OBJECTIVE: Longitudinal study with B-mode ultrasonography and Doppler ultrasonography of maternal kidneys and liver in low-risk pregnancy, to establish and quantify normality parameters, correlating them with physiological changes. MATERIALS AND METHODS: Twenty-five pregnant women were assessed and selected to participate in the study, each of them undergoing four examinations at the first, second, third trimesters and postpartum. RESULTS: Findings during pregnancy were the following: increased renal volume, pyelocaliceal dilatation with incidence of 45.4% in the right kidney, and 9% in the left kidney; nephrolithiasis, 18.1% in the right kidney, 13.6% in the left kidney. With pyelocaliceal dilatation, mean values for resistivity index were: 0.68 for renal arteries; 0.66 for segmental arteries; 0.64 for interlobar arteries; 0.64 for arcuate arteries. Without pyelocaliceal dilatation, 0.67 for renal arteries; 0.64 for segmental arteries; 0.63 for interlobar arteries; and 0.61 for arcuate arteries. Portal vein flow velocities presented higher values in pregnancy, with mean value for maximum velocity of 28.9 cm/s, and 22.6 cm/s postpartum. The waveform pattern of the right hepatic vein presented changes persisting in the postpartum period in 31.8% of the patients. Cholelithiasis was observed in 18.1% of the patients. CONCLUSION: Alterations in renal volume, pyelocaliceal dilatation, nephrolithiasis, cholelithiasis, changes in portal vein flow velocity, alterations in waveform pattern of the right hepatic vein, proved to be significant.

Keywords: Pregnancy; Pyelocaliceal dilatation; Nephrolithiasis; Cholelithiasis; Portal vein; Right hepatic vein.

OBJECTIVE: To evaluate the prevalence of exclusive lower extremity metastases, specifically in the femur and below the knee, observed at ¹⁸F-NaF PET/CT. MATERIALS AND METHODS: One thousand consecutive PET/CT studies were retrospectively evaluated for the presence of exclusive uptake in lower extremities suggesting metastatic involvement. The presumptive diagnoses based on such uptakes were subsequently obtained by evaluation of other imaging studies. RESULTS: No exclusive uptake suggestive of metastasis below the femur was observed in the present series. Exclusive uptake was observed in the proximal femur with a presumptive diagnosis of metastasis in two patients. CONCLUSION: The prevalence of exclusive metastasis below the femur is low and scanning from head to knees is appropriate in most cases.

Keywords: PET/CT; ¹⁸F-NaF; Scintigraphy; Bone; Metastasis.

OBJECTIVE: To evaluate the association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC). MATERIALS AND METHODS: The patients were evaluated by ultrasonography-guided fine needle aspiration cytology. Typical cytopathological aspects and/or classical histopathological findings were taken into consideration in the diagnosis of HT, and only histopathological results were considered in the diagnosis of PTC. RESULTS: Among 1,049 patients with multi- or uninodular goiter (903 women and 146 men), 173 (16.5%) had cytopathological features of thyroiditis. Thirty-three (67.4%) out of the 49 operated patients had PTC, 9 (27.3%) of them with histopathological features of HT. Five (31.3%) out of the 16 patients with non-malignant disease also had HT. In the groups with HT, PTC, and PCT+HT, the female prevalence rate was 100%, 91.6%, and 77.8%, respectively. Mean age was 41.5, 43.3, and 48.5 years, respectively. No association was observed between the two diseases in the present study where HT occurred in 31.1% of the benign cases and in 27.3% of malignant cases (p = 0.8). CONCLUSION: In spite of the absence of association between HT and PCT, the possibility of malignancy in HT should always be considered because of the coexistence of the two diseases already reported in the literature.

Keywords: Thyroid nodule; Cytopathology; Thyroid neoplasms; Thyroiditis; Ultrasonography.

OBJECTIVE: The present article is aimed at reporting the author's experience with transcatheter arterial embolization using a lipiodol-ethanol mixture in three cases of unresectable symptomatic giant hepatic hemangiomas. MATERIALS AND METHODS: The cases of three patients with giant unresectable symptomatic hepatic hemangiomas embolized in the period 2009-2010 were retrospectively reviewed. In all the cases, transarterial embolization was performed with an ethanol-lipiodol mixture. RESULTS: Symptoms regression and quality of life improvement were observed in all the cases. No complications were observed and all the patients were discharged within 12 hours after the procedure. CONCLUSION: Transcatheter arterial embolization using ethanol mixed with lipiodol was a safe and effective treatment for symptomatic giant hepatic hemangiomas in this small series of patients.

Keywords: Hemangioma; Therapeutic embolization; Ethanol; Ethiodized oil.

OBJECTIVE: In the present study, the authors investigated the in vitro behavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and radiosensitive peripheral blood mononuclear cells (PBMC), as a function of different radiation doses, dose rates and post-irradiation time kinetics, with a view to the interest of clinical radiotherapy. MATERIALS AND METHODS: The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min^-1 and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed. RESULTS: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDA-MB-231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48-72 hours post-radiation. CONCLUSION: Low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer.

Keywords: Radiation; MDA-MB-231; PBMC; LET; Dose; Dose rate.

Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes.

Keywords: Renal cell carcinoma; Kidney cancer; Computed tomography; Magnetic resonance imaging.

The effective evaluation for the treatment of patients with Ewing tumors depends on the accuracy in the determination of the primary tumor extent and the presence of metastatic disease. Currently, no universally accepted staging system is available to assess Ewing tumors. The present study aimed at discussing the use of PET/CT as a tool for staging, restaging and assessment of therapeutic response in patients with Ewing tumors. In spite of some limitations of PET/CT as compared with anatomical imaging methods, its relevance in the assessment of these patients is related to the capacity of the method to provide further physiological information, which often generates important clinical implications. Currently, the assessment of patients with Ewing tumor should comprise a study with PET/CT combined with other anatomical imaging modalities, such as radiography, computed tomography and magnetic resonance imaging.

Keywords: Ewing sarcoma; Imaging diagnosis; Diagnosis; Evaluation.

Tuberculosis is a disease whose incidence has increased principally as a consequence of HIV infection and use of immunosuppressive drugs. The abdomen is the most common site of extrapulmonary tuberculosis. It may be confused with several different conditions such as inflammatory bowel disease, cancer and other infectious diseases. Delay in the diagnosis may result in significantly increased morbidity, and therefore an early recognition of the condition is essential for proper treatment. In the present essay, cases with confirmed diagnosis of abdominal tuberculosis were assessed by means of computed tomography and magnetic resonance imaging, demonstrating the involvement of different organs and systems, and presentations which frequently lead radiologists to a diagnostic dilemma. A brief literature review was focused on imaging findings and their respective prevalence.

Keywords: Tuberculosis; Abdomen; Computed tomography; Magnetic resonance imaging.

Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease.

Keywords: Computed tomography; Thoracic aorta; Aortic diseases; Atherosclerosis; Cardiovascular surgery.