A review on imaging techniques and quantitative measurements for dynamic imaging of cerebral aneurysm pulsations

Measurement of intracranial aneurysm wall motion may refine the current rupture risk estimation. A golden standard for measuring aneurysm pulsation is lacking. The aim is to evaluate magnitudes of aneurysm pulsation as published in current literature. Embase and PubMed were searched for publications containing quantitative measures of cardiac-cycle related cerebral aneurysm pulsation (no date or language restrictions). Eleven studies were included, covering 197 unruptured and untreated cerebral aneurysms. Quantitative pulsation measurements were extracted from the studies. Characteristics of the study population and aneurysms were taken into account, as well as the imaging modality, scanning technique and data processing methods used. A meta-analysis was performed of studies with similar methodologies and individual IA measures and locations. The magnitude of the absolute volume pulsations varied between 14 ± 9 mm3 and 106 ± 123 mm3 and the mean relative volume change varied between 5 and 36%. The meta-analysis revealed a positive correlation between size and absolute volume change. The relative volume change in Basilar artery aneurysms seems smaller. No authors were contacted for original study data and articles only describing visual pulsations were excluded. The variation in methodologies impedes an accurate estimation of the magnitude of IA pulsations. Validation of aneurysm pulsation measurement is crucial prior to clinical studies evaluating IA pulsatility in relation to IA rupture risk. Prerequisite is a reliable and robust imaging method with high spatial and temporal resolution and standardization of the image analysis methods.

Surveillance of small, solid pulmonary nodules at digital chest tomosynthesis: data from a cohort of the pilot Swedish CArdioPulmonary bioImage Study (SCAPIS)

Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomography (CT). Purpose To investigate DTS relative to CT for surveillance of incidental, solid pulmonary nodules. Material and Methods Recruited from a population study, 106 participants with indeterminate solid pulmonary nodules on CT underwent surveillance with concurrently performed CT and DTS. Nodule size on DTS was assessed by manual diameter measurements and semi-automatic nodule segmentations were independently performed on CT. Measurement agreement was analyzed according to Bland–Altman with 95% limits of agreement (LoA). Detection of nodule volume change > 25% by DTS in comparison to CT was evaluated with receiver operating characteristics (ROC). Results A total of 81 nodules (76%) were assessed as measurable on DTS by two independent observers. Inter- and intra-observer LoA regarding change in average diameter were ± 2 mm. Calculation of relative volume change on DTS resulted in wide inter- and intra-observer LoA in the order of ± 100% and ± 50%. Comparing relative volume change between DTS and CT resulted in LoA of –58% to 67%. The area under the ROC curve regarding the ability of DTS to detect volumetric changes > 25% on CT was 0.58 (95% confidence interval [CI] = 0.40–0.76) and 0.50 (95% CI = 0.35–0.66) for the two observers. Conclusion The results of the present study show that measurement variability limits the agreement between DTS and CT regarding nodule size change for small solid nodules.

How to Assess the Relative Volume Change of Reversible Metal Hydrides Easily, Speedily and Concisely (Enough) with a Surprising Relevance for Clarifying Thermodynamic Tailoring Effects

<p>A practical way for assessing the relative volume change of reversible metal hydrides upon hydrogenation, based on the van’t Hoff reaction parameters, is outlined. Hitherto computational methods can provide that information only at a much higher level of complexity. By that method, the open issue of assessing the minimum pressure for complete [AlH₄]-formation in Ti-doped NaAlH₄ is resolved and the nature of the additional reaction pathway in KH/Ti-co-doped NaAlH₄ elucidated. This work summarizes the essentials for the thermodynamic tailoring of metal hydrides in nine points and adds thus a central missing piece to the puzzle of understanding reversible chemical hydrogen storage in metal hydrides.</p>

How to Assess the Relative Volume Change of Reversible Metal Hydrides Easily, Speedily and Concisely (Enough) with a Surprising Relevance for Clarifying Thermodynamic Tailoring Effects

<p>A practical way for assessing the relative volume change of reversible metal hydrides upon hydrogenation, based on the van’t Hoff reaction parameters, is outlined. Hitherto computational methods can provide that information only at a much higher level of complexity. By that method, the open issue of assessing the minimum pressure for complete [AlH₄]-formation in Ti-doped NaAlH₄ is resolved and the nature of the additional reaction pathway in KH/Ti-co-doped NaAlH₄ elucidated. This work summarizes the essentials for the thermodynamic tailoring of metal hydrides in nine points and adds thus a central missing piece to the puzzle of understanding reversible chemical hydrogen storage in metal hydrides.</p>

Impact of Ipsilateral Blood Draws, Injections, Blood Pressure Measurements, and Air Travel on the Risk of Lymphedema for Patients Treated for Breast Cancer

Purpose The goal of this study was to investigate the association between blood draws, injections, blood pressure readings, trauma, cellulitis in the at-risk arm, and air travel and increases in arm volume in a cohort of patients treated for breast cancer and screened for lymphedema. Patients and Methods Between 2005 and 2014, patients undergoing treatment of breast cancer at our institution were screened prospectively for lymphedema. Bilateral arm volume measurements were performed preoperatively and postoperatively using a Perometer. At each measurement, patients reported the number of blood draws, injections, blood pressure measurements, trauma to the at-risk arm(s), and number of flights taken since their last measurement. Arm volume was quantified using the relative volume change and weight-adjusted change formulas. Linear random effects models were used to assess the association between relative arm volume (as a continuous variable) and nontreatment risk factors, as well as clinical characteristics. Results In 3,041 measurements, there was no significant association between relative volume change or weight-adjusted change increase and undergoing one or more blood draws (P = .62), injections (P = .77), number of flights (one or two [P = .77] and three or more [P = .91] v none), or duration of flights (1 to 12 hours [P = .43] and 12 hours or more [P = .54] v none). By multivariate analysis, factors significantly associated with increases in arm volume included body mass index ≥ 25 (P = .0236), axillary lymph node dissection (P < .001), regional lymph node irradiation (P = .0364), and cellulitis (P < .001). Conclusion This study suggests that although cellulitis increases risk of lymphedema, ipsilateral blood draws, injections, blood pressure readings, and air travel may not be associated with arm volume increases. The results may help to educate clinicians and patients on posttreatment risk, prevention, and management of lymphedema.