PURPOSE: Geant4-DNA is used to calculate S-values for different subcellular distributions of low-energy electron sources in various cell geometries. METHOD: Calculations of cellular S-values for monoenergetic electron sources with energy from 1 to 100 keV and the Auger-electron emitting radionuclides Tc-99m, In-111, and I-125 have been made using the Geant4 Monte Carlo toolkit. The Geant4-DNA low-energy extension is employed for simulating collision-by-collision the complete slowing-down of electron tracks (down to 8 eV) in liquid water, used as a surrogate of human cells. The effect of cell geometry on S-values is examined by simulating electron tracks within different cell geometries, namely, a spherical, two ellipsoidal, and an irregular shape, all having equal cellular and nuclear volumes. Algorithms for randomly sampling the volume of the nucleus, cytoplasm, surface, and whole cell for each cell phantom are presented. RESULTS: Differences between Geant4-DNA and MIRD database up to 50% were found, although, for the present radionuclides, they mostly remain below 10%. For most source-target combinations the S-values for the spherical cell geometry were found to be within 20% of those for the ellipsoidal cell geometries, with a maximum deviation of 32%. Differences between the spherical and irregular geometries are generally larger reaching 100-300%. Most sensitive to the cell geometry is the absorbed dose to the nucleus when the source is localized on the cell surface. Interestingly, two published AAPM spectra for I-125 yield noticeable differences (up to 19%) in cellular S-values. CONCLUSION: Monte Carlo simulations of cellular S-values with Geant4-DNA reveal that, for the examined radionuclides, the widely used approximation of spherical cells is reasonably accurate (within 20-30%) even for ellipsoidal geometries. For irregular cell geometries the spherical approximation should be used with caution because, as in the present example, it may lead to erroneous results for the nuclear dose for the commonly encountered situation where the source is localized to the cell surface.
- MeSH
- Absorption, Radiation * MeSH
- Models, Biological * MeSH
- Radiation Dosage MeSH
- Electrons MeSH
- Humans MeSH
- Monte Carlo Method MeSH
- Computer Simulation MeSH
- Radiometry methods MeSH
- Models, Statistical * MeSH
- Cell Size * MeSH
- Cell Survival drug effects physiology MeSH
- Dose-Response Relationship, Radiation MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Traumata střeva a mezenteria jsou relativně vzácným typem abdominálního poranění, avšak jejich prognóza je velmi závažná. Nerozpoznáni poranění střeva vede k rozvoji zánětu pobřišnice, nerozpoznané poranění okruží k významnému krvácení nebo ischémii střeva. Během 36 měsíců bylo na pracovišti autorů vyšetřeno a následně chirurgicky ošetřeno celkem 11 nemocných s poraněním střeva nebo mezenteria. Vyšetření byla prováděna na dvouřadém (3 nemocní) nebo šestnáctiřadém přístroji (8 nemocných) s intravenózni aplikací kontrastní látky. V časném období po poranění bylo správně rozpoznáno 6 poranění střeva a všechna poranění mezenteria, jen jediné poranění v oblasti ilea odhalilo až kontrolní vyšetření s latencí 5 dní. Nejdůležitější známkou poranění střeva ve sledovaném souboru byla kombinace volné tekutiny v dutině břišní, volný plyn a ztluštění stěny střevní (specificita 100 %), u poranění okruží vylévání kontrastní látky do volné dutiny břišní (specificita 100 %).
Trauma of the bowel or mesentery becomes a relative rare type of the blunt abdominal injury, but with a serious prognosis. Undetected intestinal injury leads to the peritonitis, undetected mesenterial injury to the massive bleeding into the peritoneal cavity or intestinal ischemia. The intestinal or mesenterial injury was found in eleven patients admitted to the computed tomography during the period of thirty-six months. Examinations performed with two-detector-row computed tomography (three patients) or sixteen-detector-row computed tomography (eight patients), intravenous application of contrast agent was used m all procedures. Six injuries involved the bowel and all four mesenterial injuries were detected in the early posttraumatic interval, only one perforation of the terminal ileum remained undepicted and was discovered by follow-up examination five days later. The most important sign of the bowel trauma becomes the free peritoneal fiuid and air collection combined with intestinal mural swelling (specificity 100%), the leakage of the intravenous contrast material (specificity 100%) in cases of mesenterial injury respectively.
- MeSH
- Aneurysm epidemiology MeSH
- Carotid Artery, Internal MeSH
- Accidents, Traffic MeSH
- Adult MeSH
- Humans MeSH
- Tomography, X-Ray Computed MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Case Reports MeSH
- MeSH
- Accidents, Traffic MeSH
- Rib Fractures * etiology pathology therapy MeSH
- Thoracic Surgical Procedures MeSH
- Middle Aged MeSH
- Humans MeSH
- Manubrium * diagnostic imaging injuries MeSH
- Tomography, X-Ray Computed MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
- MeSH
- Child MeSH
- Accidents, Traffic MeSH
- Fractures, Bone * diagnostic imaging etiology complications pathology MeSH
- Myocardial Contusions * diagnostic imaging etiology complications pathology MeSH
- Conservative Treatment MeSH
- Humans MeSH
- Tomography, X-Ray Computed MeSH
- Sternum injuries MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
Tupé poranění karotidy je závažným poraněním s vysokou morbiditou a mortalitou. Symptomatologie může být nenápadná nebo může být přítomen neurologický deficit. Mechanismem poranění je většinou hyperextenze a rotace hlavy, fraktura lební báze, komprese nebo tupý úder. Diagnóza je většinou potvrzena CT scanem, CT angiografií a MRI. V léčbě je v současnosti preferován konzervativní přístup s užitím heparinových preparátů, v některých případech pak implantace endovaskulárního stentu.
Blunt injury of the carotid artery is uncommon but serious injury with high mortality and morbidity. The symptomatology may be inconspicuous, in other case a neurological deficit is present. The cause is mainly head hyperexstension and rotation, basal scull fracture, compression, blunt stroke. The diagnosis is usually confirmed by CT scan, CT angiography, MRI. In the therapy in present prevail heparin anticoagulation and endovascular stent implantation in some cases.
- MeSH
- Accidents, Traffic MeSH
- Respiratory System surgery injuries MeSH
- Thoracic Surgical Procedures methods MeSH
- Humans MeSH
- Young Adult MeSH
- Tomography, X-Ray Computed MeSH
- Postoperative Care MeSH
- Thoracic Injuries * surgery diagnostic imaging classification MeSH
- Check Tag
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Publication type
- Case Reports MeSH
- MeSH
- Diaphragm * surgery injuries MeSH
- Accidents, Traffic MeSH
- Thoracic Surgical Procedures methods MeSH
- Humans MeSH
- Adolescent MeSH
- Tomography, X-Ray Computed MeSH
- Postoperative Period MeSH
- Thoracic Injuries surgery diagnostic imaging etiology pathology MeSH
- Radiography, Thoracic MeSH
- Rupture * surgery diagnostic imaging etiology pathology MeSH
- Check Tag
- Humans MeSH
- Adolescent MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
Autoři prezentují vzácnou kazuistiku vzniku poúrazového pneumocefalu, jehož příčinou byla pleuro-durálni komunikace. Rychlou diagnostikou a neurochirurgickou léčbou bylo zabráněno vzniku komplikací.
Traumatic pleuro-dural communication causing pneumocephalus needs rapid diagnostics and surgical treatment, so as to prevent the development of possible complications.
Úvod: Plicní herniace patří mezi vzácné stavy, z nichž většina vzniká v důsledku úrazových mechanismů nebo následkem torakotomické operace. Kazuistika: Prezentujeme případ 48leté ženy zraněné při dopravní nehodě. Při vyšetření v traumacentru bylo zjištěno poranění hrudníku s herniací plicního parenchymu do hrudní stěny a zlomeniny dlouhých kostí dolních končetin. Poraněná podstoupila etapovou operační léčbu, kdy v první fázi byla provedena osteosyntéza zlomeniny levého femuru a pravé tibie, následovaná operací plicní herniace. Závěr: Není-li interkostální plicní hernie zřejmá klinicky, suverénní diagnostickou metodou je počítačová tomografie. Terapeutickým řešením je sutura defektu hrudní stěny nebo implantace záplaty.
Introduction: Pulmonary hernias are rare conditions, most are the results of an injury or previous thoracic surgery. Case report: We present a case of a 48-year-old woman injured in a car accident. The examination in the trauma centre revealed a chest injury with herniation of the lung parenchyma into the chest wall and fractures of long bones of lower limbs. Initially, an osteosynthesis of the left femur and the right tibia fracture were performed. The patient underwent a subsequent surgery to repair the pulmonary hernia. Conclusion: A pulmonary hernia is diagnosed either directly during a clinical examination or by imaging. A sovereign diagnostic method is a computed tomography. The method of treatment is a surgical repair with primary suture of the chest wall defect or implantation of a mesh to repair the pulmonary hernia.
- MeSH
- Accidents, Traffic MeSH
- Rib Fractures surgery diagnostic imaging pathology MeSH
- Hernia * diagnostic imaging complications MeSH
- Thoracic Wall * surgery injuries MeSH
- Middle Aged MeSH
- Humans MeSH
- Lung Diseases * surgery diagnostic imaging MeSH
- Tomography, X-Ray Computed MeSH
- Postoperative Complications MeSH
- Treatment Outcome MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
- Research Support, Non-U.S. Gov't MeSH
