Faculty Bibliography

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.

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.

The head and neck is a complex anatomical region that can be evaluated using many imaging modalities. It is important to discern normal structures from ones that are affected by disease and to study how these structures change in their morphological and functional properties with aging. Therefore, using magnetic resonance imaging (MRI), we retrospectively evaluated volumes of the parotid glands, submandibular glands, thyroid gland, tongue, soft palate, and lingual tonsils in 64 subjects ages 13 to 81 years. Volume, attenuation (HU), and metabolic activity (maximum SUV) of the parotid, submandibular, and thyroid glands were assessed retrospectively using positron emission tomography/computed tomography (PET/CT) imaging in 35 subjects ages 10 to 76 years. Metabolic activity (maximum SUV) of the parotid, submandibular, and sublingual glands; tongue; adenoids; and tonsils (lingual and palatine) were evaluated retrospectively using PET imaging in 15 subjects ages 6 to 20 years. Metabolic volumetric products of the parotid, submandibular, and thyroid gland were calculated and analyzed with increasing age in subjects who underwent PET/CT imaging. Structures that exhibited statistically significant changes (P < 0.05) with increasing age included the submandibular glands, thyroid gland, soft palate, and adenoids. The CT volume of the submandibular glands increased with age, and the attenuation decreased with age with statistical significance. The thyroid gland volume, as measured using MRI, showed a statistically significant decrease with aging. The volume of the soft palate and lingual tonsils, as measured by MRI, exhibited a statistically significant decrease in volume with aging. The maximum SUV of the adenoids demonstrated a statistically significant decrease with aging. In conclusion, CT, MRI, and PET may be used to quantitatively and qualitatively assess structures of the head and neck and are useful in the assessment of structural and functional changes of these structures with aging.

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/CONCLUSIONS: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.

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.

The institutional review board approved the described HIPAA-compliant study, which was performed to prospectively evaluate observer performance in the detection of artificial multiple sclerosis (MS) lesions that were randomly distributed supra- and infratentorially on simulated fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) images obtained at different echo times (TEs). MR parametric maps were derived from mixed multi-echo inversion-recovery images obtained in a 40-year-old healthy male volunteer and in a patient with MS, both of whom gave informed consent. Pseudo-randomly distributed artificial MS lesions of varying size, number, and location were equally represented on the FLAIR images (11 000/100-200/2600 [repetition time msec/TE msec/inversion time msec]). Twelve images obtained in both regions at each of 11 TEs spaced 10 msec apart were rated by seven neuroradiologists by using a four-point scale. Observer performance in the detection of MS lesions on the FLAIR images, as estimated by using areas under the alternative free-response receiver operating characteristic curve, was highest and most consistent at the 100-msec TE, both supratentorially (93.0% +/- 8.6 [standard error of the mean]) and infratentorially (87.4% +/- 10.0).

PURPOSE/OBJECTIVE: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/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/CONCLUSIONS:These results suggest that standardized T2, PD, and T1 images and their tissue-specific intensity signatures may be useful for characterizing disease.

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: 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

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.