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.

Slow-Flow Venous Vascular Malformation in the Carotid Sheath.

Slow-flow venous vascular malformation is a benign lesion characterized by an abnormal but non-cancerous growth of capillaries. In the carotid space, a slow-flow venous vascular malformation is an exceptionally uncommon occurrence. Here, we present the case of a 58-year-old man who had been experiencing a slow-growing lump on the left side of his neck for the past four years. Upon conducting magnetic resonance imaging (MRI) of the neck soft tissues and computed tomography angiography (CTA) of the neck, imaging findings revealed a venous vascular malformation within the carotid sheath. Venous vascular malformation in the carotid space is rarely reported in the medical literature. The unique imaging findings for venous vascular malformation make our case distinct, which deviates from the more common entities usually encountered in this area, such as schwannoma or carotid body tumor. The atypical presentation of this case has brought about greater awareness among the medical community and readers alike.

Case 324: CHANTER Syndrome.

HISTORY: A 69-year-old right-handed man with a history of substance use disorder, hypertension, and diabetes presented to the emergency department in an unresponsive state. Upon examination, apart from tachycardia (heart rate, 108 beats per minute), vital signs were within normal ranges (blood pressure, 134/102 mm Hg; temperature, 97.9 ºF (36.6 ºC); respiratory rate, 16 per minute; oxygen saturation, 96%). The patient had a Glasgow coma scale score of 8. Otherwise, the physical examination revealed no abnormalities. Prior psychiatric and surgical histories were unremarkable. There was no history of recent travel, camping, hiking, or vaccination. No family history could be obtained. Laboratory work-up revealed an elevated creatine kinase level (49 006 U/L [818.4 µkat/L]; normal reference range, 10-205 U/L [0.17-3.42 µkat/L]). An electrocardiogram showed sinus tachycardia without evidence of cardiac ischemia. An echocardiogram was unremarkable. Alanine aminotransferase (126 U/L [2.10 µkat/L]; normal reference range, 0-40 U/L [0-0.67 µkat/L]) and aspartate aminotransferase (488 U/L [8.15 µkat/L]; normal reference range, 3-44 U/L [0.05-0.74 µkat/L]) levels were elevated. Polymerase chain reaction results were negative for HIV-1, HIV-2, syphilis treponemal, and COVID-19 antibodies. The remaining routine laboratory work-up findings were within normal limits. Urine drug screening was positive for cocaine, marijuana, fentanyl, and benzodiazepines. Naloxone was administered, but the patient remained unresponsive. Intubation was performed for airway protection. Noncontrast and contrast-enhanced CT of the head and CT angiography were performed in the emergency department to rule out an acute intracranial abnormality. Multisequence MRI of the brain with administration of intravenous contrast material was ordered for further assessment. CT of the abdomen and pelvis was unremarkable (images not shown).

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.

Case 324.

HISTORY: A 69-year-old right-handed man with a history of substance use disorder, hypertension, and diabetes presented to the emergency department in an unresponsive state. Upon examination, apart from tachycardia (heart rate, 108 beats per minute), vital signs were within normal ranges (blood pressure, 134/102 mm Hg; temperature, 97.9°F [36.6°C]; respiratory rate, 16 breaths per minute; oxygen saturation, 96%). He had a Glasgow coma scale score of 8. Otherwise, the physical examination revealed no abnormalities. His prior psychiatric and surgical histories were unremarkable. There was no history of recent travel, camping, hiking, or vaccination. No family history could be obtained. Laboratory work-up revealed an elevated creatine kinase level (49 006 U/L [818.4 µkat/L]; normal reference range, 10-205 U/L [0.17-3.42 µkat/L]). An electrocardiogram showed sinus tachycardia without evidence of cardiac ischemia. An echocardiogram was unremarkable. Alanine aminotransferase (126 U/L [2.10 µkat/L]; normal reference range, 0-40 U/L [0-0.67 µkat/L]) and aspartate aminotransferase (488 U/L [8.15 µkat/L]; normal reference range, 3-44 U/L [0.05-0.74 µkat/L]) levels were elevated. Polymerase chain reaction results were negative for HIV-1, HIV-2, syphilis treponemal, and COVID-19 antibodies. The rest of the routine laboratory work-up findings were within normal limits. Urine drug screening was positive for cocaine, marijuana, fentanyl, and benzodiazepines. Naloxone was administered, but the patient remained unresponsive. Intubation was performed for airway protection. Noncontrast and contrast-enhanced CT of the head (Fig 1) and CT angiography were performed in the emergency department to rule out an acute intracranial abnormality. Multisequence MRI of the brain with administration of intravenous contrast material was ordered for further assessment (Figs 2-4). CT of the abdomen and pelvis was unremarkable (images not shown).

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.

Case 317: Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia.

HISTORY: A 44-year-old previously healthy man with a 9-month history of progressive cognitive decline, depression, urinary incontinence, and inability to perform tasks of daily living presented to the emergency department with worsening cognitive and neuropsychiatric symptoms. He had become more distressed, and his family noticed him departing the house without closing doors, leaving water faucets running, and sending his children to school on Sundays. History taken from the patient's wife revealed that his brother had passed away in his late 30s after a slowly progressing functional and cognitive decline over the course of 5 years. No further detailed family history could be obtained. The review of systems was negative; he had no prior medical, psychiatric, or surgical history; and he denied any history of recent travel, camping, hiking, or vaccination. The patient was not taking any dietary supplements, nor was he taking any over-the-counter or prescription medication. Examination revealed vital signs were within normal limits. Neurocognitive assessment revealed a conscious, coherent, and alert patient with impaired memory and concentration. He showed poor attention, depressed mood, and restricted affect. He was unable to spell the word world forward, nor was he able to understand a request to spell it backward. The rest of the physical and neurologic examination revealed no abnormalities. Extensive laboratory work-up was conducted and included the following: toxicology screening; screening for HIV-1, HIV-2, and syphilis treponemal antibodies; COVID-19 polymerase chain reaction; and measurement of B1 and B12 levels. The results of screening were negative. Cerebrospinal fluid (CSF) assays, including CSF oligoclonal bands and CSF flow cytometry, revealed values within normal limits. CT of the brain without intravenous contrast material was performed in the emergency department to rule out acute intracranial abnormality. Multiplanar multisequence MRI of the brain without and with intravenous contrast material was ordered for further assessment. CT images of chest, abdomen, and pelvis were unremarkable (images not shown).

Case 317.

HISTORY: A 44-year-old previously healthy man with a 9-month history of progressive cognitive decline, depression, urinary incontinence, and inability to perform tasks of daily living presented to the emergency department with worsening cognitive and neuropsychiatric symptoms. He had become more distressed, and his family noticed him departing the house without closing doors, leaving water faucets running, and sending his children to school on Sundays. History taken from the patient's wife revealed that his brother had passed away in his late 30s after a slowly progressing functional and cognitive decline over the course of 5 years. No further detailed family history could be obtained. The review of systems was negative; he had no prior medical, psychiatric, or surgical history; and he denied any history of recent travel, camping, hiking, or vaccination. The patient was not taking any dietary supplements, nor was he taking any over-the-counter or prescription medication. Examination revealed vital signs were within normal limits. Neurocognitive assessment revealed a conscious, coherent, and alert patient with impaired memory and concentration. He showed poor attention, depressed mood, and restricted affect. He was unable to spell the word world forward, nor was he able to understand a request to spell it backward. The rest of the physical and neurologic examination revealed no abnormalities. Extensive laboratory work-up was conducted and included the following: toxicology screening; screening for HIV-1, HIV-2, and syphilis treponemal antibodies; COVID-19 polymerase chain reaction; and measurement of B1 and B12 levels. The results of screening were negative. Cerebrospinal fluid (CSF) assays, including CSF oligoclonal bands and CSF flow cytometry, revealed values within normal limits. CT of the brain without intravenous contrast material was performed in the emergency department to rule out acute intracranial abnormality (Fig 1). Multiplanar multisequence MRI of the brain without and with intravenous contrast material was ordered for further assessment (Figs 2-4). CT images of chest, abdomen, and pelvis were unremarkable (images not shown).

Human parechovirus meningoencephalitis.

Human parechovirus-3 (HPeV-3) infection is one of the differential diagnoses of neonatal meningoencephalitis. A 13-day-old full-term female neonate presented with a seizure. Brain MRI showed classic imaging findings of the meningoencephalitis which was confirmed on cerebrospinal fluid analysis. Contribution: The HPeV-3 is an emerging pathogen for neonatal meningoencephalitis. The case in this study is unique with classic imaging findings, which are not routinely encountered in day-to-day practice. This case raises reader awareness.

Jugular Foramen Cerebrospinal Fluid Leak Repaired Via the Infralaybryinthine Approach With Adjunct Use of Intrathecal Fluorescein and Stereotactic Navigation.

OBJECTIVE: This report describes a case of a spontaneous cerebrospinal fluid leak at the jugular foramen that was surgically repaired via the infralabyrinthine approach with adjunct use of intrathecal fluorescein and stereotactic navigation. PATIENTS: A 39-year-old woman presenting with clear otorrhea confirmed to be cerebrospinal fluid (CSF) emanating from a defect in the jugular foramen. INTERVENTION: Surgical repair of the skull base defect using an infralabyrinthine approach to the jugular foramen. During surgery, intrathecal fluorescein and stereotactic navigation were used to localize the defect and confirm a successful repair. MAIN OUTCOME MEASURE: Recurrence of a CSF leak. RESULTS: The defect was successfully repaired using the techniques described, resulting in cessation of the patient's CSF leak. There was no recurrence of the CSF leak up to a 4-month postoperative outpatient follow-up. CONCLUSIONS: Diagnosis and repair of spontaneous otogenic CSF leaks in an uncommon location like the jugular foramen are challenging. This report demonstrates the successful use of the infralabyrinthine approach for control of a CSF from the jugular foramen. In addition, use of techniques, such as intrathecal fluorescein and stereotactic navigation that are not routinely used in otology and neurotology allowed for safe, effective repair of the leak in this case.

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.

Comparing Outcomes and Billing Costs of Middle Cranial Fossa and Transmastoid Approaches for Otogenic Encephalocele and Cerebrospinal Fluid Leak Repair.

OBJECTIVE: Comparison of outcomes and billing costs of patients treated at our institution using transmastoid (TM), middle cranial fossa (MCF), and combined approaches for repair of otogenic cerebrospinal fluid (CSF) leaks and encephaloceles. STUDY DESIGN: Retrospective cohort review. SETTING: Tertiary-care hospital. PATIENTS: Seventy-seven cases of otogenic CSF leaks or encephaloceles. INTERVENTIONS: Surgical repair of an otogenic encephalocele or CSF leak using either a TM, MCF, or combined approach. MAIN OUTCOME MEASURES: Success of repair, length of operation, cost of operating room materials, postoperative need for intensive care, and postoperative length of stay. RESULTS: Forty cases (52%) were performed by the TM approach, 27 (35%) by MCF, and 10 (13%) by combined TM/MCF. Mean length of stay was not statistically different amongst TM patients (2.1 d), MCF patients (3.3 d), and combined TM/MCF patients (3.70; p = 0.112). Only 3/40 TM cases required intensive care during their admission while all MCF and combined TM/MCF approach cases were admitted to the intensive care unit for at least one night ( p < 0.001). On follow-up, CSF leak recurred in 3/77 (4%) cases: 3/27 (11%) MCF, 0/40 TM, and 0/10 combined TM/MCF patients ( p = 0.056). The mean cost of operating room materials charged to the patient was significantly greater in the MCF group ($9,883) than the TM group ($3,748; p = 0.001). CONCLUSIONS: In carefully selected patients, the TM approach is an effective and less costly alternative to MCF approaches for repair of otogenic CSF leaks and encephaloceles.

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.

Inattentional blindness to DWI lesions in spontaneous intracerebral hemorrhage.

PURPOSE: Inattentional blindness refers to when an individual fails to recognize an event or object due to their awareness being engaged in a different task and has been described in radiology. The purpose of this study is to determine whether the sensitivity of detecting diffusion-weighted imaging (DWI) lesions in spontaneous intracerebral hemorrhage (sICH) is reduced due to inattentional blindness. METHODS: Using a prospective observational cohort, select sICH patients received an MRI scan within 72 h of admission. The scans were subject to an "official read" that occurred as part of the routine workflow. Separately, each scan underwent two "preliminary research reads" with task-specific instructions to detect DWI lesions. A "final research read" via three-party adjudication was used to calculate sensitivity and specificity for detecting these lesions. Board-certified neuroradiologists blinded to the clinical history of the patients reviewed all imaging. RESULTS: Amongst 121 sICH participants with research MRI scans, 49.6% (n = 60) scans were noted to have DWI lesion on their "final research read." The "official read" detected these DWI lesions with a sensitivity of 65% (95% CI, 52-77%). In contrast, the "preliminary research read" sensitivity for readers 1 and 2 was 98% (CI 95%, 91 to 100%) and 87% (CI 95%, 75 to 94%), respectively. Both were significantly different (p < 0.05) from the sensitivity of the "official read." CONCLUSIONS: Given the increased sensitivity with task-specific instructions, our results suggest that inattentional blindness may be leading to the decreased detection of DWI lesions in patients with concomitant sICH.

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.