CT of Skull Base Fractures: Classification Systems, Complications, and Management.

As advances in prehospital and early hospital care improve survival of the head-injured patient, radiologists are increasingly charged with understanding the myriad skull base fracture management implications conferred by CT. Successfully parlaying knowledge of skull base anatomy and fracture patterns into precise actionable clinical recommendations is a challenging task. The authors aim to provide a pragmatic overview of CT for skull base fractures within the broader context of diagnostic and treatment planning algorithms. Laterobasal, frontobasal, and posterior basal fracture patterns are emphasized. CT often plays a complementary, supportive, or confirmatory role in management of skull base fractures in conjunction with results of physical examination, laboratory testing, and neurosensory evaluation. CT provides prognostic information about short- and long-term risk of cerebrospinal fluid (CSF) leak, encephalocele, meningitis, facial nerve paralysis, hearing and vision loss, cholesteatoma, vascular injuries, and various cranial nerve palsies and syndromes. The radiologist should leverage understanding of specific strengths and limitations of CT to anticipate next steps in the skull base fracture management plan. Additional imaging is warranted to clarify ambiguity (particularly for potential sources of CSF leak); in other cases, clinical and CT criteria alone are sufficient to determine the need for intervention and the choice of surgical approach. The radiologist should be able to envision stepping into a multidisciplinary planning discussion and engaging neurotologists, neuro-ophthalmologists, neurosurgeons, neurointerventionalists, and facial reconstructive surgeons to help synthesize an optimal management plan after reviewing the skull base CT findings at hand. Online supplemental material is available for this article. ©RSNA, 2021.

Association of pulse synchronous tinnitus and sigmoid sinus wall abnormalities in patients with idiopathic intracranial hypertension.

PURPOSE: Pulse synchronous tinnitus (PT) is common in patients with idiopathic intracranial hypertension (IIH) and in those with sigmoid sinus wall abnormalities (SSWAs). Although patients with SSWAs and IIH share many clinical features, the incidence of SSWAs in patients with IIH and its relationship to PT in this cohort is less well established. The purpose of this study is to assess the incidence of SSWAs in patients with IIH and PT, and to determine if there is an association between SSWAs and PT in this population. MATERIALS AND METHODS: Prospective computed tomography (CT) study of adults with IIH. Subjective PT was correlated with presence or absence of SSWAs on CT. RESULTS: 22 subjects were enrolled and 14 subsequently underwent CT. The incidence of SSWAs was significantly higher in subjects with PT than without (70% vs. 0%, p = 0.02). Mean age, BMI and opening pressures did not differ between those with and without SSWAs or PT. CONCLUSIONS: There is a high incidence of SSWAs in subjects with IIH and PT. These findings support an association between SSWAs and PT, and implicate SSWAs as a possible cause of, or contributing factor to, PT in patients with IIH. Patients with IIH and PT that does not resolve with reducing intracranial pressure should undergo diagnostic CT and consider treatment of a SSWA if present.

Demyelination as a harbinger of lymphoma: a case report and review of primary central nervous system lymphoma preceded by multifocal sentinel demyelination.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) may rarely be preceded by "sentinel demyelination," a pathologic entity characterized by histologically confirmed demyelinating inflammatory brain lesions that mimic multiple sclerosis (MS) or acute disseminated encephalomyelitis (ADEM). Interpreting the overlapping radiologic and clinical characteristics associated with each of these conditions-contrast-enhancing demyelination of white matter and relapsing and remitting steroid-responsive symptoms respectively-can be a significant diagnostic challenge. CASE PRESENTATION: We describe a 57-year-old woman with an unusual clinical course who presented with multi-focal enhancing white matter lesions demonstrated to be inflammatory demyelination by brain biopsy. Despite a good initial response to steroids and rituximab for treatment of presumed tumefactive multiple sclerosis, the patient's condition rapidly deteriorated, and a repeat brain biopsy six months later was consistent with a diagnosis of diffuse large B-cell lymphoma. CONCLUSIONS: Early clinical suspicion for PCNSL and awareness that biopsied lesions may initially show sentinel demyelination suggestive of alternate diagnoses may be essential for early initiation of appropriate therapies and mitigation of disease progression. Clinical, pathophysiological, and diagnostic aspects of sentinel demyelination and PCNSL are discussed.

A phase I dose escalation trial of MAGE-A3- and HPV16-specific peptide immunomodulatory vaccines in patients with recurrent/metastatic (RM) squamous cell carcinoma of the head and neck (SCCHN).

BACKGROUND: We conducted a phase I dose escalation study to evaluate the safety and immunologic response to peptide immunomodulatory vaccines GL-0810 (HPV16) and GL-0817 (MAGE-A3) in HPV16 and MAGE-A3-positive RM-SCCHN patients, respectively. METHODS: Three dose levels (500, 1,000, and 1,500 µg) of GL-0810 or GL-0817 with adjuvants Montanide (1.2 ml) and GM-CSF (100 µg/m2) were administered subcutaneously q2 weeks for a total of four vaccinations in HPV16 and MAGE-A3-positive RM-SCCHN patients, respectively. RESULTS: Nine and seven patients were enrolled in the HPV16 and MAGE-A3 cohorts, respectively. No dose-limiting toxicities were observed, and toxicity was predominantly local and grade 1 (erythema, pain, and itching at the injection site). In those patients who received all four vaccinations, 80 % (4/5) of the HPV16 cohort and 67 % (4/6) of the MAGE-A3 cohort developed antigen-specific T cell and antibody responses to the vaccine. Significant concordance between T cell and antibody responses was observed for both groups. No clear dose-response correlation was seen. All patients progressed by RECIST at first repeat imaging, except for one patient in the MAGE-A3 500 µg cohort who had stable disease for 10.5 months. The median PFS and OS for the MAGE-A3 cohorts were 79 and 183 days, respectively, and for the HPV16 cohort 80 and 196 days, respectively. CONCLUSIONS: GL-0810 and GL-0817 were well tolerated in patients with RM-SCCHN with T cell and antibody responses observed in the majority of patients who received all four vaccinations.

Surgical Free Flaps and Grafts in Head and Neck Reconstruction: Principles and Postoperative Imaging.

This review article discusses the basic principles behind the use of flaps and grafts for reconstructive surgery in the head and neck, with a special emphasis on the types of commonly used free flaps, their imaging appearance as well as some frequently encountered postoperative complications. Given the ubiquity and complexity of these reconstructive techniques, it is essential that head and neck radiologists be familiar in distinguishing between the expected evolving findings, complications, and tumor recurrence.

Imaging of Complications of Chemoradiation.

Chemoradiation for head and neck cancer is associated with a variety of early and late complications. Toxicities may affect the aero-digestive tract (mucositis, salivary gland injury), regional osseous and cartilaginous structures (osteoradionecrosis (ORN) and chondronecrosis), vasculature (progressive radiation vasculopathy and carotid blow out syndromes), and neural structures (optic neuritis, myelitis, and brain injury). These may be difficult to distinguish from tumor recurrence on imaging, and may necessitate the use of advanced MRI and molecular imaging techniques to reach the correct diagnosis. Secondary radiation-induced malignancies include thyroid cancer and a variety of sarcomas that may manifest several years after treatment. Checkpoint inhibitors can cause a variety of adverse immune events, including autoimmune hypophysitis and encephalitis.

Improving Radiology Trainees' Perception Using Where's Waldo?

RATIONALE AND OBJECTIVES: Perception is an essential skill leading to expertise in diagnostic radiology. We determined if practicing "Where's Waldo?" images improves accuracy and speed with which first and second year radiology residents detect abnormalities on chest radiographs (CXRs). MATERIALS AND METHODS: Residents at three institutions were pretested using 50 CXRs, identifying locations of potential abnormalities. They were then split into trained (examining 7 "Where's Waldo?" images over three weeks) and control groups (no "Where's Waldo?"). They were then re-tested on the 50 CXRs. At one site, visual search parameters were acquired. Data were analyzed with repeated measures ANOVAs. RESULTS: There was no significant difference in performance for trained vs control (F = 0.622, p = 0.436), with both improving significantly on post-test (F = 4.72, p = 0.037). Session time decreased significantly for both groups from pre to post-test (F = 81.47, p < 0.0001) and the decrease was significantly more (F = 31.59, p < 0.0001) for the trained group than the control group as well as for PGY with PGY3 having a larger average decrease in session time than PGY2. Eye-tracking data also showed significant increases in per image search efficiency with training. CONCLUSION: Practicing "Where's Waldo?" or similar nonradiology search tasks may facilitate the acquisition of radiology image search but not detection skills, impacting reading efficiency more than detection accuracy.

The association of active and passive tobacco smoke exposure with chronic rhinosinusitis symptom severity: A cross-sectional study.

BACKGROUND: Chronic rhinosinusitis (CRS) causes a great deal of morbidity. There are a multitude of causal factors, though their precise contribution to symptom severity has yet to be defined.  We hypothesized that exposure to both primary and secondhand tobacco smoke would correlate with more severe symptoms of CRS. METHODS: This is a prospective cross-sectional study performed at an academic tertiary care medical center from 2010 to 2013. A total of 85 consecutive patients with chronic sinusitis were screened; 70 with medically refractory CRS requiring functional Endoscopic sinus surgery (FESS) were enrolled. Recent tobacco exposure was assessed using serum cotinine levels. Sinonasal mucosa was biopsied to assess ciliary architecture. Demographics, medical history, tobacco and environmental exposures, and computed tomography (CT) imaging were also collected. Two quality of life (QOL) surveys were administered: one disease specific, Sinonasal Outcomes Test-20 (SNOT-20), and one general, Short Form-12 (SF-12). Results were correlated with the aforementioned exposures. RESULTS: The 70 patients had an average age of 46 years, and 42% were male.  Variables that correlated with worse SNOT-20 scores included serum cotinine (r = 0.43, p = 0.002), number of cigarettes smoked daily (r = 0.27, p = 0.03), and number of secondhand cigarettes exposed to per day (r = 0.29, p = 0.04). There were no significant correlations between SNOT-20 scores and Lund-MacKay or axonemal ultrastructural abnormalities (AUA)-ciliary scores. The two five-variable models best predicted disease-specific QOL. CONCLUSIONS: Increased amounts of serum cotinine and primary and secondhand smoke exposure were associated with worse sinonasal QOL. This study establishes an objective relationship between smoke exposure and patient-perceived severity of CRS, emphasizing the importance of tobacco cessation counseling as part of management.

Impact of the Novel Coronavirus 2019 (COVID-19) Pandemic on Head and Neck Cancer Care.

OBJECTIVE: The study aimed to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on head and neck oncologic care at a tertiary care facility. STUDY DESIGN: This was a cross-sectional study conducted between March 18, 2020, and May 20, 2020. The primary planned outcome was the rate of treatment modifications during the study period. Secondary outcome measures were tumor conference volume, operative volume, and outpatient patient procedure and clinic volumes. SETTING: This single-center study was conducted at a tertiary care academic hospital in a large metropolitan area. METHODS: The study included a consecutive sample of adult subjects who were presented at a head and neck interdepartmental tumor conference during the study period. Patients were compared to historical controls based on review of operative data, outpatient procedures, and clinic volumes. RESULTS: In total, 117 patients were presented during the review period in 2020, compared to 69 in 2019. There was an 8.4% treatment modification rate among cases presented at the tumor conference. There was a 61.3% (347 from 898) reduction in outpatient clinic visits and a 63.4% (84 from 230) reduction in procedural volume compared to the prior year. Similarly, the operative volume decreased by 27.0% (224 from 307) compared to the previous year. CONCLUSION: Restrictions related to the COVID-19 pandemic resulted in limited treatment modifications. Transition to virtual tumor board format observed an increase in case presentations. While there were reductions in operative volume, there was a larger proportion of surgical cases for malignancy, reflecting the prioritization of oncologic care during the pandemic.

Circumferential segmental vessel-wall enhancement on black blood MRI in patients referred for the evaluation of vasculopathy.

BACKGROUND: High resolution intracranial vessel wall magnetic resonance imaging, or black blood MRI, has recently gained traction as an adjunct to computed tomography angiography, magnetic resonance angiography, and digital subtraction angiography in the characterization of atherosclerosis, vasculitides, and inflammatory changes in the aneurysm wall. However, the occurrence of uniform circumferential segmental arterial vessel wall enhancement (CSWE) in patients without these diagnoses has not previously been studied. The purpose of this study is twofold: 1) to evaluate the prevalence of CSWE in the major intracranial arteries in patients without vasculitides, symptomatic atherosclerosis, or aneurysmal subarachnoid hemorrhage and 2) to determine the association, if any, between such enhancement and risk factors for cerebrovascular atherosclerotic disease. MATERIALS & METHODS: A retrospective study of vessel wall magnetic resonance imaging examinations was performed to evaluate for CSWE in 26 patients without known vessel wall pathology such as aneurysms or vasculitides and intracranial hemorrhage. Further evaluation of CSWE association with major intracranial atherosclerotic disease risk factors including hypertension, hyperlipidemia, diabetes mellitus and cigarette smoking was performed. RESULTS AND CONCLUSION: 46% of the cohort of patients demonstrated CSWE. Among the patients with CSWE, there was increased prevalence of CSWE in the posterior circulation vasculature with particular predilection to the V4 vertebral artery segments (92%), although there was greater association of anterior circulation CSWE with risk factors for atherosclerosis. Patients with anterior circulation CSWE also demonstrated the most number of segments with CSWE. We therefore propose that CSWE, particularly in the anterior circulation, may portend early atherosclerosis.

Pattern and severity of transverse sinus stenosis in patients with pulsatile tinnitus associated with sigmoid sinus wall anomalies.

OBJECTIVE: Describe the location and severity of transverse sinus stenosis (TSS) in a consecutive series of patients with intraoperatively confirmed sigmoid sinus wall abnormalities (SSWA). METHODS: A retrospective review of imaging studies from patients undergoing sinus wall reconstruction for pulsatile tinnitus associated with SSWA "was performed." Qualitative and quantitative analyses of the TSS, including the side, type, location, extent, and severity, were performed and compared with normal controls and historical controls with idiopathic intracranial hypertension (IIH). RESULTS: Twenty-six of 36 subjects had adequate imaging data. The majority of subjects had some degree of bilateral TSS, and the majority of stenoses involved the distal transverse sinus. Subjects with diverticulum were significantly more likely than those with dehiscence to have ipsilateral distal TSS (16 of 16 vs. 4 of 10, P = 0.009). The mean minimum transverse sinus diameter, stenosis severity grade, and overall posterior venous sinus outflow were significantly worse in the subjects as compared to normal controls (P = 0.002), although not as severe as the comparable values in historical controls with IIH (P < 0.003). CONCLUSION: Subjects with SSWA have a high incidence of TSS, with patterns differing between those with dehiscence and diverticulum. Severity of TSS and overall posterior fossa venous outflow are worse as compared to normal controls but not as severe as in subjects with IIH. These findings have implications for the pathophysiology and management of SSWA. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1028-1033, 2020.

Evaluation and treatment of pulsatile tinnitus associated with sigmoid sinus wall anomalies.

OBJECTIVE: Describe clinical and radiographic features of sigmoid sinus wall anomalies (SSWA) associated with pulsatile tinnitus (PT) and determine factors predictive of response to surgery. METHODS: Preoperative diagnostic imaging and treatment response were reviewed after surgical repair of 40 ears among 38 consecutive patients presenting with PT associated with SSWA who underwent transtemporal sinus wall reconstruction. RESULTS: Twenty-three ears had isolated sigmoid sinus dehiscence, and 17 had diverticulum. The rates of transverse sinus stenosis (TSS) and empty sella, 66% and 32% respectively, were significantly higher than in historical controls (P = 0.02 and 0.001). Thirty-six out of 40 subjects (90%) had complete resolution of their PT following surgery, including all those with a diverticulum. For subjects with dehiscence alone without diverticulum, a favorable response to surgery was strongly associated with the presence of TSS (P = 0.01) and empty sella (P = 0.02). CONCLUSION: Sigmoid sinus diverticulum and dehiscence are a clinically important cause of PT. Women of childbearing age with an elevated body mass index (BMI) are commonly affected, and there is a high rate of associated TSS and empty sella. Transtemporal sinus wall reconstruction has a high rate of success in appropriately selected patients. Patients with isolated sinus wall dehiscence without diverticulum, TSS, or empty sella are less likely to respond to transtemporal sinus wall reconstruction. These data imply a multifactorial cause of PT in at least some patients with SSWA. LEVEL OF EVIDENCE: 4 Laryngoscope, 128:S1-S13, 2018.

Intrabronchial Catheter Resuscitation for Respiratory and Cardiorespiratory Arrest.

INTRODUCTION: We sought to determine whether intrabronchial oxygenation would provide adequate gas exchange during both anesthesia induced apneic and cardiopulmonary arrest and cardiac massage (CPR). METHODS: Ten pigs underwent general anesthesia with mechanical ventilation. Blood gases were measured in each animal at 4 min intervals for up to 28 min. An intrabronchial catheter (4 L/min O2) was inserted through an endotracheal tube after respirator cessation. Group A animals (6) were resuscitated with the catheter but without CPR. Group B animals (4) were rendered apneic and cardioplegic and resuscitated by CPR for 28 min using the intrabronchial device. RESULTS: All group A animals were resuscitated and survived after 24 min of apnea. Mean pO2 decreased from 378 mmHg (95% confidence interval [CI], 288-468) to 292 mmHg (95% CI, 246-339), P = 0.009; pCO2 increased from 52 mmHg (95% CI, 43-61) to 137 mmHg (95% CI, 116-158), P < 0.0001; and pH decreased from 7.32 (7.29-7.36) to 6.98 (6.92-7.03), P < 0.0001. In a control animal bronchial catheter oxygen flow ceased at baseline and pO2 decreased from 268 to 30 mmHg by 20 min. In group B animals mean pO2 decreased from 426 mmHg (95% CI, 273-579) to 130 mmHg (95% CI, 92-168) after 28 min, P < 0.0001; pCO2 increased from 49 mmHg (95% CI, 41-58) to 73 mmHg (95% CI, 61-86), P = 0.03; and pH decreased from 7.34 (7.33-7.35) to 7.07 (6.98-7.16), P < 0.0001. In the control receiving intratracheal oxygen pO2 decreased from 324 to 88 mmHg after 16 minu of CPR. CONCLUSIONS: Intrabronchial oxygenation provides sustained hyperoxemia during complete apnea and cardiac arrest with CPR.

Imaging of traumatic neurovascular injury.

Traumatic injury to the major vessels of the head and neck can result in potentially devastating neurologic sequelae. Until recently, conventional angiography was the primary imaging modality used to evaluate these often challenging patients. Advances in cross-sectional imaging have improved the ability to screen for these lesions, which have been found to be more common than previously thought; however, accepted protocols of imaging evaluation have not yet been fully established. This article presents a general approach to the patient with suspected neurovascular injury. This includes a discussion of the histopathologic spectrum, clinical presentation, mechanisms, radiologic work-up, pertinent issues of the most common lesions, and some of the endovascular techniques used in their management.

Removal of an Entrapped Lumbar Drain After Thoracic Endovascular Aortic Repair.

Cerebrospinal fluid drainage with a lumbar drain is an important aspect of spinal cord protection during thoracic endovascular aortic repair. Lumbar drains have low reported complication rates. We report a case of an entrapped lumbar drain after thoracic endovascular aortic repair. Computed tomography imaging of the lumbar spine with 3-dimensional reformatting was critical in determining where the drain was entrapped and assisted with its removal. Induction of general anesthesia to reduce muscle spasms and extreme flexion of the lumbar spine also facilitated removal. This case demonstrates a safe step-by-step approach that was used for removing an entrapped drain.

Oropharyngeal cancer as a driver of racial outcome disparities in squamous cell carcinoma of the head and neck: 10-year experience at the University of Maryland Greenebaum Cancer Center.

BACKGROUND: Racial outcome disparities have been observed in head and neck squamous cell carcinoma (HNSCC) with diminished survival for black patients compared with white patients. METHODS: We retrospectively analyzed 1318 patients with primary HNSCC treated at the University of Maryland Greenebaum Cancer Center (UMGCC) from 2000 to 2010. RESULTS: Of all the patients, 65.9% were white, 30.7% were black, and 3.3% were of other races. Black patients were less likely to present with oral cavity cancer, and more likely to present with laryngeal or hypopharyngeal cancers. White patients were more likely to have early stage disease, especially in the oral cavity. Black race was independently associated with worse overall survival (OS) in the entire cohort. Black patients had a significantly worse OS among oral cavity and oropharyngeal cancers, with the largest disparity in oropharyngeal cancer. However, in multivariate analysis, race was only still significant in oropharyngeal cancer. CONCLUSION: We observed differences by race in distribution of disease site, stage, and OS. Survival disparity in the entire cohort was driven mostly by differences among oropharyngeal cancer.

A band dispersion mechanism for Pt alloy compositional tuning of linear bound CO stretching frequencies.

The C-O stretching frequency (nu(CO)) of atop CO/Pt in PtRu alloys is compositionally tuned in proportion to the Pt mole percent. The application of a Blyholder-Bagus type mechanism (i.e., increased back-donation from the metal d-band to the hybridized 2pi CO molecular orbitals (MOs)) to compositional tuning has been paradoxical because (1) a Pt-C bond contraction, expected with increased back-donation as the Pt mole percent is reduced, is not observed (i.e., calculated Pt-C bond is either elongated or insensitive to alloying and the binding energies of CO/Pt decrease with alloying) and (2) the lowering d-band center and increased d-band vacancies upon alloying (suggesting less back-donation to the higher energy metal hybridized 2pi CO MOs) must be reconciled with the alloy-induced red shift of the nu(CO). A library of spin-optimized Pt and Pt alloy clusters was the basis of density functional theory (DFT) calculations of CO binding energies, nu(CO) values, shifts, and broadening of 5sigma/2pi CO MO upon hybridization with the alloy orbitals and a DFT derived Mulliken electron population analysis. The DFT results, combined with FEFF8 local density of states (LDOS) calculations, validate a 5sigma donation-2pi back-donation mechanism, reconciling the direction of alloy compositional tuning with the lowering of the d-band center and increased vacancies. Although the d-band center decreases in energy with alloying, an asymmetric increase in the dispersion of the d-band is accompanied by an upshift of the metal cluster HOMO level. Concomitantly, the hybridization and renormalization of the CO 5sigma/2pi states results in a broadening of the 5sigma/2pi manifold with additional lower energy states closer to the upshifted (with respect to the pure Pt cluster) HOMO of the alloy cluster. The dispersion toward higher energies of the alloy d-density of states results in more 5sigma/2pi CO filled states (i.e., enhanced 2pi-back-donation). Finally, Mulliken and FEFF8 electron population analysis shows that the increase of the average d-band vacancies upon alloying and additional 2pi back-donation are not mutually exclusive. The d-electron density of the CO-adsorbed Pt atom increases with alloying while the average d-electron density throughout the cluster is reduced. The localized electron density is manifested as an electrostatic wall effect, preventing the Pt-C bond contractions expected with increased back-donation to the 2pi CO MOs.

Superior epigastric artery perforator (SEAP) flap: a novel approach to autologous breast reconstruction.

BACKGROUND: Although free tissue breast reconstruction has been increasingly used, it remains challenging to perform outside of specialized centers due to facility and personnel limitations. We describe a preclinical study highlighting the feasibility of a pedicled, superior epigastric artery perforator (SEAP) flap utilizing lower abdominal tissues similar to a transverse rectus abdominus myocutaneous (TRAM) reconstruction, but with decreased donor-site morbidity. METHODS: Fresh cadavers were dissected generating a total of 32 SEAP flaps. These flaps were subsequently studied for transposition potential and vascularity utilizing computed tomographic (CT) imaging. RESULTS: An obvious, single, dominant SEAP was appreciated, and a developed flap was routinely capable of reaching either nipple-areola complex with simple interposition. Cadaveric CT imaging revealed global contrast filling in each dissected hemi-abdomen tested. CONCLUSIONS: We describe a preclinical study utilizing a novel pedicled, SEAP flap for aesthetic breast reconstruction. While this will not obviate the use of free tissue transfer, it may add to the surgical armamentarium for aesthetic restoration in the breast cancer patient.

Technique for retrieval of a guidewire lodged in a vena cava filter.

A case in which the guidewire used to place a percutaneous jugular central line became entangled in the limbs of a Trapease inferior vena cava filter is presented. A 7F sheath introducer was fashioned into a monorail system to uncurl the wire's J tip and remove the wire without disturbing the filter's position. This report highlights an increasingly frequent clinical scenario and an inexpensive effective method for resolution.