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A variety of congenital syndromes affecting the face occur due to defects involving the first and second BAs. Radiographic evaluation of craniofacial deformities is necessary to define aberrant anatomy, plan surgical procedures, and evaluate the effects of craniofacial growth and surgical reconstructions. High-resolution CT has proved vital in determining the nature and extent of these syndromes. The radiologic evaluation of syndromes of the first and second BAs should begin first by studying a series of isolated defects: CL with or without CP, micrognathia, and EAC atresia, which compose the major features of these syndromes and allow more specific diagnosis. After discussion of these defects and the associated embryology, we proceed to discuss the VCFS, PRS, ACS, TCS, Stickler syndrome, and HFM.

Endocrine and neuroendocrine tumors, which secrete hormones or vasoactive substances, comprise a broad and divergent group of diseases. In the following section we have chosen some of the more common functional tumors to illustrate the spectrum of imaging findings, cross sectionally as well as scintigraphically.

We present a case involving a 76-year-old man with a massive right-sided vascular neck mass that had been present since birth. The mass had been stable throughout the patient's life, but recently a portion of it had become hard. Physical examination revealed a firm, palpable focus within the vascular lesion in the right side of the neck. Computed tomography revealed the presence of numerous hyperdense foci, many more than 2 cm in size, which were confirmed by fine-needle aspiration to be phleboliths. The patient was followed for 6 months to ensure that the vascular mass and phleboliths remained stable.

Arachnoid cysts are benign intracranial lesions that are typically diagnosed incidentally. We describe the case of a 56-year-old man who presented with a multiloculated arachnoid cyst of the middle cranial fossa that extended into the sphenoid sinus. The lesion was identified on computed tomography of the head, which had been obtained for an unrelated investigation. However, establishing a definitive diagnosis proved to be difficult. Because the cyst had caused extensive skull base erosion, the patient was managed conservatively with close observation. We report the radiographic progression of this lesion during more than a decade of follow-up, and we review the literature pertaining to the presentation, pathophysiology, and treatment of arachnoid cysts.

Background Traditionally, idiopathic cerebrospinal fluid (CSF) leaks have been associated with normal intracranial pressure (ICP). We speculate that at least one subset of these leaks may be associated with elevated ICP, more specifically, idiopathic intracranial hypertension (IIH). We sought to identify radiographic manifestations suggestive of elevated ICP in 14 patients with idiopathic CSF leaks who clinically and epidemiologically resembled patients with IIH. Methods We retrospectively reviewed high-resolution CT, MRI, and/or CT cisternography in 14 patients with elevated ICP and idiopathic CSF leaks for radiographic manifestations suggesting increased ICP. Results Arachnoid pits were seen in 79% of patients, empty sella was seen in 50% of patients, meningo(encephalo)celes were seen in 50% of patients, and dural ectasia was seen in 35% of patients, respectively. Optic nerve findings were not shown as commonly seen as described in the literature. Conclusion We show a subset of patients with idiopathic CSF leaks who display radiographic signs consistent with increased ICP who may represent an alternative presentation of IIH.

In recent years, investigators have made significant progress in documenting brain structure and function as it relates to aging by using positron emission tomography, conventional magnetic resonance (MR) imaging, advanced MR techniques, and functional MR imaging. This review summarizes the latest advances in understanding physiologic maturation and aging as detected by these neuroimaging modalities. We also present our experience with MR volumetric and positron emission tomography analysis in separate cohorts of healthy subjects in the pediatric and adult age groups respectively. Our results are consistent with previous studies and include the following: total brain volume was found to increase with age (up to 20 years of age). Whole brain metabolism and frontal lobe metabolism both decrease significantly with age (38% and 42%, respectively), whereas cerebellar metabolism does not show a significant decline with age. Defining normal alterations in brain function and structure allows early detection of disorders such as Alzheimer's and Parkinson's diseases, which are commonly associated with normal aging.

Purpose To evaluate existing methods of standardization by exploiting the well-known tissue characterizing property of magnetization transfer ratio (MTR) values obtained from MT imaging, and compare the tissue characterizability of standardized T2, proton density (PD), and T1 images against the MTR images. Materials and Methods Image intensity standardization is a postprocessing method that was designed to correct for acquisition-to-acquisition signal intensity variations (nonstandardness) inherent in magnetic resonance (MR) images. The main idea of this technique is to deform the volume image histogram of each study to match a standard histogram, and to utilize the resulting transformations to map the image intensities into a standard scale. The method has been shown to produce a significant gain in similarity of resulting images and to achieve numeric tissue characterization. In this work we compared PD-, T2-, and T1-weighted images before and after standardization with the corresponding MT images for 10 patient MRI studies of the brain, in terms of the normalized median values on the corresponding image histograms. Results No statistically significant difference was observed between the standardized PD-, T2-, and T1-weighted images and the corresponding MTR images. However, a statistically significant difference was found between the pre- and poststandardized PD-, T2-, and T1-weighted images, and between the prestandardized PD-, T2-, and T1-weighted images and the corresponding MTR images. Conclusion These results suggest that standardized T2, PD, and T1 images and their tissue-specific intensity signatures may be useful for characterizing disease. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

Objectives: Head trauma is a common cause of anosmia, but diagnosis is typically late, owing to more life-threatening sequelae of the injury. Herein, we describe our workup for a case of traumatic anosmia and the magnetic resonance imaging (MRI) findings both at the time of injury and at the 18-month follow-up. Methods: We present a case report and a review of the literature. Results: A 33-year-old woman presented to our institution with a chief complaint of loss of smell and taste following an occipital blow to her head that occurred when she was hit by a car while riding a bicycle. We present the findings of MRI performed at the time of the injury and at the 18-month follow-up. We describe the clinical progression of her disease, from symptoms of parosmic and phantosmic episodes accompanied by dysgeusia to total anosmia at the 18-month follow-up. Conclusions: We advocate the use of MRI, coupled with otolaryngology consultation and formal olfactory testing, in the diagnosis, management, and counseling of patients with anosmia sustained from head injury.

Background Adult brain stem tumors are rare, and diverse pathology can be found in this location. Stereotactic biopsy of lesions in the brain stem has been performed since the 1960s with high diagnostic and low complication rates. Advances in imaging technology have raised questions regarding the utility of biopsy. We perform decision analysis to aid clinicians in their approach to management of adult brain stem lesions. Methods A structured literature search revealed 20 publications with 457 patients who had undergone brain stem lesion biopsy. These publications were reviewed to determine diagnostic rates and the incidence of complications. Standard decision analytic techniques were applied to the case of a virtual adult patient with a lesion in the brain stem. Results A 1-way sensitivity analysis revealed the likelihood that the preoperative diagnosis was correct and the rate at which incorrect treatment was based on faulty empirical diagnosis as the 2 factors with the greatest effects on patient outcome. The diagnostic rate and complication rate of biopsy, within the ranges reported in the literature, had lesser effects. A threshold analysis was constructed to compare outcomes from stereotactic biopsy vs empiric therapy for a brain stem lesion. The probability that the preoperative diagnosis is correct is plotted vs the probability that empirical treatment based on an incorrect diagnosis will have adverse effect. Conclusions Management of lesions in the adult brain stem requires careful consideration of multiple preoperative factors including clinical and radiographic diagnostic certainty, consequences of empiric therapy, and the surgeon's complication rate.

Objectives: This study was conducted to evaluate magnetic resonance imaging (MRI) as an objective measure of survival of micronized acellular human dermal graft (Cymetra, LifeCell Corporation) injected into the thyroarytenoid muscle for augmentation of unilateral vocal fold paralysis. Methods: We performed a retrospective review of MRI scans obtained in 6 patients in whom Cymetra was injected into the thyroarytenoid muscle. Gadolinium-enhanced MRI of the larynx was performed 3 days, 1 month, 8 months, 11 months, 15 months, and 21 months after injection. The survival of injected Cymetra was assessed according to information obtained from the MRI scan. Images were also obtained for 1 cm3 of reconstituted Cymetra paste. Results: The identification of Cymetra in the larynx is based on its proteinaceous content. T1-weighted images of the injected material in the true vocal fold showed hyperintense foci corresponding to injected Cymetra. Hyperintense signal was also present on the T2-weighted images. Persistence of the injected Cymetra was readily detectable by MRI for as long as 11 months. Conclusions: Cymetra is a viable treatment option for vocal fold augmentation. The duration of survival of Cymetra (as long as 11 months) makes it a good option in cases in which longer survival of the injectable material is needed.

BACKGROUND AND PURPOSE: The petrous and cavernous segments of the extradural internal carotid artery take a complex course through the skull base before entering the subarachnoid space distal to the cavernous sinus. Despite the protection from trauma afforded by the anatomy, the petrous and carotid internal carotid artery (ICA) segments of the vessel remains subject to disease, the most important of which are aneurysms. Aneurysms affecting the petrous portion of the vessel are extremely uncommon, and presentation with otologic symptoms is unusual. These symptoms include hearing loss, tinnitus, and life threatening hemorrhage. This article emphasizes the need for a high level of suspicion for aneurysm as a potential cause for otologic symptoms. We report and discuss three cases of petrous carotid aneurysms with otologic manifestations to increase the awareness and aid in the diagnosis and treatment of this uncommon disorder. METHODS: The medical records and imaging studies of three patients presenting to our institution with aneurysms involving the petrous internal carotid artery were reviewed. One presented with progressive bilateral sensorineural hearing loss. The next patient presented with pulsatile tinnitus. The last patient presented to the emergency room unresponsive with severe epistaxis. RESULTS: All three patients had imaging studies revealing petrous carotid aneurysms. Each patient had symptoms related to the aneurysms ranging from hearing loss, tinnitus, and life-threatening hemorrhage. CONCLUSION: Petrous carotid aneurysms are rare, and presentation with otologic symptoms is unusual. Awareness of these lesions as a cause of otologic symptoms, however, is highly important. These cases also illustrate the usefulness of endovascular treatments for aneurysms of the petrous portion of the internal carotid artery, which are extremely difficult to treat by using an open surgical approach.

Based on Fuzzy Connectedness (FC) object delineation principles and algorithms, a hierarchical brain tissue segmentation technique has been developed for MR images. After MR image background intensity inhomogeneity correction and intensity standardization, three FC objects for cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) are generated via FC object delineation, and an intracranial (IC) mask is created via morphological operations. Then, the IC mask is decomposed into parenchymal (BP) and CSF masks, while the BP mask is separated into WM and GM masks. WM mask is further divided into pure and dirty white matter masks (PWM and DWM). In Multiple Sclerosis studies, a severe white matter lesion (LS) mask is defined from DWM mask. Based on the segmented brain tissue images, a histogram-based method has been developed to find disease-specific, image-based quantitative markers for characterizing the macromolecular manifestation of the two diseases. These same procedures have been applied to 65 MS (46 patients and 19 normal subjects) and 25 AD (15 patients and 10 normal subjects) data sets, each of which consists of FSE PD- and T2-weighted MR images. Histograms representing standardized PD and T2 intensity distributions and their numerical parameters provide an effective means for characterizing the two diseases. The procedures are systematic, nearly automated, robust, and the results are reproducible.

This paper presents a method for the precise, accurate and efficient quantification of brain tumor (glioblastomas) via MRI that can be used routinely in the clinic. Tumor volume is considered useful in evaluating disease progression and response to therapy, and in assessing the need for changes in treatment plans. We use multiple MRI protocols including FLAIR, T1, and T1 with Gd enhancement to gather information about different aspects of the tumor and its vicinity. These include enhancing tissue, nonenhancing tumor, edema, and combinations of edema and tumor. We have adapted the fuzzy connectedness framework for tumor segmentation in this work and the method requires only limited user interaction in routine clinical use. The system has been tested for its precision, accuracy, and efficiency, utilizing 10 patient studies. The percent coefficient of variation (% CV) in volume due to operator subjectivity in specifying seeds for fuzzy connectedness segmentation is less than 1%. The mean operator and computer time required per study for estimating the volumes of both edema and enhancing tumor is about 16 min. The software package is designed to run under operator supervision. Delineation has been found to agree with the operators' visual inspection most of the time except in some cases when the tumor is close to the boundary of the brain. In the latter case, the scalp, surgical scar, or orbital contents are included in the delineation, and an operator has to exclude this manually. The methodology is rapid, robust, consistent, yielding highly reproducible measurements, and is likely to become part of the routine evaluation of brain tumor patients in our health system.

The widespread acceptance of functional endoscopic sinus surgery (FESS) underscores the importance of understanding the relevant anatomy of the paranasal sinuses as a means of providing a roadmap to the otorhinolaryngologist prior to surgery. The radiologist can address important imaging issues for the ear, nose, and throat (ENT) surgeon before FESS is undertaken. There are two main questions that the radiologist should address: 1. Are there anatomic features on the computed tomography (CT) scan that predispose the patient to impaired mucociliary clearance? 2. Are there anatomic features that pose a surgical hazard?

STUDY DESIGN A case of intradural venous varix producing a mass-like lesion in the lumbar spine is reported. OBJECTIVE To present a rare cause of an intradural mass lesion along the cauda equina. To present radiologic findings of this entity and to offer a hypothesis for its formation. SUMMARY OF BACKGROUND DATA Epidural venous varices have been described previously in the literature. To the authors' knowledge, no cases of intradural venous varix presenting as an intradural mass have been reported previously. MATERIALS AND METHODS An elongated, serpentine intradural mass was discovered on routine lumbar MRI performed for investigation of the patient's radiculopathy. The patient underwent laminectomy and intradural exploration. RESULT On surgical exploration, a serpentine, massively dilated vein was identified, which distorted the normal nerve roots. CONCLUSION A venous varix should be considered in the differential diagnosis of an intradural lesion in the lumbar spine in the appropriate clinical setting.

Lhermitte-Duclos disease is a rare benign lesion of uncertain pathogenesis characterized by distortion of the normal cerebellar laminar cytoarchitecture. There is a characteristic MR imaging appearance of a nonenhancing mass in the cerebellar hemisphere with a striated pattern. We report two cases of Lhermitte-Duclos disease and describe findings on diffusion-weighted MR imaging.

Alzheimer's is a progressive brain disease and is clinically characterized by cognitive symptoms that, in combination with behavioral disturbances, significantly interfere with activities of daily living. The purpose of this study is to investigate the possibility of developing volumetric measures of the structural damage and atrophy of brain derived from multiprotocol MR imaging. Our approach first applies intensity inhomogeneity correction and intensity standardization to PD and T2 weighted MR images to create base images for quantitative image analysis. Then, vectorial scale-based fuzzy connectedness segmentation (VSFCS) and morphological operations are applied to the base images to extract masks of cerebrospinal fluid (CSF), grey matter (GM), and white matter (WM), and further to create a clean and accurate intracranial (IC) mask. After separating CSF from brain parenchyma (BP), VSFCS is applied to BP (PD and T2) images to generate pure GM and WM masks, and then subtracting these pure from the BP mask to detect AD lesions. This method was applied to a set of conventional PD and T2 weighted MR images that were obtained from 5 patients with probable AD and 5 healthy normal control subjects. The segmented images of individual brain tissue regions (CSF, GM, WM, and AD lesion) are consistent with a Neuroradiologist's examination. The quantitative analysis shows that patients with AD have more atrophy. The mean value of the volume of brain parenchyma of patients with AD is about 10% less than that of healthy controls.

Imaging is of paramount importance in early diagnosis of epidural abscess and its intracranial complications. Typical CT imaging features of an epidural abscess include a hypodense lentiform extra-axial collection with rim enhancement. We present a case of epidural abscess that was hyperdense on CT scan due to the presence of associated epidural hematoma. The literature is reviewed regarding this unusual complication of epidural abscess.

Objectives/Hypothesis Lipomas of the retropharyngeal space are rare and do not cause symptoms until they reach a large size. Although retropharyngeal lipoma is an uncommon entity, several reports of it appear in the literature, and the treatment has routinely been surgical excision. Such fatty tumors also carry the rare possibility of being liposarcomas, which further warrants their excision. We present the case of a lipoma of the retropharyngeal space extending from the nasopharynx to the superior mediastinum causing symptoms of obstructive sleep apnea. The patient had multiple medical problems and was on a regimen of anticoagulation therapy; therefore, he opted against surgical treatment. He has used continuous positive airway pressure and has been followed clinically and radiographically for 5 years. Radiographic follow-up of a retropharyngeal lipoma after a needle biopsy confirming its benign nature is a legitimate means of management of this rare condition. Study Design Case report of a 64-year-old man presenting with this rare lesion. Methods Computed tomography-guided needle biopsy of the mass was performed to obtain tissue diagnosis. Thereafter, the patient has been followed for 5 years with annual magnetic resonance imaging scans to determine growth or changes of the retropharyngeal mass. Results Fine-needle aspiration of the mass revealed mature adipose tissue intermixed with fibroconnective tissue, consistent with lipoma. Based on this result, we opted to follow this patient with serial magnetic resonance imaging scans, which have shown no change in size. There has also been no change in the patient's symptoms. Conclusions Large lipomas warrant excision, especially when their location produces pressure symptoms. However, when surgical morbidity is high, fine-needle aspiration biopsy and serial magnetic resonance imaging scans are a safe alternative.

The authors describe a 36-year-old man with Sturge-Weber syndrome who presented with focal seizures and subsequently developed a temporary post-ictal hemianopia. Magnetic resonance imaging of the brain demonstrated focal leptomeningeal enhancement, which subsequently resolved.

Single-vessel cervical arterial dissections typically occur in young adults and are a common cause of cerebral ischemia and stroke. Although the pathogenesis of multivessel dissection is unclear, it is thought to be a consequence of underlying collagen vascular disease. We present a 34-year-old previously healthy man who developed bilateral internal carotid and vertebral artery dissection following chiropractic manipulation.

SUMMARY: An enlarged facial nerve canal can be a seen in both pathologic and nonpathologic processes. The purposes of this report are the following: 1) to present a rare cause of bony facial nerve canal enlargement, due to an enlarged vein, with high-resolution MDCT and histopathologic correlation; and 2) to discuss the vascular anatomy that gives rise to this variant. A : artery AICA : anterior inferior cerebellar artery GSPN : greater superficial petrosal nerve MDCT : multidetector row CT

Neurogenic compromise of vocal fold function exists along a continuum encompassing vocal cord hypomobility (paresis) to vocal fold immobility (paralysis) with varying degrees and patterns of reinnervation. Vocal fold paralysis (VFP) may result from injury to the vagus or the recurrent laryngeal nerves anywhere along their course from the brainstem to the larynx. In this article, we review the anatomy of the vagus and recurrent laryngeal nerves and examine the various etiologies of VFP. Selected cases are presented with discussion of key imaging features of VFP including radiologic findings specific to central vagal neuropathy and peripheral recurrent nerve paralysis.

Background Superior semicircular canal dehiscence (SSCD) may cause Tullio phenomenon (sound-induced vertigo) or Hennebert sign (valsalva-induced vertigo) due to the absence of bone overlying the SSC. We document a case series of elderly East Asian women with atypical SSCD symptoms, radiologically confirmed dehiscence and concurrent osteoporosis. Methods A retrospective record review was performed on patients with dizziness, vertigo, and/or imbalance from a neurology clinic in a community health center serving the East Asian population in Boston. SSCD was confirmed by multi-detector, high-resolution CT of the temporal bone (with Pöschl and Stenvers reformations) and osteoporosis was documented by bone mineral density (BMD) scans. Results Of the 496 patients seen in the neurology clinic of a community health center from 2008 to 2010, 76 (17.3%) had symptoms of dizziness, vertigo, and/or imbalance. Five (6.6%) had confirmed SSCD by multi-detector, high-resolution CT of the temporal bone with longitudinal areas of dehiscence along the long axis of SSC, ranging from 0.4 to 3.0 mm, as seen on the Pöschl view. Two of the 5 patients experienced motion-induced vertigo, two fell due to disequilibrium, and one had chronic dizziness. None had a history of head trauma, otologic surgery, or active intracerebral disease. On neurological examination, two patients had inducible vertigo on Dix-Hallpike maneuver and none experienced cerebellar deficit, Tullio phenomenon, or Hennebert sign. All had documented osteoporosis or osteopenia by BMD scans. Three of them had definite osteoporosis, with T-scores Conclusions We describe an unusual presentation of SSCD without Tullio phenomenon or Hennebert sign in a population of elderly, East Asian women. There may be an association of SSCD and osteoporosis in this population. Further research is needed to determine the incidence and prevalence of this disorder, as well as the relationship of age, race, osteoporosis risk, and the development of SSCD.