Skull base osteomyelitis: clinical and radiologic analysis of a rare and multifaceted pathological entity.

Skull base osteomyelitis (SBO) is a potentially life-threatening inflammation of cranial base bony structures of variable origin. Criteria for diagnosis and treatment are still controversial. Demographics, predisposing factors, symptoms, imaging, and clinical, laboratory, histological, and microbiological data of patients managed for SBO at the University Hospital of Brescia (ASST Spedali Civili) between 2002 and 2017 were retrospectively reviewed. Patients were included in different etiological groups. The topographic distribution of magnetic resonance (MR) abnormalities was recorded on a bi-dimensional model of skull base, on which three different patterns of inflammatory changes (edematous, solid, or necrotic) were reported. In patients with a history of radiotherapy, the spatial distribution of SBO was compared with irradiation fields. The association between variables and etiological groups was verified with appropriate statistical tests. A classification tree analysis was performed with the aim of inferring a clinical-radiological diagnostic algorithm for SBO. The study included 47 patients, divided into 5 etiological groups: otogenic (n = 5), radio-induced (n = 16), fungal (n = 14), immune-mediated (n = 6), and idiopathic (n = 6). At MR, five types of topographical distribution were identified (central symmetric, central asymmetric, orbital apex, sinonasal, maxillary). In patients with a history of radiotherapy, the probability to develop SBO was significantly increased in areas receiving the highest radiation dosage. The analysis of patients allowed for design of a classification tree for the diagnosis of SBO. The integration of clinical and radiologic information is an efficient strategy to categorize SBO and potentially guide its complex management.

Early Postoperative Magnetic Resonance in the Diagnosis of Persistent Juvenile Angiofibroma.

OBJECTIVES/HYPOTHESIS: Despite improvements in the treatment of juvenile angiofibroma (JA), the rate of persistence (pJA) is still not negligible. In the present study, we assessed the value of early postoperative magnetic resonance imaging (MRI) in depicting unintentional pJAs and designed a MRI-driven decisional flow-chart for pJA management and follow-up. STUDY DESIGN: Observational study. METHODS: Patients undergoing early postoperative MRI after endoscopic resection of JA in the Unit of Otorhinolaryngology - ASST Spedali Civili, University of Brescia from 2007 to 2017 were enrolled. MRI was defined as negative or positive based on defined radiological criteria. The diagnostic performance of MRI was evaluated. RESULTS: The analysis included 26 patients, with a mean age of 16.5 years (range, 11-25). Early MRI was negative for pJA in 21 (80.8%) patients and positive in five (19.2%). No patient with a negative finding was found positive at subsequent follow-up MRIs. The accuracy of a positive finding was confirmed by pathologic examination (three cases) or follow-up MRIs (two cases). The diagnostic performance of MRI was excellent with sensitivity and specificity of 100%. An MRI-driven flow-chart for pJA management and follow-up was designed. CONCLUSIONS: Early postoperative MRI demonstrated a high diagnostic accuracy in the detection of unintentional pJA. Our MRI-driven strategy and decisional flow-chart could aid in the decision-making process in the management of pJA and definition of postoperative surveillance. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2436-E2441, 2021.

Posttreatment Imaging Surveillance.

Posttreatment imaging surveillance in patients treated for anterior skull base tumors is a multifaceted issue which - as a first step - requires tailoring of the selection of imaging technique and acquisition protocol to the clinical scenario. As a general rule, acute symptoms suggesting the onset of a complication of treatment require prompt diagnosis through an easily accessible technique, such as CT; on the other hand, monitoring recurrences in asymptomatic patients is best achieved with MRI, exploiting the inherently higher contrast resolution. The interpretation of follow-up imaging studies is challenging. First of all, it is essential to be aware of specific characteristics of the natural history that may differ significantly between histologies, influencing the pattern and timing of recurrences. Additionally, resection of the lesion and reconstruction of the defect (as well as radiation treatment) produce complex anatomical changes, which may mislead inexperienced radiologists; this concept emphasizes the centrality of collecting accurate information on treatment modalities and procedures applied before scanning in each patient. This enables the pattern of expected posttreatment changes to be anticipated and, consequently, recurrences or complications to be more easily identified.

An additional challenge for head and neck radiologists: anatomic variants posing a surgical risk - a pictorial review.

Anatomic variants in the head and neck are quite numerous and occur frequently: a minority of them increase the risk of complications during surgical procedures and may be visualized on cross-sectional images. As some of these complications are potentially fatal, awareness (and accurate reporting) of such variants is a basic responsibility of radiologists, particularly when surgery in the pertinent anatomic area is under consideration.