Contamination of X-ray Cassettes with Methicillin-resistant Staphylococcus aureus and Methicillin-resistant Staphylococcus haemolyticus in a Radiology Department

BACKGROUND: We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA). METHODS: The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 microg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing. Pulsed-field gel electrophoresis (PFGE) analysis was performed to determine the clonal relationships of the contaminants. RESULTS: Six X-ray cassettes (16.2%) were contaminated with MRSA. During the isolation procedure, we also detected 19 X-ray cassettes (51.4%) contaminated with methicillin-resistant Staphylococcus haemolyticus (MRSH), identified as yellow colonies resembling MRSA on mannitol salt agar. PFGE analysis of the MRSA and MRSH isolates revealed that most isolates of each organism were identical or closely related to each other, suggesting a common source of contamination. CONCLUSIONS: X-ray cassettes, which are commonly in direct contact with patients, were contaminated with MRSA and MRSH. In hospital environments, contaminated X-ray cassettes may serve as fomites for methicillin-resistant staphylococci.

Collateral Vessels in Moyamoya Disease: Comparison of MR and MRA with Conventional Angiography

PURPOSE: To determine the value of magnetic resonance imaging(MR) and magnetic resonance angiography(MRA) inassessing collateral vessels of moyamoya disease. MATERIALS AND METHODS: Twenty-four patients with moyamoyadisease who underwent MR, 3D TOF MRA, and conventional angiography participated in this study. Two radiologistsworking independently and with no knowledge of the angiographic findings, interpreted the MR and MRA images. Todetermine the presence of parenchymal and leptomeningeal collaterals(48 hemispheres) and transdural collaterals(38hemispheres in 19 patients were depicted by angiography of the external carotid), the findings were compared withthose of angiography. RESULTS: Parenchymal, leptomeningeal, and transdural collaterals were depicted byconventional angiography in 34(71%), 32(67%), and 11(29%) hemispheres respectively. The sensitivity andspecificity of MR/MRA for collateral vessels were 79.1/ 88.1% for parenchymal collaterals, 72.1/ 88.1% forleptomeningeal collaterals, and 0.1/18.1% for transdural collaterals, respectively. Respective sensitivity andspecificity of MR/MRA were 88.94/94.1% for leptomeningeal collaterals, and 18.93/55.1% for transdural collaterals,when the prominent posterior cerebral and external carotid artery were regarded as secondary signs ofleptomeningeal and transdural collateral vessels. CONCLUSION: In moyamoya disease, MR and MRA are useful imagingmodalities for the assessment of collateral vessels. The prominent posterior cerebral artery and external carotidartery can be useful secondary signs of leptomeningeal and transdural collateral vessels.

Orbital Blowout Fracture: MR Findings

PURPOSE: To access the usefulness of magnetic resonance(MR) in the evaluation of orbital blowout fracture. MATERIALS AND METHODS: Fourteen patients with orbital blow out fractures diagnosed by plain radiography(n = 8) or computed tomography(CT)(n = 6) were examined with MR. Twenty blowout fractures including six patients with two lesions were presented and the fracture site of the orbit was the medial wall in 11 cases and the orbital floor innine cases. MR images in nine cases of six patients could be compared with CT scans. On MR images, were trospectively evaluated the presence of fracture, herniation of orbital fat, abnormality of extraocular muscle, intraorbital hematoma and intrasinus hemorrhage. In nine cases we also compared these findings with CT scans. RESULTS: Eighteen orbital blowout fractures with fat herniation could be diagnosed on MR images. In only nine of these 18 cases, the fracture itself could be seen on MR images as a disruption of the orbital wall, which produce a signal void. But two blow out fractures without orbital fat herniation, seen on CT, were not detected on MRimages. Twenty abnormalities of extraocular muscle in 18 cases were depicted on MR images. There were nosignificant differences between MR and CT in the evaluation of orbital fat herniation and extraocular muscle abnormality ; however, in one case oblique sagittal MR images provided more useful information about the status ofthe inferior rectus muscle. Intraorbital hematoma was detected by MR in three patients. We were able to establish the presence of intraorbital hematoma by using the different signal intensities from fat or muscle on T1- and/or T2-weighted images. MR was found to be superior to CT in one case of intraorbital hematoma because of the iso-density of hematoma compared to muscle. MR also detected intrasinus hemorrhage which on T1-weighted images revealed high signal intensity in ten cases. MR was more valuable in demonstrating intrasinus hemorrhage in onecase where a CT scan showed only hypodense fluid. CONCLUSION: MR is a useful diagnostic modality in the evaluation of orbital blowout fracture with orbital fat herniation. Compared with CT, it also provides more valuable information about associated extraocular muscle abnormality, subacute hemorrhage in the orbit and paranasal sinus.

Distal Ureteral Calculi: The Usefulness of Transrectal Ultrasound and Comparision with Intravenous Urography

PURPOSE: To determine the usefulness of transrectal ultrasound (TRUS) and to compare TRUS with intravenousurography (IVU) in the evaluation of distal ureteral calculi. MATERIALS AND METHODS: TRUS and IVU were perfomed in 24 patients with distal ureteral calculi. Using TRUS, we evaluated the presence and size of calculus, type of ureteral jet at the affected site and diameter of ureter proximal to calculus, and using IVU evaluated the presence and size of calculus, degree of ureteral obstruction, and degree of hydroureter. TRUS and IVU findings, were compared. RESULTS: In each patient, TRUS detected calculus of the distal ureter ; in only 18cases (75%),were the calculi demonstrated with IVU. In 18 cases where calculi were detected by both modalities, average calculus size was 4.5 X 3.0mm (longest and shortest dimensions) by IVU, and 6.1 X 3.7 mm by TRUS. Betwee TRUS and IVU(p0.05). CONCLUSION: TRUS appears to be a useful adjunctive method for the evaluation of distal ureteral calculus.

Comparisons of MR Findings of the Spinal Metastasis and the Spinal Tuberculosis

PURPOSE: MR findings of the spinal metastasis and the tuberculosis are well known, but sometimes it might be difficult to differentiate these lesions. Therefore we reviewed and analyzed the MR findings which would be useful for the differentiation. MATERIALS AND METHODS: T1- and T2-weighted spin echo images and gadolinium-enhanced Tl-weighted images were obtained with 1. 5T and 1. 0T superconductive MR imager. We reviewed MR findings in 16 cases of spinal metastases and 24 cases of spinal tuberculosis in terms of signal intensity, contrast enhancement pattern, disc space involvement, spinal canal compressing feature and paraspinal soft tissue mass. RESULTS: The signal intensities of both lesions were hypointense on T1WI and hyperintense on T2WI except those of the metastatic lesions from the prostatic carcinoma. Heterogeneous enhancement was noted in 63% of metastasis, whereas peripheral rim enhancement was noted in 83% of spinal tuberculosis(p (.001). Spinal canal compression by collapsed vertebra was only noted in spinal metastasis, and that by paraspinal soft tissue was noted in both spinal metastasis and tuberculosis(p (.001). Disc space invasion was noted in 19% of spinal metastasis and 88% of spinal tuberculosis. Spinal tuberculosis was common at lower thoracic spine(T10) and typically involved two or more adjacent vertebral bodies(96%). CONCLUSION: The important differential point between spinal metastasis and tuberculosis was the enhancement pattern, involvement of two or more contiguous vertebral bodies and the feature of spinal canal compressing. The secondary importance was the disc space involvement pattern.

Computed tomotgraphy in the preoperative evaluation of clinical stage I b-II a carcinoma of the cervix / 대한산부인과학회잡지

No abstract available.