Safety and Effectiveness of Transhepatic Access for Percutaneous Renal Mass Cryoablation: A Multicenter Cohort.

PURPOSE: To establish transhepatic percutaneous cryoablation of renal masses as a safe and effective approach. MATERIALS AND METHODS: A retrospective review of records from 3 separate medical centers was performed identifying 23 patients (median age, 63 years [range 41-84 years]; 12 female [52.2%]) who underwent percutaneous transhepatic cryoablation for right-sided renal masses (median diameter, 2.4 cm [1.5-4.6 cm]) between 2008 and 2021. The median radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry score was 5 (4-10). Adverse events (AEs) were classified according to the Society of Interventional Radiology (SIR) and Clavien-Dindo (CD) classifications. Primary and secondary technical success of each procedure were recorded. RESULTS: Renal cell carcinoma (of any subtype) was found in 10 (71.5%) of the 14 masses that were biopsied. Tract cautery was used for transhepatic probes in 14 (63.6%) of 22 procedures. Three (13%) of 23 patients had postprocedural AEs. Two cases (8.6%) were hemorrhages related to transhepatic access (SIR moderate-2, CD 2; SIR severe-3, CD 1), and 1 case (4.4%) was related to bowel injury (SIR severe-3, CD 3a). There were no instances of pneumothorax. Tract cautery was used in the procedures that resulted in an AE. Primary technical success was achieved in 84.2% (16/19) of procedures, whereas secondary technical success was achieved in 2 additional patients. The secondary technical success rate was 94.7% (18/19). Four patients did not have imaging follow-up. CONCLUSIONS: The transhepatic approach to cryoablation of renal masses appears to have an acceptable safety profile and technical success rate. Larger studies, preferably comparative to nontranshepatic approach, are recommended.

Deep Learning Improves the Temporal Reproducibility of Aortic Measurement.

Imaging-based measurements form the basis of surgical decision making in patients with aortic aneurysm. Unfortunately, manual measurement suffer from suboptimal temporal reproducibility, which can lead to delayed or unnecessary intervention. We tested the hypothesis that deep learning could improve upon the temporal reproducibility of CT angiography-derived thoracic aortic measurements in the setting of imperfect ground-truth training data. To this end, we trained a standard deep learning segmentation model from which measurements of aortic volume and diameter could be extracted. First, three blinded cardiothoracic radiologists visually confirmed non-inferiority of deep learning segmentation maps with respect to manual segmentation on a 50-patient hold-out test cohort, demonstrating a slight preference for the deep learning method (p < 1e-5). Next, reproducibility was assessed by evaluating measured change (coefficient of reproducibility and standard deviation) in volume and diameter values extracted from segmentation maps in patients for whom multiple scans were available and whose aortas had been deemed stable over time by visual assessment (n = 57 patients, 206 scans). Deep learning temporal reproducibility was superior for measures of both volume (p < 0.008) and diameter (p < 1e-5) and reproducibility metrics compared favorably with previously reported values of manual inter-rater variability. Our work motivates future efforts to apply deep learning to aortic evaluation.

Where Similar Cases Are Stated: Medical Case Studies and Provisional Knowledge in Charles Brockden Brown's Wieland.

Scholars of literature and medicine have begun to address the under-studied relationship between the medical case study and the novel, two central genres emerging out of Enlightenment empiricism. This essay contributes to this line of inquiry by focusing on Charles Brockden Brown's novel Wieland (1798) and the medical case study. It unpacks the connection between Wieland and the launching of the first medical journal in the U.S., the Medical Repository. While scholarship has attended to the influence of contagious disease and medicine on Brown's later novels, this essay demonstrates the importance of medical ways of knowing at the beginning of the novelist's brief career. Specifically, it argues that Brown borrows a provisional mode of reasoning from medical literature, a mode of reasoning that finds literary form in the case study of the pre-clinical era.

MIRMAID: A Content Management System for Medical Image Analysis Research.

Today, a typical clinical study can involve thousands of participants, with imaging data acquired over several time points across multiple institutions. The additional associated information (metadata) accompanying these data can cause data management to be a study-hindering bottleneck. Consistent data management is crucial for large-scale modern clinical imaging research studies. If the study is to be used for regulatory submissions, such systems must be able to meet regulatory compliance requirements for systems that manage clinical image trials, including protecting patient privacy. Our aim was to develop a system to address these needs by leveraging the capabilities of an open-source content management system (CMS) that has a highly configurable workflow; has a single interface that can store, manage, and retrieve imaging-based studies; and can handle the requirement for data auditing and project management. We developed a Web-accessible CMS for medical images called Medical Imaging Research Management and Associated Information Database (MIRMAID). From its inception, MIRMAID was developed to be highly flexible and to meet the needs of diverse studies. It fulfills the need for a complete system for medical imaging research management.

DEWEY: the DICOM-enabled workflow engine system.

Workflow is a widely used term to describe the sequence of steps to accomplish a task. The use of workflow technology in medicine and medical imaging in particular is limited. In this article, we describe the application of a workflow engine to improve workflow in a radiology department. We implemented a DICOM-enabled workflow engine system in our department. We designed it in a way to allow for scalability, reliability, and flexibility. We implemented several workflows, including one that replaced an existing manual workflow and measured the number of examinations prepared in time without and with the workflow system. The system significantly increased the number of examinations prepared in time for clinical review compared to human effort. It also met the design goals defined at its outset. Workflow engines appear to have value as ways to efficiently assure that complex workflows are completed in a timely fashion.

GacS-dependent regulation of polyhydroxyalkanoate synthesis in Pseudomonas putida CA-3.

To date, limited reports are available on the regulatory systems exerting control over bacterial synthesis of the biodegradable polyester group known as polyhydroxyalkanoates (PHAs). In this study, we performed random mini-Tn5 mutagenesis of the Pseudomonas putida CA-3 genome and screened transconjugants on nitrogen-limited medium for reduced PHA accumulation phenotypes. Disruption of a GacS sensor kinase in one such mutant was found to eliminate medium-chain-length PHA production in Pseudomonas putida CA-3. Recombinant expression of wild-type gacS from a pBBRgacS vector fully restored PHA accumulation capacity in the mutant strain. PCR-based screening of the P. putida CA-3 genome identified gene homologues of the GacS/GacA-rsm small RNA (sRNA) regulatory cascade with 96% similarity to published P. putida genomes. However, reverse transcription-PCR (RT-PCR) analyses revealed active transcription of the rsmY and rsmZ sRNAs in gacS-disrupted P. putida CA-3, which is atypical of the commonly reported Gac/Rsm regulatory cascade. Quantitative real-time RT-PCR analyses of the phaC1 synthase responsible for polymer formation in P. putida CA-3 indicated no statistically significant difference in transcript levels between the wild-type and gacS-disrupted strains. Subsequently, SDS-PAGE protein analyses of these strains identified posttranscriptional control of phaC1 synthase as a key aspect in the regulation of PHA synthesis by P. putida CA-3.

The Ability of Patients to Correctly Identify Their Hospitalist on a Patient Satisfaction Survey and the Impact of This Factor on Hospitalist Scores.

Background: Patient evaluations of their physician have been utilized to evaluate physician performance and calculate hospital reimbursement. Despite the routine use of these evaluations, little research has been done to evaluate the accuracy of these evaluations. We assessed patient's ability to correctly identify the hospitalist providing their care and whether identification of the hospitalist affected the cumulative satisfaction scores. Methods: This prospective observational study was conducted at a suburban voluntary hospital. Hospitalists were evaluated anonymously by their patients over a 4-month period on a questionnaire designed to assess patient satisfaction. Results: One hundred fifty-eight patients evaluated 16 hospitalists yielding an average of 9.9 evaluations per hospitalist. Forty Nine (31%) patients were able to identify their hospitalist. The top score (3) accounted for 76% of patient responses across all questions. Significant differences (p = .0007) existed in the distribution of these scores when patients who could identify their hospitalist was compared with those who couldn't. The variables for effective communication and hospitalist introduction were scored significantly higher by patients who could identify their hospitalist (2.77 vs 2.55; p = .027 and 2.90 vs 2.67; p = .005). Patients of younger age and female gender were more likely identify their hospitalist. Conclusions: Less than one-third of patients were able to correctly identify their hospitalist. The variables for effective communication and hospitalist introduction to the patient were scored significantly higher by patients who could identify their hospitalist. The elimination of scores by patients who could not correctly identify their provider resulted in marked changes in the percentile ranking of these providers.

Computer-aided detection of intracranial aneurysms in MR angiography.

Intracranial aneurysms represent a significant cause of morbidity and mortality. While the risk factors for aneurysm formation are known, the detection of aneurysms remains challenging. Magnetic resonance angiography (MRA) has recently emerged as a useful non-invasive method for aneurysm detection. However, even for experienced neuroradiologists, the sensitivity to small (<5 mm) aneurysms in MRA images is poor, on the order of 30~60% in recent, large series. We describe a fully automated computer-aided detection (CAD) scheme for detecting aneurysms on 3D time-of-flight (TOF) MRA images. The scheme locates points of interest (POIs) on individual MRA datasets by combining two complementary techniques. The first technique segments the intracranial arteries automatically and finds POIs from the segmented vessels. The second technique identifies POIs directly from the raw, unsegmented image dataset. This latter technique is useful in cases of incomplete segmentation. Following a series of feature calculations, a small fraction of POIs are retained as candidate aneurysms from the collected POIs according to predetermined rules. The CAD scheme was evaluated on 287 datasets containing 147 aneurysms that were verified with digital subtraction angiography, the accepted standard of reference for aneurysm detection. For two different operating points, the CAD scheme achieved a sensitivity of 80% (71% for aneurysms less than 5 mm) with three mean false positives per case, and 95% (91% for aneurysms less than 5 mm) with nine mean false positives per case. In conclusion, the CAD scheme showed good accuracy and may have application in improving the sensitivity of aneurysm detection on MR images.

Low Frequency EPR and EMR Point Spectroscopy and Imaging of a Surface.

Low frequency electron paramagnetic resonance (LFEPR) spectrometers operating between 100 and 500 MHz typically have large-volume magnets that accommodate large samples. LFEPR spectroscopy with a 2.9 mm diameter surface coil was used to record point spectra and image the spatial distribution of the spin probe 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and electrophotographic toner in printed letters on a flat surface. The location of the surface coil was fixed on the desired location when a spectrum was recorded. The magnetic field of the spectrometer was fixed on the location of the signal and the sample was scanned under the surface coil in parallel trajectories to produce an image of the signal in the letters "LFEPR". We speculate on the utility of this technique to study flat objects such as paintings and illuminated manuscripts with cultural heritage significance.

Anatomical study of factors contributing to zygomatic complex fracture instability in human cadavers.

BACKGROUND: Stable reduction of fractures of the zygomatic complex is essential to avoid long-term aesthetic, sensory, and ocular consequences. Delayed collapse or relapse after reduction of fractures of the zygomatic complex is attributed to muscle forces, when there has been no additional trauma. A number of studies have identified the masseter muscle as a contributor, but none has described the role of the temporalis muscle. METHODS: The origins of the temporalis muscle were examined in six cadaveric dissections. The temporal and zygomatic regions were exposed through a temporoparietal flap. Bone cuts were made above and below the frontozygomatic suture in the lateral orbital margin. The lateral orbital margin was then fractured and reflected laterally on its periosteum so that muscle attachments could be seen clearly. RESULTS: In all six dissections, the authors found that the temporalis muscle took origin not only from the floor of the temporal fossa and temporalis fascia but also from the lateral margin of the orbit and the frontal process of the zygomatic bone as far down as the body of the zygoma. CONCLUSIONS: The authors postulate that the functional forces exerted by this muscle on the zygomatic complex cause postoperative distraction at the frontozygomatic suture. The authors' findings provide further anatomical evidence to support internal fixation of all fractures of the zygomatic complex, even those that are considered clinically stable, if permanent flattening of the cheekbone is to be avoided.