Dose uncertainty due to energy dependence in dual-energy computed tomography

Purpose: To evaluate the absolute dose uncertainty at 2 different energies and for the large and small bowtie filters in dual-energy computed tomography (DECT). Material and methods: Measurements were performed using DECT at 80 kV and 140 kilovoltage peak (kVp), and single-energy computed tomography (CT) at 120 kV. The absolute dose was calculated from the mass-energy absorption obtained from the half-value layer (HVL) of aluminium. Results: The difference in the water-to-air ratio of the mean mass energy-absorption coefficients at 80 kV and 140 kV was 2.0% for the small bow-tie filter and 3.0% for the large bow-tie filter. At lower tube voltages, the difference in the absorbed dose with the large and small bow-tie filters was larger. Conclusions: The absolute dose uncertainty due to energy dependence was 3.0%, which could be reduced with single-energy beams at 120 kV or by using the average effective energy measurement with dual-energy beams

Reconstruction of Lateral Forefoot Using Reversed Medial Plantar Flap with Free Anterolateral Thigh Flap

Skin defects of the heel have frequently been reconstructed using the medial plantar flap however, forefoot coverage has remained a challenge, because the alternatives for flap coverage have been very limited. We describe a case of malignant melanoma on the lateral forefoot that was radically removed and reconstructed successfully with a distally based medial plantar flap, together with a free anterolateral thigh flap. The advantages of this flap include that it does not reduce the vascular supply to the foot owing to reconstruction of the medial plantar vascular systems, reduces the risk of flap congestion, minimizes donor site morbidity, and enables the transport of structurally similar tissues to the plantar forefoot. We believe this technique is a reasonable reconstructive option for large lateral plantar forefoot defects

Synthesized effective atomic numbers for commercially available dual-energy CT

Purpose: The objective of this study was to assess synthesized effective atomic number (Zeff) values with a new developed tissue characteristic phantom and contrast material of varying iodine concentrations using single-source fast kilovoltage switching dual-energy CT (DECT) scanner. Methods: A newly developed multi energy tissue characterisation CT phantom and an acrylic phantom with various iodine concentrations of were scanned using single-source fast kilovoltage switching DECT (GE-DECT) scanner. The difference between the measured and theoretical values of Zeff were evaluated. Additionally, the difference and coefficient of variation (CV) values of the theoretical and measured values were compared with values obtained with the Canon-DECT scanner that was analysed in our previous study. Results: The average Zeff difference in the Multi-energy phantom was within 4.5%. The average difference of the theoretical and measured Zeff values for the acrylic phantom with variation of iodine concentration was within 3.3%. Compared to the results for the single-source Canon-DECT scanner used in our previous study, the average difference and CV of the theoretical and measured Zeff values obtained with the GE-DECT scanner were markedly smaller. Conclusions: The accuracy of the synthesized Zeff values with GE-DECT had a good agreement with the theoretical Zeff values for the Multi-Energy phantom. The GE-DECT could reduce the noise and the accuracy of the Zeff values than that with Canon-DECT for the varying iodine concentrations of contrast medium. Advances in knowledge: The accuracy and precision of the Zeff values of the contrast medium with the GE-DECT could be sufficient with human equivalent materials

Amphiphilic peptide-tagged N-cadherin forms radial glial-like fibers that enhance neuronal migration in injured brain and promote sensorimotor recovery

The mammalian brain has very limited ability to regenerate lost neurons and recover function after injury. Promoting the migration of young neurons (neuroblasts) derived from endogenous neural stem cells using biomaterials is a new and promising approach to aid recovery of the brain after injury. However, the delivery of sufficient neuroblasts to distant injured sites is a major challenge because of the limited number of scaffold cells that are available to guide neuroblast migration. To address this issue, we have developed an amphiphilic peptide [(RADA)3-(RADG)] (mRADA)-tagged N-cadherin extracellular domain (Ncad-mRADA), which can remain in mRADA hydrogels and be injected into deep brain tissue to facilitate neuroblast migration. Migrating neuroblasts directly contacted the fiber-like Ncad-mRADA hydrogel and efficiently migrated toward an injured site in the striatum, a deep brain area. Furthermore, application of Ncad-mRADA to neonatal cortical brain injury efficiently promoted neuronal regeneration and functional recovery. These results demonstrate that self- assembling Ncad-mRADA peptides mimic both the function and structure of endogenous scaffold cells and provide a novel strategy for regenerative therapy

Vulvar reconstruction should be performed using gluteal-fold perforator flap because of less morbidities and complication

The autors present a case of bilateral vulvar defects after abrasion of malignant skin neoplasm, reconstructed with a gluteal-fold perforator flap, resulting in a successful outcome

Artificial dermis is not effective for resurfacing bone-exposing wounds of Gustilo–Anderson III fracture

According to the treatment of open fracture, the resurfacing of bone-exposing complex wounds of Gustilo-Anderson III B and C fracture remains challenging. To treat bone-exposing wounds, artificial dermis has been effective. We evaluated the outcome of adapting artificial dermis the resurfacing bone-exposing complex wounds of Gustilo-Anderson III B and C fracture clinically. Seven patients who had sustained Gustilo-Anderson III B and C fracture of the legs underwent open reduction and Ilizarov external fixation. The bone-exposing wounds were covered with slit artificial dermis, and a basic fibroblast growth factor was sprayed every day. Wounds in all patients showed insufficient granulation on the bone. Four patients developed osteomyelitis. Consequently, all cases required a local flap for resurfacing the wounds. Although the artificial dermis allows wounds to heal earlier, it is impossible to prepare a favorable wound bed on the bone when the fracture is classified as Gustilo-Anderson III B and C. We concluded that artificial dermis is not a recommendable resurfacing option for patients with Gustilo-Anderson III B and C fracture because the poor circulation of bone may result in osteomyelitis