Lung Ultrasound Elastography by SWE2D and "Fibrosis-like" Computed Tomography Signs after COVID-19 Pneumonia: A Follow-Up Study

The aim of this study was to assess the shear wave velocity by LUS elastography (SWE2D) for the evaluation of superficial lung stiffness after COVID-19 pneumonia, according to "fibrosis-like" signs found by Computed Tomography (CT), considering the respiratory function. Seventy-nine adults participated in the study 42 to 353 days from symptom onset. Paired evaluations (SWE2D and CT) were performed along with the assessment of arterial blood gases and spirometry, three times with 100 days in between. During the follow-up and within each evaluation, the SWE2D velocity changed over time (MANOVA, p < 0.05) according to the extent of "fibrosis-like" CT signs by lung lobe (ANOVA, p < 0.05). The variability of the SWE2D velocity was consistently related to the first-second forced expiratory volume and the forced vital capacity (MANCOVA, p < 0.05), which changed over time with no change in blood gases. Covariance was also observed with age and patients' body mass index, the time from symptom onset until hospital admission, and the history of diabetes in those who required intensive care during the acute phase (MANCOVA, p < 0.05). After COVID-19 pneumonia, SWE2D velocity can be related to the extent and regression of "fibrotic-like" involvement of the lung lobes, and it could be a complementary tool in the follow-up after COVID-19 pneumonia.

[Answer to "Comment on article: "Correlation between ultrasonography and thorax portable radiography in patients with COVID-19""]

Science, through scientific research, is an activity that generates new ideas. However, for the construction of new knowledge it is necessary to confront ideas with peers in the scientific world; which is exercised through scientific communication.

[ROC curves: general characteristics and their usefulness in clinical practice]

The use of diagnostic tests to determine the presence or absence of a disease is essential in clinical practice. The results of a diagnostic test may correspond to numerical estimates that require quantitative reference parameters to be transferred to a dichotomous interpretation as normal or abnormal and thus implement actions for the care of a condition or disease. For example, in the diagnosis of anemia it is necessary to define a cut-off point for the hemoglobin variable and create two categories that distinguish the presence or absence of anemia. The method used for this process is the preparation of diagnostic performance curves, better known by their acronym in English as ROC (Receiver Operating Characteristic). The ROC curve is also useful as a prognostic marker, since it allows defining the cut-off point of a quantitative variable that is associated with greater mortality or risk of complications. They have been used in different prognostic markers in COVID-19, such as the neutrophil/lymphocyte ratio and D-dimer, in which cut-off points associated with mortality and/or risk of mechanical ventilation were identified. The ROC curve is used to evaluate the diagnostic performance of a test in isolation, but it can also be used to compare the performance of two or more diagnostic tests and define which one is more accurate. This article describes the basic concepts for the use and interpretation of the ROC curve, the interpretation of an area under the curve (AUC) and the comparison of two or more diagnostic tests.

[Correlation between ultrasonography and thorax portable radiography in patients with COVID-19]

BACKGROUND

During the COVID-19 pandemic, portable chest radiography (portable CRx) and lung ultrasonography (LUS) have been widely used to follow up hospitalized patients. Yet, it is scarce the information about the relation between the signs observed by means of each method in patients with COVID-19.

OBJECTIVE

To assess the correlation between concurrent images acquired by LUS and portable CRx during the follow-up of hospitalized patients with COVID-19.

MATERIAL AND METHODS

We performed 113 LUS and 113 corresponding CRx during the follow-up of 44 patients (30 men/14 women, 30-85 years old) with COVID-19 (RT-qPCR). Images were stored in a picture communication system and were revised by two specialists of each imaging method independently. Statistical analysis was performed using Gamma correlation and t test (significance level of 0.05).

RESULTS

The most frequent LUS sign was confluent B lines, and it was related to the most frequent portable CRx signs (ground-glass opacities and consolidations). An inverse relationship was observed between A lines (gas in the lungs) and B7 lines (suggestive of interstitial edema). Confluent B lines also showed a strong inverse correlation with A lines (more frequent confluent B lines were related to low frequent A lines), a moderate inverse correlation with B7 lines, and a mild inverse correlation with B3 lines.

CONCLUSION

During the follow-up of hospitalized patients with COVID-19, LUS and portable CRx may complement each other to provide information about lung damage.

Risk factors associated with thyroid nodular disease in acromegalic patients: A case-cohort study in a tertiary center

INTRODUCTION

Goiter is very common in patients with acromegaly; its development is correlated to the duration of the disease. Thyroid cells express the IGF-1 receptor and the TSH/IGF-1 interaction has been demonstrated to have a synergistic effect in thyroid cell growth. There is a correlation between IGF-1 levels and the thyroid volume of patients with acromegaly. The aim of this study was to evaluate, in a retrospective case-cohort study of patients with acromegaly, the associated risk factors for thyroid nodules disease in this population.

METHODS

This was a case-cohort study matched by age, gender, and growth hormone at diagnosis. Cases consisted of acromegalic patients that developed thyroid nodules during the follow up, and controls consisted in acromegalic patients without thyroid nodules. A Cox proportional hazard estimation was carried out for measure the associated risk factors for thyroid nodules disease in acromegalic patients. A nodular thyroid disease-free survival analysis was estimated using the Kaplan-Meier analysis.

RESULTS

We recruited 49 cases and 56 controls. In a multivariate Cox proportional hazard analysis age and IGF-1 ≥ 2.2 x ULN were significantly related with the presence of thyroid nodules [HR of 2.21 (95% CI; 1.15-4.25, p = 0.01)]. Nodularity-free survival rates in patients who had an IGF-1 X ULN ≥ 2.2 was found to be lower in comparison to those who had IGF-1 X ULN < 2.2, according to a Kaplan-Meier survival analysis.

CONCLUSIONS

Our findings support that exist more probability to develop thyroid nodular disease in patients with acromegaly that present IGF-1 X ULN ≥ 2.2, suggesting a possible direct effect between the time of exposure to the IGF-1 axis hyperactivity and the genesis of thyroid nodules.

Shear-wave elastography as a tool in the assessment of thyroid nodules

INTRODUCTION

Shear-wave elastography (SWE) has been shown to be predictive of malignancy in thyroid nodules.

OBJECTIVE

To determine, by SWE, the stiffness cutoff point with the highest specificity and sensitivity to detect thyroid nodules that require surgery.

METHODS

Cross-sectional study of ultrasonographically-evaluated patients for thyroid nodules over a period of three years; the TI-RADS classification system was used, and nodule stiffness was determined by SWE. Histopathological specimens were classified using the Bethesda system, and the stiffness cutoff point with the highest specificity and sensitivity was obtained using ROC curves.

RESULTS

Forty-one percent of the nodules were classified as TI-RADS 5, and 59 %, as TI-RADS 1-4. In TI-RADS 5 nodules, median stiffness of those in Bethesda system IV-VI categories was 35.9 kPa; in nodules with TI-RADS 1-4, 21.6 kPa. In TI-RADS 5 nodules, a cutoff point > 32.5 kPa had a specificity of 75 % and sensitivity of 57 % to detect those requiring surgery; in TI-RADS 1 to 4 nodules, a cutoff point of 21.5 kPa had a specificity of 63 % and sensitivity of 51 %.

CONCLUSION

SWE-determined stiffness is useful to detect nodules that require surgical evaluation.

Double-task exercise programmes to strengthen cognitive and vascular health in older adults at risk of cognitive decline: protocol for a randomised clinical trial

INTRODUCTION

Cognitive and physical declines are frequent causes of disability among older adults (OAs) in Mexico that imposes significant burden on the health system and OAs' families. Programmes to prevent or delay OAs' cognitive and physical decline are scarce.

METHODS AND ANALYSIS

A double-blind randomised clinical trial will be conducted. The study will aim to evaluate two 24-week double-task (aerobic and cognitive) square-stepping exercise programmes for OAs at risk of cognitive decline-one programme with and another without caregiver participation-and to compare these with an aerobic-balance-stretching exercise programme (control group). 300 OAs (100 per group) affiliated with the Mexican Institute of Social Security (IMSS) between 60 and 65 years of age with self-reported cognitive concerns will participate. They will be stratified by education level and randomly allocated to the groups. The intervention will last 24 weeks, and the effect of each programme will be evaluated 12, 24 and 52 weeks after the intervention. Participants' demographic and clinical characteristics will be collected at baseline. The outcomes will include: (1) general cognitive function; (2) specific cognitive functions; (3) dual-task gait; (4) blood pressure; (5) carotid intima-media thickness; (6) OAs' health-related quality of life; and (7) caregiver burden. The effects of the interventions on each outcome variable will be examined using a repeated-measures analysis of variance (ANOVA), with study groups as the between-subjects variable and time as the within-subject variable.

ETHICS AND DISSEMINATION

The study was approved by the IMSS Ethics and Research Committees (registration number: 2018-785-095). All participants will sign a consent form prior to their participation. The study results will be disseminated to the IMSS authorities, healthcare providers and the research community.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04068376).

[Elastography in the evaluation of thyroid nodules]

BACKGROUND

Thyroid nodules are a very common pathology in clinical practice and in imaging studies. Autopsy results indicate a 50% prevalence of thyroid nodules greater than 1 cm in patients with no clinical symptomatology. The goal is to evaluate the accuracy of elastography in the evaluation of thyroid nodules with suspicion of malignancy by comparing the results obtained in qualitative and semi-quantitative elastography with the cytopathological study obtained by BAAF of thyroid nodules and The TI-RADS system.

METHODS

We included male or female patients over 18 years old, entitled to IMSS, with diagnosis of one or more thyroid nodules, sent to the ultrasound service for FNA and histopathological report at the end of the study. In the statistical analysis, values of sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) were obtained.

RESULTS

The results showed that the qualitative elastography by the Asteria Score presents a sensitivity of 86% and a specificity of 53%, PPV of 36% and NPV of 92% , for the semiquantitative elastography a sensitivity of 40%, specificity of 87%, PPV of 50% and NPV of 82%.

CONCLUSIONS

The elastography in its qualitative and semicuantitative mode are useful to help determine the possibility of malignancy of thyroid nodules as an additional element to ultrasound, but it does not replace the citopathologic result or other diagnostic tests, so it should not be taken as a single test. Additionally the high result of NPV is useful to dismiss the possibility of malignancy.