OBJECTIVE: To evaluate the qualitative (morphological) and quantitative characteristics of hepatic hemangiomas with magnetic resonance imaging. MATERIAL AND METHODS: Twenty-seven patients with 57 hemangiomas were prospectively studied with magnetic resonance imaging using a system operating at 1.5 T. T1- and T2-weighted spin-echo images were obtained, including heavily T2-weighted images with TE of 160 ms. The morphological characteristics of the hemangiomas were studied and the lesions were classified as typical or atypical. Quantitative parameters (T2 relaxation time, simplified T2 index and lesion/liver signal intensity ratio) were also calculated. The values obtained for typical and atypical hemangiomas were compared as well as for the hemangiomas measuring £ 2.0 cm and > 2.0 cm. RESULTS: 78.9% of hemangiomas showed typical morphological features. There was no difference between the quantitative values for typical and atypical hemangiomas. There was not significant difference in T2 relaxation times and values of simplified T2 index in hemangiomas measuring £ 2.0 cm and > 2.0 cm. Lesion/liver signal intensity ratios showed significant differences between the two groups. T2 relaxation times, the simplified T2 index and the lesion/liver signal intensity ratios correctly characterized 96.5%, 93%, and 89.5% of the hemangiomas, respectively. CONCLUSION: Quantitative analysis of hepatic hemangiomas is a simple technique that in conjunction with morphological evaluation provides a more reliable characterization of these tumors.

Keywords: Liver, Hemangioma, Magnetic resonance imaging

Although rare, transitional cell carcinoma of the urinary tract is the second most common tumor of the kidneys. We studied retrospectively the computed tomography images of 10 patients with confirmed transitional cell carcinoma of the urinary tract. There was involvement of the bladder in 60% of the cases whereas the calyceal system and the ureters were involved in 60% and 10% of the cases, respectively. Concomitant tumors were present in 40% of the cases. The findings were sessile masses, ureteral wall thickening and renal infiltrative lesions. Calcified tumors were seen in two patients and a transitional cell tumor arising from a bladder diverticulum was identified in another patient. Local tumor dissemination was observed in 80% of the patients and distant dissemination in 20% of the patients. Computed tomography allowed the detection of local and distant tumor dissemination, thus allowing a selected group of patients to be treated conservatively.

Keywords: Transitional cell carcinoma, Computed tomography, Renal tumors

We analyzed the dose area product (DAP) of 12 patients submitted to videofluoroscopic swallowing studies. The aim of this study was to establish, in a preliminary manner, the values of radiation exposure for patients submitted to this type of examination. A Diamentor equipment was used to register the cumulative radiation doses emitted by the x-ray tubes. Two different rooms with identical radiological equipment were used to collect the data. The protocol used was rigorously the same and the same experienced professional performed the examinations. DAP's values for the three phases (oral, pharyngeal and esophagogastric) of the videofluoroscopic swallowing study were, for the room A (7 patients), 4,101 cGy.cm², DAP/min. = 577 cGy.cm²/min., and for the room B (5 patients), 804 cGy.cm², DAP/min = 119 cGy.cm²/min. These different results were obtained from patients of the same height and weight, using the same examination time (around 7 minutes) for all patients. We concluded that the data showing doses five times lower in room B are more reliable that those obtained for room A and that DAP and DAP/min. are good elements to inform patient doses imparted by videofluoroscopic swallowing examination. We believe that the high dose differences observed between the two groups are due to lack of calibration of the x-ray equipment, since unfortunately "quality assurance programs" are not routinely implemented.

Keywords: Dosimetry, Videofluoroscopy, Dose area product (DAP), Swallowing

Considering the subtle findings observed in mammography images, it is relevant to know how detectability of fibers and microcalcifications can be influenced by the luminance of the viewing boxes. Our goal was to determine the influence of the luminance on the detectability of tiny simulated objects. We obtained seven images with different exposure levels using a phantom that allows statistical analysis. The results were computed using a five point scale to report the confidence levels (100 if the evaluator was sure that the object is present; 75 if likely; 50 if uncertain; 25 if not likely; zero if definitely absent). The images were analyzed by specialists using a "standard" and a specific viewing box for mammography. The detectability was compared using the Pearson chi-square test (p < 0.05). The values varied from 0.79 to 0.87. We concluded that the detectability determined from simulated objects through readings on the specific viewing boxes is higher when compared with the readings using standard viewing boxes.

Keywords: View box, Quality control, Mammography, Luminance, Illuminators, Fluorescent tube

An occupational monitoring program in diagnostic radiology was implemented at the "Hospital Universitário Clementino Fraga Filho - UFRJ", Rio de Janeiro, Brazil, in accordance with the Brazilian legislation. Previously, a survey of all personnel involved with ionizing radiation was performed. Many problems were observed: the great majority of the workers were not properly monitored; only three departments of the hospital kept an independent survey of the occupational doses; there was not a follow-up control of the high doses. With the implementation of the program, a new laboratory was chosen to read the dosemeters and this initiative resulted in reduction of the hospital costs. The inclusion of seven more departments in the program represented an increase of 60% in the number of monitored workers. The program also provided a system to control the high doses, especially in the Hemodynamics department, which presented the highest mean dose value (0.32 mSv/month). An area survey program was performed during different periods in places considered of high risk for the workers and for the public as well. At the same time, a software was used to build a database with the aim of controlling all personnel data. The implementation of the program provided all personnel involved a better knowledge of the risks associated with ionizing radiation and of radioprotection, and also awareness of the need of correct use of the personal dose monitors.

Keywords: Radiological protection, Occupational exposure, Quality control, Radiation dosimetry, Radiology

The sublingual space is a semilunar shaped space of the floor of the mouth that extends from the internal surface of the alveolar edge to the base of the tongue. The sublingual space is located medially to the mylohyoid muscle, which separates the sublingual space from the submandibular space, anteriorly to the hyoglossus-styloglossus complex, and is medially bounded by the genioglossus muscle. It contains the sublingual gland, the deep portion of the submandibular gland, the submandibular duct, the lingual artery and vein, the lingual nerve and the cranial nerves IX and XII. The relationships of the sublingual space are very important since lesions originating from the oropharynx and oral cavity can extend into this area whereas lesions arising from the sublingual space readily spread to involve the adjacent submandibular space. The authors present an anatomical and functional description of the structures within the sublingual space and discuss the diseases occurring in this region. Imaging methods are useful in the assessment and understanding of the lesions in the sublingual space and may help in the clinical and surgical management of the patients.

Keywords: Sublingual space, Computed tomography, Magnetic resonance imaging

Intraoperative ultrasonography influences surgical strategy in a significant number of patients operated due to benign or malignant conditions, and is the most sensitive technique for the detection of small lesions, particularly in the liver and in the pancreas. In pancreatic surgery, intraoperative ultrasonography is helpful in the localization of islet cell tumors and in the assessment of the resectability of adenocarcinomas. The technique may also play a role in chronic pancreatitis surgery. The authors present an up-to-date review of the evolution of intraoperative ultrasonography in pancreatic surgery.

Keywords: Ultrasonography, Intraoperative ultrasonography, Pancreas

Bronchial atresia is a rare congenital abnormality that usually shows a juxta-hilar mass with distal radiolucency on conventional x-ray films. Most patients are young and have no symptoms. Computed tomography usually confirms the diagnosis, allowing conservative management of the asymptomatic cases. The authors report three cases of bronchial obstruction. One of the patients was of particular importance and interest, a 45-year-old female patient with symptoms of respiratory infection, due to the association with a bulky bronchocele. The diagnosis was made by analyzing the findings of conventional x-ray films and computed tomography, and the comparison with previous conventional x-ray films and linear tomography, which had already demonstrated abnormalities. A literature review on the clinical and radiological findings of this pulmonary malformation is presented.

Keywords: Bronchial atresia, Bronchocele, Bronchial mucocele

Vascular tumors encompass a spectrum of lesions, which may vary from benign hemangiomas to malignant angiosarcomas. Hemangioendotheliomas can be considered intermediary between these two types of lesions. We report a case of hepatic hemangioendothelioma in a newborn female and review the most important aspects of this disease.

Keywords: Hemangioendotheliomas, Hepatic tumors, Vascular tumors, Computed tomography

Conjoined twins are rare malformations and a challenge for both radiologists and pediatric surgeons. Antenatal evaluation is essential for the identification of anatomic fusions and other associated abnormalities, which will enable an adequate surgical planning and the assessment of fetal prognosis. The authors present the clinical and imaging findings of thoracopagus twins, joined by the anterior portion of the thorax, sharing the heart and the liver. Diagnosis was made by ultrasonography and confirmed with fetal magnetic resonance imaging.

Keywords: Pregnancy twins, Conjoined twins, Imperfect twinning