clinical and Multimodality Neuroimaging in the Evaluation of Brain Death/Death by Neurologic Criteria and Recent Highlights from 2023 Updated Guidelines.

Purpose of Review: This review aims to provide a comprehensive overview of the diagnosis of brain death/death by neurologic criteria (BD/DNC) by emphasizing the clinical criteria established by the American Academy of Neurology (AAN) in light of their updated guidelines released in 2023. In this review, we will focus on the current implementation of ancillary tests including the catheter cerebral angiogram, nuclear scintigraphy, and transcranial Doppler, which provide support in diagnoses when clinical examination and apnea tests are inconclusive. Finally, we will also provide examples to discuss the implementation of certain imaging studies in the context of diagnosing BD/DNC. Recent Findings: Recent developments in the field of neurology have emphasized the importance of clinical criteria for diagnosing BD/DNC, with the AAN providing clear updated guidelines that include coma, apnea, and the absence of brainstem reflexes. Current ancillary tests, including the catheter cerebral angiogram, nuclear scintigraphy, and transcranial Doppler play a crucial role in confirming BD/DNC when the clinical assessment is limited. The role of commonly used imaging studies including computed tomography and magnetic resonance angiographies of the brain as well as CT/MR perfusion studies will also be discussed in the context of these new guidelines. Summary: BD/DNC represents the permanent cessation of brain functions, including the brainstem. This review article provides the historical context, clinical criteria, and pathophysiology that goes into making this diagnosis. Additionally, it explores the various ancillary tests and selected imaging studies that are currently used to diagnose BD/DNC under the newly updated AAN guidelines. Understanding the evolution of how to effectively use these diagnostic tools is crucial for healthcare professionals who encounter these BD/DNC cases in their practice.

Revisiting the "Puffed Cheek" Technique: Advantages, Fallacies, and Potential Solutions.

The "puffed cheek" technique is routinely performed during CT neck studies in patients with suspected oral cavity cancers. The insufflation of air within the oral vestibule helps in the detection of small buccal mucosal lesions, with better delineation of lesion origin, depth, and extent of spread. The pitfalls associated with this technique are often underrecognized and poorly understood. They can mimic actual lesions, forfeiting the technique's primary purpose. This review provides an overview of the puffed cheek technique and its associated pitfalls. These pitfalls include pneumoparotid, soft palate elevation that resembles a nasopharyngeal mass, various tongue displacements or distortions that obscure tongue lesions or mimic them, sublingual gland herniation, an apparent exacerbation of the airway edema, vocal cord adduction that hinders glottic evaluation, and false indications of osteochondronecrosis in laryngeal cartilage. Most stem from a common underlying mechanism of unintentional Valsalva maneuver engaged in by the patient while trying to perform a puffed cheek, creating a closed air column under positive pressure with resultant surrounding soft-tissue displacement. These pitfalls can thus be avoided by instructing the patient to maintain continuous nasal breathing while puffing out their cheek during image acquisition, preventing the formation of the closed air column. Keywords: CT, Head/Neck © RSNA, 2024.

Computed Tomography Imaging Patterns of Sinonasal Inverted Papillomas: Comparison of Primary and Recurrent Disease.

OBJECTIVE: To analyze clinical and radiographic features that may impact the rate of focal hyperostosis (FH) on computed tomography (CT) for primary and recurrent sinonasal inverted papillomas (IPs) as well as highlight factors that may affect concordance between FH and IP true attachment point (TAP). METHODS: All IPs resected between 2006 and 2022 were retrospectively reviewed. CTs were read by a neuroradiologist blinded to operative details. IP with malignancy was excluded. Operative reports and long-term follow-up data were evaluated. RESULTS: Of 92 IPs, 60.1% had FH, 25% had no CT bony changes, and 20.7% were revision cases. The recurrence rate for rhinologists was 10.5% overall and 7.3% for primary IPs. Primary and revision IPs had a similar rate of FH (63% vs. 52.6%; p = 0.646) and FH-TAP agreement (71.7% vs. 90%; p = 0.664). Nasal cavity IPs, especially with septal attachment, were more likely to lack bony changes on CT (57.1%) compared to other subsites (p = 0.018). Recurrent tumors were 16 mm larger on average (55 mm vs. 39 mm; p = 0.008). FH (75.0% vs. 60.9%; p = 0.295), FH-TAP concordance (91.7% vs. 74.4%; p = 0.094), and secondary IP (18.8% vs. 20.3%; p = 0.889) rates were similar between recurrent and nonrecurrent tumors. CONCLUSION: Primary and revision IPs have a similar rate of FH and FH-TAP agreement. Nasal cavity IPs are less likely to exhibit bony CT changes. Lower recurrence was associated with smaller size and fellowship training but not multiple TAPs, revision, FH absence, or FH-TAP discordance. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1591-1596, 2024.

Role of 18F-Fluorocholine Positron Emission Tomography (PET)/Computed Tomography (CT) in Diagnosis of Elusive Parathyroid Adenoma.

Accurate localization of parathyroid adenomas is paramount in hypercalcemia and elevated parathyroid hormone (PTH) levels. This narrative of a 56-year-old female diagnosed with primary hyperparathyroidism underscores the intricacies faced when conventional imaging falls short. Despite a series of diagnostic and surgical endeavors, including an initial nuclear sestamibi scan and diverse imaging examinations like ultrasound, 4D CT, and MRI, it was the 18F-Fluorocholine positron emission tomography (PET)/computed tomography (CT) scan that illuminated the presence of the elusive adenoma in the left para esophageal superior mediastinum. The surgical outcome reinforced the diagnosis, marking the resolution of the adenoma. This case accentuates the necessity of a multifaceted diagnostic methodology, especially in convoluted primary hyperparathyroidism presentations. It highlights the yet-to-be widely adopted 18F-Fluorocholine PET/CT scan, emphasizing its prospective significance awaiting Food and Drug Administration (FDA) endorsement.

Embryonal tumor with multilayered rosettes: a report of a rare case.

The authors report a case of an embryonal tumor with multilayered rosettes (ETMR) in an 18-month-old female infant who presented with gait imbalance and progressive left-sided weakness for 2 months. ETMR is a rare small round blue cell aggressive tumor of the central nervous system characterized by the amplification of the C19MC region on chromosome 19 (Chr19q13.42). This report in detail the clinical-radiologic and histopathological workup and diagnosis. Because ETMRs are newly described rare pediatric central nervous system tumors with only a few reported cases, we aim to document this typical case to add to the existing data on these tumors.

Treatment of Metastatic Spinal Disease; what the Radiologist needs to know.

Advancements in technology and multidisciplinary management have revolutionized the treatment of spinal metastases. Imaging plays a pivotal role in determining the treatment course for spinal metastases. This article aims to review the relevant imaging findings in spinal metastases from the perspective of the treating clinician, describe the various treatment options, and discuss factors influencing choice for each available treatment option. Cases that once required radical surgical resection or low-dose conventional external beam radiation therapy, or both, are now being managed with separation surgery, spine stereotactic radiosurgery/stereotactic body radiation therapy, or both, with decreased morbidity, improved local control, and more durable pain control. The primary focus in determining treatment choice is now on tumor control outcomes, treatment-related morbidity, and quality of life.

A Comparison of CT-Guided Bone Biopsy and Fluoroscopic-Guided Disc Aspiration as Diagnostic Methods in the Management of Spondylodiscitis.

BACKGROUND AND PURPOSE: Percutaneous tissue biopsy is a key step in the diagnosis and management of spondylodiscitis, often utilizing CT-guided bone biopsy or fluoroscopic-guided disc aspirations. Our objective was to compare radiation exposure, procedure time, sedation requirement & yield between the two modalities. MATERIALS AND METHODS: 103 patients in 2 cohorts underwent fluoroscopic-guided disc aspirations (n = 47) or CTguided bone biopsy (n = 46) for diagnosis of spondylodiscitis. Patient and imaging data were gathered to ensure matched cohorts. Interventional and post-procedural data included radiation exposure, procedure time, complications, and microbiological details. Yield was calculated using MRI findings as the gold standard for infection. RESULTS: There were no significant differences between cohorts in demographics, symptom duration, or pre-procedure antibiotics use. CT-guided bone biopsy required more general anesthesia (26% vs 0%, P < 0.001), had longer radiation exposure time (60 ± 24s vs 2 ± 3s, P < 0.001), radiation dose (114.4 ± 71.6 mGy vs 70.4 ± 147.2 mGy), and procedure time (62 ± 14m vs 31 ± 23m, P < 0.001) than fluoroscopic-guided disc aspirations. There was no significant difference in yield (34% vs 32%, P = 0.661), and it was not affected by antibiotic use. CONCLUSIONS: Both modalities have similar utility in isolating causative organisms in suspected cases of spondylodiscitis. Our results suggest that increased radiation exposure, longer procedure time, and increased anesthesia use are relative disadvantages of CT-guided biopsy without an increase in yield. Controlled trials may be beneficial in determining the optimal choice in different scenarios.

Myxopapillary ependymoma with interval postoperative CSF seeding: A report of an unusual case.

Myxopapillary ependymoma (MPE) is a unique slow-growing benign (WHO grade 1) subtype of spinal cord ependymoma arising predominantly in the filum terminale. Despite its benign nature, it occasionally disseminates through the cerebrospinal fluid and metastasizes to distant sites. Here, we report an extremely rare case of MPE with interval CSF seeding and metachronous metastasis in a 47 -year-old female presented as a gradually increasing low back pain for three months with bilateral radiculopathy down to the knees. Magnetic resonance imaging (MRI) showed an intradural extramedullary spinal mass of iso-intense signal to the cord on T1 weighted-images (WIs), heterogeneous, predominantly hyperintense signal on T2WIs with homogenous enhancement after contrast administration. L2 laminectomy with gross total resection (GTR) was performed, and histopathological results confirmed the diagnosis of MPE. Adjuvant radiotherapy was administered, followed by series of MRI scans. 28 months after GTR, Lumbar MRI showed multiple tiny enhancing nodules in the cauda equina. 44 months follow-up whole spine MRI revealed multiple intradural extramedullary nodules throughout the entire spine. The largest one measures about 1.5cm opposite to T3 -T4 intervertebral disc space. The patient underwent T3 and T4 laminectomy and GTR under general anesthesia using microsurgical techniques, and the histopathological result came with the diagnosis of MPE.

Timing of diffusion weighted imaging lesions in spontaneous intracerebral hemorrhage.

INTRODUCTION: Diffusion weighted imaging (DWI) lesions are common after spontaneous intracerebral hemorrhage (sICH). However, their timing relative to a patient's admission to the hospital is unknown. The purpose of this study is to estimate the timing of new DWI lesions after admission for acute sICH. MATERIAL AND METHODS: Select patients enrolled in a single center prospective study examining the prevalence DWI lesions in acute primary sICH received two MRI scans of the brain after admission. The presence of a new DWI lesion between MRI scans was defined as a new DWI event. A lognormal parametric model was used to estimate the median time (50% percentile) to develop a new DWI lesion. RESULTS: Among the 121 participants enrolled in the study, 63 (52%) had two brain MRIs. The median time from admission to 1st MRI was 1 day (IQR 1.2, range 0.1-8.4). The median time between the 2 MRI scans was 2.1 (IQR 2.9, range 0.02-17.4) days. 30.2% (n = 19) of participants developed a new DWI lesion between MRI scans. The estimated median time from 1st MRI to new DWI event was 6.3 days (95% CI, 4.1 to 9.6). DISCUSSION AND CONCLUSION: Accounting for time from admission to 1st MRI, we found that 50% of new DWI lesions occurred by 7.3 days after sICH admission. Pathophysiologic changes in sICH during this time frame need to be studied in order to elucidate a mechanism for DWI lesions.

Dural Ectasia and Cauda Equina Syndrome: A Rare Complication of Long-standing Fusion.

The clinicoradiological combination of cauda equina syndrome (CES) and dural ectasia is rare and has been described in a few of patients with ankylosing spondylitis (AS). Simultaneous occurrence of these entities in the absence of AS and in patients with long-standing spinal fusion is extremely rare. We present a case of dural ectasia and CES occurring as a long-term complication of instrumented spinal fusion and discuss the pathogenesis, imaging findings, and management options of this elusive disease process.

A Case of Bilateral Atrophy of the Inferior Vestibular Nerves.

: We report a case of a 62-year-old woman who was found to have bilateral atrophy of the inferior vestibular nerves on magnetic resonance imaging (MRI) after presenting to our clinic with 6 years of intermittent vertigo and residual unsteadiness. The nerve atrophy may be associated with an episode of vestibular neuritis, a common cause of vertigo that exclusively involves the inferior vestibular nerve in less than 3% of cases. While MRI may demonstrate vestibular nerve enhancement in cases of acute vestibular neuritis, no single MRI finding has been demonstrated consistently among cases of acute or chronic vestibular neuritis. Physical therapy is likely an effective long-term treatment for this patient to achieve central compensation for symptomatic relief.

Isolated Extracranial Vasospasm and Intracranial Dissection: An Unusual Imaging Manifestation of Reversible Cerebral Vasoconstriction Syndrome.

Reversible cerebral vasoconstriction syndrome (RCVS) is a distinct clinical syndrome characterized by thunderclap headache and reversible cerebral vasoconstriction. An association between RCVS and arterial dissection has emerged in recent years, where dissection typically involves the cervical vertebral arteries. In this vignette, we describe isolated reversible vasoconstriction, involving the extracranial arteries and intracranial dissection-a combination hitherto never reported.

Isolated intraventricular hemorrhage after spinal surgery.

Intracerebral hemorrhage after spinal surgery is a rare but dreaded complication. The most commonly described form of intracranial hemorrhage after spinal surgery is remote cerebellar hemorrhage (i.e. anatomically distant from the surgical site) (Brockmann MA, Groden C. Remote cerebellar hemorrhage: a review. The Cerebellum 2006;5:64-8); however subdural, subarachnoid, and intraventricular hemorrhage can also occur in combination or isolated (Kaloostian PE, Kim JE, Bydon A, Sciubba DM, Wolinsky JP, Gokaslan ZL, Witham TF. Intracranial hemorrhage after spine surgery. J Neurosurg Spine 2013;19:370-80; Khalatbari MR, Khalatbari J, Moharamzad Y. Intracranial hemorrhage following lumbar spine surgery. Eur Spine J 2012;21:2092-96). Isolated intraventricular hemorrhage after spinal surgery is extremely rare; to our knowledge, there are only two cases reported in the literature (Kaloostian PE, Kim JE, Bydon A, Sciubba DM, Wolinsky JP, Gokaslan ZL, Witham TF. Intracranial hemorrhage after spine surgery. J Neurosurg Spine 2013;19:370-80; Khalatbari MR, Khalatbari J, Moharamzad Y. Intracranial hemorrhage following lumbar spine surgery. Eur Spine J 2012;21:2092-96). Here, we present a 76-year-old female patient who developed isolated intraventricular hemorrhage after spinal surgery.