Recent studies have suggested that wall enhancement of unruptured intracranial aneurysms in high-resolution MR imaging might serve as an imaging biomarker for higher risk of rupture. Histologic ...studies have revealed a possible association among inflammatory processes, degeneration, and destabilization of the aneurysm wall preceding rupture. Understanding the histologic condition underlying aneurysm wall enhancement could be an important step toward assessing the value of this method for risk stratification. We present our observations of aneurysm wall enhancement in MR vessel wall imaging and underlying histologic changes.
We reviewed records of patients with an unruptured middle cerebral artery aneurysm who underwent MR vessel wall imaging before aneurysm clipping. Contrast enhancement of the aneurysm wall was dichotomized into either none/faint or strong. Histologic analysis included myeloperoxidase stain for detection of inflammatory cell invasion and CD34 stain for assessment of neovascularization and vasa vasorum.
Thirteen aneurysms were included. Five aneurysms showed strong wall enhancement. Among these, myeloperoxidase staining revealed inflammatory cell infiltration in 4. Three showed neovascularization. In 2 aneurysms, vasa vasorum were present. Seven aneurysms did not show wall enhancement; 1 had only mild enhancement. None of these bore evidence of inflammatory cell invasion or neovascularization, and they all lacked vasa vasorum.
Wall enhancement in MR vessel wall imaging is associated with inflammatory cell invasion, neovascularization, and the presence of vasa vasorum. Enhancement does not occur when histologic signs of inflammation are absent. Our results support the hypothesis that MR vessel wall imaging could provide valuable information for risk stratification.
We extended the original easyLINKAGE program by enabling linkage analyses for large-scale SNP data in addition to those of microsatellites. We implemented new modules for Allegro, Merlin, SimWalk, ...GeneHunter Imprinting, GeneHunter TwoLocus, SuperLink and extended FastSLink by automatic loop breaking and new outputs. We added conditional linkage analyses as well as multipoint simulation studies, and extended error test routines by checking for Mendelian/non-Mendelian genotyping errors and for deviations from Hardy–Weinberg equilibrium. Data can be analyzed in sets of markers, in defined centimorgan intervals and by using different allele frequency algorithms. The outputs consist of genome-wide as well as chromosomal postscript plots of LOD scores, NPL scores, P-values and other parameters. Availability: http://www.uni-wuerzburg.de/nephrologie/molecular_genetics/molecular_genetics.htm Contact: tom.lindner@mail.uni-wuerzburg.de Supplementary information: Supplementary information is available on the website. The current version is v4.01beta.
Purpose
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Ga-FAPI (fibroblast activation protein inhibitor) is a rapidly evolving and highly promising radiotracer for PET/CT imaging, presenting excellent results in a variety of tumor entities, ...particularly in epithelial carcinomas. This retrospective analysis sought to evaluate the potential and impact of FAPI-PET/CT in rare cancer diseases with respect to improvement in staging and therapy, based on tracer uptake in normal organs and tumors.
Material and methods
Fifty-five patients with rare tumor entities, defined by a prevalence of 1 person out of 2000 or less, received a
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Ga-FAPI-PET/CT scan. Fourteen women and 41 men (median age 60) were included within the following subgroups: cancer of unknown primary (
n
= 10), head and neck cancer (
n
= 13), gastrointestinal and biliary-pancreatic cancer (
n
= 17), urinary tract cancer (
n
= 4), neuroendocrine cancer (
n
= 4), and others (
n
= 7). Tracer uptake was quantified by standardized uptake values SUVmax and SUVmean and the tumor-to-background ratio (TBR) was determined (SUVmax tumor/SUVmean organ).
Results
In 20 out of 55 patients, the primary tumor was identified and 31 patients presented metastases (
n
= 88), characterized by a high mean SUVmax in primary (10.1) and metastatic lesions (7.6). The highest uptake was observed in liver metastases (
n
= 6) with a mean SUVmax of 9.8 and a high TBR of 8.7, closely followed by peritoneal carcinomatosis (
n
= 16) presenting a mean SUVmax of 9.8 and an excellent TBR of 29.6. In terms of the included subgroups, the highest uptake regarding mean SUVmax was determined in gastrointestinal and biliary-pancreatic cancer with 9.8 followed closely by urinary tract cancer with 9.5 and head and neck cancer (9.1).
Conclusion
Due to excellent tumor visualization and, thereby, sharp contrasts in terms of high TBRs in primary and metastatic lesions in different rare malignancies,
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Ga-FAPI-PET/CT crystallizes as a powerful and valuable imaging tool, particularly with respect to epithelial carcinomas, and therefore an enhancement to standard diagnostics imaging methodologies. The realization of further and prospective studies is of large importance to confirm the potential of FAP imaging in oncology.
Objective
Arterial spin labeling blood perfusion signal relies on the difference between a label and a control image. Background suppression pulses are commonly used to improve the contrast, yet ...these are based on estimates of tissue relaxation times. The aim of this study is to improve the perfusion contrast by individualizing the timing of these background suppression pulses by means of T1 mapping.
Methods
The optimized timing of the background suppression pulses is obtained by rapid T1 mapping employing the variable flip angle technique. Ten healthy volunteers were included in this study. To compare the results, visual grading and the Wilcoxon signed-rank test was used comparing three categories of image quality.
Results
The readers confirmed that the images of the proposed method generally show a higher signal-to-background ratio and cortical structures are better visible. Noise was mostly comparable to the standard method. Relative blood flow was statistically significant higher in the modified method.
Conclusion
The individually optimized background suppression pulses improve the image appearance and allow for a better visualization of cortical structures. The proposed technique however prolongs scan time, which can be seen as negative result, yet needs to be further evaluated.
Key Points
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Background suppression timing in ASL can vary.
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Both the label and control condition can be modified for T1 mapping.
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Adapting the pulse timing improves the signal-to-background ratio.
Abstract The design task for distributed propulsion (DP) aircraft is more complex than conventional twin-engine designs due to the pronounced propeller wing interaction. DP concepts rely on a ...beneficial and robust interaction of propulsion and lifting surface. Additionally, a good DP design is optimised as a system such that each element is not optimised by itself (i.e. η prop and C L /C D ) , but with consideration of the close coupled interaction. The evaluation of such an interaction driven setup is scope of this work. Thrust and torque of a periodic co-rotating DP wing are measured simultaneously with airfoil coefficients. Thereby the influence of propeller on the wing and vice versa are identified. Two different sets of propeller geometries with a diameter of D = 0.6 m are studied. One propeller set is designed for minimum induced propeller loss (MIL). The second propeller set is designed to have a constant induced axial velocity over the radius (CIV). We shall compare how the different strategies perform in the DP system. The two element wing has a span of B = 2.4 m and a reference chord of c = 0.8 m, operating at Re = 2.1 × 10 6 . For this study, the propellers are pitched to meet a constant c T , J and Ma tip . The results focus on the system performance for the combined setup in take-off configuration. While the isolated propeller efficiency benefits from the integration in front of the wing by > Δ η prop = 12%, the system efficiency suffers from increased drag on the trailing wing that is roughly tripled over the clean wing. Depending on the propeller position relative to the wing, interaction losses can be minimised so that a system efficiency gain over the isolated wing and propeller of > Δ η sys = 4% is achieved.
Arterial Spin Labeling (ASL) allows for the non-invasive visualization of brain perfusion to detect abnormalities. In unilateral carotid artery stenosis, one hemisphere is less supplied with blood ...which results in a lower cerebral blood flow (CBF) compared to the healthy side. ASL can be performed time-resolved using multiple post labeling delay (PLD) times after labeling or static with a single delay, the latter allowing for a faster and more robust acquisition while bearing the risk of a falsely set delay resulting in unusable images. The purpose of this study is to compare the performance of multi-PLD and single-PLD ASL in patients with unilateral carotid artery stenosis both as means of diagnosis and therapeutic follow-up examination.
ASL perfusion data of 17 patients with known unilateral carotid artery stenosis was used to compare the diagnostic performance of the multi-PLD and single-PLD approach. Comparisons were made based on the CBF values and the added benefit of arrival time maps showing slower blood flow in multi-PLD ASL which might be overlooked in the individual delay images both before and after therapy.
Both the multi-PLD and the single-PLD data could identify the side of the stenosis with hemispheric differences in each approach (p < 0.001) and depict the normalization of CBF after therapy (p > 0.05). There were no differences between the individual methods (p > 0.05).
In this work, we could show that multi-PLD ASL in patients with unilateral carotid artery stenosis is beneficial as it provides both CBF and arrival time maps, however when only a single-PLD acquisition is available, this appears sufficient in a clinical setting to investigate the presence of a unilateral stenosis.
Purpose
A high expression of fibroblast activation protein (FAP) was observed in multiple sarcomas, indicating an enormous potential for PET/CT using
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Ga-radiolabeled inhibitors of FAP (FAPI). ...Therefore, this retrospective study aimed to evaluate the role of the novel hybrid imaging probe for sarcomas as a first clinical evaluation.
Methods
A cohort of 15 patients underwent
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Ga-FAPI-PET/CT for staging or restaging. The acquisition of PET scans was performed 60 min after administration of 127 to 308 MBq of the tracer. The uptake of
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Ga-FAPI in malignant tissue as well as in healthy organs was quantified by standardized uptake values SUVmean and SUVmax.
Results
Excellent tumor-to-background ratios (> 7) could be achieved due to low background activity and high SUVmax in primary tumors (median 7.16), local relapses (median 11.47), and metastases (median 6.29). The highest uptake was found for liposarcomas and high-grade disease (range 18.86–33.61). A high SUVmax (> 10) was observed for clinically more aggressive disease.
Conclusion
These preliminary findings suggest a high potential for the clinical use of
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Ga-FAPI-PET/CT for patients diagnosed with sarcoma.
Abstract Background Despite continuous innovation in trauma care, fatal trauma remains a significant medical and socioeconomic problem. Traumatic cardiac arrest (tCA) is still considered a hopeless ...situation, whereas management errors and preventability of death are neglected. We analyzed clinical and autopsy data from tCA patients in an emergency-physician-based rescue system in order to reveal epidemiologic data and current problems in the successful treatment of tCA. Material and methods Epidemiological and autopsy data of all unsuccessful tCPR cases in a one-year-period in Berlin, Germany ( n = 101, Group I) and clinical data of all cases of tCPR in a level 1 trauma centre in an 6-year period ( n = 52, Group II) were evaluated. Preventability of traumatic deaths in autopsy cases ( n = 22) and trauma-management failures were prospectively assessed. Results In 2010, 23% of all traumatic deaths in Berlin received tCPR. Death after tCPR occurred predominantly prehospital (PH;74%) and only 26% of these patients were hospitalized. Of 52 patients (Group II), 46% required tCPR already PH and 81% in the emergency department (ED). In 79% ROSC was established PH and 53% in the ED. The survival rate after tCPR was 29% with 27% good neurological outcome. Management errors occurred in 73% PH; 4 cases were judged as potentially or definitive preventable death. Conclusion Trauma CPR is beyond routine with the need for a tCPR-algorithm, including chest/pericardial decompression, external pelvic stabilization and external bleeding control. The prehospital trauma management has the highest potential to improve tCPR and survival. Therefore, we suggested a pilot prehospital tCPR-algorithm.
Therapeutic hypothermia (TH) after out-of-hospital cardiac arrest (OHCA) was adopted early in Norway. Since 2004 the general recommendation has been to cool all unconscious OHCA patients treated in ...the intensive care unit (ICU), but the decision to cool individual patients was left to the responsible physician. We assessed factors that were associated with use of TH and predicted survival.
We conducted a retrospective observational study of prospectively collected cardiac arrest and ICU registry data from 2004 to 2008 at three university hospitals.
A total of 715 unconscious patients older than 18 years of age, who suffered OHCA of both cardiac and non-cardiac causes, were included. With an overall TH use of 70%, the survival to discharge was 42%, with 90% of the survivors having a favourable cerebral outcome. Known positive prognostic factors such as witnessed arrest, bystander cardio pulmonary resuscitation (CPR), shockable rhythm and cardiac origin were all positive predictors of TH use and survival. On the other side, increasing age predicted a lower utilisation of TH: Odds Ratio (OR), 0.96 (95% CI, 0.94 to 0.97); as well as a lower survival: OR 0.96 (95% CI, 0.94 to 0.97). Female gender was also associated with a lower use of TH: OR 0.65 (95% CI, 0.43 to 0.97); and a poorer survival: OR 0.57 (95% CI, 0.36 to 0.92). After correcting for other prognostic factors, use of TH remained an independent predictor of improved survival with OR 1.91 (95% CI 1.18-3.06; P <0.001). Analysing subgroups divided after initial rhythm, these effects remained unchanged for patients with shockable rhythm, but not for patients with non-shockable rhythm where use of TH and female gender lost their predictive value.
Although TH was used in the majority of unconscious OHCA patients admitted to the ICU, actual use varied significantly between subgroups. Increasing age predicted both a decreased utilisation of TH as well as lower survival. Further, in patients with a shockable rhythm female gender predicted both a lower use of TH and poorer survival. Our results indicate an underutilisation of TH in some subgroups. Hence, more research on factors affecting TH use and the associated outcomes in subgroups of post-resuscitation patients is needed.
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