Morphometric variants of the paranasal sinuses in a Mexican population: expected changes according to age and gender

BACKGROUND

There are developmental variations in the paranasal sinuses. Our objective is to determine their dimensions and volume stratified by age and sex and define the expected growth pattern.

MATERIALS AND METHODS

A retrospective, observational study was performed including computed tomography (CT) of patients between 1 and 20 years of age. The volumes of the frontal, sphenoid, and maxillary sinuses were obtained.

RESULTS

A total of 210 CT were included with a mean age of 10±6.1 years, 106(50.5%) were female. Groups were categorized in ranges of 5 years. Spearman correlation coefficients between the right and left sides were 0.843, 0.711, 0.916 for the frontal, sphenoid and maxillary sinuses. Post-hoc for the categorical age groups demonstrated statistically significant differences with values of p < 0.01, except between age groups 11-15 against ≥ 16 years of age (p = 0.8). Gender-related differences were evident with a higher air volume in girls in the 5-10-year-old group, while boys predominated in the rest of the groups.

CONCLUSIONS

CT is ideal for pre-surgical sinus assessment. The maximum volume of paranasal sinuses is reached at age 15. There is a clear volumetric difference between age and gender groups. There is a direct relationship between a volume and its contralateral counterpart.

[Diffusion tensor imaging of the corticospinal pathway and its association with the prognosis of acute cerebral infarction: experience with a cohort in Mexico]

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.

Comparison of Gadoterate Meglumine and Gadobutrol in the MRI Diagnosis of Primary Brain Tumors: A Double-Blind Randomized Controlled Intraindividual Crossover Study (the REMIND Study)

BACKGROUND AND PURPOSE

Effective management of patients with brain tumors depends on accurate detection and characterization of lesions. This study aimed to demonstrate the noninferiority of gadoterate meglumine versus gadobutrol for overall visualization and characterization of primary brain tumors.

MATERIALS AND METHODS

This multicenter, double-blind, randomized, controlled intraindividual, crossover, noninferiority study included 279 patients. Both contrast agents (dose = 0.1 mmol/kg of body weight) were assessed with 2 identical MRIs at a time interval of 2-14 days. The primary end point was overall lesion visualization and characterization, scored independently by 3 off-site readers on a 4-point scale, ranging from "poor" to "excellent." Secondary end points were qualitative assessments (lesion border delineation, internal morphology, degree of contrast enhancement, diagnostic confidence), quantitative measurements (signal intensity), and safety (adverse events). All qualitative assessments were also performed on-site.

RESULTS

For all 3 readers, images of most patients (>90%) were scored good or excellent for overall lesion visualization and characterization with either contrast agent; and the noninferiority of gadoterate meglumine versus gadobutrol was statistically demonstrated. No significant differences were observed between the 2 contrast agents regarding qualitative end points despite quantitative mean lesion percentage enhancement being higher with gadobutrol (P < .001). Diagnostic confidence was high/excellent for all readers in >81% of the patients with both contrast agents. Similar percentages of patients with adverse events related to the contrast agents were observed with gadoterate meglumine (7.8%) and gadobutrol (7.3%), mainly injection site pain.

CONCLUSIONS

The noninferiority of gadoterate meglumine versus gadobutrol for overall visualization and characterization of primary brain tumors was demonstrated.

Thyroid nodules in Hispanic patients with systemic lupus erythematosus

A thyroid nodule (TN) is a discrete lesion in the thyroid gland radiologically distinct from the adjacent parenchyma, with a prevalence variable depending on the diagnostic method used and the study population. Thyroid disorders have been identified in more than 50% of patients with systemic lupus erythematosus (SLE); however, the prevalence of TN has not been frequently studied. We identified a prevalence of 27% TN in 55 SLE patients > 16 years of age. One-third of TN were >1 cm with radiological features of malignancy. The mean age of patients with TN was 39 ± 11 years, 93% women, and SLE duration 10 ± 6 years. Among patients, we reported family history of cancer in three cases (20%), thyroid disease in one (7%), and autoimmune disease in six (40%). Regarding treatment, 50% of patients with TN were treated with azathioprine vs. 23% of patients without TN (p = 0.02), with an OR of 3.94 (95% CI 1.12-13.84, p = 0.03). As a conclusion a high prevalence of TN in SLE patients was found. Prevalence of TN correlated only with history of azathioprine use. We don't know the long-term implications of our findings; however, a functional and morphological evaluation of the thyroid gland is warranted in all patients with SLE.

[Vertebral fixation with a transpedicular approach. Relevance of anatomical and imaging studies]

The number of patients with spine conditions has grown exponentially in recent years leading to an increase in the number of cases requiring surgical treatment. Currently vertebral fusion surgery with a transpedicular approach represents the most commonly used technique to treat any type of vertebral disorder. The morphometric characteristics of vertebrae, particularly the pedicle, determine the size of pedicular implants, including width and length, as well as the shape and direction of the screw and its ideal angulation at the time of introduction. Knowing these characteristics is important to prevent injuring important adjacent structures and to decrease the postoperative complication rate. In recent decades numerous studies on the morphometric characteristics of the vertebral pedicle have been conducted in different populations to determine its real dimensions by means of direct measurement and imaging methods. These studies have concluded that there are significant differences in these measurements among the different ethnic groups, races, genders, ages and the vertebral regions studied. This paper analyzes the different morphometric studies of the pedicle and all the other vertebral elements studied in Mexico and the rest of the world and explain the importance of their knowledge and surgical application for the correct development of vertebral fusion surgery with a transpedicular approach.

Enhanced T1 differentiation between normal and dystrophic muscles

Proton spin-lattice relaxation times (T1) of pectoralis major muscles from normal (Line 412) and homozygous dystrophic (Line 413) chicks was measured by FONAR QED 80 at 1.69 MHz. The T1 values of dystrophic muscles (216.8 +/- 17.3 ms) was two-fold higher than those of normal muscles (110.2 +/- 8.1 msec). When these values were compared with the T1 values obtained at high frequencies (20 MHz and 32 MHz), the T1 differentiation between normal and dystrophic muscles was considerably enhanced at 1.69 MHz. Based on these results, we suggest that the high resolution of T1 obtained at low frequency (1.69 MHz) could be effectively used to detect the degenerative processes in muscles by the NMR techniques.