Postoperative CT findings of orthognathic surgery and its complications: A guide for radiologists.

Orthognathic surgery is the standard procedure to correct congenital, developmental, or acquired dentofacial deformities. The maxillomandibular relationship corrected by orthognathic surgery can improve facial esthetics, masticatory function, articulation, and breathing. The most common types of osteotomies include the combination of Le Fort I osteotomy, bilateral sagittal split mandibular ramus osteotomy, and genioplasty. High-resolution low-dose computed tomography is useful for evaluating the facial skeleton and soft tissues after surgery as well as for depicting a variety of possible complications. This article reviews the postoperative imaging findings of the most common orthognathic surgeries and their potential complications on multidetector-row computed tomography.

Postoperative Imaging of the Temporal Bone.

The anatomy of the temporal bone is complex, and postoperative imaging evaluation of this bone can be challenging. Surgical approaches to the temporal bone can be categorized didactically into tympanoplasty and ossicular reconstruction, mastoidectomy, and approaches to the cerebellopontine angle and internal auditory canal (IAC). In clinical practice, different approaches can be combined for greater surgical exposure. Postoperative imaging may be required for follow-up of neoplastic lesions and to evaluate unexpected outcomes or complications of surgery. CT is the preferred modality for assessing the continuity of the reconstructed conductive mechanism, from the tympanic membrane to the oval window, with use of grafts or prostheses. It is also used to evaluate aeration of the tympanic and mastoid surgical cavities, as well as the integrity of the labyrinth, ossicular chain, and tegmen. MRI is excellent for evaluation of soft tissue. Use of a contrast-enhanced fat-suppressed MRI sequence is optimal for follow-up after IAC procedures. Non-echo-planar diffusion-weighted imaging is optimal for detection of residual or recurrent cholesteatoma. The expected imaging findings and complications of the most commonly performed surgeries involving the temporal bone are summarized in this review. Online supplemental material is available for this article. ©RSNA, 2021.

Imaging of pediatric skull lytic lesions: A review.

Skull lesions in pediatric population are common findings on imaging and sometimes with heterogeneous manifestations, constituting a diagnostic challenge. Some lesions can be misinterpreted for their aggressiveness, as with larger lesions eroding cortical bone, containing soft tissue components, leading to excessive and, in some cases, invasive inappropriate etiological investigation. In this review, we present multiple several conditions that may present as skull lesions or pseudolesions, organized by groups (anatomic variants, congenital and development disorders, traumatic injuries, vascular issues, infectious conditions, and tumoral processes). Anatomic variants are common imaging findings that must be recognized by the neuroradiologist. Congenital malformations are rare conditions, such as aplasia cutis congenita and sinus pericranii, usually seen at earlier ages, the majority of which are benign findings. In case of trauma, cephalohematoma, growing skull fractures, and posttraumatic lytic lesions should be considered. Osteomyelitis tends to be locally aggressive and may mimic malignancy, in which cases, the clinical history can be the key to diagnosis. Vascular (sickle cell disease) and tumoral (aneurismal bone cyst, eosinophilic granuloma, metastases) lesions are relatively rare lesions but should be considered in the differential diagnosis, in the presence of certain imaging findings. The main difficulty is the differentiation between the benign and malignant nature; therefore, the main objective of this pictorial essay is to review the main skull lytic lesions found in pediatric age, describing the main findings in different imaging modalities (CT and MRI), allowing the neuroradiologist greater confidence in establishing the differential diagnosis, through a systematic and simple characterization of the lesions.

The role of magnetic resonance imaging in Ménière disease: the current state of endolymphatic hydrops evaluation.

Technical advances in magnetic resonance imaging have allowed to accurately detect and grade endolymphatic space distension in Ménière disease; this was only possible in post-mortem histological studies until a few years ago. Magnetic resonance imaging rules out other causes of vertigo and hearing loss, and is able to evaluate the cochlear and vestibular compartments of the endolymphatic space using a dedicated protocol.

The role of magnetic resonance imaging in Ménière disease: the current state of endolymphatic hydrops evaluation / O papel da ressonância magnética na doença de Ménière: a avaliação da hidropsia endolinfática nos dias atuais

ABSTRACT Technical advances in magnetic resonance imaging have allowed to accurately detect and grade endolymphatic space distension in Ménière disease; this was only possible in post-mortem histological studies until a few years ago. Magnetic resonance imaging rules out other causes of vertigo and hearing loss, and is able to evaluate the cochlear and vestibular compartments of the endolymphatic space using a dedicated protocol.

RESUMO Os avanços técnicos na ressonância magnética têm permitido detectar e classificar com acurácia a distensão do espaço endolinfático na doença de Ménière; isso só era possível nos estudos histológicos post-mortem até poucos anos atrás. Além de afastar outras causas de vertigem e de perda auditiva, a ressonância magnética é capaz de avaliar os compartimentos coclear e vestibular do espaço endolinfático por meio de um protocolo dedicado.