Effect of Clinical Decision Support on Appropriateness of Advanced Imaging Use Among Physicians-in-Training.

OBJECTIVE: Clinical decision support (CDS) tools have been shown to reduce inappropriate imaging orders. We hypothesized that CDS may be especially effective for house staff physicians who are prone to overuse of resources. MATERIALS AND METHODS: Our hospital implemented CDS for CT and MRI orders in the emergency department with scores based on the American College of Radiology's Appropriateness Criteria (range, 1-9; higher scores represent more-appropriate orders). Data on CT and MRI orders from April 2013 through June 2016 were categorized as pre-CDS or baseline, post-CDS period 1 (i.e., intervention with active feedback for scores of ≤ 4), and post-CDS period 2 (i.e., intervention with active feedback for scores of ≤ 6). Segmented regression analysis with interrupted time series data estimated changes in scores stratified by house staff and non-house staff. Generalized linear models further estimated the modifying effect of the house staff variable. RESULTS: Mean scores were 6.2, 6.2, and 6.7 in the pre-CDS, post-CDS 1, and post-CDS 2 periods, respectively (p < 0.05). In the segmented regression analysis, mean scores significantly (p < 0.05) increased when comparing pre-CDS versus post-CDS 2 periods for both house staff (baseline increase, 0.41; 95% CI, 0.17-0.64) and non-house staff (baseline increase, 0.58; 95% CI, 0.34-0.81), showing no differences in effect between the cohorts. The generalized linear model showed significantly higher scores, particularly in the post-CDS 2 period compared with the pre-CDS period (0.44 increase in scores; p < 0.05). The house staff variable did not significantly change estimates in the post-CDS 2 period. CONCLUSION: Implementation of active CDS increased overall scores of CT and MRI orders. However, there was no significant difference in effect on scores between house staff and non-house staff.

Spuriously aggressive features of a lactating adenoma prompting repeated biopsies.

We present an atypical presentation of a common pregnancy-related breast mass, a lactating adenoma with imaging and pathologic correlation. The patient presented with a rapidly enlarging left breast mass associated with skin changes and severe pain in the perinatal period. Core biopsies were considered discordant, and the patient went on to surgical excision for the definitive diagnosis of an infarcted lactating adenoma. The symptoms of infarction may obscure the diagnosis of common entities and result in additional evaluation.

Continuous flow-driven inversion for arterial spin labeling using pulsed radio frequency and gradient fields.

Continuous labeling by flow-driven adiabatic inversion is advantageous for arterial spin labeling (ASL) perfusion studies, but details of the implementation, including inefficiency, magnetization transfer, and limited support for continuous-mode operation on clinical scanners, have restricted the benefits of this approach. Here a new approach to continuous labeling that employs rapidly repeated gradient and radio frequency (RF) pulses to achieve continuous labeling with high efficiency is characterized. The theoretical underpinnings, numerical simulations, and in vivo implementation of this pulsed continuous ASL (PCASL) method are described. In vivo PCASL labeling efficiency of 96% relative to continuous labeling with comparable labeling parameters far exceeded the 33% duty cycle of the PCASL RF pulses. Imaging at 3T with body coil transmission was readily achieved. This technique should help to realize the benefits of continuous labeling in clinical imagers.

Efficiency of inversion pulses for background suppressed arterial spin labeling.

Background suppression strategies for arterial spin labeling (ASL) MRI offer reduced noise from motion and other system instabilities. However, the inversion pulses used for suppression can also attenuate the ASL signal, which may offset the advantages of background suppression. Numerical simulations were used to optimize the inversion efficiency of four candidate pulses over a range of radiofrequency (RF) and static magnetic field variations typical of in vivo imaging. Optimized pulses were then used within a pulsed ASL sequence to assess the pulses' in vivo inversion efficiencies for ASL. The measured in vivo inversion efficiency was significantly lower than theoretical predictions (e.g., 93% experimental compared to 99% theoretical) for the tangent hyperbolic pulse applied in a background suppression scheme. This inefficiency was supported by an in vitro study of human blood. These results suggest that slow magnetization transfer (MT) in blood, either with bound water or macromolecular protons, dominates the inversion inefficiency in blood. Despite the attenuated signal relative to unsuppressed ASL, the signal-to-noise ratio (SNR) with suppression was improved by 23-110% depending on the size of the region measured. Knowledge of efficiency will aid optimization of the number of suppression pulses and provide more accurate quantification of blood flow.