Low-dose Intravenous N-acetylcysteine for the Prevention of Contrast-Induced Nephropathy in Emergency Patients Undergoing Computed Tomography

PURPOSE: To evaluate the effects of low-dose intravenous N-acetylcysteine on the prevention of contrast-induced nephropathy (CIN) in patients undergoing computed tomography (CT). METHODS: All patients presenting to our emergency department and undergoing CT with intravenous contrast media between August 2014 and April 2016 were retrospectively enrolled. We included hospitalized patients with renal dysfunction [estimated glomerular filtration rate (GFR) between 30 and 89 mL/min/1.73 m²]. A 600-mg injection of Nacetylcysteine was given to patients once before and once immediately after CT, depending on the preference of physician. The primary outcome was CIN defined as an increase in creatinine level of ≥25% or ≥0.5 mg/dL from the baseline within 48 to 72 hours after CT. A trained person blindly reviewed all medical records. RESULTS: Of the 1903 admitted patients, CIN occurred in 9.8% of patients who received 1200 mg intravenous N-acetylcysteine (24/244) and 6.8% of patients who did not (113/1659, p=0.090). In a multivariable regression analysis, N-acetylcystine was not relevant to the prevention of CIN (odds ratio=1.42 [95% CI, 0.90–2.26]). Even in the stratified analysis using the propensity score matching, N-acetylcysteine was irrelevant (GFR 30–59: odds ratio=1.06 [95% CI, 0.43–2.60]; GFR 60–89: odds ratio=1.76 [95% CI, 0.75–4.14]). After adjustment, crystalloids were significantly associated with the reduction in CIN compared with dextrose water (odds ratio=0.60 [95% CI, 0.37–0.97]). CONCLUSION: No effect was found when low-dose intravenous N-acetylcysteine was used to prevent CIN. However, there seems to be an association between crystalloids and reduction in CIN.

Comparison of the capsular width measured on ultrasonograph and MR image of the temporomandibular joint / 대한구강악안면방사선학회지

PURPOSE: To evaluate the reliability and clinical usefulness of ultrasonography in the temporomandibular joint (TMJ). MATERIALS AND METHODS: Parasagittal and paracoronal 1.5 T MR images and 7.5 MHz ultrasonographs of 40 TMJs in 20 asymptomatic volunteers were obtained. Disc position using MR imaging was evaluated and the distance between the lateral surface of mandibular condyle and the articular capsule using MR image and ultrasonograph of 27 TMJs with normal disc position was measured and compared. Intraobserver and interobserver measurements reliability was evaluated by using interclass correlation coefficients (ICC) and measurement error. Also, the distance measured on ultrasonographs was compared, according to mouth position and disc postion. RESULTS: The normal disc position was found in 27 of 40 asymptomatic joints. At the intraobserver reliability of measurement, ICC at the closed and open mouth position were 0.89 and 0.91. The measurement error was 0.4% and 0.5%. At the interobserver reliability, ICC at the closed and open mouth position were 0.92 and 0.81. The measurement error was 0.4% and 0.7%. At the TMJ with normal disc position, the distances between the lateral surface of mandibular condyle and the articular capsule measured on MR images and ultrasonographs were 2.0+/- 0.7 mm, 1.8+/-0.5 mm, respectively (p<0.05). On the ultrasonographs, the distances at open mouth position were 1.2+/-0.5 mm (p<0.05). At the TMJ with medially displaced disc, the distances at the closed and open mouth position were 1.3+/-0.3 mm and 0.9+/-0.2mm(p<0.05). CONCLUSION: The results suggest ultrasonography of TMJ is a reliable imaging technique for assessment of normal disc position.

The effect of different radiographic parameters on the height, width and visibility of cross-sectional image of mandible in spiral tomography / 대한구강악안면방사선학회지

PURPOSE: To evaluate the differences in bone height, bone width, and visibility of posterior spiral tomographic images according to various exposure directions, image layer thickness, and inclination of the mandibular inferior border. MATERIALS AND METHODS: Six partially and completely edentulous dry mandibles were radiographed using Scanora spiral tomography. Spiral tomography was performed at different exposure directions (dentotangential and maxillotangential projection), image layer thicknesses (2 mm, 4 mm and 8 mm), and at various inclinations to the mandibular border (+/-10, 0 and -10 ). The bone height and width was measured using selected tomographic images. The visibility of mandibular canal, crestal bone, and buccal and lingual surfaces were graded as 0, 1, or 2. RESULTS: The bone width at the maxillo-tangential projection was wider than at the dento-tangential projection (p< 0.05). The visibility of buccal and lingual surface at the maxillo-tangential projection was higher than at the dento-tangential projection (p< 0.05). Thinner image layer thicknesses resulted in greater visibility of buccal and lingual surfaces (p< 0.05). Bone height was greatest in the -10 group, and at the same time the bone width of the same group was the narrowest (p< 0.05). The visibility of alveolar crest and buccal surface of the+/-10 group was the highest, while the visibility of the mandibular canal was greatest in the 0 group. CONCLUSION: When spiral tomography is performed at the mandibular posterior portion for visualization prior to implant surgery, it is important that the inferior border of mandible be positioned as parallel as possible to the floor. A greater improvement of visibility can be achieved by maintaining a thin image layer thickness when performing spiral tomography.