Phase II randomized trial of radiation therapy, cetuximab, and pemetrexed with or without bevacizumab in patients with locally advanced head and neck cancer.

BACKGROUND: We previously reported the safety of concurrent cetuximab, an antibody against epidermal growth factor receptor (EGFR), pemetrexed, and radiation therapy (RT) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN). In this non-comparative phase II randomized trial, we evaluated this non-platinum combination with or without bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF). PATIENTS AND METHODS: Patients with previously untreated stage III-IVB SCCHN were randomized to receive: conventionally fractionated radiation (70 Gy), concurrent cetuximab, and concurrent pemetrexed (arm A); or the identical regimen plus concurrent bevacizumab followed by bevacizumab maintenance for 24 weeks (arm B). The primary end point was 2-year progression-free survival (PFS), with each arm compared with historical control. Exploratory analyses included the relationship of established prognostic factors to PFS and quality of life (QoL). RESULTS: Seventy-eight patients were randomized: 66 oropharynx (42 HPV-positive, 15 HPV-negative, 9 unknown) and 12 larynx; 38 (49%) had heavy tobacco exposure. Two-year PFS was 79% [90% confidence interval (CI) 0.69-0.92; P < 0.0001] for arm A and 75% (90% CI 0.64-0.88; P < 0.0001) for arm B, both higher than historical control. No differences in PFS were observed for stage, tobacco history, HPV status, or type of center (community versus academic). A significantly increased rate of hemorrhage occurred in arm B. SCCHN-specific QoL declined acutely, with marked improvement but residual symptom burden 1 year post-treatment. CONCLUSIONS: RT with a concurrent non-platinum regimen of cetuximab and pemetrexed is feasible in academic and community settings, demonstrating expected toxicities and promising efficacy. Adding bevacizumab increased toxicity without apparent improvement in efficacy, countering the hypothesis that dual EGFR-VEGF targeting would overcome radiation resistance, and enhance clinical benefit. Further development of cetuximab, pemetrexed, and RT will require additional prospective study in defined, high-risk populations where treatment intensification is justified.

Ecchordosis Physaliphora: Does It Even Exist?

The term ecchordosis physaliphora (EP) has been used historically to describe a benign notochordal remnant with no growth potential, most commonly occuring in the central clivus. Unfortunately, the radiologic appearance of EP overlaps considerably with the appearance of low-grade chordomas, which do have the potential for growth. In this article, we review new pathologic terminology that better describes this family of diseases, and we propose new radiologic terms that better address the uncertainty of the radiologic diagnosis. The surgical importance of accurate terminology and the implications for patient care are discussed.

Sagittal Angle of the Trigeminal Nerve at the Porus Trigeminus: A Novel Measurement to Distinguish Different Causes of Classic Trigeminal Neuralgia.

BACKGROUND AND PURPOSE: Classic trigeminal neuralgia is a clinical syndrome of facial pain, most often attributable to vascular compression of the proximal cisternal segment of the trigeminal nerve and treatable with microvascular decompression of the nerve. Some patients, however, meet all clinical criteria for classic trigeminal neuralgia yet do not respond to microvascular decompression. Because the reasons for surgical failure are not well understood, the aim of this study was to determine if a subset of patients with classic trigeminal neuralgia could be distinguished by measuring the angle of the trigeminal nerve in the sagittal plane as the nerve traverses the porus trigeminus. MATERIALS AND METHODS: We retrospectively identified patients with either classic trigeminal neuralgia (n = 300) or hemifacial spasm (n = 300) who had undergone MR imaging, including 3-plane steady-state free precession imaging. Patients with hemifacial spasm served as controls. On sagittal steady-state free precession images, we measured the angle of each trigeminal nerve as it crosses through the porus trigeminus into the Meckel cave (SATNaPT). In patients with classic trigeminal neuralgia, we separated the nerves into symptomatic and asymptomatic sides. We compared these 3 groups using the Student t test. RESULTS: Control patients had a mean SATNaPT of 170° (SD, 11°) with a normal distribution. The contralateral asymptomatic nerve in patients with classic trigeminal neuralgia had the same distribution of angles. The symptomatic nerves in patients with classic trigeminal neuralgia had a bimodal distribution; 83% of patients fell into the same distribution as the asymptomatic nerves, but the other 15% had an average angle of 143° (SD, 7°). This difference was statistically significant (P < .0001). CONCLUSIONS: Patients with the clinical syndrome of classic trigeminal neuralgia fell into 2 categories based on the radiologic measurement of the SATNaPT. Most patients had an anatomically normal nerve that was affected by vascular compression, but 17% of these patients had aberrant anatomy that may cause or contribute to their clinical presentation. Further study is needed to determine whether this subset of patients should receive a different surgery to better address their underlying anatomic abnormality. The SATNaPT measurement should be included in every MR imaging interpretation performed on patients with classic trigeminal neuralgia.

Phase I trial of pemetrexed in combination with cetuximab and concurrent radiotherapy in patients with head and neck cancer.

BACKGROUND: We studied the combination of pemetrexed, a multi-targeted antifolate, and cetuximab, an mAb against the epidermal growth factor receptor, with radiotherapy in poor prognosis head and neck cancer. PATIENTS AND METHODS: Patients received pemetrexed on days 1, 22, and 43 on a dose-escalation scheme with starting level (0) 350 mg/m(2) (level -1, 200 mg/m(2); level +1, 500 mg/m(2)) with concurrent radiotherapy (2 Gy/day) and cetuximab in two separate cohorts, not previously irradiated (A) and previously irradiated (B), who received 70 and 60-66 Gy, respectively. Genetic polymorphisms of thymidylate synthase and methylenetetrahydrofolate reductase were evaluated. RESULTS: Thirty-two patients were enrolled. The maximum tolerated dose of pemetrexed was 500 mg/m(2) in cohort A and 350 mg/m(2) in cohort B. Prophylactic antibiotics were required. In cohort A, two dose-limiting toxicities (DLTs) occurred (febrile neutropenia), one each at levels 0 and +1. In cohort B, two DLTs occurred at level +1 (febrile neutropenia; death from perforated duodenal ulcer and sepsis). Grade 3 mucositis was common. No association of gene polymorphisms with toxicity or efficacy was evident. CONCLUSION: The addition of pemetrexed 500 mg/m(2) to cetuximab and radiotherapy is recommended for further study in not previously irradiated patients.

A re-evaluation of auditory filter shape in delphinid odontocetes: evidence of constant-bandwidth filters.

The auditory filter shape of delphinid odontocetes was previously considered to be typically mammalian constant-quality in which filter bandwidths increase proportionally with frequency. Recent studies with porpoises demonstrate constant-bandwidth portions of the auditory filter. The critical ratios for a bottlenose dolphin were measured between 40 and 120 kHz by behaviorally determining the subject's ability to detect pure tones in the presence of white noise. Critical ratios as a function of frequency were constant, indicating the auditory filter acts as a constant-bandwidth system in this frequency range. Re-analysis of past studies supports these findings, and suggests the delphinid auditory system is best characterized as a constant-Q system below 40 kHz and a constant-bandwidth-like system between 40 kHz and 120 kHz before returning to a constant Q pattern at the highest frequencies.

Response assessment by combined PET-CT scan versus CT scan alone using RECIST in patients with locally advanced head and neck cancer treated with chemoradiotherapy.

PURPOSE: RECIST have limitations when applied to potentially curable locally advanced squamous cell carcinoma of the head and neck (SCCHN). [¹8F]fluorodeoxyglucose-positron emission tomography (PET) scan may be useful in assessing treatment response and predicting patient outcome. PATIENTS AND METHODS: We studied patients with previously untreated stages III-IVb SCCHN treated with primary concurrent chemoradiotherapy on five prospective clinical trials. Response was assessed by clinical exam, computed tomography (CT), and PET portions of combined PET-CT scan ∼8 weeks after completion of chemoradiotherapy. RESULTS: Fifty-three patients were analyzed. Complete response (CR) was demonstrated in 42 patients (79%) by clinical exam, 15 (28%) by CT, and 27 (51%) by PET. CR as assessed by PET, but not as assessed by clinical exam or CT using RECIST, correlated significantly with progression-free status (PFS) (P < 0.0001). The 2-year PFS for patients with CR and without CR by PET was 93% and 48%, respectively (P = 0.0002). CONCLUSIONS: A negative PET scan on combined PET-CT after chemoradiotherapy is a powerful predictor of outcome in patients receiving curative chemoradiotherapy for SCCHN. PET-CT is indicated for response evaluation in this setting to improve the accuracy of post-treatment assessment by CT.

Positive Predictive Value of Neck Imaging Reporting and Data System Categories 3 and 4 Posttreatment FDG-PET/CT in Head and Neck Squamous Cell Carcinoma.

BACKGROUND AND PURPOSE: The Neck Imaging Reporting and Data System is a standardized reporting system intended to risk stratify patients treated for head and neck squamous cell carcinoma. The purpose of this study is to investigate the positive predictive value of the Neck Imaging Reporting and Data System categories 3 and 4 on posttreatment PET/CT in patients treated definitively for head and neck squamous cell carcinoma. MATERIALS AND METHODS: We retrospectively identified patients treated definitively for head and neck squamous cell carcinoma between 2006 and 2018. Patients whose posttreatment PET/CT scans were interpreted as Neck Imaging Reporting and Data System 3 (suspicious) or 4 (definitive recurrence) at the primary site, regional nodes, or at distant sites were included. The reference standard was histopathology or unequivocal imaging or clinical evidence of treatment failure. The positive predictive values of Neck Imaging Reporting and Data System 3 and 4 posttreatment PET/CT were calculated. RESULTS: Seventy-two of 128 patients with posttreatment PET/CT interpreted as Neck Imaging Reporting and Data System 3 at the primary site, regional nodes, or distant sites were proved to have treatment failure at the suspicious sites, yielding an overall positive predictive value of 56% (95% CI, 48%-65%). The positive predictive values of Neck Imaging Reporting and Data System 3 by subsite were as follows: primary site, 56% (44/79); regional nodes, 65% (34/52); and distant sites, 79% (42/53). All 69 patients with posttreatment PET/CT interpreted as Neck Imaging Reporting and Data System 4 had true treatment failure, yielding a positive predictive value of 100% (95% CI, 96%-100%): primary site, 100% (28/28); regional nodes, 100% (32/32); and distant sites, 100% (29/29). CONCLUSIONS: The positive predictive value of Neck Imaging Reporting and Data System 3 on posttreatment PET/CT is relatively low. Thus, Neck Imaging Reporting and Data System 3 findings should be confirmed with tissue sampling before instituting new salvage treatment regimens to avoid unnecessary overtreatment and its associated toxicities. Neck Imaging Reporting and Data System 4 reliably indicates recurrent disease.

Prevalence of Superior Semicircular Canal Dehiscence on High-Resolution CT Imaging in Patients without Vestibular or Auditory Abnormalities.

BACKGROUND AND PURPOSE: Prior studies of radiologic superior semicircular canal dehiscence have suggested that CT may overcall dehiscence. However, many of those studies were performed before the advent of multichannel helical CT. Furthermore, there are limited data investigating the prevalence of radiologic superior semicircular canal dehiscence in asymptomatic individuals. The purpose of this study was to determine the rate of radiologic superior semicircular canal dehiscence in an asymptomatic population using 64-channel helical CT. MATERIALS AND METHODS: We retrospectively enrolled 500 consecutive adult patients without symptoms of superior semicircular canal dehiscence who had undergone CT of the temporal bones in the emergency department of a tertiary academic center between February 2012 and June 2017. The superior semicircular canals were evaluated bilaterally by 2 dedicated head and neck radiologists and subjectively classified as either dehiscent or nondehiscent. A secondary group of 110 scans of patients with symptoms consistent with superior semicircular canal dehiscence was similarly interpreted, and the rate of radiologic superior semicircular canal dehiscence was calculated for each group. RESULTS: Ten of the 500 asymptomatic patients (2.0%; 95% CI, 1.1%-3.6%) had CT evidence of superior semicircular canal dehiscence, compared with 15 of 110 symptomatic patients (13.6%; 95% CI, 7.8%-21.5%). There was excellent interobserver agreement (κ = 0.91). CONCLUSIONS: Only 2% of asymptomatic patients had radiologic evidence of superior semicircular canal dehiscence on 64-detector row helical CT. This is markedly lower than previous reports and approaches the postmortem rate of asymptomatic superior semicircular canal dehiscence. We therefore recommend that asymptomatic patients with CT evidence of superior semicircular canal dehiscence undergo audiologic evaluation because the rate of false-positive scans is extremely low.

Improved Detection of Subtle Mesial Temporal Sclerosis: Validation of a Commercially Available Software for Automated Segmentation of Hippocampal Volume.

BACKGROUND AND PURPOSE: Identification of mesial temporal sclerosis is critical in the evaluation of individuals with temporal lobe epilepsy. Our aim was to assess the performance of FDA-approved software measures of hippocampal volume to identify mesial temporal sclerosis in patients with medically refractory temporal lobe epilepsy compared with the initial clinical interpretation of a neuroradiologist. MATERIALS AND METHODS: Preoperative MRIs of 75 consecutive patients who underwent a temporal resection for temporal lobe epilepsy from 2011 to 2016 were retrospectively reviewed, and 71 were analyzed using Neuroreader, a commercially available automated segmentation and volumetric analysis package. Volume measures, including hippocampal volume as a percentage of total intracranial volume and the Neuroreader Index, were calculated. Radiologic interpretations of the MR imaging and pathology from subsequent resections were classified as either mesial temporal sclerosis or other, including normal findings. These measures of hippocampal volume were evaluated by receiver operating characteristic curves on the basis of pathologic confirmation of mesial temporal sclerosis in the resected temporal lobe. Sensitivity and specificity were calculated for each method and compared by means of the McNemar test using the optimal threshold as determined by the Youden J point. RESULTS: Optimized thresholds of hippocampal percentage of a structural volume relative to total intracranial volume (<0.19%) and the Neuroreader Index (≤-3.8) were selected to optimize sensitivity and specificity (89%/71% and 89%/78%, respectively) for the identification of mesial temporal sclerosis in temporal lobe epilepsy compared with the initial clinical interpretation of the neuroradiologist (50% and 87%). Automated measures of hippocampal volume predicted mesial temporal sclerosis more accurately than radiologic interpretation (McNemar test, P < .0001). CONCLUSIONS: Commercially available automated segmentation and volume analysis of the hippocampus accurately identifies mesial temporal sclerosis and performs significantly better than the interpretation of the radiologist.

Negative Predictive Value of NI-RADS Category 2 in the First Posttreatment FDG-PET/CT in Head and Neck Squamous Cell Carcinoma.

BACKGROUND AND PURPOSE: FDG PET/CT has a high negative predictive value in patients with head and neck squamous cell carcinoma who responds completely to non-operative therapy. However, the treatment failure rate in patients with a partial but incomplete response is unclear. Our aim was to investigate the negative predictive value of the first posttreatment FDG-PET/CT in patients with head and neck squamous cell carcinoma with incomplete response interpreted as Neck Imaging Reporting and Data System (NI-RADS) category 2. MATERIALS AND METHODS: We retrospectively identified patients with head and neck squamous cell carcinoma treated with chemoradiation or radiation therapy with curative intent in our institution between 2008 and 2016. We included patients whose first posttreatment FDG-PET/CT was interpreted as showing marked improvement of disease but who had a mild residual mass or FDG avidity in either the primary tumor bed or lymph nodes (NI-RADS 2). The negative predictive value of FDG-PET/CT was calculated, including the 95% CI, using the Newcombe method. Two-year disease-free survival was the reference standard. RESULTS: Seventeen of 110 patients (15%) experienced locoregional treatment failure within 2 years of completing treatment, yielding a negative predictive value of 85% (95% Cl, 77%-90%). The most common location of tumor recurrence was the cervical lymph nodes (59%). The median time interval between completion of therapy and treatment failure was 10 months (range, 5-24 months). CONCLUSIONS: In patients with an incomplete response after treatment of head and neck squamous cell carcinoma, the negative predictive value of the first posttreatment FDG-PET/CT was 85%, which is lower than the 91% negative predictive value of FDG-PET/CT in patients with an initial complete response. Patients with an incomplete response (NI-RADS 2) should undergo more frequent clinical and imaging surveillance than patients with an initial complete response (NI-RADS 1).

Solid Lymph Nodes as an Imaging Biomarker for Risk Stratification in Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma.

BACKGROUND AND PURPOSE: Human papillomavirus-related oropharyngeal squamous cell carcinoma is associated with cystic lymph nodes on CT and has a favorable prognosis. A subset of patients with aggressive disease experience treatment failure. Our aim was to determine whether the extent of cystic lymph node burden on staging CT can serve as an imaging biomarker to predict treatment failure in human papillomavirus-related oropharyngeal squamous cell carcinoma. MATERIALS AND METHODS: We identified patients with human papilloma virus-related oropharyngeal squamous cell carcinoma and staging neck CTs. Demographic and clinical variables were recorded. We retrospectively classified the metastatic lymph node burden on CT as cystic or solid and assessed radiologic extracapsular spread. Biopsy, subsequent imaging, or clinical follow-up was the reference standard for treatment failure. The primary end point was disease-free survival. Cox proportional hazard regression analyses of clinical, demographic, and anatomic variables for treatment failure were performed. RESULTS: One hundred eighty-three patients were included with a mean follow-up of 38 months. In univariate analysis, the following variables had a statistically significant association with treatment failure: solid-versus-cystic lymph nodes, clinical T-stage, clinical N-stage, and radiologic evidence of extracapsular spread. The multivariate Cox proportional hazard model resulted in a model that included solid-versus-cystic lymph nodes, T-stage, and radiologic evidence of extracapsular spread as independent predictors of treatment failure. Patients with cystic nodal metastasis at staging had significantly better disease-free survival than patients with solid lymph nodes. CONCLUSIONS: In human papilloma virus-related oropharyngeal squamous cell carcinoma, patients with solid lymph node metastases are at higher risk for treatment failure with worse disease-free survival. Solid lymph nodes may serve as an imaging biomarker to tailor individual treatment regimens.

Fluoroscopic and CT fistulography of the first branchial cleft.

We present an unusual case of a complete first branchial cleft fistula communicating between the external auditory canal and the skin near the angle of the mandible. CT and fluoroscopic fistulography were used to establish the presence and course of the tract and to assist in surgical planning. The embryology and classification of first branchial cleft anomalies are discussed, with emphasis on the impact of imaging.

The CT Prevalence of Arrested Pneumatization of the Sphenoid Sinus in Patients with Sickle Cell Disease.

BACKGROUND AND PURPOSE: Arrested sphenoid pneumatization is an incidental radiologic finding on CT and MR imaging that may be confused with more aggressive pathologic conditions. No definite etiology for arrested sphenoid pneumatization has been established, though changes in regional blood flow during childhood, as is seen with sickle cell disease, have been proposed. The purpose of our study was to compare the prevalence of arrested pneumatization of the sphenoid sinus in patients with and without sickle cell disease. MATERIALS AND METHODS: We retrospectively identified 146 patients with sickle cell disease who had undergone CT scans of the skull base between January 1990 and May 2015. We identified 292 control patients without sickle cell disease matched for age and sex in a 1:2 ratio. We tabulated the prevalence of arrested pneumatization as well as the location and size of the lesions. We used the Fisher exact test to correlate sickle cell disease with arrested pneumatization of the sphenoid sinus and the t test to correlate sickle cell disease with lesion size. RESULTS: Of the 146 patients with sickle cell disease, 14 (9.6%) had arrested pneumatization of the sphenoid sinus. In the 292 control patients, 6 (2.1%) had arrested pneumatization. Patients with sickle cell disease had a statistically significant higher rate of arrested pneumatization compared with patients without sickle cell disease (P < .001). There was no statistically significant correlation between lesion size and diagnosis of sickle cell disease. CONCLUSIONS: Patients with sickle cell disease have a greater prevalence of arrested pneumatization of the sphenoid sinus than patients without sickle cell disease. This supports the theory that either regional blood flow anomalies or increased serum erythropoietin causes arrested sinus pneumatization.

Imaging Appearance of SMARCB1 (INI1)-Deficient Sinonasal Carcinoma: A Newly Described Sinonasal Malignancy.

SMARCB1 (INI1)-deficient sinonasal carcinomas were first described in 2014, and this series of 17 cases represents the first imaging description. This tumor is part of a larger group of SMARCB1-deficient neoplasms, characterized by aggressive behavior and a rhabdoid cytopathologic appearance, that affect multiple anatomic sites. Clinical and imaging features overlap considerably with other aggressive sinonasal malignancies such as sinonasal undifferentiated carcinoma, which represents a common initial pathologic diagnosis in this entity. SMARCB1 (INI1)-deficient sinonasal tumors occurred most frequently in the nasoethmoidal region with invasion of the adjacent orbit and anterior cranial fossa. Avid contrast enhancement, intermediate to low T2 signal, and FDG avidity were frequent imaging features. Approximately half of the lesions demonstrated calcification, some with an unusual "hair on end" appearance, suggesting aggressive periosteal reaction.

Chloroquine-sensitive transplasmalemma electron transport in Tetrahymena pyriformis: a hypothesis for control of parasite protozoa through transmembrane redox.

Plasma membrane electron transport was studied in a protozoan cell, Tetrahymena pyriformis, by assaying transmembrane ferricyanide reduction and the reduction of iron compounds. The rates of ferricyanide reduction varied between 0.5 and 2.5 mumol/g dry wt. per min, with a pH optimum at 7.0-7.5. Other active non-permeable electron acceptors, with redox potentials from +360 to -125 mV, were cytochrome c, hexaammine ruthenium chloride, ferric-EDTA, ammonium ferric citrate, and indigo di-, tri- and tetrasulfonates. It was found that Tetrahymena cells can reduce external electron acceptors with redox potentials at pH 7.0 down to -125 mV. Ferricyanide stimulates ciliary action. Transmembrane ferricyanide reduction by Tetrahymena was not inhibited by such mitochondrial inhibitors as antimycin A, 2-n-heptyl-4-hydroxyquinoline N-oxide, or potassium cyanide, but it responded to inhibitors of glycolysis. Transmembrane ferricyanide reduction by Tetrahymena appears to involve a plasma membrane electron transport chain similar to those of other animal cells. As in other cells, the transmembrane electron transport is associated with proton release which may be involved in internal pH control. The transmembrane redox system differs from that of mammalian cells in a 20-fold greater sensitivity to chloroquine and quinacrine. The Tetrahymena ferricyanide reduction is also inhibited by chlorpromazine and suramin. Sensitivity to these drugs indicates that the transplasma membrane electron transport and associated proton pumping may be a target for drugs used against malaria, Trypanosomes and other protozoa.

Residual Cervical Thymus: A Normal CT Finding That May Be Present Throughout Patients' Lives.

BACKGROUND AND PURPOSE: Although the thymus is centered in the mediastinum, often a cervical component can be seen in children and young adults. The frequency of radiologically evident residual cervical thymus in older adults is not known. The purpose of our study was to determine the proportion of adults who have residual cervical thymus visible on contrast-enhanced neck CT. MATERIALS AND METHODS: We retrospectively identified 700 patients who had undergone contrast-enhanced CT between February 2013 and August 2013. We categorized the patients by decade of life and calculated the proportion in which residual cervical thymic tissue could be detected. The location of the tissue focus, greatest axial diameter, and distance above the manubrium were recorded. A multivariate model was used to determine whether age or sex predicted the likelihood of identifiable cervical thymus, the size of residual thymus, or the distance of residual thymus above the sternum. RESULTS: Of the 700 patients, 157 (22.4%) had residual cervical thymus. The mean distance of the residual thymus above the manubrium was 13.4 ± 7.26 mm. The mean size of the residual cervical thymus was 12.5 ± 4.11 mm. The frequency of residual thymus decreased exponentially with age. There was a statistically significant relationship between age and the size of the residual cervical thymus (P = .02). Most of the cervical thymic tissue was found in the left paratracheal region. CONCLUSIONS: Residual cervical thymus may be present at any age, though the frequency decreases with increasing age.

MRI findings in patients with a history of failed prior microvascular decompression for hemifacial spasm: how to image and where to look.

BACKGROUND AND PURPOSE: A minority of patients who undergo microvascular decompression for hemifacial spasm do not improve after the first operation. We sought to determine the most common locations of unaddressed neurovascular contact in patients with persistent or recurrent hemifacial spasm despite prior microvascular decompression. MATERIALS AND METHODS: Eighteen patients with a history of a microvascular decompression presented with persistent hemifacial spasm. All patients underwent thin-section steady-state free precession MR imaging. Fourteen patients underwent repeat microvascular decompression at our institution. Images were evaluated for the following: the presence of persistent vascular compression of the facial nerve, type of culprit vessel (artery or vein), name of the culprit artery, segment of the nerve in contact with the vessel, and location of the point of contact relative to the existing surgical pledget. The imaging findings were compared with the operative findings. RESULTS: In 12 of the 18 patients (67%), persistent vascular compression was identified by imaging. In 11 of these 12 patients, the culprit vessel was an artery. Compression of the attached segment (along the ventral surface of the pons) was identified in most patients (58%, 7/12). The point of contact was proximal to the surgical pledget in most patients (83%, 10/12). The imaging interpretation was concordant with the surgical results regarding artery versus vein in 86% of cases and regarding the segment of the nerve contacted in 92%. CONCLUSIONS: In patients with persistent hemifacial spasm despite microvascular decompression, the unaddressed vascular compression is typically proximal to the previously placed pledget, usually along the attached segment of the nerve. Re-imaging with high-resolution T2-weighted MR imaging will usually identify the culprit vessel.

The CT appearance of thyroglossal duct carcinoma.

BACKGROUND AND PURPOSE: Thyroid carcinoma arising in a thyroglossal duct cyst may be clinically indistinguishable from a benign thyroglossal duct cyst. The preoperative diagnosis of carcinoma, however, can have important implications for surgical planning and postoperative treatment. Our purpose was to describe the CT appearance of thyroglossal duct carcinoma and identify the features that distinguish thyroglossal duct carcinoma from benign thyroglossal duct cysts. METHODS: Retrospective review of the medical records from the University of Pittsburgh Medical Center and Geisinger Medical Center (Danville, Pennsylvania) identified six patients with papillary thyroid carcinoma within the thyroglossal duct who had undergone preoperative CT examinations of the neck. There were two women and four men. Their ages ranged from 14 to 59 years. Three patients underwent contrast-enhanced CT of the neck, and three underwent unenhanced CT. All CT examinations consisted of 3- to 5-mm-thick contiguous axial sections. RESULTS: Each patient had an anterior neck mass with a cystic component. Two of the masses had dense or enhancing mural nodules, two had irregular calcification throughout the mass, and two had dense or enhancing mural nodules with additional foci of calcification. One patient had cervical lymphadenopathy. CONCLUSION: Carcinoma should be considered in thyroglossal duct cysts that have a mural nodule or calcification or both.