Risk Stratification for Oropharyngeal Squamous Cell Carcinoma Using Texture Analysis on CT - A Step Beyond HPV Status.

Background and Purpose: Human papillomavirus-associated oropharyngeal squamous cell carcinoma (OPSCC) is increasingly prevalent. Despite the overall more favorable outcome, the observed heterogeneous treatment response within this patient group highlights the need for additional means to prognosticate and guide clinical decision-making. Promising prediction models using radiomics from primary OPSCC have been derived. However, no model/s using metastatic lymphadenopathy exist to allow prognostication in those instances when the primary tumor is not seen. The aim of our study was to evaluate whether radiomics using metastatic lymphadenopathy allows for the development of a useful risk assessment model comparable to the primary tumor and whether additional knowledge of the HPV status further improves its prognostic efficacy. Materials and Methods: 80 consecutive patients diagnosed with stage III-IV OPSCC between February 2009 and October 2015, known human papillomavirus status, and pre-treatment CT images were retrospectively identified. Manual segmentation of primary tumor and metastatic lymphadenopathy was performed and the extracted texture features were used to develop multivariate assessment models to prognosticate treatment response. Results: Texture analysis of either the primary or metastatic lymphadenopathy from pre-treatment enhanced CT images can be used to develop models for the stratification of treatment outcomes in OPSCC patients. AUCs range from .78 to .85 for the various OPSCC groups tested, indicating high predictive capability of the models. Conclusions: This preliminary study can form the basis multi-centre trial that may help optimize treatment and improve quality of life in patients with OPSCC in the era of personalized medicine.

Case series of mild behavioral impairment: toward an understanding of the early stages of neurodegenerative diseases affecting behavior and cognition.

Mild behavioral impairment (MBI) is characterized by later life acquired, sustained, and impactful neuropsychiatric symptoms (NPS) of any severity that cannot be better accounted for by other formal medical and psychiatric nosology. MBI is an "at risk" state for incident cognitive decline and dementia, and for some, MBI is the index manifestation of neurodegeneration, observed in advance of cognitive impairment. Initially described in Frontotemporal Dementia (FTD), MBI evolved to describe a preclinical stage of all cause dementia, and has been operationalized in the International Society to Advance Alzheimer's Research and Treatment-Alzheimer's Association (ISTAART-AA) proposed research diagnostic criteria. Here, we describe three cases in which patients diagnosed with a variety of dementing conditions initially presented with NPS to the Cognitive Neurosciences Clinic at the University of Calgary, Canada. All patients described in our series were given a final diagnosis of dementia; the etiology supported by clinical, cognitive, and neuroimaging findings. In all three cases, the progression to dementia was preceded by NPS that meet criteria for MBI. With these examples, we are able to illustrate that MBI can represent a premonitory stage of dementia of different etiologies. These cases demonstrate early use of the MBI checklist (MBI-C). The cases presented in this series serve as examples of NPS as early manifestations of dementia. Our case examples include both FTD and AD, and demonstrate that before a diagnosis of a neurodegenerative disease is considered, often patients will be diagnosed with and treated for a psychiatric condition. These early NPS can be characterized within the domains outlined in the ISTAART-AA MBI criteria, and detected with the MBI-C, which may help clinicians consider neurodegenerative disease in the differential diagnosis of later life onset psychiatric symptomatology.

Neuroradiology Using Secure Mobile Device Review.

BACKGROUND: Image review on computer-based workstations has made film-based review outdated. Despite advances in technology, the lack of portability of digital workstations creates an inherent disadvantage. As such, we sought to determine if the quality of image review on a handheld device is adequate for routine clinical use. METHODS: Six CT/CTA cases and six MR/MRA cases were independently reviewed by three neuroradiologists in varying environments: high and low ambient light using a handheld device and on a traditional imaging workstation in ideal conditions. On first review (using a handheld device in high ambient light), a preliminary diagnosis for each case was made. Upon changes in review conditions, neuroradiologists were asked if any additional features were seen that changed their initial diagnoses. Reviewers were also asked to comment on overall clinical quality and if the handheld display was of acceptable quality for image review. RESULTS: After the initial CT review in high ambient light, additional findings were reported in 2 of 18 instances on subsequent reviews. Similarly, additional findings were identified in 4 of 18 instances after the initial MR review in high ambient lighting. Only one of these six additional findings contributed to the diagnosis made on the initial preliminary review. CONCLUSIONS: Use of a handheld device for image review is of adequate diagnostic quality based on image contrast, sharpness of structures, visible artefacts and overall display quality. Although reviewers were comfortable with using this technology, a handheld device with a larger screen may be diagnostically superior.

Canadian Expert Panel Recommendations for MRI Use in MS Diagnosis and Monitoring.

BACKGROUND: A definitive diagnosis of multiple sclerosis (MS), as distinct from a clinically isolated syndrome, requires one of two conditions: a second clinical attack or particular magnetic resonance imaging (MRI) findings as defined by the McDonald criteria. MRI is also important after a diagnosis is made as a means of monitoring subclinical disease activity. While a standardized protocol for diagnostic and follow-up MRI has been developed by the Consortium of Multiple Sclerosis Centres, acceptance and implementation in Canada have been suboptimal. METHODS: To improve diagnosis, monitoring, and management of a clinically isolated syndrome and MS, a Canadian expert panel created consensus recommendations about the appropriate application of the 2010 McDonald criteria in routine practice, strategies to improve adherence to the standardized Consortium of Multiple Sclerosis Centres MRI protocol, and methods for ensuring effective communication among health care practitioners, in particular referring physicians, neurologists, and radiologists. RESULTS: This article presents eight consensus statements developed by the expert panel, along with the rationale underlying the recommendations and commentaries on how to prioritize resource use within the Canadian healthcare system. CONCLUSIONS: The expert panel calls on neurologists and radiologists in Canada to incorporate the McDonald criteria, the Consortium of Multiple Sclerosis Centres MRI protocol, and other guidance given in this consensus presentation into their practices. By improving communication and general awareness of best practices for MRI use in MS diagnosis and monitoring, we can improve patient care across Canada by providing timely diagnosis, informed management decisions, and better continuity of care.

Tumor volumes in T3 supraglottic cancers treated with radiotherapy in the modern era: A study of the Canadian Head & Neck Collaborative Research Initiative.

PURPOSE: To evaluate the association of primary tumor volume (TV) with overall survival (OS) and disease-free survival (DFS) in T3 N0-3M0 supraglottic cancers treated with intensity-modulated radiotherapy (IMRT). METHODS: This was a retrospective cohort study involving 239 patients diagnosed with T3 N0-3M0 supraglottic cancers between 2002 and 2018 from seven regional cancer centers in Canada. Clinical data were obtained from the patient records. Supraglottic TV was measured by neuroradiologists on diagnostic imaging. Kaplan-Meier method was used for survival probabilities, and a restricted cubic spline Cox proportional hazards regression analysis was used to analyze TV associations with OS and DFS. RESULTS: Mean (SD) of participants was 65.2 (9.4) years; 176 (73.6%) participants were male. 90 (38%) were N0, and 151 (64%) received concurrent systemic therapy. Mean TV (SD) was 11.37 (12.11) cm3 . With mean follow up (SD) of 3.28 (2.60) years, 2-year OS was 72.7% (95% CI 66.9%-78.9%) and DFS was 53.6% (47.4%-60.6%). Increasing TV was associated (per cm3 increase) with worse OS (HR, 1.01, 95% CI 1.00-1.02, p < 0.01) and DFS (HR, 1.01, 95% CI 1.00-1.02, p = 0.02). CONCLUSIONS: Increasing primary tumor volume is associated with worse OS and DFS in T3 supraglottic cancers treated with IMRT, with no clear threshold. The findings suggest that patients with larger tumors and poor baseline laryngeal function may benefit from upfront laryngectomy with adjuvant radiotherapy.

Association of Primary Tumor Volume With Survival in Patients With T3 Glottic Cancer Treated With Radiotherapy: A Study of the Canadian Head & Neck Collaborative Research Initiative.

Importance: The association of primary tumor volume with outcomes in T3 glottic cancers treated with radiotherapy with concurrent chemotherapy remains unclear, with some evidence suggesting worse locoregional control in larger tumors. Objective: To evaluate the association of primary tumor volume with oncologic outcomes in patients with T3 N0-N3 M0 glottic cancer treated with primary (chemo)radiotherapy in a large multi-institutional study. Design, Setting, and Participants: This multi-institutional retrospective cohort study involved 7 Canadian cancer centers from 2002 to 2018. Tumor volume was measured by expert neuroradiologists on diagnostic imaging. Clinical and outcome data were extracted from electronic medical records. Overall survival (OS) and disease-free survival (DFS) outcomes were assessed with marginal Cox regression. Laryngectomy-free survival (LFS) was modeled as a secondary analysis. Patients diagnosed with cT3 N0-N3 M0 glottic cancers from 2002 to 2018 and treated with curative intent intensity-modulated radiotherapy (IMRT) with or without chemotherapy. Overall, 319 patients met study inclusion criteria. Exposures: Tumor volume as measured on diagnostic imaging by expert neuroradiologists. Main Outcomes and Measures: Primary outcomes were OS and DFS; LFS was assessed as a secondary analysis, and late toxic effects as an exploratory analysis determined before start of the study. Results: The mean (SD) age of participants was 66 (12) years and 279 (88%) were men. Overall, 268 patients (84%) had N0 disease, and 150 (47%) received concurrent systemic therapy. The mean (SD) tumor volume was 4.04 (3.92) cm3. With a mean (SD) follow-up of 3.85 (3.04) years, there were 91 (29%) local, 35 (11%) regional, and 38 (12%) distant failures. Increasing tumor volume (per 1-cm3 increase) was associated with significantly worse adjusted OS (hazard ratio [HR], 1.07; 95% CI, 1.03-1.11) and DFS (HR, 1.04; 95% CI, 1.01-1.07). A total of 62 patients (19%) underwent laryngectomies with 54 (87%) of these within 800 days after treatment. Concurrent systemic therapy was associated with improved LFS (subdistribution HR, 0.63; 95% CI, 0.53-0.76). Conclusions and Relevance: Increasing tumor volumes in cT3 glottic cancers was associated with worse OS and DFS, and systemic therapy was associated with improved LFS. In absence of randomized clinical trial evidence, patients with poor pretreatment laryngeal function or those ineligible for systemic therapy may be considered for primary surgical resection with postoperative radiotherapy.

TRK Inhibition with Entrectinib in Metastatic Salivary Secretory Carcinoma (SC): A Case Report.

NTRK gene fusions are rare oncogenic driver mutations that can be found in a broad range of neoplasms. In secretory carcinoma (SC), ETV6-NTRK3 gene fusion is seen in a majority of the cases and represents a druggable target for patients with advanced disease in the absence of a currently accepted standard of care. In our case, we describe a patient with recurrent, metastatic SC treated with first line entrectinib with clinically meaningful, durable ongoing response after 49 months. The patient experienced grade 1 fatigue, dysgeusia, skin sensitivity, arthralgias, an increase in serum creatinine, and weight-gain as well as grade 2 hypotension which resolved after a dose reduction. Entrectinib is a well-tolerated treatment with the potential for durable responses and TRK inhibition should be considered the standard of care in SC and other NTRK gene fusion-positive advanced neoplasms without acceptable alternative treatment options.

Novel imaging classification system of nodal disease in human papillomavirus-mediated oropharyngeal squamous cell carcinoma prognostic of patient outcomes.

BACKGROUND: Matted nodes in human papillomavirus (HPV)-mediated oropharyngeal squamous cell carcinoma (OPC) is an independent predictor of distant metastases and decreased overall survival. We aimed to classify imaging patterns of metastatic lymphadenopathy, analyze our classification system for reproducibility, and assess its prognostic value. METHODS: The metastatic lymphadenopathy was classified based on radiological characteristics for 216 patients with HPV-mediated OPC. Patient outcomes were compared and inter-rater reliability was calculated. RESULTS: The presence of ≥3 abutting lymph nodes with imaging features of surrounding extranodal extension (ENE), one subtype of matted nodes, was associated with worse 5-year overall survival, overall recurrence-free survival, regional recurrence-free survival, and distant recurrence-free survival (p ≤ 0.03). Other patterns were not significantly associated with outcome measures. Overall inter-rater agreement was substantial (κ = 0.73). CONCLUSION: One subtype of matted nodes defined by ≥3 abutting lymph nodes with imaging features of surrounding ENE is the radiological marker of worst prognosis.

Volumetric changes in pharyngeal structures following head and neck cancer chemoradiation therapy.

OBJECTIVES/HYPOTHESIS: To determine the volumetric changes in pharyngeal structures in patients with head and neck squamous cell carcinoma (HNSCC) treated with curative chemoradiation therapy (CRT). Patients treated with CRT for esophageal carcinoma (EC), where pharyngeal structures were not part of the radiation treatment fields, were controlled for dysphagia-associated weight loss. We hypothesize that tissue volume alteration is a contributing factor of post-CRT dysphagia. STUDY DESIGN: Case series. METHODS: This study measured pre- and 1-year posttreatment volumes of the base of tongue (BOT), parapharyngeal spaces, posterior pharyngeal constrictors (PCs), and retropharyngeal space (RPS) in patients undergoing CRT for HNSCC or EC treated January 1, 2012 to December 31, 2015. All HNSCC patients were treated to doses of 66 to 70 Gy in 30 to 33 fractions using intensity-modulated radiotherapy techniques. RESULTS: Our cohort included 49 HNSCC and 11 EC patients. Within the HNSCC cohort, the PCs volume increased 1.55 cm3 (95% confidence interval [CI]: 0.77 to 2.34 cm3 , P = .0002), RPS increased 1.22 cm3 (95% CI: 0.67 to 1.77 cm3 , P < .0001), and BOT decreased 2.29 cm3 (95% CI: -0.20 to 4.79 cm3 , P = .070). The EC cohort showed no significant volumetric changes for any anatomic space, with combined PCs and RPS volume changes statistically less than the HNSCC cohort (P = .031). There was no difference in mean body mass index reduction between groups (P = .10). CONCLUSIONS: Volumetric changes following CRT may play a role in posttreatment dysphagia. Our findings support loss of physiologic function from posterior pharynx tissue thickening combined with reduced pharyngeal constriction capacity, and BOT atrophy secondary to radiation effects contribute to dysphagia. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:597-602, 2020.

Asymptomatic unruptured intracranial aneurysms: approach to screening and treatment.

ABSTRACTOBJECTIVETo review the current knowledge of screening and treatment of asymptomatic unruptured intracranial aneurysms (AUIAs) using a case-based approach.SOURCES OF INFORMATIONPubMed was searched from January 1995 to January 2008 using the phrase unruptured intracranial aneurysm. Scientific statements of the Stroke Council of the American Heart Association pertaining to intracranial aneurysms were also reviewed.MAIN MESSAGEMost small AUIAs ( 5 mm) should be considered on a case-by-case basis.CONCLUSIONThere is currently a lack of sound scientific evidence to support treatment of unruptured intracranial aneurysms. A prospective randomized controlled trial-Trial on Endovascular Aneurysm Management-is now under way to address this issue. It is expected to conclude in 2021.

Correlation of CT scan versus plain radiography for measuring urinary stone dimensions.

OBJECTIVES: To correlate the measured dimensions of urinary stones from spiral non-contrast computerized tomography (CT) with that of plain radiography (KUB). METHODS: The transverse diameter as reported on CT was compared to the measured transverse diameter on KUB for 61 stones. The transverse and craniocaudal dimensions on CT were then re-measured for 30 urinary stones and again compared to the re-measured values for KUB. The craniocaudal dimension on CT was determined by measuring the stone on reconstructed coronal CT images. Measurements between imaging modalities were blinded and performed consecutively by a dedicated investigator. RESULTS: The mean transverse size of the stones on the initial CT report was 6.0 mm +/- 2.8 mm versus 5.6 mm +/- 2.3 mm on KUB (paired t-test, p = 0.05, 95% CI difference between the means -1.3 to 0.5). The stones were categorized in transverse size ranges of 1.0 mm to 5.0 mm, > 5.0 mm to 10.0 mm, and > 10.0 mm. A total of 14 stones failed to be put into the same size categories by the two methods. The largest difference in measurements was 5 mm. In the second analysis, where the CT dimensions were re-measured, the mean transverse dimension on CT was 4.5 mm +/- 2.1 mm versus 4.7 mm +/- 2.0 mm on plain radiography (paired t-test, p = 0.06, 95% CI difference between the means -0.02 to 0.6). Mean craniocaudal dimension of the stones on CT was 7.4 mm +/- 3.2 mm versus 6.0 mm +/- 2.7 mm on plain radiography (paired t-test, p = 0.0001, 95% CI between the means -2.0 to -0.9). When the stones were categorized in transverse size ranges of 1.0 mm to 5.0 mm, >5.0mm to 10.0mm, and >10.0mm, CT and KUB agreed for 30/30 stones. CONCLUSIONS: In this study, the initially reported CT transverse values were found to be significantly different from measured KUB values; moreover, large differences of up to 5 mm were found between the measurements. With fastidious measurement of stone dimensions on both CT and KUB, we found that the transverse dimension of stones measured by the two imaging modalities were similar. The craniocaudal measurements of the stones were found to be significantly different on CT versus KUB, with CT measurement being 1.4 mm larger on average.

Improved transoral surgical tool design by CT measurements of the oral cavity and pharynx.

The majority of head and neck cancers arise from the oral cavity and oropharynx. Many of these lesions will be amenable to surgical resection using transoral approaches including transoral robotic surgery (TORS). To develop and control TORS tools, precise dimensions of the oral cavity and pharynx are desirable. CT angiograms of 76 patients were analyzed. For the oral cavity, only the maximum length and width were measured, while for the pharynx, the width, length, and areas of the airway were all measured and the volume calculated. A prototype TORS tool was developed and tested based on the findings and dimensions. The design modification of the tool is in progress. The mean male oral cavity width and length were 93.3 ± 4.3 and 77.0 ± 7.2 mm, respectively, and the mean male pharyngeal width, length, area, and volume were 26.5 ± 7.2 mm, 16.2 ± 8.8 mm, 325 ± 149 mm2, and 28,440 ± 14,100 mm3, respectively, while the mean female oral cavity width and length were 84.5 ± 12.9 and 71.0 ± 6.3 mm, respectively, and the mean female pharyngeal width, length, area, and volume were 24.8 ± 5.6 mm, 13.7 ± 3.2 mm, 258 ± 98 mm2, and 17,660 ± 7700 mm3, respectively. The developed TORS tool was tested inside the oral cavity of an intubation mannequin. These data will also be used to develop an electronic no-go cone-shape tunnel to improve the safety of the surgical field. Reporting the oral cavity and pharyngeal dimensions is important for design of TORS tools and creating control zones for the workspace of the tool inside the oral cavity.

Secondary Neuroendocrine Carcinoma Following High-Dose Radiotherapy for Head and Neck Cancer: Report of Two Cases.

Patients treated with radiation have an increased risk of developing second cancers, of which carcinomas, sarcomas, and hematological malignancies have most commonly been reported. Neuroendocrine carcinomas (NEC) are rarely reported in patients previously treated with radiation. Two patients, who had successfully undergone chemoradiotherapy for head and neck cancers at our institution, developed secondary NEC within the radiation field more than five years after the treatment. Both patients underwent curative-intent treatment of secondary malignancies, one with chemotherapy, radiation and surgery (Case 1) and the other with chemotherapy and surgery (Case 2). Both had no evidence of disease at a short follow-up of twelve months (Case 1), and three months (Case 2) after treatment. NEC can develop post-radiotherapy; a multidisciplinary approach is necessary to successfully treat these patients.

Diagnostic utility of central node necrosis in predicting extracapsular spread among oral cavity squamous cell carcinoma.

BACKGROUND: Oral cavity squamous cell carcinoma (SCC) represents the most common SCC affecting the head and neck region. Long-term survival of patients with oral cavity SCC is adversely affected by lymph node metastasis and further decreased by the presence of lymph node extracapsular spread (ECS). METHODS: Using a case-control design, preoperative CT scans from patients with oral cavity SCC and metastatic lymphadenopathy were evaluated by 2 independent neuroradiologists, blinded to the study, for a number of radiologic parameters, including central node necrosis. Multivariate logistic regression was used to identify parameters independently predicting pathologic ECS. RESULTS: For both neuroradiologists, central node necrosis was a significant predictor of ECS, with high interrater agreement (kappa = 0.71). On multivariate analysis, only central node necrosis independently predicted ECS (odds ratio [OR] = 12.1; 95% confidence interval [CI] = 1.24-119). Central node necrosis predicted ECS with 91% sensitivity and 88% negative predictive values. CONCLUSION: Our findings suggest that central node necrosis on preoperative CT scans is strongly associated with the presence of ECS.

Radiologic reporting for paranasal sinus computed tomography: a multi-institutional review of content and consistency.

OBJECTIVES/HYPOTHESIS: To optimize clinical care, radiologic reporting should consistently include clinically pertinent information. The purpose of this study was to: 1) determine the current satisfaction of otolaryngologists with paranasal sinus computed tomography (CT) radiologic reporting and 2) evaluate the comprehensiveness of paranasal sinus CT radiologic reporting. STUDY DESIGN: Two parts: 1) A national survey of all practicing otolaryngologists in Canada and 2) a retrospective review of paranasal sinus CT scan radiologic reporting. METHODS: A national survey of all Canadian otolaryngologists was conducted in September 2011. Questions were focused on eliciting the current satisfaction with sinus CT radiologic reporting. At two major centers (Alberta Health Services-Calgary Zone and the Ottawa Hospital), all sinus CT scans performed over a 2-year period were identified (9,739), and 100 from each center were randomly selected for analysis. The radiology reports were scrutinized to determine if seven critical and 11 noncritical items were mentioned. RESULTS: Many (22%) otolaryngologists are dissatisfied with current sinus CT radiologic reporting, and the majority (67%) would like more clinically useful information. All predefined sinus CT items were inconsistently reported. Anterior ethmoid artery anatomy, ethmoid skull base integrity, and sphenoethmoidal cell were the most infrequently reported critical items. CONCLUSIONS: This study has demonstrated that important information is inconsistently reported for sinus CT, and most otolaryngologists would like to see more clinically relevant content in radiology reports. Optimizing the reporting of sinus CT scans will improve communication between the radiologist and other clinicians managing patients with sinonasal disease. LEVEL OF EVIDENCE: 2b.

Impact of neuroradiologist second opinion on staging and management of head and neck cancer.

OBJECTIVE: Patients with head and neck cancer frequently present to academic tertiary referral centers with imaging studies that have been performed and interpreted elsewhere. At our institution, these outside head and neck imaging studies undergo formal second opinion reporting by a fellowship-trained academic neuroradiologist with expertise in head and neck imaging. The purpose of this study was to determine the impact of this practice on cancer staging and patient management. METHODS: Our institutional review board approved the retrospective review of randomized original and second opinion reports for 94 consecutive cases of biopsy proven or clinically suspected head and neck cancer in calendar year 2010. Discrepancy rates for staging and recommended patient management were calculated and, for the 32% (30/94) of cases that subsequently went to surgery, the accuracies of the reports were determined relative to the pathologic staging gold standard. RESULTS: Following neuroradiologist second opinion review, the cancer stage changed in 56% (53/94) of cases and the recommended management changed in 38% (36/94) of patients with head and neck cancer. When compared to the pathologic staging gold standard, the second opinion was correct 93% (28/30) of the time. CONCLUSION: In a majority of patients with head and neck cancer, neuroradiologist second opinion review of their outside imaging studies resulted in an accurate change in their cancer stage and this frequently led to a change in their management plan.

Impact of newer generation multidetector computed tomography on the diagnosis of abscesses in the head and neck.

OBJECTIVE: To understand how newer generation multidetector computed tomographic (NGCT) scanner technology (≥ 16 slices) has affected the imaging characteristics of head and neck abscesses. DESIGN: Retrospective chart review. SETTING: Tertiary referral centre. METHODS: Forty-eight patients with a head and neck abscess who underwent a soft tissue neck computed tomographic (CT) scan were identified from September 1, 2001, to December 1, 2008. The degree of rim enhancement, delta (Δ), was graded using mean Hounsfield units (HU) from five peripheral points and five central points from a representative CT slice. The difference was then calculated and compared between older generation computed tomography (OGCT; < 16 slices) and newer generation multidetector computed tomography (NGCT; ≥ 16 slices) using the Student t-test. A p value < .05 was considered significant. RESULTS: Forty-eight patients met our inclusion criteria. Of these, 20 were scanned with OGCT and 28 were scanned with NGCT. The mean peripheral point values were OGCT  =  78 HU (95% CI 71-86 HU), NGCT  =  74 HU (95% CI 68-80 HU); p  =  .3. The mean central point values were OGCT  =  24 HU (95% CI 21-28 HU), NGCT  =  26 HU (95% CI 21-31 HU), p  =  0.7. The mean delta values (mean peripheral HU--mean central HU) were OGCT  =  52 HU (95% CI 43-61 HU), NGCT  =  46 HU (95% CI 41-52 HU), p  =  .2. CONCLUSION: There is no significant difference between OGCT and NGCT in the amount of rim enhancement seen on CT scans of head and neck abscesses.

Variations in calcaneonavicular morphology demonstrated with radiography.

PURPOSE: To determine and classify radiographically demonstrated variations in calcaneonavicular morphology and to estimate prevalence in a clinically relevant patient population. MATERIALS AND METHODS: Retrospective review was performed of foot radiographs obtained during diagnostic evaluation of 460 consecutive patients who presented to the emergency department with acute foot pain. Variations in calcaneonavicular morphology depicted on the medial oblique view (obtained at a 45 degrees angle) were classified into four groups according to morphologic type (types 1-4), and the prevalence of each type was calculated. Chi2 analysis was used to compare the prevalence of each type in male patients and in female patients. One-way analyses of variance were used to compare mean ages of patients for each type and mean calcaneonavicular gaps for each type. RESULTS: The prevalence of morphologic types 1, 2, and 3 was 94.3%, 2.8%, and 2.8%, respectively. The combined prevalence of types 2 and 3 (calcaneonavicular coalitions produced by synchondrosis and syndesmosis, respectively) was 5.6% (95% CI: 3.5%, 7.8%). There were no patients with type 4 morphology (synostosis). The numbers of male patients and female patients with morphologic types 1-3 were approximately equal (P =.9), and there was no statistically significant correlation between any of these three morphologic types and patient age (P =.2). The calcaneonavicular gap was significantly narrower in types 2 and 3 than in type 1 (P =.01), which was characterized as the normal morphology. CONCLUSION: The general prevalence of calcaneonavicular coalition (synchondrosis and syndesmosis) may be greater than previously reported, but further research is needed to prove the validity of this hypothesis.