The present article reports the case of a 14-year-old male patient who developed acute chest pain following increased vocal effort during a soccer game. Chest radiography and computed tomography demonstrated pneudomediastinum with small bilateral pneumothorax. Clinical, laboratory and radiological studies did not demonstrate any predisposing factor, and the case was classified as spontaneous pneudomediastinum.

Keywords: Spontaneous pneumomediastinum, Mediastinal emphysema, Computed tomography, Vocal effort, Chest

OBJECTIVE: To propose a model to standardize computed tomography reports on abdominal aortic aneurysms. MATERIALS AND METHODS: Interviews were carried out with members of Vascular Surgery Division of our institution, in the period between April and October 2004, aiming at developing a standardized model of computed tomography reports on abdominal aortic aneurysms. Based on this model, a questionnaire was elaborated and sent to other nine surgeons, all of them experienced in the field of abdominal aortic surgery. The questionnaires response rate was 55.5% (5/9). RESULTS: The most frequently mentioned parameters of interest for evaluation of abdominal aortic aneurysms were: maximum diameter of proximal aortic neck, proximal aortic neck length to lower renal arteries, shape of proximal aortic neck, maximum diameter of the aneurysm and diameter of the common iliac arteries. These data allowed the development of a proposal for a model to standardize computed tomography reports. CONCLUSION: A model for standardized tomographic analysis of abdominal aortic aneurysms has met vascular surgeons' needs for following-up patients and planning their treatment.

Keywords: Aorta, Aneurysm, Computed tomography

OBJECTIVE: To present the experience of Santa Cecília Hospital (São Paulo, SP, Brazil) radiology service in the handling of computed tomography-guided fine-needle aspiration biopsy and percutaneous core biopsy of pulmonary lesions, analyzing their importance and associated complications. MATERIALS AND METHODS: One hundred and sixty-eight computed tomography-guided biopsies were performed in 84 men and 84 women. Sixty-four patients underwent fine-needle aspiration biopsy, 68 underwent percutaneous core biopsy and 36 patients underwent both techniques. RESULTS: Pneumothorax occurred in 38 patients, and pulmonary hemorrhage in then cases. The biopsied lesions ranged in size from 0.5 to 15 cm. The diagnosis was achieved at the first attempt in 132 cases and at the second attempt in ten cases. CONCLUSION: The accuracy of fine-needle aspiration and percutaneous core biopsies depends both on the size of the lesion and the patient's cooperation. These techniques are relatively safe and present a high diagnostic accuracy when performed by an experienced professional.

Keywords: Biopsy, Cancer, Computed tomography

Isolated renal lymphoma is rare due to the absence of lymphoid tissue in kidneys. Secondary involvement occurs more frequently and is reported in up to 1/3 of the autopsies of patients who died from lymphoma. Some authors believe this is actually the only existing form of renal lymphoma. The involvement of the kidney by lymphoma would occur through hematogenic metastasis or direct tumor invasion of the perirenal space. These different types of involvement determine the several forms of renal lymphoma presentation: multiple nodules, solitary mass, renal invasion from contiguous retroperitoneal disease, perirenal disease and diffuse infiltration. In this study the imaging findings features of the different forms of involvement are presented and discussed.

Keywords: Kidney, Lymphoma, Computed tomography

We evaluated the adrenals of individuals without tuberculosis (group 1 - G1) and with tuberculosis (group 2 - G2) using computed tomography. The antero-posterior length, the thickness, and the longitudinal length of the adrenals were compared in G1 and G2. The duration of the disease, the occurrence of morphologic abnormalities in G2, the distribution according to sex, age and skin color were also studied. There was difference in the antero-posterior length and thickness of right adrenal between G1 and G2. A higher prevalence of white skin male individuals was observed in G2. There was no association between duration of the disease and the occurrence of morphologic abnormalities in G2. A higher occurrence of adrenal enlargement was observed in G2. The main computed tomography findings in patients with tuberculosis were enlargement of the adrenal without calcification, enlargement of the adrenal with punctiform calcifications, and residual calcification of the adrenal.

Keywords: Adrenal, Tuberculosis, Computed tomography

OBJECTIVE: Approximately 35% of the patients with acute appendicitis have a doubtful or incorrect preoperatory diagnosis, particularly in pregnant women and children. Ultrasonography has demonstrated to be an important means of diagnosis due to its low cost and easy access. This study is intended to show the main imaging findings of the many phases of appendicitis, thus helping the ultrasonographist to establish an early diagnosis. MATERIALS AND METHODS: From January to June 2001, 14 patients with acute abdominal pain were submitted to abdominal ultrasound using 3.5 MHz and 7.5 MHz transducers. RESULTS: The ultrasound findings when perforation had not occurred demonstrated a noncompressible appendix, thickening and focal lack of definition of the walls. After perforation had occurred the appendix could no longer be visualized at ultrasonography. Secondary changes such as mass effect, phlegmous changes, liquefaction and abscess formation, and gas bubbles within a collection were identified. CONCLUSION: An early diagnosis of appendicitis is essential in order to minimize morbidity that is high when perforation occurs. Atypical presentations result in misdiagnosis and treatment delay. The main diagnostic challenges are retrocecal, focal or perforated appendicitis.

Keywords: Appendicitis, Ultrasonography, Computed tomography

Computed tomography is currently the method of choice for the diagnosis and staging of lymphomas. Computed tomography enables accurate measurement of both tumor extent and volume and provides information that can be used to plan an appropriate strategy for the treatment. The purpose of the present article is to describe and analyze the chest and abdomen computed tomography and ultrasound findings in HIV-negative patients with lymphoma. Clinical abnormalities, such as the reason the patient sought medical assistance already showing evidence of lymphocytic disease (not yet diagnosed at this point) and the physical examination abnormalities seen on the first consultation were also studied. This study comprised 30 patients: 40% with non-Hodgkin lymphoma, 46.6% with Hodgkin lymphoma, 10% with Burkitt's lymphoma and 3.3% with lymphoblastic lymphoma.

Keywords: Lymphoma, Computed tomography, Ultrasonography

The authors report a rare case of a 71-year-old male patient with a 9-year history of appearance of a "little node" in the right superior eyelid, which increased significantly in size in the last year. Computed tomography showed thickening of the lateral rectus muscle and adjacent soft tissues. The diagnosis after biopsy was xanthelasma.

Keywords: Eyelid xanthelasma, Computed tomography

We retrospectively studied the computed tomography scans of the orbit in 75 patients in order to identify the presence of incidental calcifications (scleral and trochlear apparatus calcifications). These imaging findings should integrate the vast list of differential diagnosis of orbital calcifications, as they may help radiologists to distinguish these calcifications from orbital foreign bodies.

Keywords: Orbit. Computed tomography. Calcification.

Some technical aspects should be taken into consideration in order to guarantee the reliability of the assessment of pulmonary emphysema with lung computed tomography densitometry. Changes in lung density associated with variations in lungs inspiratory and expiratory levels, computed tomography slice thickness, reconstruction algorithm and type of computed tomography apparatus make tomographic comparisons more difficult in follow up studies of pulmonary emphysema. Nevertheless, quantitative computed tomography has replaced the visual assessment competing with pulmonary function tests as a sensitive method to measure pulmonary emphysema. The present review discusses technical variables of lung computed tomography and their influence on measurements of pulmonary emphysema.

Keywords: Accuracy; Measurement; Pulmonary emphysema; Computed tomography.

Objective: The present paper addresses the dosimetric evaluation of carbon ion radiotherapy as compared with proton therapy. Materials and Methods: Computer simulations were undertaken with the Geant4 (GEometry ANd Tracking) code. An eye model discretized into voxels and implemented in the Siscodes system (computer system for dosimetry in radiation therapy) was utilized to generate and superimpose depth dose profiles and isodose curves. Different values for beam energy were adopted in the simulations of carbon ion beams, while in the simulation with proton beams irradiation line devices were included with different absorbing material thicknesses. Results: The simulations outputs were processed and integrated into the Siscodes to generate the spatial dose distribution in the eye model, considering changes in the beam entrance position. The dose rates were normalized as a function of the maximum dose for a beam at a specific entrance position, incident particle energy and number of incident carbon ions and protons. Conclusion: The described benefits together with the presented results contribute to the development of clinical applications and researches on carbon ion and proton therapy.

Keywords: Carbon ion therapy; Proton therapy; Geant4; Siscodes.

Pulmonary interstitial emphysema is a rare condition that generally affects low-weight preterm infants submitted to mechanical ventilation. The prognosis is variable, depending on early diagnosis and treatment. The radiologist plays a key role in this scenario. The authors report a case of persistent pulmonary interstitial emphysema, describing the main characteristics of such entity.

Keywords: Pulmonary interstitial emphysema; Newborns; Mechanical ventilation.

OBJECTIVE: To perform a quantitative analysis of the lung parenchyma and pulmonary vasculature of patients with pulmonary hypertension (PH) on computed tomography angiography (CTA) images, using automated software. MATERIALS AND METHODS: We retrospectively analyzed the CTA findings and clinical records of 45 patients with PH (17 males and 28 females), in comparison with a control group of 20 healthy individuals (7 males and 13 females); the mean age differed significantly between the two groups (53 ± 14.7 vs. 35 ± 9.6 years; p = 0.0001). RESULTS: The automated analysis showed that, in comparison with the controls, the patients with PH showed lower 10th percentile values for lung density, higher vascular volumes in the right upper lung lobe, and higher vascular volume ratios between the upper and lower lobes. In our quantitative analysis, we found no differences among the various PH subgroups. We inferred that a difference in the 10th percentile values indicates areas of hypovolemia in patients with PH and that a difference in pulmonary vascular volumes indicates redistribution of the pulmonary vasculature and an increase in pulmonary vasculature resistance. CONCLUSION: Automated analysis of pulmonary vessels on CTA images revealed alterations and could represent an objective diagnostic tool for the evaluation of patients with PH.

Keywords: Hypertension, pulmonary; Tomography, X-ray computed; Image processing, computer-assisted.

OBJECTIVE: To determine whether the radiomic features of lung lesions on computed tomography correlate with overall survival in lung cancer patients. MATERIALS AND METHODS: This was a retrospective study involving 101 consecutive patients with malignant neoplasms confirmed by biopsy or surgery. On computed tomography images, the lesions were submitted to semi-automated segmentation and were characterized on the basis of 2,465 radiomic variables. The prognostic assessment was based on Kaplan–Meier analysis and log-rank tests, according to the median value of the radiomic variables. RESULTS: Of the 101 patients evaluated, 28 died (16 dying from lung cancer), and 73 were censored, with a mean overall survival time of 1,819.4 days (95% confidence interval [95% CI]: 1,481.2–2,157.5). One radiomic feature (the mean of the Fourier transform) presented a difference on Kaplan–Meier curves (p < 0.05). A high-risk group of patients was identified on the basis of high values for the mean of the Fourier transform. In that group, the mean survival time was 1,465.4 days (95% CI: 985.2–1,945.6), with a hazard ratio of 2.12 (95% CI: 1.01–4.48). We also identified a low-risk group, in which the mean of the Fourier transform was low (mean survival time of 2,164.8 days; 95% CI: 1,745.4–2,584.1). CONCLUSION: A radiomic signature based on the Fourier transform correlates with overall survival, representing a prognostic biomarker for risk stratification in patients with lung cancer.

Keywords: Tomography, X-ray computed; Radiographic image interpretation, computer-assisted; Lung neoplasms; Prognosis.

OBJECTIVE: To evaluate the maximum and mean standardized uptake values, together with the metabolic tumor value and the total lesion glycolysis, at the primary tumor site, as determined by ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG-PET/CT), performed before and after neoadjuvant chemoradiotherapy (nCRT), as predictors of residual disease (RD) in patients with esophageal cancer. MATERIALS AND METHODS: The standardized uptake values and the volumetric parameters (metabolic tumor value and total lesion glycolysis) were determined by ¹⁸F-FDG-PET/CT to identify RD in 39 patients before and after nCRT for esophageal carcinoma. We used receiver operating characteristic curves to analyze the diagnostic performance of ¹⁸F-FDG-PET/CT parameters in the definition of RD. The standard of reference was histopathological analysis of the surgical specimen. RESULTS: Eighteen patients (46%) presented RD after nCRT. Statistically significant areas under the curve (approximately 0.72) for predicting RD were obtained for all four of the variables evaluated after nCRT. Considering the presence of visually detectable uptake (higher than the background level) at the primary tumor site after nCRT as a positive result, we achieved a sensitivity of 94% and a specificity of 48% for the detection of RD. CONCLUSION: The use of ¹⁸F-FDG-PET/CT can facilitate the detection of RD after nCRT in patients with esophageal cancer.

Keywords: Esophageal neoplasms; Neoadjuvant therapy; Positron-emission tomography; Nuclear medicine.