Central giant cell granuloma of the hard palate.
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Aged↗
Biomedical subjects
D M Yousem
Publications and source records attributed to D M Yousem.
Allergic fungal sinusitis: CT findings.
PURPOSE: To determine the computed tomographic (CT) findings in patients with allergic fungal sinusitis. MATERIALS AND METHODS: The authors retrospectively reviewed CT scans and surgical and histopathologic reports in 45 patients (27 male, 18 female; age range, 8-68 years) with allergic fungal sinusitis from multiple institutions. The median age (25 years) and demographics of the patients were determined. Two head and neck radiologists together evaluated the CT scans for the presence of intrasinus high-attenuation areas, extent of sinus involvement, bone expansion and thinning, bone erosion, and extension of disease into the adjacent soft tissues. RESULTS: Allergic fungal sinusitis was more common in male patients and in patients aged 20-30 years. All patients had increased intrasinus attenuation at non-contrast material-enhanced CT. Multiple sinus involvement occurred in 43 patients. Bilateral involvement was more common than unilateral disease. Forty-four patients had complete opacification of at least one of the involved sinuses; 43 of these patients had expansion of an involved sinus, 42 had remodeling and thinning of the bony sinus walls, and 41 had erosion of the sinus wall. CONCLUSION: Allergic fungal sinusitis is a distinct clinical entity with nonspecific symptoms that may be initially suggested by the CT findings. These findings should alert the clinician to the possibility of allergic fungal sinusitis and prompt other diagnostic studies to establish the diagnosis and treatment plan.
Adolescent↗
Neoplastic fixation to the prevertebral compartment by squamous cell carcinoma of the head and neck.
OBJECTIVE: The purpose of this study was to determine the accuracy of MR imaging in determining fixation of squamous cell carcinomas to the prevertebral space. MATERIALS AND METHODS: MR images of 15 patients with large pharyngeal carcinoma (n = 13) or laryngeal carcinomas with pharyngeal extension (n = 2) were retrospectively reviewed independently by two head and neck radiologists who were unaware of the surgical findings. MR images were evaluated for four criteria in the prevertebral longus muscle complex: muscle concavity, irregular tumor-muscle interface, T2 hyperintensity, and enhancement. All patients underwent panendoscopy where fixation or mobility of the tumor relative to the prevertebral fascia was assessed by manual manipulation. Tumors in six patients were fixed to the prevertebral space and inoperable. In nine patients whose tumors were not fixed, open neck explorations were performed and tumors were resected in seven patients. MR findings were compared with panendoscopy in all patients and with intraoperative assessment in nine patients. RESULTS: Eleven of 15 patients had at least two of the MR imaging criteria present. None of the MR findings were both sensitive and specific for tumor fixation. Although muscle concavity and enhancement each had a sensitivity of 88%, both criteria suffered from low specificity (14% and 29%, respectively). An irregular tumor-muscle interface and muscle T2 hyperintensity were criteria that suffered from both low sensitivity and specificity. Accuracy of the imaging criteria independently ranged from 53% to 60%. CONCLUSION: Although abnormal muscle contour, T2 hyperintensity, and enhancement are frequently present in neck carcinomas that are fixed to the prevertebral space, these findings may also be present in patients in whom the tumor is mobile and resectable. MR imaging may not be able to differentiate between neoplastic fixation and nonneoplastic changes in the prevertebral space.
Adipose Tissue↗
Facial nerve stimulation from cochlear implants.
OBJECTIVE: To evaluate the incidence of facial nerve stimulation from cochlear implants and to better define the segment of nerve being stimulated and the causes of stimulation. STUDY DESIGN: Retrospective patient case review and a temporal bone dissection study. SETTING: A tertiary care setting. PATIENTS: All patients given a cochlear implant at the Hospital of the University of Pennsylvania. This encompassed only adult patients. INTERVENTION: All patients had surgical insertion of either a 3M single channel, Nucleus 22-channel, or CLARION multichannel cochlear implant. MAIN OUTCOME MEASURES: Demonstration of facial nerve stimulation with a cochlear implant and determination of affected electrodes; measurement of electrode location and distances between the labyrinthine segment of the facial nerve and the cochlea in temporal bone dissections: and determination of the relationship between the labyrinthine facial nerve and the cochlea using computed tomography evaluation. RESULTS: The overall incidence of facial nerve stimulation using all three devices was 14% (8 of 58). Otosclerosis and otosyphilis appear to be predisposing conditions to stimulation. The mid-cochlear electrodes, located near the labyrinthine facial nerve, appear to cause stimulation of the VIIth nerve most commonly. Computed tomographic evaluation of the bone between the labyrinthine fallopian canal and the cochlea may provide some indication of potential facial nerve problems. CONCLUSION: Facial nerve stimulation from the use of cochlear implants is more prevalent in patients with otosclerosis and otosyphilis. The labyrinthine segment of the facial nerve is the most likely area being stimulated in most patients. Preoperative computed tomographic evaluation may be beneficial in determining the possibility of this problem.
Adult↗
Olfactory dysfunction in multiple sclerosis.
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Brain↗
Olfactory dysfunction in patients with head trauma.
BACKGROUND: The ability to smell is commonly altered by head trauma (HT). However, the nature, prevalence, prognosis, and etiology of such alterations are poorly understood. OBJECTIVES: To quantitatively determine the degree of olfactory function in patients with HT-related chemosensory complaints and to examine the influences of age, sex, HT severity, time since HT, and other variables on such function. Also, to use quantitative magnetic resonance imaging (MRI) to establish whether and to what degree damage to the olfactory bulbs and tracts, frontal lobes, and temporal lobes occurs. PATIENTS AND METHODS: Two hundred sixty-eight patients with HT from the University of Pennsylvania Smell and Taste Center, Philadelphia, were administered a quantitative odor identification test, a depression inventory, and a medical history questionnaire; 66 were retested after individual test-retest periods ranging from 1 month to 13 years. The volume of olfactory-related brain structures was determined in 15 patients and 15 controls using MRI. RESULTS: One hundred seventy-nine patients (66.8%) had anosmia, 55 (20.5%) had microsmia, and 34 (12.7%) had normosmia. Frontal impacts produced less dysfunction than back or side impacts. Of the 66 retested patients, 24 (36%) improved slightly, 30 (45%) had no change, and 12 (18%) worsened; only 3 patients, none of whom initially had anosmia, regained normal olfactory function. Trauma severity was related to olfactory test scores in patients with microsmia. Parosmia prevalence decreased from 41.1% to 15.4% over an 8-year posttrauma period. Olfactory bulb and tract volumes of male, but not female, patients with HT were greatly reduced relative to volumes of controls. CONCLUSIONS: Patients complaining of HT-related olfactory dysfunction typically have anosmia and rarely regain normal olfactory ability, parosmia prevalence decreases over time in such patients, and damage to olfaction-related brain structures can be observed in most such patients using an appropriate MRI protocol.
Adult↗
Pupil-involving third-nerve palsy and carotid stenosis: rapid recovery following endarterectomy.
We report a patient who presented with a painful pupil-involving third-nerve palsy. Cerebral angiography revealed a high-grade stenosis of the ipsilateral internal carotid artery with a 4-cm intraluminal thrombus. Following emergent carotid endarterectomy, the patient's partial third-nerve palsy resolved in 1 hour. A pupil-involving third-nerve palsy may be an unusual presentation of impending carotid occlusion.
Carotid Stenosis↗
Computed tomography in lacrimal outflow obstruction.
BACKGROUND: Acquired nasolacrimal duct obstruction is a common ophthalmologic problem. Despite widespread understanding of treatments available for nasolacrimal duct obstruction, few authors have commented on its etiology. Because the nasolacrimal system is anatomically related to important nasal and sinus structures, the authors postulated that acquired nasolacrimal duct obstruction and its complications might occur simultaneous to, and possibly as a consequence of, rhinologic or sinus disease. MATERIALS AND METHODS: Twenty-three patients with acquired nasolacrimal duct obstruction and 100 control patients were evaluated by coronal computed tomography for evidence of sinus disease or nasal abnormalities. Specifically, five findings were noted: ostiomeatal complex disease, ethmoidal opacification, agger nasi cell opacification, concha bullosa, and nasal septal deviation. RESULTS: Overall, 20 (87%) patients with acquired nasolacrimal duct obstruction demonstrated one or more radiologic finding of sinus disease or rhinologic abnormality whereas 63 (63%) control subjects exhibited these findings. This difference was determined to be statistically significant (P < 0.05). A statistically significant higher incidence of ethmoidal opacification, agger nasi cell opacification, and nasal septal deviation was observed in patients with nasolacrimal outflow obstruction than in controls. Differences in the incidence of ostiomeatal complex disease and concha bullosa were not found to be statistically significant. CONCLUSION: These data demonstrate a correlation between computed tomography findings of sinus disease or nasal abnormality and the presence of acquired nasolacrimal outflow obstruction. This association between radiologic evidence of sinorhinologic disorders and lacrimal outflow obstruction may imply that dacryocystitis, like sinus disease, may be produced by disease of the lateral nasal wall. When evaluating a patient with acquired nasolacrimal duct obstruction, the physician should consider evaluation for concomitant nasal and sinus disease.
Humans↗
Reproducibility and reliability of volumetric measurements of olfactory eloquent structures.
RATIONALE AND OBJECTIVES: The authors assessed the reliability and reproducibility of volumetric measurements of olfactory bulbs and tracts (OBTs) and temporal lobes (TLs) with magnetic resonance (MR) imaging. METHODS: Repetitive MR imaging of two phantoms and OBTs and TLs of patients was performed. Regions of interest were manually drawn around the relevant structures, and their volumes were measured at workstations. Intra- and interobserver variability for the two readers were measured. Intraclass and Pearson correlation coefficients and mean percentage differences were calculated. RESULTS: The measured phantom volumes were within 1.9%-12% of the true volumes with a variability of < or = 5%. Intraclass and Pearson correlation coefficients were > or = 0.919 for measurements by a single reader and > or = 0.924 for measurements by different readers. The inter- and intraobserver variabilities were < or = 4.2% for TL and 11.3%-14.6% for OBTs. CONCLUSION: Volumetric measurements of the olfactory apparatus can be reliably and accurately reproduced from MR images.
Humans↗
Functional MR imaging during odor stimulation: preliminary data.
PURPOSE: To determine the locations and extent of activation in areas of the brain at functional magnetic resonance (MR) imaging with olfactory stimulation and to determine whether accommodation or amplification of brain activation occurs with sequential olfactory stimulation. MATERIALS AND METHODS: Five adult men with normal senses of smell underwent multisection, gradient-echo, echo-planar imaging according to a blood-oxygen-level-dependent experimental paradigm. Odorants that nearly exclusively stimulate the olfactory system and odorants that stimulate the olfactory and trigeminal nerves were compared by using repetitive imaging procedures. RESULTS: Activation with olfactory nerve-mediated odorants was demonstrated in the orbitofrontal cortex (Brodmann area 11) with a right-sided predominance. Mild cerebellar stimulation was also observed. With repeated testing, overall activation with olfactory nerve-mediated odorants declined. Odorants that also stimulated the trigeminal nerve produced additional cingulate, temporal, cerebellar, and occipital activation. Activation with combined trigeminal and olfactory system odors increased more than sixfold with repeated testing. CONCLUSION: Olfactory nerve-mediated and combined olfactory and trigeminal nerve-mediated odorants activate different regions of the brain. Orbitofrontal stimulation spreads to all parts of the brain when a trigeminal component is added. Habituation (deactivation) occurs with repeated testing of olfactory nerve-mediated odorants, while, paradoxically, activation increases with repeated exposure to odors that also stimulate the trigeminal nerve.
Adult↗
Synovial sarcomas of the head and neck: MR findings.
OBJECTIVE: MR images of six synovial sarcomas of the head and neck were evaluated to determine their characteristic sites of origin, size, extent, intensity, and contrast enhancement. It was hoped that specific MR characteristics could be defined to suggest this entity. CONCLUSION: A nonmucosal head and neck mass that is isointense to gray matter on T1-weighted images and is well defined yet heterogeneous, with septations, hemorrhage, cysts, calcification, or multilocularity, should raise suspicion of a synovial sarcoma. Because the appearance of synovial sarcomas varies and other masses may appear similar, no specific imaging characteristics define the entity.
Adult↗
Can radiologists accurately predict preepiglottic space invasion with MR imaging?
OBJECTIVE: The purpose of this study was to evaluate whether observers of MR imaging can accurately predict invasion of the preepiglottic fat (PEF) in patients with oropharyngeal and supraglottic laryngeal squamous cell carcinoma. MATERIALS AND METHODS: For 41 patients with pathologically proven squamous cell carcinoma of the oropharynx and supraglottic larynx, we retrospectively analyzed their MR images for the presence or absence of PEF neoplastic invasion. Unenhanced T1-weighted, fat-suppressed T2-weighted, and contrast-enhanced fat-suppressed T1-weighted scans were analyzed independently by two neuroradiologists who were unaware of the surgical findings. Proof of diagnosis was determined by pathologic analysis, intraoperative assessment, or both. RESULTS: Sixteen patients had neoplastic infiltration of the PEF. All infiltration was correctly predicted by the two observers of MR imaging, resulting in a sensitivity of 100%. Twenty-five patients had no invasion of the PEF by pathologic or surgical evaluation or both. Of these patients, negative findings were correctly predicted on MR imaging in 21 patients, whereas positive findings were incorrectly predicted on MR imaging in the remaining four patients, resulting in a specificity of 84% and an accuracy of 90%. In two of the four false-positive cases, effacement of the fat in the preepiglottic space by large tumors was mistaken for invasion. In a third patient, spread to the paraglottic space was mistaken for PEF extension. In the fourth false-positive case, glandular tissue along the ventral epiglottis may have been mistaken for tumor. The observers believed that unenhanced sagittal and axial T1-weighted scans were particularly useful because fat saturation artifacts may degrade T2-weighted and contrast-enhanced T1-weighted scans. CONCLUSION: Unenhanced T1-weighted MR images are highly sensitive for neoplastic infiltration of the preepiglottic space in patients with oropharyngeal and supraglottic laryngeal carcinoma who are at risk for such spread. Identification of PEF invasion is important because it affects prognosis and may affect surgical management.
Adipose Tissue↗
Heterotopic brain in the pterygopalatine fossa.
Heterotopic brain outside the cranial vault is uncommon. It occurs most frequently in the nasal region, although rests elsewhere in the aerodigestive tract have been reported. We describe a case of heterotopic brain in the pterygopalatine fossa.
Biopsy↗
Adenoidal width and HIV factors.
PURPOSE: To determine the factors that correspond to adenoidal hypertrophy, often prominent in human immunodeficiency virus (HIV)-positive patients. METHODS: The sagittal T1-weighted MR images of 21 HIV-positive patients (age range, 25 to 50 years; mean, 37 years) and 21 healthy control subjects (age range, 24 to 55 years; mean, 35 years) were reviewed blindly and independently by two radiologists who measured the maximal dimension of the nasopharyngeal lymphoid tissue. Twenty-six additional HIV-positive patients were combined with the original 21 HIV-positive patients, and the hematologic studies of these 47 patients were compared with the adenoidal measurements to assess whether a relationship existed between nasopharyngeal prominence and hematocrit, white blood cell count, and CD4 count. RESULTS: Mean adenoidal width was 6.76 mm (SD, 5.82) in the HIV-positive population, but was only 3.36 mm (SD, 2.48) in the age-matched control group. Age and HIV status correlated with nasopharyngeal width measurements. No relationship between adenoidal width and hematocrit, CD4 count, or white blood cell count was evident. CONCLUSION: After correcting for age, we found that adenoidal lymphoid tissue is more abundant in HIV-positive persons than in control subjects. The hematologic ramifications of this finding remain uncertain.
Adenoids↗
Primary malignant melanoma of the sinonasal cavity: MR imaging evaluation.
To evaluate the magnetic resonance (MR) imaging characteristics of primary malignant melanoma of the sinonasal cavity, T1- and T2-weighted MR images of 12 patients with primary sinonasal melanoma were retrospectively reviewed. Gadolinium-enhanced imaging was performed in seven cases. The MR images were compared with histopathologic results. There were seven melanotic melanomas and five amelanotic melanomas; hemorrhage was present in three melanotic and two amelanotic melanomas. The seven melanotic melanomas were hyperintense to gray matter on T1-weighted images (whether hemorrhage was present or not), consistent with the paramagnetic effect of melanin. Four of the five amelanotic melanomas had intermediate signal intensity on T1-weighted images; one was not detected. On T2-weighted images, all of the melanomas detected had intermediate though variable signal intensity compared with that of gray matter. On gadolinium-enhanced images, all cases demonstrated mild to moderate enhancement. The signal intensity of sinonasal melanoma appears to vary according to the histopathologic components of the tumor. High signal intensity within the lesion on T1-weighted images suggests the presence of melanin.
Aged↗
Whither thou goest, magnetization transfer?
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Head and Neck Neoplasms↗
Radiologic findings in a carcinoma-associated laryngocele.
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Aged↗
MR evaluation of patients with congenital hyposmia or anosmia.
OBJECTIVE: The purpose of this study was to evaluate patients with reduced or no sense of smell since birth for sites of abnormality by MR imaging. MATERIALS AND METHODS: Twenty-five patients who reported no olfactory function since birth were evaluated by olfactory testing, sinonasal endoscopy, and MR imaging. Surface coil and head coil images of the olfactory bulbs, olfactory tracts, subfrontal cortex, and temporal lobes in contiguous 3-mm sections were obtained. Two reviewers determined unilateral olfactory bulb and tract volumes and temporal lobe volumes in two separate sessions. Qualitative grading for olfactory bulb, olfactory tract, olfactory sulcus, subfrontal region, hippocampus, and temporal lobe damage also was performed. RESULTS: The absence of olfactory bulbs and tracts (68-84%) or the presence of hypoplasia (16-32%) was noted in all cases. Eight individuals had Kallmann's syndrome (hypogonadotropic hypogonadism with anosmia). Temporal and/or frontal lobe volume loss was noted in five individuals and was mild in all but one individual. CONCLUSION: Congenital anosmia or hyposmia appears to be an olfactory bulb-olfactory tract phenomenon rather than a cerebral process.
Adult↗