V současnosti existují dva základní koncepty akvizice dat pro 4D CT-angiografii zobrazení (4DCTA). Prvním je založena na mnohonásobné dynamické akvizici dat po aplikaci bolu kontrastní látky v různých fázích jejího průchodu cévním systémem. Dynamická 4DCTA potom dovoluje zobrazit lokální hemodynamiku cirkulace. Dynamickou 4DCTA lze hodnotit mozkovou cirkulaci, dále dynamiku arteriálního zásobení nádorů a jejich venózní drenáže. Druhý koncept 4DCTA byl odvozen od CT-angiografie srdce a věnčitých tepen s EKG gatingem. Retrospektivní segmentace dat do deseti až dvaceti fází v jednom R-R intervalu je principem zobrazení pulzatorních nebo kývavých pohybů tepen a umožňuje také zobrazit tryskání kontrastní látky při krvácení nebo vířivé mísení kontrastní látky a krve v srdečních síních nebo v aneuryzmatech. Prezentovaná práce podává přehled o možnostech provedení a potenciálních indikacích čtyřdimenzionální CT-angiografie. V práci jsou diskutovány současná omezení této nové zobrazovací metody, jako je zvýšená dávka nebo problémy s pokrytím většího objemu tkáně společně s možnými řešeními nastíněných problémů.
The presented work reviews current technical possibilities and clinical indications of four dimensional angiography using computed tomography (4D-CTA). There are two contemporary concepts of 4D imaging of cardiovascular system. The first is based on dynamic multiple acquisitions after intravenous application of iodinated contrast material with the data acquisitions in several phases of the first pass of the contrast agent. The dynamic 4D-CTA allows to display the hemodynamics in the local circulation like brain vessels or tumorous arterial supply with venous drainage. Second concept was derived from the ECG-gated CT angiography of the heart and coronary arteries. The retrospective data segmentation within one R-R interval into ten to twenty phases is the principle of the imaging of the pulsatory or shuttle-like movement of the arteries and allows also the display of the rapid flow dynamic for example jet of the rapid bleeding or whirlpool mixing of the blood with contrast agent in cardiac atria or in aneurysms. The presented review discuss the current problems of the novel imaging method with the increased dose or limited tissue coverage, the possible troubleshoots are listed.
- MeSH
- Angiography methods MeSH
- Financing, Organized MeSH
- Humans MeSH
- Tomography, X-Ray Computed MeSH
- Check Tag
- Humans MeSH
Radioterapie, a především pak brachyterapie jsou hlavní modalitou léčby pokročilého karcinomu hrdla dělohy už déle než 100 let. Po většinu tohoto času bylo plánování brachyterapie založeno především na rtg projekcích s dozimetrií založené na referenčních bodech. Díky výsledkům výzkumu gynekologické skupiny Evropské společnosti pro radioterapii a onkologii (European Society for Radiotherapy and Oncology, GEC-ESTRO) se v posledním desetiletí stává standardem 3D plánování brachyterapie pomocí magnetické rezonance s adaptací léčby podle aktuální regrese nádorového procesu v čase (4D). Fakultní nemocnice v Hradci Králové je prvním pracovištěm v České republice, kde byla zavedena adaptivní brachyterapie karcinomu hrdla dělohy plánovaná při každé frakci výhradně magnetickou rezonancí.
Radiotherapy and particulary brachytherapy have been major treatment modalities for cervical cancer for over 100 years. Most of this time the brachytherapy treatment planning was based on radiographs and reference point dosimetry. Due to research of European Society for Radiotherapy and Oncology (GEC-ESTRO) a 3D brachytherapy planning, based on the magnetic resonance imaging with adaptation of the treatment to actual tumor regression in time (4D), has become a standard of care in the last decade. University hospital in Hradec Kralove is the first center in the Czech Republic to implement the adaptive brachytherapy planning of cervical carcinoma based solely on the magnetic resonance imaging for each fraction.
- MeSH
- Brachytherapy * methods trends MeSH
- Four-Dimensional Computed Tomography * methods trends MeSH
- Humans MeSH
- Magnetic Resonance Imaging methods trends MeSH
- Uterine Cervical Neoplasms * diagnostic imaging radiotherapy MeSH
- Hospitals, Teaching MeSH
- Radiotherapy Planning, Computer-Assisted methods trends MeSH
- Tomography, X-Ray Computed methods trends MeSH
- Statistics as Topic MeSH
- Outcome and Process Assessment, Health Care MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Subklinické ztluštění a omezená pohyblivost cípů bioprotézy po katetrizační náhradě aortální chlopně byla dokumentována pomocí 4D‑CT vyšetření. Studie zkoumala, zda výskyt tohoto fenoménu může být ovlivněn antikoagulační léčbou rivaroxabanem. V této podstudii hlavní studie GALILEO byli pacienti, kteří neměli indikaci k antikoagulační léčbě, po úspěšné katetrizační náhradě randomizováni k tříměsíční léčbě kombinací 10 mg rivaroxabanu s kyselinou acetylsalicylovou nebo k léčbě kombinační protidestičkovou léčbou klopidogrelem s kyselinou acetylsalicylovou. Kombinovaná léčba rivaroxabanem byla ve snížení výskytu abnormalit cípů účinnější než duální protidestičková léčba. Nicméně v hlavní studii byla léčba rivaroxabanem spojena s vyšší mortalitou a vyšším výskytem tromboembolických a krvácivých komplikací.
Subclinical leaflet thickening and reduced leaflet motion of bioprosthetic aortic valves have been documented using four‑dimensional computed tomography (4D‑CT). The aim of this study was to establish whether anticoagulation with rivaroxaban can reduce these phenomena after transcatheter aortic‑valve replacement. In this substudy of the main GALILEO trial, the patients were randomized to the 3‑month treatment with combination of 10 mg rivaroxaban and aspirin or treatment with combination of clopidogrel with aspirin. Treatment with rivaroxaban was more effective than an antiplatelet‑based strategy in preventing subclinical leaflet motion abnormalities. However, in the main trial, the rivaroxaban‑based strategy was associated with a higher risk of death or thromboembolic complications and a higher risk of bleeding than the antiplatelet‑based strategy.
- Keywords
- studie GALILEO-4D,
- MeSH
- Anticoagulants therapeutic use MeSH
- Aortic Valve MeSH
- Diagnostic Imaging MeSH
- Humans MeSH
- Tomography, X-Ray Computed MeSH
- Rivaroxaban administration & dosage therapeutic use MeSH
- Heart Valve Prosthesis * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Randomized Controlled Trial MeSH
PURPOSE: To assess the benefit of 4D-CT angiography (4D-CTA) in determination and precise measurement of middle cerebral artery (MCA) occlusion in comparison to CTA. Possible relationship of measured occlusion lengths with recanalization after intravenous thrombolysis was analysed as a second objective. METHODS: Detailed evaluation of complete MCA occlusions in 80 patients before intravenous thrombolysis using temporal maximum intensity projection (tMIP) dataset, calculated from 4D-CTA and conventional single-phase CTA was performed. Further, manual measurement technique was compared to results of semiautomatic procedure (vessel analysis) as reference. Statistical analysis of correlation between MCA occlusion length and IVT efficacy (24 h recanalization rate according modified Thrombolysis In Myocardial Infarction criteria-mTIMI) was performed. RESULTS: The distal end of occlusion was identified in all patients using tMIP, but only in 48 patients (60%) using CTA. The manual measurement method was not statistically different and well correlated with reference tMIP-vessel analysis. (15.4 vs. 16.3 mm; p = 0.434; r = 97). In measurable occlusions by CTA, no significant difference was proved in manually measured lengths using tMIP and CTA (14.5 vs. 13.3 mm; p = 0.089). Favorable recanalization (mTIMI 2-3) was achieved in 37 patients (47%). Length of occlusion in M1 segment (p = 0.002) and M2 segment involvement (p = 0.017) were proved as independent negative predictors of recanalization. Using receiver operating characteristics analysis, the cutoff length of the M1 segment occlusion for favorable recanalization was found to be 12 mm. CONCLUSION: The feasibility of MCA occlusion assessment using tMIP datasets and benefit over conventional CTA were confirmed. The manual measurement method was proved as feasible and simple with good correlation to reference semiautomatic analysis. The significant correlation of the MCA occlusion length and early recanalization was found. The length of 12 mm was recognized as cut-off length for favorable recanalization.
- MeSH
- Acute Disease MeSH
- Four-Dimensional Computed Tomography MeSH
- Adult MeSH
- Fibrinolytic Agents administration & dosage MeSH
- Infarction, Middle Cerebral Artery drug therapy radiography MeSH
- Injections, Intravenous MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Drug Monitoring methods MeSH
- Cerebral Angiography MeSH
- Observer Variation MeSH
- Prognosis MeSH
- Reproducibility of Results MeSH
- Retrospective Studies MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Sensitivity and Specificity MeSH
- Tissue Plasminogen Activator administration & dosage MeSH
- Thrombolytic Therapy methods MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
- Publication type
- Meeting Abstract MeSH
- Publication type
- Meeting Abstract MeSH
PURPOSE: The optimal motion management strategy for patients receiving stereotactic arrhythmia radioablation (STAR) for the treatment of ventricular tachycardia (VT) is not fully known. We developed a framework using a digital phantom to simulate cardiorespiratory motion in combination with different motion management strategies to gain insight into the effect of cardiorespiratory motion on STAR. METHODS AND MATERIALS: The 4-dimensional (4D) extended cardiac-torso (XCAT) phantom was expanded with the 17-segment left ventricular (LV) model, which allowed placement of STAR targets in standardized ventricular regions. Cardiac- and respiratory-binned 4D computed tomography (CT) scans were simulated for free-breathing, reduced free-breathing, respiratory-gating, and breath-hold scenarios. Respiratory motion of the heart was set to population-averaged values of patients with VT: 6, 2, and 1 mm in the superior-inferior, posterior-anterior, and left-right direction, respectively. Cardiac contraction was adjusted by reducing LV ejection fraction to 35%. Target displacement was evaluated for all segments using envelopes encompassing the cardiorespiratory motion. Envelopes incorporating only the diastole plus respiratory motion were created to simulate the scenario where cardiac motion is not fully captured on 4D respiratory CT scans used for radiation therapy planning. RESULTS: The average volume of the 17 segments was 6 cm3 (1-9 cm3). Cardiac contraction-relaxation resulted in maximum segment (centroid) motion of 4, 6, and 3.5 mm in the superior-inferior, posterior-anterior, and left-right direction, respectively. Cardiac contraction-relaxation resulted in a motion envelope increase of 49% (24%-79%) compared with individual segment volumes, whereas envelopes increased by 126% (79%-167%) if respiratory motion also was considered. Envelopes incorporating only the diastole and respiration motion covered on average 68% to 75% of the motion envelope. CONCLUSIONS: The developed LV-segmental XCAT framework showed that free-wall regions display the most cardiorespiratory displacement. Our framework supports the optimization of STAR by evaluating the effect of (cardio)respiratory motion and motion management strategies for patients with VT.
- MeSH
- Four-Dimensional Computed Tomography MeSH
- Respiration * MeSH
- Phantoms, Imaging MeSH
- Humans MeSH
- Motion MeSH
- Heart * diagnostic imaging radiation effects MeSH
- Arrhythmias, Cardiac MeSH
- Heart Ventricles diagnostic imaging radiation effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Publication type
- Meeting Abstract MeSH
BACKGROUND AND PURPOSE: The length of large vessel occlusion is considered a major factor for therapy in patients with ischemic stroke. We used 4D-CT angiography evaluation of middle cerebral artery occlusion in prediction of recanalization and favorable clinical outcome and after intravenous thrombolysis (IV-tPA). METHODS: In 80 patients treated with IV-tPA for acute complete middle cerebral artery/M1 occlusion determined using CT angiography and temporal maximum intensity projection, calculated from 4D-CT angiography, the length of middle cerebral artery proximal stump, occlusion in M1 or M1 and M2 segment were measured. Univariate and multivariate analyses were performed to define independent predictors of successful recanalization after 24 hours and favorable outcome after 3 months. RESULTS: The length of occlusion was measureable in all patients using temporal maximum intensity projection. Recanalization thrombolysis in myocardial infarction 2 to 3 was achieved in 37 individuals (46%). The extension to M2 segment as a category (odds ratio, 4.58; 95% confidence interval, 1.39-15.05; P=0.012) and the length of M1 segment occlusion (odds ratio, 0.82; 95% confidence interval, 0.73-0.92; P=0.0007) with an optimal cutoff value of 12 mm (sensitivity 0.67; specificity 0.71) were significant independent predictors of recanalization. Favorable outcome (modified Rankin scale 0-2) was achieved in 25 patients (31%), baseline National Institutes of Health Stroke Scale (odds ratio, 0.82; 95% confidence interval, 0.72-0.93; P=0.003) and the length of occlusion M1 in segment (odds ratio, 0.79; 95% confidence interval, 0.69-0.91; P=0.0008) with an optimal cutoff value of 11 mm (sensitivity 0.74; specificity 0.76) were significant independent predictors of favorable outcome. CONCLUSIONS: The length of middle cerebral artery occlusion is an independent predictor of successful IV-tPA treatment.
- MeSH
- Four-Dimensional Computed Tomography instrumentation methods MeSH
- Adult MeSH
- Fibrinolytic Agents administration & dosage pharmacology MeSH
- Infarction, Middle Cerebral Artery * drug therapy pathology radiography MeSH
- Middle Aged MeSH
- Humans MeSH
- Cerebral Angiography MeSH
- Cerebrovascular Circulation drug effects physiology MeSH
- Predictive Value of Tests MeSH
- Retrospective Studies MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Tissue Plasminogen Activator administration & dosage pharmacology MeSH
- Thrombolytic Therapy methods MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
PURPOSE/OBJECTIVE: To evaluate lung tumor motion during respiration and to describe factors affecting the range and variability of motion in patients treated with stereotactic ablative radiation therapy. METHODS AND MATERIALS: Log file analysis from online respiratory tumor tracking was performed in 145 patients. Geometric tumor location in the lungs, tumor volume and origin (primary or metastatic), sex, and tumor motion amplitudes in the superior-inferior (SI), latero-lateral (LL), and anterior-posterior (AP) directions were recorded. Tumor motion variability during treatment was described using intrafraction/interfraction amplitude variability and tumor motion baseline changes. Tumor movement dependent on the tumor volume, position and origin, and sex were evaluated using statistical regression and correlation analysis. RESULTS: After analysis of >500 hours of data, the highest rates of motion amplitudes, intrafraction/interfraction variation, and tumor baseline changes were in the SI direction (6.0 ± 2.2 mm, 2.2 ± 1.8 mm, 1.1 ± 0.9 mm, and -0.1 ± 2.6 mm). The mean motion amplitudes in the lower/upper geometric halves of the lungs were significantly different (P<.001). Motion amplitudes >15 mm were observed only in the lower geometric quarter of the lungs. Higher tumor motion amplitudes generated higher intrafraction variations (R=.86, P<.001). Interfraction variations and baseline changes >3 mm indicated tumors contacting mediastinal structures or parietal pleura. On univariate analysis, neither sex nor tumor origin (primary vs metastatic) was an independent predictive factor of different movement patterns. Metastatic lesions in women, but not men, showed significantly higher mean amplitudes (P=.03) and variability (primary, 2.7 mm; metastatic, 4.9 mm; P=.002) than primary tumors. CONCLUSION: Online tracking showed significant irregularities in lung tumor movement during respiration. Motion amplitude was significantly lower in upper lobe tumors; higher interfraction amplitude variability indicated tumors in contact with mediastinal structures, although adhesion to parietal pleura did not necessarily reduce tumor motion amplitudes. The most variable lung tumors were metastatic lesions in women.
- MeSH
- Analysis of Variance MeSH
- Time Factors MeSH
- Four-Dimensional Computed Tomography MeSH
- Respiration * MeSH
- Dose Fractionation, Radiation MeSH
- Humans MeSH
- Lung Neoplasms diagnostic imaging pathology radiotherapy secondary MeSH
- Motion MeSH
- Movement * MeSH
- Radiosurgery * MeSH
- Regression Analysis MeSH
- Sex Factors MeSH
- Tumor Burden MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
