OBJECTIVE: To evaluate the potential influence of transaxillary augmentation mammoplasty on future detection of sentinel lymph node. MATERIALS AND METHODS: Prospective controlled study where 22 patients were selected and divided into two groups (post-mammoplasty and control) corresponding to 43 breasts (22 in the post-mammoplasty group and 21 in the control group) evaluated by lymphoscintigraphy immediately after periareolar 99mTc-phytate injections. In the statistical analysis, p values < 0.05 were considered as significant. RESULTS: All the breasts in the post-mammoplasty group presented lymphatic drainage to the axillary chain, with no difference as compared with the control group (p = 0.488). The average number of hot lymph nodes was 1.27 ± 0.46 in the post-mammoplasty group, and 1.33 ± 0.58 in the control group (p = 0.895). The mean time required to visualize the first lymph node was 3.14 ± 4.42 minutes in the post-mammoplasty group, and 5.48 ± 5.06 minutes in the control group (p = 0.136). CONCLUSION: Transaxillary augmentation mammoplasty did not affect the future detection of sentinel lymph node.

Keywords: Sentinel lymph node biopsy, Mammoplasty, Scintigraphy, Breast implants, Breast neoplasms

OBJECTIVE: To determine the role of the unenhanced phase of abdominal computed tomography in patients without a definite diagnosis or undergoing tumor staging. MATERIALS AND METHODS: A prospective and transversal study was developed with 100 consecutive patients submitted to unenhanced and contrast-enhanced abdominal computed tomography. Two observers evaluated all the computed tomography images in the contrast-enhanced phase (first analysis) and, later, in the unenhanced phase (second analysis) in an attempt to establish the primary and secondary diagnoses as a function of the clinical indication for the study. The frequency of changes in the diagnoses resulting from a combined analysis of the images in the pre- and post-contrast phases was evaluated. Cases with changes in the diagnosis were reviewed by clinical specialists for determining possible changes in the therapeutic approach. RESULTS: Primary and secondary diagnoses were changed in respectively 1 and 18 cases (p = 1.000; p = 0.143) as follows: steatosis, adrenal nodules, nephrolithiasis, renal cysts and hepatic calcification. In the cases where the unenhanced phase changed the diagnosis, the specialists changed the therapeutic approach in 14 of the 19 patients (73%) (p = 0.038). CONCLUSION: No significant change was observed in the primary or secondary diagnosis as a result of the findings in the unenhanced phase. However, changes in secondary diagnoses affected the therapeutic approach adopted by the specialists.

Keywords: Computed tomography, Contrast media, Abdomen

OBJECTIVE: The purpose of this study was to describe the tomographic findings of gastric gastrointestinal stromal tumor. MATERIALS AND METHODS: Fourteen patients with histopathologically and immunohistochemically confirmed gastric gastrointestinal stromal tumors, who had already been submitted to computed tomography scans before the treatment, were evaluated in the period between January 1999 and December 2006. The following tomographic variables were analyzed: lesion topography, size/dimensions, homogeneity, contour, margins, morphology, pattern and intravenous contrast-enhancement intensity, growth pattern, invasion of adjacent organs, presence of ulceration, fistula, calcifications, mesenteric fat infiltration, lymphadenomegaly and presence of distant metastasis. RESULTS: Tumors were found in the body (57.1%) or in the gastric fundus (42.9%), with sizes ranging between 6.0 cm and 23.0 cm (mean, 11.5 cm). Predominantly extraluminal growth was observed in 57.1% of cases and intra/extraluminal in 35.7%. Subtle contrast-enhancement was observed in 50%, moderate in 50%, and heterogeneous in 64.3% of cases. Additionally, central hypodensity was observed in 64.3%, invasion of adjacent organs in 42.9%, and hepatic metastasis in 7.2% of cases. CONCLUSION: In the present study, the majority of tumors were found in the gastric body, with an average size of 11.5 cm, presenting with central hypodensity, heterogeneous contrast-enhancement and predominantly extraluminal growth.

Keywords: Gastrointestinal stromal tumors, Stomach neoplasms, Spiral computed tomography

OBJECTIVE: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. MATERIALS AND METHODOS: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. RESULTS: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). CONCLUSION: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement.

Keywords: Portal flow, Measurement, Doppler ultrasonography, Reproducibility, Portal hypertension

OBJECTIVE: To utilize ultrasonography for evaluating the esophageal transit time as well as the esophagus capability of differentiating among non-solid substances ingested (water and yoghurt). MATERIALS AND METHODS: Twenty-two young adults of both sexes with no gastric or esophageal complaint were evaluated, with a B-mode 3.5 MHz, convex transducer placed over the epigastric area. The esophageal transit time was determined by means of a chronometer activated when the deglutition was initiated (glottic movement), and stopped upon visualization of the bolus through the intra-abdominal esophagus. RESULTS: The mean esophageal transit time for water was 6.64 ± 1.83 sec, and 8.59 ± 2.70 sec for yoghurt. The comparative statistical analysis by a t-paired test has demonstrated statistically significant differences between the mean esophageal transit times for the two substances. CONCLUSION: This new experimental method for evaluating the esophageal transit time by ultrasonography demonstrates significant differences in the time required for a determined liquid or pasty food passing through the esophagus, elucidating clinical suspicions and allowing a more precise indication for further, more complex clinical studies.

Keywords: Ultrasonography, Esophageal transit time, Abdominal esophagus

OBJECTIVE: The present study was aimed at evaluating by means of magnetic resonance imaging a series of fetuses with sonographic diagnosis of malformation, establishing the diagnostic benefits and limitations of fetal magnetic resonance imaging as compared with ultrasonography. MATERIALS AND METHODS: Forty women between 15-35 gestational weeks and previously diagnosed with fetal abnormality by ultrasonography were referred to undergo complementary fetal magnetic resonance imaging, particularly for evaluating abnormalities in the fetal central nervous system, thorax, abdomen, renal system, skeletal system, and tumors. The whole evaluation process included a review of the fetal ultrasonography and magnetic resonance images, postnatal follow-up, laboratory tests, imaging studies and necropsy. RESULTS: The present study has demonstrated that complementary magnetic resonance imaging did provide further information in 60% of cases, with the following benefits: improved information on the fetus as a whole, with a large field of view, higher anatomic resolution provided by fast sequences, superior soft tissue contrast resolution, besides the fact that the visualization of the fetus is not significantly affected by maternal obesity or oligohydramnios. Limitations of the method include contraindication in the first gestational trimester and in cases of maternal claustrophobia, sensitivity to fetal motion, low sensitivity for detecting cardiovascular and skeletal malformations. CONCLUSION: Fetal magnetic resonance imaging plays a significant role as a complementary method for the diagnosis of fetal anomalies.

Keywords: Fetal magnetic resonance imaging, Ultrasonography, Malformations, Single-shot, HASTE, Prenatal diagnosis

OBJECTIVE: The present study evaluates the dose distribution received by physicians involved in hemodynamic procedures of coronary angiography and coronariography. The influence of some factors such as pulsed or continuous fluoroscopy mode and vein and/or artery access site was investigated. MATERIALS AND METHODS: Measurements have been performed with LiF:Mg,Ti thermoluminescent dosimeters placed on seven different sites of the practitioners' bodies: hands, left knee, neck, forehead and chest, under and over the lead apron. Radiation doses for each procedure were evaluated in physicians who had performed 60 coronariography and 30 angioplasty procedures. The thermoluminescent dosimeters were calibrated in the operational quantity personal dose equivalent, Hp(d), at depths of 0.07, 3 and 10 mm. RESULTS: The results of the present study demonstrate the significant role played by thyroid protectors and lead aprons for reducing radiation doses received by practitioners. Occupational doses in continuous mode fluoroscopy through brachial access were higher than with pulsed mode fluoroscopy through femoral access. CONCLUSION: The present study has demonstrated the necessity of implementing additional protective measures as well as a mechanism of training in radiation protection for physicians involved in interventional cardiological procedures.

Keywords: Interventional radiology, Fluoroscopy, Hemodynamic procedures, Radiation protection, Thermoluminescent dosimetry

OBJECTIVE: The present study was aimed at: a) evaluating radiographic procedures and estimating entrance surface air kerma in preterm neonates submitted to chest and abdominal radiography at the unit of neonatology in a public hospital of Belo Horizonte, MG, Brazil; b) estimating the dose to organs and respective risks for cancer as a result from radiation exposure. MATERIALS AND METHODS: Records of patients admitted to the unit of neonatology of this hospital in the period between May and September 2004 were reviewed. Anthropometric data, admission/discharge dates and radiographic studies performed were recorded for each of the patients. The calculation of the entrance surface air kerma was based on the x-ray tube output and irradiation parameters adopted for examinations. Dose to organs was calculated with the aid of the software PCXMC, and the lifetime risk for cancer, with the software IREP. RESULTS: Mean entrance surface air kerma per examination was below the diagnostic reference levels recommended by the European Community. In the most severely irradiated patients, liver, breast and stomach were the organs at highest risk for cancer, with maximum excess relative risk of respectively 3.4%, 2.3%, and 1.7%. CONCLUSION: The present study demonstrated the need for optimization of radiographic procedures in order to reduce the risks for neonates that, in spite of being considered to be low as compared with the benefits, should be reduced to values as low as reasonably achievable.

Keywords: Patient dosimetry, Radiological protection, Pediatric radiology, Cancer risk

OBJECTIVE: The present paper describes the implementation and evaluation of a medical images management system with content-based retrieval support (PACS-CBIR) integrating modules focused on images acquisition, storage and distribution, and text retrieval by keyword and images retrieval by similarity. MATERIALS AND METHODS: Internet-compatible technologies were utilized for the system implementation with freeware, and C++, PHP and Java languages on a Linux platform. There is a DICOM-compatible image management module and two query modules, one of them based on text and the other on similarity of image texture attributes. RESULTS: Results demonstrate an appropriate images management and storage, and that the images retrieval time, always < 15 sec, was found to be good by users. The evaluation of retrieval by similarity has demonstrated that the selected images extractor allowed the sorting of images according to anatomical areas. CONCLUSION: Based on these results, one can conclude that the PACS-CBIR implementation is feasible. The system has demonstrated to be DICOM-compatible, and that it can be integrated with the local information system. The similar images retrieval functionality can be enhanced by the introduction of further descriptors.

Keywords: CBIR, PACS, DICOM, Medical images, Health information system

Several diseases should be considered in the differential diagnosis of disorders affecting the temporomandibular joints. Internal derangement is the main condition responsible for pain related to this joint. Clinical signs may, though, be quite non-specific, and many other conditions present with similar and not infrequently indistinguishable signs and symptoms. In the present study, the authors describe several non-dysfunctional conditions affecting the temporomandibular joints through computed tomography and magnetic resonance imaging, emphasizing the importance of these imaging methods in the diagnosis of inflammatory, neoplastic and traumatic diseases of this region. Considering that clinical presentations are frequently non-specific, radiologists play a critical role in the differential diagnosis.

Keywords: Temporomandibular joint, Computed tomography, Magnetic resonance imaging

Image-guided percutaneous procedures have increasingly been established as safe and effective interventional tools in the diagnosis and management of masses and collections in several body segments. However, lesions in deep pelvic sites still pose a challenge for radiologists because of overlying anatomic structures. The success of a percutaneous biopsy depends on a safe access route planning based on a deep understanding of cross sectional anatomy of the pelvis. Anterior and lateral transabdominal, anterolateral extraperitoneal, transvaginal, transrectal and transgluteal approaches are described. The present study was aimed at reviewing the normal pelvic cross-sectional anatomy, demonstrating the different access routes for ultrasonography and computed tomography guided pelvic biopsies and drainages as well as discussing the main advantages and complications associated with these approaches.

Keywords: Biopsies, Percutaneous drainage, Interventional procedures, Pelvic anatomy, Pelvic abscesses

The present study reports the case of a 46-year-old female patient complaining of mild premenstrual pain and increase in the volume of the periumbilical region. The condition progressed with a gradual increase of the pain intensity. Ultrasonography, computed tomography and magnetic resonance imaging were performed. Biopsy of tissue collected during exploratory laparotomy confirmed the diagnosis of leiomyomatosis peritonealis disseminata.

Keywords: Leiomyomatosis peritonealis disseminata, Oral contraceptive method, Computed tomography, Magnetic resonance imaging