Bronchial Atresia.

BACKGROUND: A 48-year-old male smoker with no significant previous medical history presented to the emergency department with acute respiratory distress, characterized by dyspnea and nonspecific chest pain. Laboratory findings and electrocardiography (ECG) were normal.

Comparison of low-dose with standard-dose multidetector CT in cervical spine trauma.

BACKGROUND AND PURPOSE: The purpose of this work was to evaluate the possible use of low-dose multidetector CT (MDCT) in cervical clearance of patients with blunt trauma. MATERIALS AND METHODS: A total of 191 patients underwent cervical spine MDCT with 6- and 16-MDCT: standard-dose (n = 51) and low-dose MDCT with tube current modulation at high (n = 70) and low (n = 70) tube voltage (kilovolts). Effective dose, image noise, and subjective image quality were calculated in all of the patients. RESULTS: MDCT found 18 patients (9.4%) with a cervical spine fracture, 3 in the standard-dose and 15 in the low-dose group, 14 of them with unstable lesions. Tube current modulation reduced the dose by 50%-61% in all of the low-dose examinations. The mean effective dose was 3.75, 1.57, and 1.08 mSv, and mean image noise was 14.82, 17.46, and 19.72 Hounsfield units for standard dose and low dose with high and low kilovolt examinations, respectively. These differences in mean effective dose and image noise were significant between the 3 examination groups (Kruskal-Wallis test: P < .0001 and P = .0001). Evaluation of subjective image quality by 2 radiologists and 2 residents showed no significant difference in image quality score among the 3 examination groups (Kruskal-Wallis tests, P = .61, .32, .18, and .31). All of the reviewers correctly detected 18 fractures, except 1 resident, who missed 3 fractures. CONCLUSION: Low-dose cervical spine MDCT in patients with blunt trauma gives a substantial dose reduction of 61%-71%, compared with standard-dose MDCT, with a small increase in image noise and without difference in subjective image quality evaluation.

Comparison of effective doses for low-dose MDCT and radiographic examination of sinuses in children.

OBJECTIVE: Our objective was to show that in low-dose MDCT of the sinuses in children the effective dose can be lowered to a level comparable to that used for standard radiographic images, with resultant CT scans that are still of diagnostic image quality. MATERIALS AND METHODS: In standard radiographic examinations of sinuses (anteroposterior and lateral views) with 75 kV, 20 mAs, and 3-mm aluminum filtration in 69 children (mean age, 4.2 years), the dose-area-product (DAP; mGy x cm2) was measured and converted to effective dose (mSv) according to coefficients published by the British National Radiological Protection Board. Another group of 125 children (mean age, 6.8 years) underwent low-dose MDCT of the sinuses with 6- or 16-MDCT in two phases and with different scanning protocols. An effective dose for MDCT was calculated from conversion of the dose-length-product (DLP, mGy xm) according to age. RESULTS: The mean effective dose (E) for standard radiography was 0.0528 mSv. The mean E value for low-dose MDCT was 0.096 mSv in the first phase of the study but could be lowered in the second phase to 0.0531 mSv by a combination of higher pitch and faster scan rotation time in our scan protocols, which results in diagnostic image quality at a very low dose. Statistical analysis showed no significant differences in effective dose between radiography and MDCT of the second phase. CONCLUSION: With modern MDCT technology, low-dose CT of the sinuses in children can yield diagnostic image quality using an effective dose comparable to that used for standard radiography.

MRI of acoustic schwannoma: a retrospective study of 89 tumours.

Magnetic resonance imaging (MRI) is now considered the diagnostic study of choice for evaluation of patients with suspected acoustic schwannoma. This retrospective study of 118 MR examinations presents an analysis of the MR findings of 89 acoustic tumours in 86 patients. The method of examination included precontrast and gadolinium(Gd)-enhanced MRI in 72 and plain MRI in 14 patients. The common MR-appearances of acoustic schwannomas were: on T1-weighted images (WI) isointense (36%) or slightly hypointense (64%) relative to the brainstem; intense and homogeneous contrast enhancement in 62%; the shape of the tumour was round or oval in 71%; the tumour was centred at/or located in the internal auditory canal (IAC) in 80%. The small acoustic schwannomas were mostly round or oval in shape and showed homogeneous signal intensity (SI) both before and after Gd. The larger acoustic tumours were more heterogeneous in morphology and SI. The significance of these and other signs, early diagnosis and differential diagnosis are discussed.

Acoustic schwannoma: MR findings in 84 tumors.

MR imaging is the study of choice for the examination of patients with suspected acoustic schwannoma, because of its high sensitivity, especially after the use of contrast material. This essay illustrates the common MR features of acoustic schwannomas as seen in a study of 84 tumors. We pay special attention to the role of MR imaging in the distinction between acoustic schwannoma and meningioma.

Bilateral ureteral inverted papillomas in association with bladder carcinoma: a case report and review of the literature.

A case of multiple inverted papillomas of both ureters, in association with a bladder carcinoma, is presented. Inverted papilloma is a rare benign urothelial tumor. Because of its curability by conservative surgery, it should be considered in the differential diagnosis of a ureteral filling defect and ureteral obstruction. Inverted papilloma may be associated with carcinomas of the urinary tract.