ABSTRACT
Imaging can identify pathologic cervical adenopathy in a significant number of patients with head and neck cancer who have no palpable adenopathy on physical examination. This article reviews nodal classification, drainage patterns of different head and neck cancers, various cross-sectional imaging features of metastatic lymph nodes from head and neck cancer, nodal staging, and certain features like extracapsular spread and carotid and vertebral invasion that the clinician should know because they have therapeutic and prognostic implications. New imaging techniques and the role of fluorodeoxyglucose positron emission tomography imaging in recurrent disease are discussed.
Subject(s)
Carcinoma, Squamous Cell/diagnosis , Head and Neck Neoplasms/diagnosis , Lymph Nodes , Lymphatic Metastasis/diagnosis , Magnetic Resonance Imaging , Positron-Emission Tomography , Tomography, X-Ray Computed , Adult , Contrast Media , Female , Fluorodeoxyglucose F18 , Humans , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis/diagnostic imaging , Magnetic Resonance Imaging/methods , Male , Neck , Neoplasm Invasiveness , Neoplasm Recurrence, Local/diagnosis , Neoplasm Staging , Palpation , Positron-Emission Tomography/methods , Prognosis , Radiopharmaceuticals , Sensitivity and Specificity , Tomography, X-Ray Computed/methods , UltrasonographyABSTRACT
The goal of this study was to use diffusion-tensor magnetic resonance (MR) imaging to define the location and organization of corticospinal tracts (CSTs) in the posterior limb of the internal capsule (PLIC). The Institutional Review Board approved the study, and informed consent was obtained from all subjects. Eight volunteers and two patients with brain tumor were imaged at 3 T. All CSTs were found to lie in a compact area in one part of the PLIC: If the PLIC is divided into four equal quarters from anterior to posterior, the CST was shown to be in the third quarter. Seventeen of 20 CSTs were organized somatotopically, with hand fibers anterolateral to foot fibers, not anteromedial as is currently believed. In three of 20, hand and foot fibers were intermixed. Classically, it was thought that the CST was located in the anterior third of the PLIC. The present data confirm recent results that the CST is located more posteriorly. In the majority of cases, however, the CST is organized somatotopically.
Subject(s)
Brain/anatomy & histology , Diffusion Magnetic Resonance Imaging/methods , Pyramidal Tracts/anatomy & histology , Adult , Brain/pathology , Brain Neoplasms/pathology , Female , Humans , Image Processing, Computer-Assisted , Male , Pyramidal Tracts/pathologyABSTRACT
The anatomy of the brain is extremely complex, and certain, even large structures, such as the corticospinal tract (CST), remain poorly understood. Diffusion tractography provides an opportunity to explore the white matter tracts in a fundamentally new way. In the current paper, we show how this technique has already added to our understanding of the anatomy of the CST. We also explore the future projects involving diffusion tractography of the motor white matter tracts that will advance this method and further our understanding of brain anatomy.
Subject(s)
Brain Mapping/methods , Diffusion Magnetic Resonance Imaging/methods , Image Processing, Computer-Assisted/methods , Motor Cortex/anatomy & histology , Pyramidal Tracts/anatomy & histology , Diffusion Magnetic Resonance Imaging/trends , Functional Laterality/physiology , Humans , Image Processing, Computer-Assisted/trends , Internal Capsule/anatomy & histology , Internal Capsule/physiology , Motor Cortex/physiology , Nerve Fibers, Myelinated/physiology , Nerve Fibers, Myelinated/ultrastructure , Neuroanatomy/methods , Neuroanatomy/trends , Neuronavigation/methods , Neuronavigation/trends , Pyramidal Tracts/physiologyABSTRACT
We present a 7-year-old boy, with a history of neonatal intraventricular hemorrhage, leading to hydrocephalus with multiple shunt revisions. The current presentation of shunt failure and resultant hydrocephalus was complicated by herniation of the trigone of the lateral ventricle into the posterior fossa. Despite the dramatic radiological appearance, this herniation of the lateral ventricle was not accompanied by any additional clinical signs or symptoms other than those usually attributed to hydrocephalus. Following successful shunt revision, the patient returned to his baseline clinically with the trigone reverting back to its normal position. We also present a second companion case.
Subject(s)
Cerebellar Diseases/diagnostic imaging , Encephalocele/diagnostic imaging , Cerebellar Diseases/complications , Cerebellar Diseases/surgery , Cerebral Ventriculography , Cerebrospinal Fluid Shunts , Child , Encephalocele/complications , Encephalocele/surgery , Female , Humans , Hydrocephalus/complications , Hydrocephalus/diagnostic imaging , Hydrocephalus/surgery , Male , Reoperation , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: The purpose of this study was to evaluate the role of helical CT in detecting right ventricular dysfunction (RVD) after acute pulmonary embolism (PE). METHODS: This was a retrospective study consisting of 25 patients with CT scans positive for acute pulmonary embolism who had either follow-up echocardiography (23 patients) or pulmonary angiography (2 patients). CT scans were reviewed for findings suggestive of RVD. Scans were considered positive for RVD if the right ventricle (RV) was dilated or if the interventricular septum was deviated towards the left ventricle. Results were then correlated with the results of echocardiography or pulmonary angiography to estimate the sensitivity and specificity of CT in detecting RVD associated with PE. RESULTS: Within this group of 25 patients with PE, CT demonstrated sensitivity of 78% (7/9), specificity of 100% (16/16), and positive predictive value of 100% (7/7) in detection of RVD. CONCLUSION: CT may be useful in detecting RVD in patients with acute PE.
