OBJECTIVE: Magnetic resonance imaging has been utilized in the evaluation of the lacrimal apparatus with some advantages over conventional dacryocystography. The present study was aimed at acquiring high-resolution images utilizing microscopic coils for evaluating typical structures of the lacrimal apparatus as compared with the findings observed with conventional surface coils. MATERIALS AND METHODS: Five asymptomatic volunteers with no history of epiphora were submitted to high-field magnetic resonance imaging with microscopic and conventional surface coils, and STIR sequence after instillation of saline solution. The definition of normal anatomic structures of lacrimal apparatuses was compared utilizing conventional and microscopic surface coils. Based on a consensual scoring system, the mean values for each structure were calculated by two observers. RESULTS: In 90% of cases, higher scores were attributed to images acquired with the microscopic coil. On average, a 1.17 point increase was observed in the scoring of anatomic structures imaged with the microscopic coil. Additionally, a subjective improvement was observed in the signal-to-noise ratio with the microscopic coil. CONCLUSION: Magnetic resonance dacryocystography with microscopic coils is the appropriate method for evaluating the lacrimal apparatus, providing images with better quality as compared with those acquired with conventional surface coils.

Keywords: Magnetic resonance imaging, Lacrimal apparatus, Dacryocystography, Microscopic coil

OBJECTIVE: The aim of this study was to quantitatively evaluate the histological changes produced by radiation therapy both on the stroma and the parenchyma of submandibular gland in rats. MATERIALS AND METHODS: The sample size consisted of 30 Wistar rats, divided in two groups: test and control. The 15 animals of the test group were irradiated daily on the head and neck region with a dose of 2 Gy for six weeks using a rotational fractionated modality of 60Co-gamma rays. At the end of the experimental period the animals had received a total dose of 60 Gy. Sixty hours after the last radiation therapy session the submandibular glands of the animals from both groups were excised, processed using paraffin technique, stained with hematoxiline-eosin and analyzed by optical microscopy. RESULTS: The mean proportional volume of the glandular parenchyma and stroma was obtained using a stereological method of manual point counting. The proportional volume of the acini on the irradiated group (60.67% ± 6.43) was significantly lower than the control group (67.42% ± 10.90) (p = 0.048), however there was no statistical difference between the groups for parenchyma, ducts and stroma (Student t test, p > 0.05). CONCLUSION: The radiation therapy produced acinar atrophy in submandibular glands. No total quantitative changes in the stroma or in the parenchyma were observed.

Keywords: Rats, Salivary gland, Radiotherapy, Microscopy