Consensus Recommendations for Gastric Emptying Scintigraphy: A Joint Report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72757/1/j.1572-0241.2007.01636.x.pd

Utility of sedation for young children undergoing dimercaptosuccinic acid renal scans

BACKGROUND: No studies have examined whether use of sedation during a Tc-99m dimercaptosuccinic acid (DMSA) renal scan reduces patient discomfort. OBJECTIVE: To compare discomfort level during a DMSA scan to the discomfort level during other frequently performed uroradiologic tests, and to determine whether use of sedation during a DMSA scan modifies the level of discomfort. MATERIALS AND METHODS: We examined the discomfort level in 798 children enrolled in the Randomized Intervention for children with Vesicoureteral Reflux (RIVUR) and Careful Urinary Tract Infection Evaluation (CUTIE) studies by asking parents to rate their child's discomfort level with each procedure on a scale from 0 to 10. We compared discomfort during the DMSA scan and the DMSA image quality between centers in which sedation was used >90% of the time (sedation centers), centers in which sedation was used <10% of the time (non-sedation centers), and centers in which sedation was used on a case-by-case basis (selective centers). RESULTS: Mean discomfort level was highest for voiding cystourethrogram (6.4), followed by DMSA (4.0), followed by ultrasound (2.4; P<0.0001). Mean discomfort level during the DMSA scan was significantly higher at non-sedation centers than at selective centers (P<0.001). No difference was apparent in discomfort level during the DMSA scan between sedation centers and selective centers (P=0.12), or between the sedation centers and non-sedation centers (P=0.80). There were no differences in the proportion with uninterpretable DMSA scans according to sedation use. CONCLUSION: Selective use of sedation in children 12–36 months of age can reduce the discomfort level experienced during a DMSA scan

Diminished organelle motion in murine Kupffer cells during the erythrocytic stage of malaria

Parasitized erythrocytes are ingested by murine hepatic macrophages during malaria infection. We non-invasively monitored how this altered the motion of intracellular phagosomes in Kupffer cells using magnetometry. Submicrometric γFe2O3 particles were injected prior to malaria infection. They were cleared from the blood, primarily by Kupffer cells, and retained within their phagosomes. The mice were periodically magnetized. After removing this external magnet, the aligned iron particles created a remnant magnetic field (RMF) which then decayed (relaxation), reflecting the motion of particle-containing phagosomes. After baseline measurements of relaxation, the mice were injected intravenously with Plasmodium chabaudi-parasitized or normal murine red blood cells (RBCs). During the next 15 days, relaxation measurements, parasitaemia and haematocrit values were monitored. At 6 days post injection with 3 × 107 parasitized RBCs, relaxation rates had decreased. At this time, all mice had parasitaemias greater than 58 per cent and haematocrits less than 20 per cent. At day 7, while the parasitaemias were declining, the rate of relaxation continued to decrease. Throughout the experiment, relaxation remained constant in animals injected with normal RBCs. Electron microscopy revealed Kupffer cells filled with damaged and parasitized erythrocytes, and haemoglobin degradation pigment. We conclude that ingestion and metabolism of parasitized erythrocytes by liver macrophages during malaria infection decreases their organelle motion with likely consequences of compromised host defences