RESUMO
The lateral lumbar interbody fusion (LLIF) approach is a minimally invasive surgery that can be used as an alternative to traditional lumbar interbody fusion techniques. LLIF accesses the intervertebral disk through the retroperitoneum and psoas muscle to avoid major vessels and visceral organs. The exposure of retroperitoneal structures during LLIF leads to unique complications compared with other surgical approaches. An understanding of the surgical technique and its associated potential complications is necessary for radiologists who interpret imaging before and after LLIF. Preoperative imaging must carefully assess the location of anatomic structures, including major retroperitoneal vasculature, lumbar nerve roots, lumbosacral plexus, and the genitofemoral nerve, relative to the psoas muscle. Multiple imaging modalities can be used in postoperative assessment including radiographs, CT, CT myelography, and MRI. Of these, CT is the preferred modality, because it can assess a range of complications relating to both the retroperitoneal exposure and the spinal instrumentation, as well as bone integrity and fusion status. This article describes surgical approaches for lumbar interbody fusion, comparing the approaches' indications, contraindications, advantages, and disadvantages; reviews the surgical technique of LLIF and relevant anatomic considerations; and illustrates for interpreting radiologists the normal postoperative findings and potential postsurgical complications of LLIF.
Assuntos
Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Imagem Multimodal/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Fusão Vertebral/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Radiografia/métodos , Tomografia Computadorizada por Raios X/métodosAssuntos
Leucoencefalopatia Multifocal Progressiva/virologia , Paresia/diagnóstico , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Humanos , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Leucoencefalopatia Multifocal Progressiva/diagnóstico por imagem , Leucoencefalopatia Multifocal Progressiva/patologia , Masculino , Pessoa de Meia-Idade , Paresia/virologia , Sarcoidose/complicaçõesRESUMO
Intracranial haemorrhage after supra-tentorial craniotomies can occur in a typical pattern and location which may suggest the diagnosis of remote cerebellar haemorrhage (RCH) which is quite a rare occurrence. The 'Zebra Sign' refers to a pattern of hyperdensity indicative of blood and hypodensity indicative of normal cerebellar parenchyma in a curvilinear, stripe-like fashion along the cerebellar folia and is a characteristic imaging finding in RCH. RCH in general doesn't require surgical treatment, however in cases of significant hydrocephalus or progressive deterioration of consciousness surgical treatment may be warranted. The knowledge of this condition is important as it can pre-empt unnecessary further investigations and biopsy. Although imaging appearance may be striking, close imaging follow-up and clinical monitoring are often enough for the management of this entity.
RESUMO
Fat-containing lesions of the head and neck are commonly encountered in day-to-day practice. Our aim was to review the various imaging presentations of common and some uncommon fat-containing lesions within the head and neck with potential pitfalls and mimics. While most soft-tissue masses have a fairly similar density, the presence of fat in a mass lesion is easy to identify on both CT/MRI and can help narrow the differential. Case-based examples of lipomas, liposarcomas, lipoblastomas, dermoids, teratomas and other fatty lesions will be used to describe imaging features. While fat density can be helpful, differentiating benign from malignant fat-containing lesions can still pose a challenge. Lesions simulating pathology such as brown fat, fatty changes within organs and post-operative flaps are presented. Finally, examples of fatty lesions in atypical locations are shown to illustrate examples that should be kept in mind in any differential. The presence of fat in head and neck masses can aid radiologists in arriving at an accurate diagnosis. Knowledge of the imaging appearance of these fat-containing lesions and their mimics can help avoid unnecessary biopsy or surgery.
Assuntos
Diagnóstico por Imagem , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Cabeça/diagnóstico por imagem , Cabeça/patologia , Lipoma/diagnóstico por imagem , Lipoma/patologia , Lipomatose/diagnóstico por imagem , Lipomatose/patologia , Pescoço/diagnóstico por imagem , Pescoço/patologia , Diagnóstico Diferencial , HumanosRESUMO
Vertebral arteriovenous fistulas are uncommon in neurofibromatosis. We describe MRI findings of a patient with an unusual association of bilateral vertebral arteriovenous fistulas with an atlantoaxial dislocation in the setting of neurofibromatosis.