Nestor de Barros

The value of teaching sectional anatomy to improve CT scan interpretation.

A specific course on sectional anatomy was developed to help medical students improve their knowledge of cross‐sectional imaging. The educational methodology consists of identifying anatomical structures displayed in plastinated sections from human cadavers and corresponding anatomical structures in computed tomography (CT) sections from healthy patients. The course has a self‐study format. To assess and verify the impact of learning sectional anatomy on radiological knowledge, students were asked to identify ten anatomical structures in CT images. This test was applied to two groups of students: Group I had been taught sectional anatomy with CT images 2 years before the test; Group II had not received instruction in sectional anatomy prior to the test. Analysis of the results revealed a significant difference in test scores (median percentages of correctly identified structures) between Group I and Group II, with scores of 100% and 63.4%, respectively. These results provide evidence that the inclusion of sectional anatomy training in medical school curricula has a great impact on subsequent CT interpretation. Clin. Anat. 14:36–41, 2001.

Thyroid nodules: Evaluation with power Doppler and duplex Doppler ultrasound:

This study purposes a new classification of thyroid nodules blood flow by power duplex Doppler ultrasound. A total of 177 nodules were studied with B-mode scanning, power Doppler, and spectral analysis. These data were compared with cytological results from ultrasound-guided fine-needle aspiration biopsy. Univariate and multivariate logistic regression analysis were performed. The power Doppler analysis of the nodules produced 5 vascular patterns: I, absence of signal blood flow; II, exclusively perinodular blood flow; III, perinodular > central blood flow; IV, central blood flow > perinodular blood flow; V, exclusively central blood flow. Statistical analysis revealed a significant relationship between these vascular patterns and cytological results. The spectral analysis demonstrated that the resistance index were higher in nodules with malignant versus other cytology (P >0.001). The results indicate that power duplex Doppler facilitates screening of thyroid nodules at high risk for malignancy with elevated sensitivity (92.3%) and specificity (88%).

Estudo Doppler na hipertensão portal

Ultrasonography and Doppler ultrasonography have dramatically improved the diagnosis of portal hypertension thanks to the noninvasive visualization of the liver, spleen and splanchnic blood flow. In this article the authors discuss some important issues raised by the use of ultrasound and Doppler in the evaluation of portal hypertension.

Mammography-based screening program: preliminary results from a first 2-year round in a Brazilian region using mobile and fixed units

BackgroundBreast cancer is the most frequently diagnosed cancer and the leading cause of cancer deaths among women worldwide. The use of mobile mammography units to offer screening to women living in remote areas is a rational strategy to increase the number of women examined. This study aimed to evaluate results from the first 2 years of a government-organized mammography screening program implemented with a mobile unit (MU) and a fixed unit (FU) in a rural county in Brazil. The program offered breast cancer screening to women living in Barretos and the surrounding area.MethodsBased on epidemiologic data, 54 238 women, aged 40 to 69 years, were eligible for breast cancer screening. The study included women examined from April 1, 2003 to March 31, 2005. The chi-square test and Bonferroni correction analyses were used to evaluate the frequencies of tumors and the importance of clinical parameters and tumor characteristics. Significance was set at p < 0.05.ResultsOverall, 17 964 women underwent mammography. This represented 33.1% of eligible women in the area. A mean of 18.6 and 26.3 women per day were examined in the FU and MU, respectively. Seventy six patients were diagnosed with breast cancer (41 (54%) in the MU). This represented 4.2 cases of breast cancer per 1000 examinations. The number of cancers detected was significantly higher in women aged 60 to 69 years than in those aged 50 to 59 years (p < 0.001) or 40 to 49 years (p < 0.001). No difference was observed between women aged 40 to 49 years and those aged 50 to 59 years (p = 0.164). The proportion of tumors in the early (EC 0 and EC I) and advanced (CS III and CS IV) stages of development were 43.4% and 15.8%, respectively.ConclusionsPreliminary results indicate that this mammography screening program is feasible for implementation in a rural Brazilian territory and favor program continuation.

Post-treatment malignant liver lesions: MR imaging☆

MR imaging is very accurate in the diagnosis and staging of tumors and in surgical planning. MR imaging is also an excellent method for evaluation of the liver after surgical resection, systemic or local tumor therapies, and liver transplantation. It permits early recognition of complications and the presence of recurrent tumor, providing an opportunity to repeat treatment or use alternative treatment. Surgical resection remains the standard therapy for treating liver metastases. The relatively small number of patients who are candidates for curative resection have provided impetus for the implementation and improvement of other techniques. The variety of techniques and the sensitivity for contrast enhancement have made MR imaging an ideal method to follow the response of tumors to various treatment approaches. The appearance of tumor recurrence and the response to treatment are relatively consistently shown on MR images; however, the time course of change in lesion appearance has not been fully elucidated, particularly in the setting of chemotherapy. Evaluating the response to chemotherapy is rendered complex because of the longer duration of the therapy, the types of response that various chemotherapeutic agents engender, the method of action of this therapy and the time of imaging in relation to therapy. The various local therapies share some general principles of action, and many have similar MR imaging findings. Some local therapies are effective only with certain malignancies (e.g., alcohol therapy and HCC), whereas other therapies are more limited because of the size of the tumor kill zone (e.g., interstitial laser therapy). We are in the early stages of using MR imaging to guide local therapies and to monitor response during treatment in real time. This appears to be an important future direction for MR imaging. The role of MR imaging in liver transplantation involves pre- and postoperative investigation of both donors (in the case of living-related transplantation) and recipients. These issues are described further in the section on MR imaging of liver transplantation.

Observer agreement of spine stenosis on magnetic resonance imaging analysis of patients with cervical spine myelopathy.

OBJECTIVES The purpose of this study was to measure the intraobserver and interobserver reliability of magnetic resonance detection of cervical spondylotic myelopathy with and without operational guidelines. METHODS Seven radiologists examined images from 10 patients with cord signal abnormalities and clinical signs of myelopathy. Radiologist examined films twice, with and without operational guidelines designed to define stenotic changes, while blinded to the clinical findings of the patients. Analyses included a Fleiss kappa assessment of intraobserver and interobserver reliability. RESULTS Results demonstrated high percentage of agreement and strong intraobserver reliability and variable Fleiss kappa values for interobserver assessment. Operational guidelines did not improve the intraobserver or interobserver agreement. CONCLUSION Although the percentage of agreement was high in some cases, the kappa agreement was low-most likely a result of the base rate problem of a kappa analysis. Sample bias toward severe degenerative changes resulted in highly prevalent selections and kappa adjusted values. Nonetheless, the results do suggest that substantial intraobserver kappa agreement and a wide range of interobserver kappa agreement exists among trained radiologists during detection of stenotic changes associated with cervical spondylotic myelopathy.

Evaluation of Pain in Three Hysterosalpingography Techniques: Metal Cannula With and Without Paracervical Blockage and Balloon Catheter

OBJECTIVE The objective of this study was to assess discomfort or pain in patients undergoing hysterosalpingography using three different techniques. SUBJECTS AND METHODS Eighty-nine patients were randomly assigned to one of three groups. In group 1, 30 patients underwent the technique performed with a metal cannula without anesthetic; in group 2, 29 patients underwent the technique performed with a metal cannula with previous paracervical anesthetic block; in group 3, 30 patients submitted to the procedure performed with a flexible balloon catheter. Each patient completed two questionnaires, Q1 and Q2: Q1 assessed their personal, clinical, and surgical history, and Q2 provided the visual analog scale (VAS) for pain assessment. The investigator also evaluated discomfort at each potentially painful stage of the procedure based on the patients verbal expression, physical manifestations, or both. RESULTS In terms of global discomfort experienced during hysterosalpingography, group 1 had the highest mean VAS score, whereas scores did not significantly differ between groups 2 and 3. During cervical grasping, group 2 experienced less discomfort than group 1. A comparison of pain associated with cervical grasping and balloon inflation (group 3 only) revealed that the highest levels of discomfort occurred during cervical grasping without anesthesia (group 1), followed by balloon inflation inside the cervix (group 3), and, last, cervical grasping after paracervical block (group 2). CONCLUSION Performing hysterosalpingography with a flexible balloon catheter or metal cannula with previous paracervical block produced similar levels of pain; however, both techniques appear to be more comfortable than the traditional technique (i.e., metal cannula without anesthesia).

Hemangiomas hepáticos: aspectos ultra-sonográficos e clínicos

Hemangiomas are the most common benign tumors of the liver, occurring in all age groups, and more frequently in adults. The vast majority of hemangiomas are small, asymptomatic, and are incidentally discovered. Larger lesions may eventually produce symptoms. The sonographic aspect of these tumors varies, the lesions being typically small, well defined and hyperechoic. In this study the authors review clinical and sonographic features of hemangiomas, highlighting the clinical significance of such features to be taken into consideration in the treatment of affected patients.

Can Doppler or contrast-enhanced ultrasound analysis add diagnostically important information about the nature of breast lesions?

OBJECTIVES: Despite evidence suggesting that Doppler ultrasonography can help to differentiate between benign and malignant breast lesions, it is rarely applied in clinical practice. The aim of this study was to determine whether certain vascular features of breast masses observed by duplex Doppler and color Doppler ultrasonography (before and/or after microbubble contrast injection) add information to the gray-scale analysis and support the Breast Imaging-Reporting and Data System (BI-RADS) classification. METHODS: Seventy solid lesions were prospectively evaluated with gray-scale ultrasonography, color Doppler ultrasonography, and contrast-enhanced ultrasonography. The morphological analysis and lesion vascularity were correlated with the histological results. RESULTS: Percutaneous core biopsies revealed that 25/70 (17.5%) lesions were malignant, while 45 were benign. Hypervascular lesions with tortuous and central vessels, a resistive index (RI)≥0.73 before contrast injection, and an RI≥0.75 after contrast injection were significantly predictive of malignancy (p<0.001). CONCLUSION: The combination of gray-scale ultrasonography data with unenhanced or enhanced duplex Doppler and color Doppler US data can provide diagnostically useful information. These techniques can be easily implemented because Doppler devices are already present in most health centers.

Value of computed tomography for evaluating the subglottis in laryngeal and hypopharyngeal squamous cell carcinoma

CONTEXT AND OBJECTIVE Subglottic involvement in squamous cell carcinoma is a determining factor for contraindicating conservative partial surgery. The subglottis is easily identified by axial computed tomography sections. The present study aimed to evaluate the occurrence of false-negative and false-positive results, and the overall accuracy of staging by computed tomography, in order to detect the involvement of the subglottic laryngeal compartment, in cases of laryngeal and hypopharyngeal squamous cell carcinoma. DESIGN AND SETTING Retrospective, non-randomized study of patients treated at Hospital Heliópolis, São Paulo, Brazil. METHODS Computed tomography scans were performed on third-generation equipment with 5-mm slice thickness. Afterwards, all patients underwent surgical and anatomopathological examinations as the gold standard procedures. RESULTS Among 60 patients, 14 were diagnosed with subglottic extension by surgical and histopathological examination. There were three false-negative and no false-positive results from computed tomography scans. The sensitivity and negative predictive value were 100.0%. Accuracy was 95.0%, specificity was 93.5% and positive predictive value was 82.4%. CONCLUSIONS Computed tomography could serve as a powerful auxiliary method for staging laryngeal and hypopharyngeal cancer. However, precautions should be taken in analyzing computed tomography scan data, because vegetating lesions may also be projected into the subglottic compartment, without real involvement of the subglottis, which may cause a false-positive result.