Preoperative Risk Stratification of Adnexal Masses in the Pediatric and Adolescent Population: Evaluating the Decision Tree System

Study ObjectiveTo evaluate the diagnostic performance of the Decision Tree System (DTS) rules 2 and 3 for surgically managed adnexal masses in the North American population and to compare it with the risk stratification criteria used at The Hospital for Sick Children (≥8 cm and complex/solid).DesignA retrospective cohort study of patients who presented with adnexal masses and were surgically treated between April 2011 and March 2016.SettingThe Hospital for Sick Children (Toronto, Ontario, Canada).ParticipantsPatients 1-18 years of age with adnexal masses who underwent surgical treatment.Interventions and Main Outcome MeasuresMain outcome measures included diagnostic performance (preoperative sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV] for malignancy) of the DTS rules 2 and 3 and ≥8 cm and complex/solid criteria.ResultsThe malignancy rate was 10.4%. The DTS rules 2 and 3 had a sensitivity of 84% (95% confidence interval [CI], 79-90), specificity of 77% (95% CI, 71-83), PPV of 30% (95% CI, 17-42), and NPV of 98% (95% CI, 94-100). The 8 cm or larger and complex/solid criteria had a sensitivity of 89% (95% CI, 85-94), specificity of 71% (95% CI, 64-77), PPV of 27% (95% CI, 16-38), and NPV of 98% (95% CI, 96-100).ConclusionOur study showed that DTS rules 2 and 3 had similar diagnostic performance as the 8 cm or larger and complex/solid criteria in the same population, with a very high NPV and a low PPV. Future prospective investigations should be conducted to further assess how DTS components can be incorporated into future algorithms for the management of adnexal masses in the pediatric population.     

Nerve regeneration and elastin formation within poly(glycerol sebacate)-based synthetic arterial grafts one-year post-implantation in a rat model

The objective of this study was to evaluate the long-term performance of cell-free vascular grafts made from a fast-degrading elastic polymer. We fabricated small arterial grafts from microporous tubes of poly(glycerol sebacate) (PGS) reinforced with polycaprolactone (PCL) nanofibers on the outer surface. Grafts were interpositioned in rat abdominal aortas and characterized at 1 year post-implant. Grafts remodeled into “neoarteries” (regenerated arteries) with similar gross appearance to native rat aortas. Neoarteries mimic arterial tissue architecture with a confluent endothelium and media and adventita-like layers. Patent vessels (80%) showed no significant stenosis, dilation, or calcification. Neoarteries contain nerves and have the same amount of mature elastin as native arteries. Despite some differences in matrix organization, regenerated arteries had similar dynamic mechanical compliance to native arteries in vivo. Neoarteries responded to vasomotor agents, albeit with different magnitude than native aortas. These data suggest that an elastic vascular graft that resorbs quickly has potential to improve the performance of vascular grafts used in small arteries. This design may also promote constructive remodeling in other soft tissues.     

In situ measurements of gas/particle-phase transitions for atmospheric semivolatile organic compounds

An understanding of the gas/particle-phase partitioning of semivolatile compounds is critical in determining atmospheric aerosol formation processes and growth rates, which in turn affect global climate and human health. The Study of Organic Aerosol at Riverside 2005 campaign was performed to gain a better understanding of the factors responsible for aerosol formation and growth in Riverside, CA, a region with high concentrations of secondary organic aerosol formed through the phase transfer of low-volatility reaction products from the oxidation of precursor gases. We explore the ability of the thermal desorption aerosol gas chromatograph (TAG) to measure gas-to-particle-phase transitioning for several organic compound classes (polar and nonpolar) found in the ambient Riverside atmosphere by using in situ observations of several hundred semivolatile organic compounds. Here we compare TAG measurements to modeled partitioning of select semivolatile organic compounds. Although TAG was not designed to quantify the vapor phase of semivolatile organics, TAG measurements do distinguish when specific compounds are dominantly in the vapor phase, are dominantly in the particle phase, or have both phases present. Because the TAG data are both speciated and time-resolved, this distinction is sufficient to see the transition from vapor to particle phase as a function of carbon number and compound class. Laboratory studies typically measure the phase partitioning of semivolatile organic compounds by using pure compounds or simple mixtures, whereas hourly TAG phase partitioning measurements can be made in the complex mixture of thousands of polar/nonpolar and organic/inorganic compounds found in the atmosphere.     

Mechanical stress-induced sarcomere assembly for cardiac muscle growth in length and width

A ventricular myocyte experiences changes in length and load during every beat of the heart and has the ability to remodel cell shape to maintain cardiac performance. Specifically, myocytes elongate in response to increased diastolic strain by adding sarcomeres in series, and they thicken in response to continued systolic stress by adding filaments in parallel. Myocytes do this while still keeping the resting sarcomere length close to its optimal value at the peak of the length-tension curve. This review focuses on the little understood mechanisms by which direction of growth is matched in a physiologically appropriate direction. We propose that the direction of strain is detected by differential phosphorylation of proteins in the costamere, which then transmit signaling to the Z-disc for parallel or series addition of thin filaments regulated via the actin capping processes. In this review, we link mechanotransduction to the molecular mechanisms for regulation of myocyte length and width.     

Perforator flap magnetic resonance angiography for reconstructive breast surgery: A review of 25 deep inferior epigastric and gluteal perforator artery flap patients

Purpose

To evaluate the accuracy of magnetic resonance angiography (MRA) for preoperative mapping of rectus and gluteal muscle perforating arteries prior to autologous flap breast reconstruction.

Materials and Methods

Preoperative MRA on 25 consecutive patients undergoing perforator artery‐based autologous breast reconstruction was performed at 1.5 T using 3D liver accelerate volume acquisition (LAVA) of abdominal or gluteal regions acquired during injection of 20 mL of gadobenate dimeglumine with bolus timing optimized using MR fluoroscopy or SmartPrep. Perforator artery size and coordinates relative to umbilicus or top of gluteal crease on 3D MRA were compared to findings at surgery. Reconstructed breast volume estimates from MRA were also compared to weights at harvesting.

Results

In all, 132 perforator arteries were found at surgery to be located within 1 cm of the coordinates measured on MRA and were surgically verified to be suitable for flap perfusion. Surgery verified the arterial course and caliber through the rectus and gluteal muscles visualized on MRA in 48 of 49 arteries. Volume rendering of 3D MRA predicted a breast reconstruction volume with a mean difference of 47 g compared to measurements at harvesting.

Conclusion

MRA accurately maps rectus and gluteal muscle perforator arteries for preoperative planning of autologous flaps for breast reconstruction. J. Magn. Reson. Imaging 2010;31:1176–1184. © 2010 Wiley‐Liss, Inc.     

Magnetic resonance imaging, ultrasound and real-time ultrasound elastography of the thigh muscles in congenital muscle dystrophy

Congenital muscle dystrophy includes a range of genetic disorders characterized by muscle weakness and contractures. We report the magnetic resonance (MR), ultrasound (US) and real-time sonoelastography (RTE) imaging findings of the thigh muscles of a 15-year-old boy with Bethlem myopathy diagnosed with clinical, electromyographic and histopathological criteria. Ultrasound and MR showed hyperechoic appearance and high signal intensity on T1- and T2-weighted sequences respectively at the periphery of the vastus lateralis and the long head of the biceps femoris muscles, and at a central area within the rectus femoris muscles. RTE was employed to examine the elastic properties of the muscle. The elastograms were presented as colour-coded maps superimposed on the B-mode images and revealed that the elastographic pattern correlated with the MR and US pattern of involvement. The abnormal muscle areas were stiffer (blue) than the normal-appearing areas (green), a finding that probably correlates with the presence of dystrophic collagen at the affected areas. This report suggests that RTE could be used as an additional imaging tool to evaluate the pattern of muscle changes in congenital myopathy. Further studies are needed to investigate the specificity and clinical value of RTE in the diagnosis and monitoring of neuromuscular disease.