Middle ear morphology and mastoid pneumatization: a computed tomography study.

BACKGROUND: Mastoid pneumatization is subject to numerous influencing factors including race, sex, and surrounding structures of the middle ear. This study aims to determine the mastoid air cell system (MACS) volume and its relationship with middle ear structures, and the influence of sex. MATERIALS AND METHODS: A cross-sectional study was performed analyzing computed tomography (CT) scans in which MACS volume and the Estachian tube length (ETL) were visible. MACS volume, ETL, and width and height of the aditus ad antrum were obtained. RESULTS: A total of 100 CT were included with a mean age of 38.5 ± 15.3 years, of which 56 were women and 44 were men. The mean right and left MACS volume were 5.43 ± 3.15 cm³ and 5.54 ± 3.43 cm3 respectively , with a ETL of 24.55 ± 3.07 mm in right side and 24.24 ± 2.60 mm on left side. A aditus ad antrum width of 2.98 ± 0.65 in right and 2.98 ± 0.58 on the left and height of 4.51 ± 1.05 and 4.32 ± 0.85, on right and left side respectively. There were statistical differences between sexes in left ETL, and in MACS volume bilaterally. A low positive correlation between aditus ad antrum height and MACS volume was identified. CONCLUSIONS: Mastoid pneumatization was bigger in men than women. There was a low positive correlation between mastoid volume and ETL on both sides, and a significant correlation between right mastoid volume and aditus ad antrum height. This could lead us to believe that the length of ETL does not affect the pneumatization of MACS.

Consistent spatial lesion-symptom patterns: A comprehensive analysis using triangulation in lesion-symptom mapping in a cohort of stroke patients.

INTRODUCTION: The relationship between brain lesions and stroke outcomes is crucial for advancing patient prognosis and developing effective therapies. Stroke is a leading cause of disability worldwide, and it is important to understand the neurological basis of its varied symptomatology. Lesion-symptom mapping (LSM) methods provide a means to identify brain areas that are strongly associated with specific symptoms. However, inner variations in LSM methods can yield different results. To address this, our study aimed to characterize the lesion-symptom mapping variability using three different LSM methods. Specifically, we sought to determine a lesion symptom core across LSM approaches enhancing the robustness of the analysis and removing potential spatial bias. MATERIAL & METHODS: A cohort consisting of 35 patients with either right- or left-sided middle cerebral artery strokes were enrolled and evaluated using the NIHSS at 24 h post-stroke. Anatomical T1w MRI scans were also obtained 24 h post-stroke. Lesion masks were segmented manually and three distinctive LSM methods were implemented: ROI correlation-based, univariate, and multivariate approaches. RESULTS: The results of the LSM analyses showed substantial spatial differences in the extension of each of the three lesion maps. However, upon overlaying all three lesion-symptom maps, a consistent lesion core emerged, corresponding to the territory associated with elevated NIHSS scores. This finding not only enhances the spatial accuracy of the lesion map but also underscores its clinical relevance. CONCLUSION: This study underscores the significance of exploring complementary LSM approaches to investigate the association between brain lesions and stroke outcomes. By utilizing multiple methods, we can increase the robustness of our results, effectively addressing and neutralizing potential spatial bias introduced by each individual method. Such an approach holds promise for enhancing our understanding of stroke pathophysiology and optimizing patient care strategies.

Imagen del tensor de difusión de la vía corticoespinal y su asociación con el pronóstico del infarto cerebral agudo: experiencia de una cohorte en México / Diffusion tensor imaging of the corticospinal pathway and its association with the prognosis of acute cerebral infarction: experience with a cohort in Mexico

INTRODUCCIÓN: La imagen del tensor de difusión por resonancia magnética a través de la fracción de anisotropía permite evaluar la integridad de las vías motoras después de un infarto cerebral. OBJETIVO: Correlacionar la fracción de anisotropía con las escalas clínicas y el pronóstico del infarto cerebral. Sujetos y métodos: Estudio prospectivo de pacientes con infarto cerebral para comparar la fracción de anisotropía en diferentes regiones de interés con evaluaciones funcionales y con controles sin infarto. En un subgrupo con rehabilitación, se realizó una resonancia magnética inicial y a los tres meses, con un seguimiento clínico durante seis meses. RESULTADOS: Se incluyó a 38 pacientes consecutivos con infarto cerebral de la arteria cerebral media. Los valores de la fracción de anisotropía fueron menores en la vía corticoespinal ipsilateral que en la vía corticoespinal de los controles. Los valores de la fracción de anisotropía en la vía corticoespinal ipsilateral se asociaron con el valor de la escala funcional en el momento de su admisión. Los cambios en los valores de la fracción de anisotropía entre la resonancia magnética inicial y a los tres meses se correlacionaron con la puntuación en la escala funcional y en la escala de Rankin modificada a los tres y a los seis meses. CONCLUSIONES: El valor de la fracción de anisotropía en la cápsula interna ipsilateral se asocia a la presencia de lesión y a su presentación clínica. Los cambios en la fracción de anisotropía a los tres meses sugieren la recuperación clínica a largo plazo

INTRODUCTION: Magnetic resonance diffusion tensor imaging through the fraction of anisotropy allows evaluation of the integrity of the motor pathways after cerebral infarction. AIMS. To correlate the fraction of anisotropy with the clinical scales and the prognosis of cerebral infarction. SUBJECTS AND METHODS: Prospective study of patients with cerebral infarction to compare the fraction of anisotropy in different regions of interest with functional evaluations and with controls free of infarction. A subgroup of subjects with rehabilitation underwent an initial MRI scan and another at three months, with clinical follow-up for six months. RESULTS: Thirty-eight consecutive patients with middle cerebral artery infarction were included. The fraction of anisotropy values were lower in the ipsilateral corticospinal pathway than the fraction of anisotropy of the corticospinal pathway of the controls. The values of the fraction of anisotropy in the ipsilateral corticospinal pathway were associated with the value of the functional scale on admission. Changes in the fraction of anisotropy values between the initial MRI and the scan performed at three months correlated with the score on the functional scale and the modified Rankin scale at three and six months. CONCLUSIONS: The value of the fraction of anisotropy in the ipsilateral internal capsule is associated with the presence of a lesion and with its presenting symptoms. Changes in the fraction of anisotropy at three months suggest long-term clinical recovery

Prevalence of facial canal dehiscence and other bone defects by computed tomography.

INTRODUCTION: The facial nerve is the most vulnerable structure during otological surgeries. Facial canal dehiscence (FCD) is the main risk factor for iatrogenic injuries. Its prevalence in clinical studies ranges between 6 and 33.3%, while anatomical studies report 25-57%. The objective was to determine the prevalence of FCD stratified by age and gender in a healthy population. MATERIALS AND METHODS: Temporal bones from high-resolution computed tomography (CT) were analyzed. Patients with a history of trauma or tumors of the temporal bone, cholesteatomas, chronic middle ear disease, and any pathology that could modify the bone's anatomy, were excluded. RESULTS: A total of 184 temporal bones were included. FCD was observed in 94 (51.2%) of the analyzed bones. The tympanic portion was the most frequently affected site with 91 (49.5%), followed by the mastoid segment with 3 (1.6%). No dehiscence was found in the labyrinth portion. We observed 30 (31.9%) of the FCD involved the oval window. Other bone defects identified with the FCD included: 11 (11.7%) with a lateral semicircular canal fistula and 7 (7.4%) with tegmen tympani erosions. CONCLUSION: FCD has a high prevalence among healthy patients. A pre-surgical otological evaluation using high-resolution CT should be indicated to properly assess the patient and reduce the risk of injury.

Does axillary lymph node size predict better metastatic involvement than apparent diffusion coefficient (ADC) value in women with newly diagnosed breast cancer?

BACKGROUND: It has been demonstrated that the number of metastatic axillary lymph nodes (mALNs) influence disease-free and overall survival in patients with breast cancer. PURPOSE: To determine if the ALN size is more accurate than the ALN apparent diffusion coefficient (ADC) value to predict metastatic involvement in newly diagnosed breast cancer. MATERIAL AND METHODS: A total of 44 patients with breast cancer were included. Magnetic resonance imaging (MRI) examinations were performed on a 1.5-T system with sagittal T1-weighted fast spin-echo non-fat saturated, sagittal T2-weighted fast spin-echo non-fat saturated, axial diffusion-weighted imaging echo-planar (b values of 0 and 700 s/mm2), and non-contrast axial VIBRANT sequences. The size and the ADC value were obtained for ALN ipsilateral and contralateral to breast cancer. The reference standard was the histopathologic lymph node status. RESULTS: mALN had a greater cortical thickness compared to contralateral non-mALN (10.3 ± 5.32 mm vs. 4 ± 1.17 mm, P ≤ 0.001). The threshold of ≥6.7 mm for predicting axillary metastatic involvement had a sensitivity and a specificity of 80.0% and 97.7%, respectively. The ADC value of mALN was significantly higher than the contralateral non-mALN (0.90 ± 0.12 × 10-3mm2/s vs. 0.78 ± 0.12 × 10-3mm2/s; P = 0.001). The threshold of ≥0.86 × 10-3mm2/s had a sensitivity and a specificity of 66.7% and 76.7%, respectively. CONCLUSION: Our results indicate that the cortical thickness has a better diagnostic performance in the differentiation of metastatic and non-metastatic lymph nodes than the lymph node ADC.

Impact of bilateral nasal polyposis on the interoptic and interzygomatic distance.

PURPOSE: To identify and determine variations on eye distance in patients with bilateral nasal polyposis (BNP) compared to a healthy control group. METHODS: This is a case-control study that included 20 BNP patients and 40 healthy controls. We included all patients with BNP confirmed by pathology and a computed tomography scan. A healthy control group was admitted, filtered by the exclusion criteria of nasal polyposis, craniofacial malformations, and encephalocele. Paranasal sinus CT scans were performed in all participants, and two measures were evaluated, the interoptic (soft tissue) and the interzygomatic (bone structure) distances. RESULTS: A total of 20 BNP subjects, 13 (65%) male and 7 (35%) female, with a mean age of 38.8 years, and 40 healthy controls, 16 (40%) male and 24 (60%) female with a mean age of 43.2 years, were included. The mean interoptic distance was 69.7 mm (71.9 mm men, 66.4 mm women) and interzygomatic distance was 103.1 mm (104.5 mm men, 100.6 mm women). A significant increase of the interoptic (p < 0.001) and interzygomatic (p < 0.002) measurements was found in patients with polyposis compared to the controls. In the receptor operative curve analysis, the interoptic distance had an area under a curve of 96% and the threshold that maximizes the sensitivity and specificity was 59.85 mm (sensitivity 90%, specificity 95%, PPV 90%, NPV 95%). CONCLUSIONS: An increase in ocular and orbital distances was identified in patients with BNP. Polyposis may be identified by measuring eye separation. The established cut point distance identifies patients that may benefit from follow-up. Further research in this study line is suggested.

Anatomical variations of the ethmoidal roof: differences between men and women.

AIM: During the paranasal sinuses surgery different complications may occur, both vascular and bony. The objective of the present study was to evaluate the ethmoidal roof configuration through the Keros and Yenigun classifications, analyzing results stratified by gender and side. MATERIALS AND METHODS: We retrospectively analyzed 120 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in a coronal view and the anterior-posterior length in a cross section. RESULTS: The Keros Type II was the most frequent and no statistically significant difference was found when comparing by gender. Yenigun type I was more prevalent, and a statistically significant difference was found between men and women in types I and II (p = 0.010 and p = 0.049, respectively). Statistical difference was observed in anterior-posterior means in the comparison between both classifications. In both, right and left side for men (p = 0.003 and p = 0.05) and women (p = 0.029 and p = 0.039). CONCLUSION: We demonstrate the morphological variability that exists in this region. Gender differences that must be considered by the surgeon to avoid complications. Further studies are needed to evaluate the value of these findings when predicting surgical complications. A CT before PNS surgery is already widely accepted.

Imagen por resonancia magnética en lesiones de la base del cráneo / Magnetic resonance imaging of skull base lesions

Se revisaron las características de las imágenes por resonancia magnética (IMR) de 55 lesiones que involucraban la base del cráneo a nivel intra y/o extracraneal. No se consideraron las lesiones de origen intraaxial. Se valoró la utilidad de la IRM en la extensión y posible caracterización de las mismas. La mayor parte de los tumores presentaban prolongación en sus tiempos de relajación; sin embargo, los tumores de origen fibro-óseo se demostraron como lesiones de baja señal en imágenes dependientes de T1 y T2. Presentaron escaso o nulo edema cerebral y fueron fácilmente detectadas las alteraciones del parénquima cerebral, sin embargo no siempre fue posible diferenciar entre edema perilesional o invasión. La IRM con su capacidad multiplanar, permitieron un análisis detallado de los contornos tumorales, el comportamiento en intensidades, la valoración en las extensiones, que en conjunto con los hallazgos clínicos llevan a un refinamientoi en el diaagnóstico diferencial.