Comparing diagnosis of midfacial fractures by radiologists and plastic surgeons.

BACKGROUND: Clinicians who manage facial fractures often rely on radiologist interpretations to help with assessment and management. Among treating physicians, facial fractures are categorized into clinically relevant patterns of injury. On the other hand, while radiologists are unsurpassed at identifying individual breaks in the bone, larger fracture patterns are not always conveyed in radiology reports. PURPOSE: This study aims to assess the frequency with which the terminology describing midfacial fracture patterns is concordant among radiologists and treating clinicians. METHODS: The authors identified patients with different patterns of midfacial injury including Le Fort I, Le Fort II, Le Fort III, naso-orbito-ethmoid (NOE), and zygomaticomaxillary complex (ZMC) fractures. Plastic surgery consult notes and radiological imaging reports were reviewed for concordance in documentation of injury patterns. Identification of individual fractures consistent with the diagnosed fracture pattern was also recorded. RESULTS: Radiologists were noted to be highly successful in describing individual fractures of the facial bones, identifying at least two defining components of a fracture pattern in 96% of Le Fort, 88% of NOE, and 94% of ZMC injuries. However, when injury patterns were considered, only 32% of Le Fort, 28% of ZMC, and 6% of NOE fractures were explicitly identified in radiology reports. CONCLUSIONS: Radiologists are highly skilled in discerning individual fractures in facial trauma cases. However, less reliability was seen in the identification of fracture patterns in midfacial injury, with particular weaknesses in descriptions of NOE and ZMC fractures. This data suggests that greater focus on patterns of midfacial injury would improve the clinical applicability of radiological reports.

Adding non-contrast and delayed phases increases the diagnostic performance of arterial CTA for suspected active lower gastrointestinal bleeding.

OBJECTIVES: When assessing for lower gastrointestinal bleed (LGIB) using CTA, many advocate for acquiring non-contrast and delayed phases in addition to an arterial phase to improve diagnostic performance though the potential benefit of this approach has not been fully characterized. We evaluate diagnostic accuracy among radiologists when using single-phase, biphasic, and triphasic CTA in active LGIB detection. METHOD AND MATERIALS: A random experimental block design was used where 3 blinded radiologists specialty trained in interventional radiology retrospectively interpreted 96 CTA examinations completed between Oct 2012 and Oct 2017 using (1) arterial only, (2) arterial/non-contrast, and (3) arterial/non-contrast/delayed phase configurations. Confirmed positive and negative LGIB studies were matched, balanced, and randomly ordered. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive and negative predictive values, and time to identify the presence/absence of active bleeding were examined using generalized estimating equations (GEE) with sandwich estimation assuming a binary distribution to estimate relative benefit of diagnostic performance between phase configurations. RESULTS: Specificity increased with additional contrast phases (arterial 72.2; arterial/non-contrast 86.1; arterial/non-contrast/delayed 95.1; p < 0.001) without changes in sensitivity (arterial 77.1; arterial/non-contrast 70.2; arterial/non-contrast/delayed 73.1; p = 0.11) or mean time required to identify bleeding per study (s, arterial 34.8; arterial/non-contrast 33.1; arterial/non-contrast/delayed 36.0; p = 0.99). Overall agreement among readers (Kappa) similarly increased (arterial 0.47; arterial/non-contrast 0.65; arterial/non-contrast/delayed 0.79). CONCLUSION: The addition of non-contrast and delayed phases to arterial phase CTA increased specificity and inter-reader agreement for the detection of lower gastrointestinal bleeding without increasing reading times. KEY POINTS: • A triphasic CTA including non-contrast, arterial, and delayed phase has higher specificity for the detection of lower gastrointestinal bleeding than arterial-phase-only protocols. • Inter-reader agreement increases with additional contrast phases relative to single-phase CTA. • Increasing the number of contrast phases did not increase reading times.

Effect of patient size on mean sterile water attenuation during multiphase CT examinations.

OBJECTIVE: The purpose of this study was to determine the variability of attenuation measurements in a water phantom included in the FOV during multiphase 64-MDCT. SUBJECTS AND METHODS: Ninety-seven consecutively registered patients undergoing multiphase kidney and liver protocol CT of the abdomen on the same 64-MDCT scanner had a sealed water bottle placed on their anterior abdomen during the examination. Region of interest (ROI) measurements of the mean attenuation (in HU) of the water bottle were made during the unenhanced, dynamic, and delayed phases of contrast enhancement. Generalized estimating equations were used to model mean attenuation in the ROI as a function of cross-sectional patient area, contrast phase, and protocol. Day of month and time of day were covariates. A phantom was created to model the patient study. RESULTS: The mean attenuation values in the water bottle ROIs were -13.1 HU for the kidney protocol and -9.1 HU for the liver protocol in the unenhanced phase, -11.7 HU for the kidney and -9.5 HU for the liver protocol in the dynamic phase, and -11.9 HU for the kidney and 11.0 HU for the liver protocol in the delayed phase. Kidney protocol water bottle ROI attenuation values were lower than the liver values (p = 0.04). In all phases with both protocols, the values differed from 0 HU (all p < 0.0001). Water bottle ROI attenuation decreased as patient cross-sectional area increased (-0.01 HU/cm(2), p < 0.0001). Three patients had absolute water bottle attenuation changes greater than 20 HU between phases. Day of the month (p = 0.08) and time of day (p = 0.93) were not significant factors. Phantom data supported the study findings. CONCLUSION: The mean attenuation of water decreased as patient diameter increased. Both artifactual enhancement and decrease in enhancement greater than 20 HU were found in three larger patients.

Nucleolar binding of an anti-NMDA receptor antibody in hydra: a non-canonical role for an NMDA receptor protein?

Two emerging concepts in cell biology are the back-and-forth trafficking of receptor proteins and nuclear transcription factors between the nucleus and the cell membrane, and the alternative splicing of messenger RNA to produce similar proteins targeted to different cell sites. Recent evidence suggests that the nucleolus is a dynamic structure whose components may be involved in both types of trafficking. In the nervous system of higher animals, the N-methyl-D-aspartate (NMDA)-specific glutamate receptor has various roles in development and cell communication. It is involved in learning, memory, axonal guidance and nerve regeneration. We have reported earlier that the NR1 subunit of the NMDA receptor is present in the cell periphery and the nucleus of stem cells, neurons and epitheliomuscular cells of the early-evolved cnidarian, Hydra vulgaris (Scappaticci et al., 2004. Cell Tissue Res 316:263-270); it is involved in coordinating hydra's neuroeffector systems (Kass-Simon and Scappaticci, 2003. Hydrobiologia 530/531:67-71; Pierobon et al., 2004. Eur J Neurosci 20:2598-2604; Scappaticci and Kass-Simon, 2008. Comp Biochem Physiol A 150:415-422; Kay and Kass-Simon, 2009. Bio Bull 216:113-129). Here we report immunocytochemical experiments, using a mouse monoclonal antibody raised against the mammalian NR1 receptor subunit, and an in silico genomic and gene expression analysis identifying the homologues in hydra of mammalian NR1 and fibrillarin (FBL) genes, and their expressed proteins. The experiments reveal that the NR1 antibody specifically labels the nucleoli of large and small interstitial cells (stem cells), nematoblasts, neuroblasts, and epitheliomusclar cells; antibody labeling of the nucleolar marker, FBL, confirms the nucleolar localization of NR1 antibody labeling. Genomic analysis reveals that NR1 and FBL genes are conserved in hydra, and suggests that there are at least two NR1 splice variants, one of which contains both nuclear and nucleolar targeting signals. The finding that an NR1 receptor subunit (or a portion of it) appears in nucleoli of hydra cells is unique, and has not been reported for any other organism. Its presence in nucleoli of hydra may signal the existence of a yet-undescribed shuttle mechanism between the cell surface and the nucleous, or the alternative deployment of NR1 splice variants to different cell sites.