Ronchi shearing interferometry for wavefronts with circular symmetry.

Ronchi testing of a focused electromagnetic wave has in the last few years been used extensively at X-ray free-electron laser (FEL) facilities to qualitatively evaluate the wavefront of the beam. It is a quick and straightforward test, is easy to interpret on the fly, and can be used to align phase plates that correct the focus of aberrated beams. In general, a single Ronchigram is not sufficient to gain complete quantitative knowledge of the wavefront. However the compound refractive lenses that are commonly used at X-ray FELs exhibit a strong circular symmetry in their aberration, and this can be exploited. Here, a simple algorithm that uses a single recorded Ronchigram to recover the full wavefront of a nano-focused beam, assuming circular symmetry, is presented, and applied to experimental measurements at the Matter in Extreme Conditions instrument at the Linac Coherent Light Source.

Administering Blood Products Before Selected Interventional Radiology Procedures: Developing, Applying, and Monitoring a Standardized Protocol.

PURPOSE: To apply and monitor a single institution's adherence to internally established guidelines for the preoperative administration of platelets and/or fresh frozen plasma (FFP) before a specified subset of minimally invasive interventional radiology (IR) procedures. MATERIALS AND METHODS: Beginning in December 2008, we implemented a set of restrictive guidelines for preoperative platelet and/or FFP administration before IR procedures at a single academic hospital. Basing our program on the methodology of Lean Six Sigma, we compared the number and appropriateness of transfusions between the months of January and October in 2008 (prepolicy), again in 2010 (postpolicy), and finally in 2015 (follow-up). Patients with a platelet count less than or equal to 50,000 or an international normalized ratio greater than or equal to 1.7 met criteria for receiving platelets or FFP, respectively, before their IR procedure. For all three periods, we compared the rates of transfusion, hemorrhagic complications, and proportion of appropriate versus inappropriate blood product administration (BPA) per our guidelines. RESULTS: There was a significant increase in the number of appropriate BPAs between 2008 and 2010 from 58% to 76% (P = .021). Between 2010 and 2015, the rate trended up further, from 76% to 88% (P = .051). Overall, between 2008 and 2015, the improvement from 58% to 88% was significant (P < .001). The rate of hemorrhagic complications was extremely low in all three groups. CONCLUSION: Restrictive guidelines for receiving platelets and FFP administrations before IR procedures can sustainably decrease the rate of overall BPA while increasing the proportion of appropriate BPA without impacting the rate of hemorrhagic complications.

The phase-contrast imaging instrument at the matter in extreme conditions endstation at LCLS.

We describe the phase-contrast imaging instrument at the Matter in Extreme Conditions (MEC) endstation of the Linac Coherent Light Source. The instrument can image phenomena with a spatial resolution of a few hundreds of nanometers and at the same time reveal the atomic structure through X-ray diffraction, with a temporal resolution better than 100 fs. It was specifically designed for studies relevant to high-energy-density science and can monitor, e.g., shock fronts, phase transitions, or void collapses. This versatile instrument was commissioned last year and is now available to the MEC user community.

Tract embolization with gelatin sponge slurry for prevention of pneumothorax after percutaneous computed tomography-guided lung biopsy.

PURPOSE: To determine the effect of embolization with absorbable gelatin sponge slurry on the incidence of pneumothorax (PTX) and need for chest tube placement after percutaneous lung biopsy. MATERIALS AND METHODS: Seven hundred fifty-two percutaneous lung biopsy procedures and fiducial seed placements were performed using computed tomography (CT)-guidance at a single institution. A retrospective review was performed including 145 patients with embolization (19.28%) of the tract with gelatin sponge slurry during needle withdrawal and 607 patients who did not undergo tract embolization. Patient- and lesion-related characteristics were collected through the electronic health record and PACS. Outcome measures included the occurrence of PTX during or after the biopsy procedure and the need for chest tube placement. Analysis was performed by multivariate logistic regression. RESULTS: Although tract embolization did not significantly decrease the chances of developing PTX (p = 0.06), it did decrease the likelihood of progressing to requiring chest tube insertion. Without tract embolization, 10.7% of cases required a chest tube, whereas only 6.9% of the patients whose tract was embolized needed a chest tube (p = 0.01). A history of emphysema was associated with 151% increased odds of PTX requiring chest tube placement after lung biopsy (p = 0.009). Tract length >24 mm was associated with a 262% increase in the odds of requiring chest tube placement (p = 0.003). CONCLUSION: Embolization of the needle tract during percutaneous lung biopsy with gelfoam slurry significantly decreased the odds of requiring a chest tube for PTX and should be considered for all patients, particularly those with emphysema and deep lesions.