Radiologia Brasileira最新文献

Objective: To perform an agreement analysis between volBrain and HIPS software for measuring hippocampal volume and its associated asymmetry index.

Materials and methods: We evaluated volumetric T1-weighted magnetic resonance imaging scans from radiologically normal subjects (n = 50; age range, 25-75 years). Correlation and Bland-Altman plots were generated. The Pearson correlation coefficient (r) and the intraclass correlation coefficient of absolute agreement between volBrain and HIPS software were calculated for each measurement.

Results: For each hippocampus and its combined volume, a very high correlation was found between the methods (r ≥ 0.96 for absolute values and r ≥ 0.93 for relative values), along with a systematic bias (primarily additive). Consistently, HIPS (with the Kulaga-Yoskovitz protocol) reported smaller volumes than did volBrain. The average difference ranged from 8.2% to 9.1% for absolute values and from 7.9% to 8.7% for relative values. The asymmetry index exhibited a strong correlation (r = 0.82) with no significant bias, although 14% of cases showed opposite signs. The average asymmetry index difference was 32.7%. The intraclass correlation coefficient of absolute agreement ranged from 0.61 to 0.83, reflecting moderate to good agreement overall.

Conclusion: Our results indicate that the two methods are not interchangeable for evaluating hippocampal volume and its associated asymmetry index.

Objective: The purpose of this study was to evaluate the agreement between and reproducibility of specific two-dimensional (2D) and three-dimensional (3D) ultrasound methods in assessing cervical volume in pregnant women in their second trimester.

Materials and methods: This was a prospective cross-sectional study of 48 asymptomatic pregnant women at 20-24 weeks of gestation. All cervical volumes were determined by transvaginal ultrasound, with a 2D method employing a geometric formula {π * [(anteroposterior diameter + transverse diameter) * ¼] * length}, where π = 3.14, and a 3D method employing a virtual organ computer-aided analysis. Intraobserver and interobserver reliability was analyzed by calculating the intraclass correlation coefficient (ICC).

Results: The mean maternal age and timing of the ultrasound examination were 26 ± 6 years and 21 ± 1 weeks of gestation, respectively. The mean cervical volumes measured by the 2D and 3D ultrasound methods were 27.71 ± 9.27 cm³ and 35.21 ± 8.85 cm³, respectively. Cervical length and volume showed a positive correlation with both methods-r = 0.77 (p < 0.001) and r = 0.70 (p < 0.001), respectively. Intraobserver reliability was excellent for both methods, with ICCs of 0.92 and 0.93 for the 2D and 3D methods, respectively. Interobserver reliability was good (ICC: 0.81) for the 3D method, whereas it was poor (ICC: 0.37) for the 2D method. Reproducibility of the transverse diameter measurement was low, with an intraobserver ICC of 0.41 and an interobserver ICC of 0.48.

Conclusion: Cervical volume measurements obtained with 2D and 3D ultrasound methods seem to show satisfactory agreement and good intraobserver reliability. In our study sample, the 2D ultrasound method showed low interobserver reliability, whereas the 3D ultrasound method was more reliable, with good intraobserver and interobserver reliability.

Takotsubo cardiomyopathy is an important differential diagnosis for acute chest pain. Imaging tests, such as ventriculography, echocardiography, computed tomography of the heart, and cardiac magnetic resonance, are valuable tools for diagnostic confirmation in this context. This study reviews the literature and exemplifies the spectrum of typical and atypical cardiac magnetic resonance findings in this disease, on the basis of the experience of our facility. Recognition of these characteristics underscores the roles that radiologists and cardiologists play in the care of patients with acute chest pain, enabling an accurate diagnosis and appropriate treatment.

Objective: To determine the proportion of men with completely negative multiparametric magnetic resonance imaging (MRI) scans and which individual sequence-T2-weighted imaging (T2WI) or diffusion-weighted imaging (DWI)-best predicts an overall negative examination result.

Materials and methods: This was a single-center retrospective study evaluating 492 MRI scans compliant with Prostate Imaging Reporting and Data System (PI-RADS), version 2.1. Radiology reports described the absence of lesions or suspicious lesions with PI-RADS scores of 3-5, signifying positive T2WI or DWI results. Positivity on a dynamic contrast-enhanced (DCE) study was determined by early or simultaneous focal enhancement consistent with lesions on T2WI or DWI. All scans reported as negative were prospectively reviewed to ensure that each sequence truly met the criteria for negativity according to the PI-RADS guidelines. Descriptive statistics were employed to summarize the data, and the chi-square test was employed to assess the relationship between a negative T2WI result and a negative DWI/DCE result, as well as that between a negative DWI result and a negative DWI/DCE result, with logistic regression models identifying predictors of such combined results.

Results: Among the patients evaluated, approximately one-third of those with suspected prostate cancer and 10% of those with known cancer could have concluded their examination after a single negative sequence. A negative T2WI result predicted negative DWI/DCE findings in 62.4% of scans (95% CI: 55.3-68.9), with an odds ratio of 245.3 (p < 0.001). Similarly, a negative DWI result predicted negative T2WI/DCE findings in 88.9% of scans (95% CI: 83.1-92.7) with an odds ratio of 76.4 (p < 0.001). These associations remained robust after adjustment for age, prostate-specific antigen level, prostate-specific antigen density, cancer status, and radiologist.

Conclusion: Findings from T2WI or DWI may serve as preliminary indicators for the subsequent diagnostic yield of other sequences, with DWI appearing to hold a slight advantage. Although the accuracy of this approach is not yet sufficient for clinical implementation, these results are promising and merit further investigation.

Objective: To characterize the main causes of the reversed halo sign (RHS) on computed tomography (CT) of the chest and its imaging features.

Materials and methods: This was a retrospective study reviewing all chest CT scans for which the report contained the term "reversed halo sign" among those performed between 2015 and 2020 at a tertiary care hospital.

Results: A total of 286 cases were identified, and the corresponding CT images and clinical data were reviewed. In this population, the most common cause of an RHS was pulmonary infarction (in 42%), followed by cryptogenic organizing pneumonia (in 17%) and bacterial pneumonia (in 16%). In addition, the CT characteristics of the RHS were identified in various conditions, such as pulmonary thromboembolism with pulmonary infarction, in which the RHS was typically smooth-walled and solitary with a peripheral distribution.

Conclusion: The RHS can be observed in many contexts, and its CT characteristics, in combination with the clinical picture, can help narrow the differential diagnosis.

Objective: To evaluate the frequency of the typical computed tomography (CT) pattern in individuals with coronavirus 2019 (COVID-19), comparing those who were vaccinated with those who were unvaccinated.

Materials and methods: This was a retrospective study of the medical records of patients with clinical suspicion of COVID-19 between August 2021 and February 2022. The vaccination status was classified as absent/incomplete (0 or 1 dose) or complete (2 or more doses). The pattern seen on the first chest CT was defined as typical, atypical, indeterminate, or normal, the last three patterns being combined to form what was designated the non-typical group.

Results: Binary logistic regression analysis showed that individuals with a complete vaccination status were less likely to present with the typical CT pattern than were those with an absent/incomplete vaccination status (adjusted OR = 0.19, 95% CI: 0.06-0.60).

Conclusion: This information is important because it demonstrates that the frequency of the CT pattern considered typical of COVID-19 is currently lower than it was before the vaccines became available. Therefore, the typical CT pattern is no longer expected.

The anatomy of the sural nerve is highly variable, and the nerve can present injuries of various etiologies, including iatrogenic injury during surgery. Precise knowledge of the course and morphology of the sural nerve is valuable, and the ability to assess the nerve properly before surgery increases the postoperative success rate, as well as facilitating the execution of nerve conduction studies and biopsies. The purpose of this article is to describe and illustrate the anatomy of the sural nerve, as seen on ultrasonography, which is a practical and economical imaging method.