Susceptibility-weighted imaging of retinal hemorrhages in abusive head trauma.

BACKGROUND: Retinal hemorrhages are one of the most important supportive evidences for abusive head trauma (AHT). Susceptibility-weighted imaging (SWI) is highly suited to identify various forms of intracranial hemorrhage in AHT. However its utility in imaging retinal hemorrhage is not well established. OBJECTIVE: SWI is a sensitive sequence for identifying retinal hemorrhage on MRI. MATERIALS AND METHODS: In this retrospective analysis, 26 consecutive infants and young children with a suspected admission diagnosis of AHT underwent indirect ophthalmoscopy and brain MRI protocol for AHT along with SWI. Brain susceptibility-weighted images of 14 age-matched children were used as controls. For detecting retinal hemorrhage, susceptibility-weighted images of patients and controls were reviewed randomly and independently by two neuroradiologists who were blinded to the history and ophthalmology findings. A pediatric ophthalmologist graded the indirect ophthalmoscopy images. RESULTS: A diagnosis of AHT was confirmed in all 26 cases from a multidisciplinary meeting. Indirect ophthalmoscopy images were available in 21 cases. Ophthalmoscopy was positive for retinal hemorrhage in the right eye in 18 cases (85.7%) and in the left eye in 16 cases (76.2%). On SWI, retinal hemorrhage was identified in the right eye in 9/21 cases (42.8%) and in the left eye in 8/21 cases (38.1%) of AHT. Analysis of SWI in 21 cases of AHT demonstrated a sensitivity of 50%, specificity of 100%, positive predictive value of 100% and negative predictive value of 32% for detecting retinal hemorrhage. CONCLUSION: SWI is moderately sensitive and highly specific for identifying retinal hemorrhage in AHT. Further studies are needed to identify steps to improve the efficiency of SWI in detecting retinal hemorrhage.

Pericatheter leak in a peritoneal dialysis patient: SPECT/CT diagnosis.

A 62-year-old patient with end-stage renal disease who is managed with continuous ambulatory peritoneal dialysis developed anterior abdominal wall swelling and pain that extended from just above peritoneal catheter site caudally. CT of the abdomen suggested pericatheter abscess with panniculitis. Tc-99m sulfur colloid peritoneal distribution planar scintigraphy suggested the diagnoses of pericatheter leak. The addition of SPECT/CT confirmed the latter diagnosis and pinpointed the exact location of the peritoneal leakage that was around insertion site. SPECT/CT was useful in establishing unequivocal diagnosis of peritoneal leak.

Mebrofenin clearance rate for liver function testing: standardization of methodology aimed to improve intraobserver reproducibility.

OBJECTIVE: This study aimed to assess which region of interest results in the best intraobserver reproducibility of mebrofenin clearance rate (MCR) processing. METHODS: Mebrofenin clearance rate was calculated according to Ekman's formalism. Processing methods included smaller left ventricular (LV) versus larger regions, nearly the whole heart (WH), which were applied to either anterior (ANT) or geometric mean (GEO) data. Each variation was processed twice by an expert operator, and Pearson linear correlation (r) was used to test for reproducibility. RESULTS: Studies from 50 patients (16 women) were available for processing. Mean (SD) for age, model for end-stage liver disease, and Child scores were 54 (10) years (range, 23-70 y), 13.1 (4.9) (range, 6-30), and 7.8 (2.1) (range, 5-14), respectively. The linear correlation equations (r, significance) between the 2 processing takes were y=0.34x+4.3 (r=0.5442, P<0.0001) for MCR-LV-ANT, y=0.94x+0.33 (r=0.9464, P<0.0001) for MCR-LV-GEO, y=0.87x+0.50 (r=0.9760, P<0.0001) for MCR-WH-ANT, and y=0.92x+0.24 (r=0.9898, P<0.0001) for MCR-WH-GEO. The MCR-WH-GEO method had statistically better reproducibility when compared with the other methods. CONCLUSIONS: The highest reproducibility was found with the technique that used geometric mean data and the larger blood pool region of interest. Further work should address training approaches that foster optimal interoperator reproducibility, which could allow for wider implementation of this liver function parameter.