Intra-parotid facial nerve path by MRI tractography: radio-clinical comparison in parotid tumors.

PURPOSE: The objective of our study was to evaluate the ability of preoperative MRI tractography to visualize and predict the path of the facial nerve with respect to an intra-parotid mass. METHODS: We performed an observational bicentric study from June 2019 to August 2020. All patients older than 18 years old, treated for a parotid mass with surgical indication, without MRI contraindication and who agreed to participate in the study were enrolled prospectively. All patients underwent a cervico-facial MRI with tractographic analysis. Postprocessed tractography images of the intra-parotid facial nerve were analyzed by two expert radiologists in head and neck imaging. The intraoperative anatomical description of the facial nerve path and its relationship to the mass was performed by the surgeon during the operation, with no visibility on MRI examination results. A statistical study allowed for the description of the data collected as well as the measurement of inter-observer agreement and agreement between tractography and surgery using kappa coefficients. RESULTS: Fifty-two patients were included. The facial nerve trunk and its first two divisional branches were visualized via tractography in 93.5% of cases (n = 43). The upper distal branches were visualized in 51.1% of cases (n = 23), and the lower branches were visualized in 73.3% of cases (n = 33). Agreement with the location described per-operatively was on average 82.9% for the trunk, 74.15% for the temporal branch, and 75.21% for the cervico-facial branch. CONCLUSION: Fiber tractography analysis by MRI of the intra-parotid facial nerve appears to be a good test for predicting the path of the nerve over the parotid mass and could be an additional tool to guide the surgeon in the operative procedure.

Aetiology, clinical features, diagnostic studies, and outcomes of community-acquired pneumonia in kidney transplant recipients admitted to hospital: a multicentre retrospective French cohort study.

OBJECTIVES: To assess the aetiology, clinical features, diagnostic studies and outcomes of community-acquired pneumonia (CAP) in a French cohort of hospitalized kidney transplant recipients. METHODS: We performed a retrospective, multicentre study in kidney transplant recipients admitted to ten French centres for CAP from January 2016 to December 2018. CAP discharge diagnoses were clinically and radiologically validated. We assessed a descriptive analysis of all confirmed CAP including medical ward and intensive care unit admissions. RESULTS: One hundred sixty-five CAP episodes in 132 patients were included. Median time from transplantation to admission was 6.4 (interquartile range, 1.6-12.3) years, with corticosteroid exposure in 112/165 (67.9%) cases. Sputum culture was performed in 47/165 (28.5%) cases including 7/47 (14.9%) positive samples. Bronchoscopy was performed in 87/165 (52.7%) cases with pathogens identified in 39/87 (44.8%) cases. Microbiological studies led to identifying a respiratory pathogen in 64/165 (38.8%) CAP episodes including 11/64 (17.2%) polymicrobial cases. Among these 64 episodes, 75 microorganisms were identified; 46/75 (61.3%) were core respiratory pathogens and 29/75 (38.7%) were opportunistic or drug-resistant organisms including Pneumocystis jirovecii 9/75 (12%), Pseudomonas aeruginosa 5/75 (6.7%), multidrug-resistant Enterobacteriaceae 4/75 (5.3%), and Aspergillus 4/75 (5.3%). Patients required intensive care unit admission in 26/165 (15.8%) episodes, invasive ventilation in 20/165 (12.1%) cases, and 22/165 (13.3%) needed in-hospital dialysis. DISCUSSION: CAP episodes occurred in kidney transplant recipients with a long history of immunosuppressive drug exposure. Diagnostic studies identified a microorganism in more than one-third of CAP episodes, including drug-resistant and opportunistic pathogens.

Recurrent massive hemoptysis from distal pulmonary pseudoaneurysms complicating invasive aspergillosis in a teenager.

Invasive pulmonary aspergillosis in children rarely complicates life-threatening massive hemoptysis. Here, we report the case of a 15-year-old girl with acute lymphoblastic leukemia who was hospitalized for fever and medullary aplasia 1 month after beginning chemotherapy for invasive pulmonary aspergillosis. Despite voriconazole and caspofungine treatment, excavation of some lesions caused a unilateral small pneumothorax and bilateral pleural effusion, justifying intensive care management. The massive hemoptysis that occurred on day 23 was complicated with heart failure, and the patient was promptly resuscitated. Fibroscopy and computed tomography angiography (CTA) did not reveal the origin or cause of the bleeding. A second massive bleeding event occurred on day 32, and heart failure resolved after 10min of low flow. A new CTA showed 2 pseudoaneurysms of the subsegmental pulmonary arteries that were treated with embolization. Sedation was gradually decreased owing to improvement in respiratory status, but the patient did not regain consciousness because of deep brain sequelae. A limitation of care was decided upon, and the patient died in the following weeks. Massive hemoptysis is a rare life-threatening complication of invasive pulmonary aspergillosis, especially in children. Pulmonary artery pseudoaneurysms are unusual and should be detected as soon as possible to guide therapy. Intensive care management should be followed by embolization if the patient is stable; otherwise, surgery is indicated, ideally after identifying the source of bleeding by CTA or bronchoscopy. Early CTA follow-up can be proposed if the source of bleeding is still unknown as pseudoaneurysms can appear or grow rapidly.

Response to Induction Therapy in Pediatric Hodgkin's Lymphoma: Performance of First-Order Texture Parameters of CT Images.

Objectives: The aim of this study was to examine whether texture analysis features on pretreatment contrast-enhanced CT images could predict adequate response (AR) or inadequate response (IR) after two cycles of chemotherapy in pediatric Hodgkin's lymphoma (PHL). Materials and methods: This retrospective single-center study included 32 children and adolescents with HL. Texture analysis was independently performed by two radiologists using pretreatment CT scans. The mean gray level, standard deviation, entropy, kurtosis, and skewness were derived from pixel distribution histograms before and after spatial filtration ranging from two (fine texture) to six (coarse texture). Interobserver reliability was studied using interobserver correlation coefficients (ICCs) to select texture parameters. Relationships between early response assessment (ERA) to induction therapy and associated factors were studied using Student's t-tests and a lasso penalized logistic regression analysis. Results: Of the 32 patients, IR was observed in 13 and AR in 19. Inter-reader agreement was good to excellent (ICC > 0.75) for all parameters except skewness and kurtosis without filtration and at spatial scale filtration (SSF) = 2. These parameters were excluded from the analysis. The t-test identified only entropy at SSF = 2 (p value = 0.039) as a potential predictor of ERA. No parameters were significantly associated with ERA, according to a lasso penalized logistic regression. Conclusion: No textural parameters were identified as predictors of ERA after two cycles of chemotherapy in PHL.

Measurement of pediatric regional cerebral blood flow from 6 months to 15 years of age in a clinical population.

OBJECTIVES: To investigate changes in cerebral blood flow (CBF) in gray matter (GM) between 6 months and 15 years of age and to provide CBF values for the brain, GM, white matter (WM), hemispheres and lobes. METHODS: Between 2013 and 2016, we retrospectively included all clinical MRI examinations with arterial spin labeling (ASL). We excluded subjects with a condition potentially affecting brain perfusion. For each subject, mean values of CBF in the brain, GM, WM, hemispheres and lobes were calculated. GM CBF was fitted using linear, quadratic and cubic polynomial regression against age. Regression models were compared with Akaike's information criterion (AIC), and Likelihood Ratio tests. RESULTS: 84 children were included (44 females/40 males). Mean CBF values were 64.2 ±â€¯13.8 mL/100 g/min in GM, and 29.3 ±â€¯10.0 mL/100 g/min in WM. The best-fit model of brain perfusion was the cubic polynomial function (AIC = 672.7, versus respectively AIC = 673.9 and AIC = 674.1 with the linear negative function and the quadratic polynomial function). A statistically significant difference between the tested models demonstrating the superiority of the quadratic (p = 0.18) or cubic polynomial model (p = 0.06), over the negative linear regression model was not found. No effect of general anesthesia (p = 0.34) or of gender (p = 0.16) was found. CONCLUSION: we provided values for ASL CBF in the brain, GM, WM, hemispheres, and lobes over a wide pediatric age range, approximately showing inverted U-shaped changes in GM perfusion over the course of childhood.

Magnetic resonance imaging in children presenting migraine with aura: Association of hypoperfusion detected by arterial spin labelling and vasospasm on MR angiography findings.

Objective A child presenting with a first attack of migraine with aura usually undergoes magnetic resonance imaging (MRI) to rule out stroke. The purpose of this study was to report vascular and brain perfusion findings in children suffering from migraine with aura on time-of-flight MR angiography (TOF-MRA) and MR perfusion imaging using arterial spin labelling (ASL). Methods We retrospectively included all children who had undergone an emergency MRI examination with ASL and TOF-MRA sequences for acute neurological deficit and were given a final diagnosis of migraine with aura. The ASL perfusion maps and TOF-MRA images were independently assessed by reviewers blinded to clinical data. A mean cerebral blood flow (CBF) value was obtained for each cerebral lobe after automatic data post-processing. Results Seventeen children were finally included. Hypoperfusion was identified in one or more cerebral lobes on ASL perfusion maps by visual assessment in 16/17 (94%) children. Vasospasm was noted within the intracranial vasculature on the TOF-MRA images in 12/17 (71%) children. All (100%) of the abnormal TOF-MRA images were associated with homolateral hypoperfusion. Mean CBF values were significantly lower ( P < 0.05) in visually hypoperfused lobes than in normally perfused lobes. Conclusion ASL and TOF-MRA are two totally non-invasive, easy-to-use MRI sequences for children in emergency settings. Hypoperfusion associated with homolateral vasospasm may suggest a diagnosis of migraine with aura.

MDCT Linear and Volumetric Analysis of Adrenal Glands: Normative Data and Multiparametric Assessment.

OBJECTIVES: To study linear and volumetric adrenal measurements, their reproducibility, and correlations between total adrenal volume (TAV) and adrenal micronodularity, age, gender, body mass index (BMI), visceral (VAAT) and subcutaneous adipose tissue volume (SAAT), presence of diabetes, chronic alcoholic abuse and chronic inflammatory disease (CID). METHODS: We included 154 patients (M/F, 65/89; mean age, 57 years) undergoing abdominal multidetector row computed tomography (MDCT). Two radiologists prospectively independently performed adrenal linear and volumetric measurements with semi-automatic software. Inter-observer reliability was studied using inter-observer correlation coefficient (ICC). Relationships between TAV and associated factors were studied using bivariate and multivariable analysis. RESULTS: Mean TAV was 8.4 ± 2.7 cm(3) (3.3-18.7 cm(3)). ICC was excellent for TAV (0.97; 95 % CI: 0.96-0.98) and moderate to good for linear measurements. TAV was significantly greater in men (p < 0.0001), alcoholics (p = 0.04), diabetics (p = 0.0003) and those with micronodular glands (p = 0.001). TAV was lower in CID patients (p = 0.0001). TAV correlated positively with VAAT (r = 0.53, p < 0.0001), BMI (r = 0.42, p < 0.0001), SAAT (r = 0.29, p = 0.0003) and age (r = 0.23, p = 0.005). Multivariable analysis revealed gender, micronodularity, diabetes, age and BMI as independent factors influencing TAV. CONCLUSIONS: Adrenal gland MDCT-based volumetric measurements are more reproducible than linear measurements. Gender, micronodularity, age, BMI and diabetes independently influence TAV. KEY POINTS: • Volumetric measurements are more reproducible than linear measurements for adrenal glands. • Inter-observer reproducibility of adrenal gland volume is excellent using semiautomatic software. • Gender, age, BMI, and diabetes independently influence total adrenal gland volume. • Adrenal micronodularity is associated with increased total adrenal gland volume.