Assessing Sunscreen Protection Using UV Photography: Descriptive Study.

BACKGROUND: Photography using a UV transmitting filter allows UV light to pass and can be used to illuminate UV blocking lotions such as sunscreens. OBJECTIVE: The aim of this study is to compare currently available UV photography cameras and assess whether these devices can be used as visualization tools for adequate coverage of sun protection lotions. METHODS: This study was conducted in 3 parts: in phase 1, 3 different UV cameras were tested; in phase 2, we explored whether UV photography could work on a range of sun protection products; and in phase 3, a UV webcam was developed and was field-tested in a beach setting. In phase 1, volunteers were recruited, and researchers applied 3 sun protection products (ranging from sun protection factor [SPF] 15 to 50+) to the participants' faces and arms. UV photography was performed using 3 UV cameras, and the subsequent images were compared. In phase 2, volunteers were recruited and asked to apply their own SPF products to their faces in their usual manner. UV photographs were collected in the morning and afternoon to assess whether the coverage remained over time. Qualitative interviews were conducted to assess the participants' level of satisfaction with the UV image. In phase 3, a small portable UV webcam was designed using a plug-and-play approach to enable the viewing of UV images on a larger screen. The developed webcam was deployed at a public beach setting for use by the public for 7 days. RESULTS: The 3 UV camera systems tested during phase 1 identified the application of a range of sun protection lotions of SPF 15 to 50+. The sensitivity of the UV camera devices was shown to be adequate, with SPF-containing products applied at concentrations of 2 and 1 mg/cm2 clearly visible and SPF-containing products applied at a concentration of 0.4 mg/cm2 having lower levels of coverage. Participants in phase 2 reported high satisfaction with the UV photography images, with 83% (29/35) of participants likely to use UV photography in the future. During phase 2, it was noted that many participants used tinted SPF-containing cosmetics, and several tinted products were further tested. However, it was observed that UV photography could not identify the areas missed for all tinted products. During phase 3, the electrical components of the UV webcam remained operational, and the camera was used 233 times by the public during field-testing. CONCLUSIONS: In this study, we found that UV photography could identify the areas missed by sun protection lotions with chemical filters, and participants were engaged with personalized feedback. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12619000975190; http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377089 ; Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12619000145101; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376672.

Internet of Things Smart Sunscreen Station: Descriptive Proof-of-Concept Study.

BACKGROUND: Skin cancer is the most prevalent but also most preventable cancer in Australia. Outdoor workers are at increased risk of developing skin cancer, and improvements in sun protection are needed. Sunscreen, when applied at the recommended concentration (2 mg/cm2), has been shown to block the harmful molecular effects of ultraviolet radiation in vivo. However, sunscreen is often not applied, reapplied sufficiently, or stored adequately to yield protection and reduce sunburns. OBJECTIVE: The primary aim of this study was to test an Internet of Things approach by deploying a smart sunscreen station to an outdoor regional mining site. METHODS: We deployed a smart sunscreen station and examined the key technological considerations including connectivity, security, and data management systems. RESULTS: The smart sunscreen station was deployed for 12 days at a mining workplace (Dalby, Australia). The smart sunscreen station's electrical components remained operational during field testing, and data were received by the message queuing telemetry transport server automatically at the end of each day of field testing (12/12 days, 100% connectivity). CONCLUSIONS: This study highlights that an Internet of Things technology approach can successfully measure sunscreen usage and temperature storage conditions.

Circulating levels of vascular endothelial growth factor and post-stroke long-term functional outcome.

OBJECTIVES: Vascular endothelial growth factor (VEGF) acts in angiogenesis and neuroprotection, although the beneficial effects on experimental ischemic stroke (IS) have not been replicated in clinical studies. We investigated serum VEGF (s-VEGF) in the acute stage (baseline) and 3 months post-stroke in relation to stroke severity and functional outcome. METHODS: The s-VEGF and serum high-sensitivity C-reactive protein (hs-CRP) concentrations were measured in patients enrolled in the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS) at the acute time-point (median 4 days, N = 492, 36% female; mean age, 57 years) and at 3 months post-stroke (N = 469). Baseline stroke severity was classified according to the National Institutes of Health Stroke Scale (NIHSS), and functional outcomes (3 months and 2 years) were evaluated using the modified Rankin Scale (mRS), dichotomized into good (mRS 0-2), and poor (mRS 3-6) outcomes. Multivariable logistic regression analyses were adjusted for covariates. RESULTS: The baseline s-VEGF did not correlate with stroke severity but correlated moderately with hs-CRP (r = .17, P < .001). The baseline s-VEGF was 39.8% higher in total anterior cerebral infarctions than in lacunar cerebral infarctions. In binary logistic regression analysis, associations with 3-month functional outcome were non-significant. However, an association between the 3-month s-VEGF and poor 2-year outcome withstood adjustments for age, sex, cardiovascular covariates, and stroke severity (per 10-fold increase in s-VEGF, odds ratio [OR], 2.56, 95% confidence interval [CI] 1.12-5.82) or hs-CRP (OR 2.53, CI 1.15-5.55). CONCLUSIONS: High 3-month s-VEGF is independently associated with poor 2-year functional outcome but not with 3-month outcome.

Postoperative Thromboprophylaxis With New Oral Anticoagulants is Superior to LMWH in Hip Arthroplasty Surgery: Findings from the Swedish Registry.

BACKGROUND: Although the use of thromboprophylaxis is well established, there is no consensus on the preferred thromboprophylaxis regimen after THA; large, population-based studies offer an opportunity to examine this problem in a robust way that can complement results from randomized trials. QUESTIONS/PURPOSES: Using data from a large national registry, we asked: (1) Is there any difference between low-molecular weight heparin (LMWH) and new oral anticoagulants in preventing symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE), after THA? (2) Are there any differences in safety parameters, such as bleeding, reoperations and mortality, between LMWH and new oral anticoagulants? METHODS: Between 2008 and 2012, 78,066 THAs were performed in Sweden. This study evaluated 32,663 (42%) of them, selected through the merger of several national registries. These patients underwent unilateral THA due to primary osteoarthritis. They had not experienced any venous thromboembolic events 5 years before the index operation and were not prescribed potent antithrombotic agents, of any type, in the 6 months before the index operation. Additionally, their postoperative thromboprophylaxis was confirmed in a national registry by purchase of prescribed medications. We divided the cohort into two groups: those patients who received new oral anticoagulants (5752, 18%) and those who received LMWH (26,881, 82%) as postoperative thromboprophylaxis. Our primary endpoints were the frequencies of symptomatic DVT and symptomatic PE within 3 months of surgery. Our secondary comparison was a between-group comparison of bleeding (by way of diagnostic coding), reoperation, and mortality within 3 months of surgery. Odds ratios (OR) are presented with 95% confidence intervals (CIs) as pooled results for the two groups after adjustment for duration of thromboprophylaxis (short or extended for at least 28 days), year of the index operation, Elixhauser comorbidity index, sex, age and previous treatment with platelet aggregation inhibitors. RESULTS: The risk of symptomatic DVT was lower in the group that received new oral anticoagulants than the group that received LMWH (0.3% versus 0.6%, OR, 0.47; 95% CI, 0.27-0.76; p = 0.026). The risk of symptomatic PE was lower in the group that received new oral anticoagulants than the group that received LMWH (0.1% versus 0.4%, OR, 0.36; 95% CI, 0.16-0.69; p = 0.005). There was no difference in the risk of bleeding (by way of diagnostic coding) (OR, 1.03; 95% CI, 0.82-1.28; p = 0.688), reoperation (OR, 1.02; 95% CI, 0.71-1.44; p = 0.860) or mortality (OR, 0.83; 95% CI, 0.31-1.88; p = 0.883) between groups. CONCLUSIONS: New oral anticoagulants were associated with a lower risk of symptomatic DVT and symptomatic PE in this large, registry study, and we observed no differences in the risk of bleeding, reoperation, or death between the groups. Although we were able to control for a number of potential confounding variables, we cannot ascertain the indications that drove the prescription decisions in this setting, and there were important between-group differences in terms of duration of thromboprophylaxis (new oral anticoagulants generally were used for a longer period of time after surgery). Future studies, preferably large randomized trials with pragmatic inclusion criteria, to analyze symptomatic DVT, symptomatic PE and death are needed to confirm or refute our findings. LEVEL OF EVIDENCE: Level III, therapeutic study.

Use of dual-mobility cup in revision hip arthroplasty reduces the risk for further dislocation: analysis of seven hundred and ninety one first-time revisions performed due to dislocation, reported to the Swedish Hip Arthroplasty Register.

PURPOSE: Dislocation after total hip arthroplasty (THA) is a common reason for revision. The last decade fostered a significant increase in the use of dual-mobility cups (DMCs). Here we report our study on the short-term survival rate of a cemented DMC reported to the Swedish Hip Arthroplasty Register (SHAR) compared with other cemented designs used in first-time revision due to dislocation. METHODS: During 2005-2015, 984 first-time revisions for dislocation were reported to SHAR. In 436 of these cases a cemented dual articular cup was used. During the same time period, 355 revisions performed with a standard cemented cup (femoral head size 28-36 mm) were reported to the SHAR. Patients receiving a DMC were slightly older (75 years, p = 0.005). Re-revision for all reasons was used as primary endpoint. We also anlaysed risk for re-revision of the acetabular component and re-revision due to dislocation. Kaplan-Meier implant survival and a Cox regression analyses adjusted for age and gender were performed. RESULTS: Implant survival at 4 years for all reasons (91% ± 3.7% vs 86% ± 4.1%, p = 0.02), and especially for re-operation because of dislocation, favours the DMC group (96% ± 3.0% vs 92% ± 3.3%, p = 0.001). DISCUSSION: Our findings indicate that use of a cemented DMC reduces the short- to mid-term risk of a second revision in first-time revisions compared with classic cup designs. Longer follow-up is needed to establish any long-term clinical advantages when DMCs are used in revisions performed due to dislocation.

Stability of two angular stable locking plates for open wedge high tibial osteotomy (HTO): TomoFix™ versus LOQTEQ® HTO plate.

INTRODUCTION: The aim of this study was to test the mechanical stability of LOQTEQ® HTO plate in comparison to the TomoFix™ internal plate fixator. MATERIALS AND METHODS: An unstable fracture gap model with two standardized polyoxymethylene (POM) cylinders was used for this study. With this model 5 LOQTEQ® HTO plates and 5 TomoFix™ were cyclically loaded. The start load was 100 N and increased by 50 N after each successful completed cycle. Each load step included 250,000 cycles. All tests were performed in accordance with the American Society for Testing and Materials (ASTM) Standard Specification and Test Method for Metallic Bone Plates F382-99(2003)e1. RESULTS: The mean fatigue strength of the LOQTEQ® HTO Plate was 155 % of the value gained by the TomoFix™ implant. This difference was statistically significant (t test <0.001). There was also a significant difference in the cycles but both implants survived. The LOQTEQ® HTO Plate system survived 1,520,336.8 (±121,687.7) cycles, whereas the TomoFix™ group passed on average 847,802,600 (±134,660.7) cycles. In both groups, the only failure mode was plate breakage in a shaft hole. CONCLUSIONS: The results of the present study showed that fatigue strength of the LOQTEQ® HTO plate was significantly higher in comparison to TomoFix™. These results justify the clinical use of the LOQTEQ® HTO plate.

Tumor blood volume determination by using susceptibility-corrected DeltaR2* multiecho MR.

PURPOSE: To evaluate a susceptibility-corrected multiecho magnetic resonance (MR) relaxometry technique for an accurate and robust determination of DeltaR2* as a noninvasive surrogate parameter of the perfused tumor blood volume. MATERIALS AND METHODS: All experiments were approved by the institutional animal care committee. In a glass tube phantom with different superparamagnetic iron oxide (SPIO) particle concentrations and at tumor mice xenografts with DU-4475, HT-1080, and MDA-MB-435 tumors (n = 15 total, n = 5 per model) with different degrees of neovascularization after injection of different ultrasmall SPIO (USPIO) doses changes of the transverse relaxation rate (DeltaR2*) were determined by using a fixed echo time (TE) of 22 msec and a susceptibility-corrected multigradient-echo technique. The mean DeltaR2* value and the vascular volume fraction (VVF) of each tumor was determined and compared with independent in vivo fluorescent tumor perfusion measurements and histologic analysis helped determine microvessel density (MVD). Statistical differences were tested by using analysis of variance and linear correlations. RESULTS: For the phantom study, DeltaR2* maps calculated with a fixed TE of 22 msec showed a higher standard deviation of the noise index compared with the susceptibility-corrected multiecho technique. For the xenograft model, mean tumor DeltaR2* values (+/- standard error of the mean) showed significant differences between the various tumors (eg, DU-4475: 12.3 sec(-1) +/- 2.67, HT-1080: 36.47 sec(-1) +/- 5.84, and MDA-MB-435: 64.01 sec(-1) +/- 8.87 at 80 mumol of iron per kilogram; P < .05). DeltaR2* values increased dose dependently and in a linear fashion, resulting in reproducibly stable VVF measurements. Fluorescent tumor perfusion measurements and MVD counts corroborated the MR results. CONCLUSION: Susceptibility-corrected multiecho MR relaxometry allows a highly accurate and robust determination of DeltaR2* and VVF with an excellent dynamic range for tumor characterization at clinically relevant doses of USPIO.

In vivo optical imaging of cellular inflammatory response in granuloma formation using fluorescence-labeled macrophages.

UNLABELLED: Near-infrared imaging such as fluorescence reflectance imaging (FRI) and fluorescence-mediated tomography (FMT) yields high signal-to-noise ratios (SNRs) and should thus be well suited for cell-tracking studies. Extravasation of monocytes or macrophages (Ms) is one of the earliest events in inflammation. The purpose of this study was to assess whether FRI and FMT allow for the visualization and quantification of early inflammatory processes by tracing the migration of fluorescence-labeled murine Ms in a cutaneous granuloma model. METHODS: Ms were labeled with a membrane-selective carbocyanine dye (1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide [DiR]). Cellular viability and function (nitric oxide production, phagocytosis, adherence) were assessed in vitro. Local inflammation was induced in mice by the subcutaneous injection of polyacrylamide gel pellets including or excluding a strong inflammatory stimulus (lipopolysaccharide). Labeled Ms were injected intravenously, and FRI and FMT were performed up to 7 d. SNRs were calculated for the pellets, and the 3-dimensional distribution of Ms was assessed using FMT. Cells were harvested from gel pellets and analyzed by flow cytometry. RESULTS: DiR labeling did not affect cell viability or cell function. FRI revealed the migration of labeled Ms into gel pellets and the homing of Ms to different body compartments. The lipopolysaccharide-containing pellets exhibited significantly higher SNRs than did pellets without lipopolysaccharide. FMT showed that Ms distributed mainly in the periphery of the pellets. The cellular infiltrates extracted from the harvested pellets revealed the presence of approximately 10%-23% DiR-positive Ms-expressing typical markers, confirming the transendothelial migration of injected Ms. CONCLUSION: The tagging of Ms with DiR allows the noninvasive tracking of inflammatory cells for several days in vivo. FRI and FMT are versatile techniques to monitor and quantify cellular inflammatory responses in vivo.

Comparison of 1.0 M gadobutrol and 0.5 M gadopentetate dimeglumine-enhanced magnetic resonance imaging in five hundred seventy-two patients with known or suspected liver lesions: results of a multicenter, double-blind, interindividual, randomized clinical phase-III trial.

OBJECTIVE: To evaluate the diagnostic efficacy (accuracy, sensitivity, specificity) of 1.0 M gadobutrol versus 0.5 M gadopentetate for the classification of lesions as either benign or malignant in patients with known or suspected liver lesions. METHODS AND MATERIALS: A multicenter, phase-III, randomized, interindividually controlled comparison study with blinded reader evaluation was performed to investigate the diagnostic efficacy of a bolus injection of 1.0 M gadobutrol compared with 0.5 M gadopentetate at a dose of 0.1 mmol Gd/kg BW. The imaging protocol included a dynamic 3D-evaluation, static conventional, and fat saturated T1-weighted sequences. MR datasets were evaluated by 3 independent radiologists. The standard of reference was defined by an independent truth panel (radiologist or hepatologist). The safety evaluation included adverse events, vital signs, and physical examination. RESULTS: A total of 497 of 572 patients were eligible for the final efficacy analysis. Noninferiority of gadobutrol-enhanced magnetic resonance imaging (MRI) for the classification of liver lesions was demonstrated on the basis of diagnostic accuracy determined by the on-site investigators (-0.098, 0.021) as well as for the average reader of the blinded evaluation (-0.096, 0.014) (95% confidence interval), compared with the predefined standard of reference. Very similar increases in sensitivity (ranging from approximately 10% to approximately 55%) and specificity (ranging from approximately 1% to approximately 18%) compared with precontrast MRI were also observed for the 2 contrast agent groups, with maximum differences of 4%.Very similar, low rates of adverse events were recorded for each of the 2 groups. No clinically relevant changes in vital signs or the results of the physical examination were observed in any patient. CONCLUSION: This study documents evidence for the noninferiority of a single i.v. bolus injection of 1.0 M gadobutrol (0.1 mmol/kg body weight) to 0.5 M gadopentetate (0.1 mmol/kg body weight) in the diagnostic assessment of liver lesions with contrast-enhanced MRI. The known excellent safety profile of gadobutrol was confirmed in this clinical trial and is similar to that of gadopentetate.

Differentiation of angiogenic burden in human cancer xenografts using a perfusion-type optical contrast agent (SIDAG).

INTRODUCTION: Use of fluorescence imaging in oncology is evolving rapidly, and nontargeted fluorochromes are currently being investigated for clinical application. Here, we investigated whether the degree of tumour angiogenesis can be assessed in vivo by planar and tomographic methods using the perfusion-type cyanine dye SIDAG (1,1'-bis- [4-sulfobutyl]indotricarbocyanine-5,5'-dicarboxylic acid diglucamide monosodium). METHOD: Mice were xenografted with moderately (MCF7, DU4475) or highly vascularized (HT1080, MDA-MB435) tumours and scanned up to 24 hours after intravenous SIDAG injection using fluorescence reflectance imaging. Contrast-to-noise ratio was calculated for all tumours, and fluorochrome accumulation was quantified using fluorescence-mediated tomography. The vascular volume fraction of the xenografts, serving as a surrogate marker for angiogenesis, was measured using magnetic resonance imaging, and blood vessel profile (BVP) density and vascular endothelial growth factor expression were determined. RESULTS: SIDAG accumulation correlated well with angiogenic burden, with maximum contrast to noise ratio for MDA-MB435 (P < 0.0001), followed by HT1080, MCF7 and DU4475 tumours. Fluorescence-mediated tomography revealed 4.6-fold higher fluorochrome concentrations in MDA-MB435 than in DU4475 tumours (229 +/- 90 nmol/l versus 49 +/- 22 nmol/l; P < 0.05). The vascular volume fraction was 4.5-fold (3.58 +/- 0.9% versus 0.8 +/- 0.53%; P < 0.01), blood vessel profile density 5-fold (399 +/- 36 BVPs/mm2 versus 78 +/- 16 BVPs/mm2) and vascular endothelial growth factor expression 4-fold higher for MDA-MB435 than for DU4475 tumours. CONCLUSION: Our data suggest that perfusion-type cyanine dyes allow assessment of angiogenesis in vivo using planar or tomographic imaging technology. They may thus facilitate characterization of solid tumours.

Prediction of antiangiogenic treatment efficacy by iron oxide enhanced parametric magnetic resonance imaging.

RATIONALE AND OBJECTIVES: Tools for monitoring modern target-specific antiangiogenic and antivascular therapies are highly desirable because treatment strategies are time consuming, expensive, and yet sometimes ineffective. Therefore, the aim of this experimental study was to evaluate the predictive value of steady-state ultrasmall particles of iron oxide (USPIO; SH U 555 C)-enhanced magnetic resonance imaging (MRI) for early assessment of antivascular tumor-treatment effectiveness. METHODS: Mice were inoculated with an HT-1080 fibrosarcoma xenograft and subjected to target-specific antivascular therapy using a selective thrombogenic vascular-targeting agent (truncated tissue factor fused to RGD peptide) or saline as control. Four to 8 hours after treatment, the USPIO-induced change in the transverse relaxation rate DeltaR2* was measured by MRI, and the vascular volume fraction (VVF) was calculated by calibrating DeltaR2* of the tumor by DeltaR2* of muscle tissue. Treatment response was defined by histologic grading of vascular thrombosis and tumor necrosis. RESULTS: After thrombogenic treatment, half of the HT-1080 xenograft-bearing animals showed only minor (=nonresponder) whereas the other half showed extensive tumor thrombosis (=responders). For responders, a significant decrease of DeltaR2* and VVF was observed compared with the control group (DeltaR2*: controls: 16 +/- 1 s-1 vs. responder: 4 +/- 2 s-1; P < 0.001) whereas DeltaR2* and VVF remained nearly unchanged for nonresponders (DeltaR2*: nonresponder 14 +/- 2 s-1). VVF and DeltaR2* values correlated inversely with the histologic grading of vascular thrombosis and tumor necrosis (VVF: r = -0.8; DeltaR2*: r = -0.71; P < 0.01). CONCLUSION: USPIO-enhanced MRI allows a noninvasive, early assessment of treatment efficacy of thrombogenic vascular-targeting agents.

Antiangiogenic tumor treatment: early noninvasive monitoring with USPIO-enhanced MR imaging in mice.

PURPOSE: To prospectively investigate steady-state blood volume measurements for early quantitative monitoring of antiangiogenic treatment with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: The institutional animal care committee approved all experiments. HT-1080 fibrosarcoma-bearing nude mice were injected with a thrombogenic vascular targeting agent (VTA) (11 nude mice, 20 tumors) or saline (12 nude mice, 20 tumors). USPIO-enhanced (SH U 555C) MR imaging was performed after the VTA was administered. USPIO-induced changes in tissue R2* (DeltaR2*) were measured with a T2-weighted dual-echo echo-planar imaging sequence, and the vascular volume fraction (VVF) was calculated. Parametric DeltaR2* maps were analyzed with respect to tumor perfusion patterns. Correlative histologic analysis was performed for grading of tissue thrombosis, and tissue perfusion was quantified with fluorescent microbeads. Unpaired Student t test and Spearman nonparametric correlation coefficient were used for statistical analysis. RESULTS: The DeltaR2* values were significantly (P < .001) reduced shortly after treatment initiation (mean DeltaR2*, 0.017 msec(-1) +/- 0.0014 [standard error] in control animals vs 0.005 msec(-1) +/- 0.0007 in animals that received VTA), which was also reflected by a decrease in the VVF (2.47% +/- 0.18 vs 0.41% +/- 0.48, P < .001). Histologic analysis revealed various degrees of tumor thrombosis after VTA treatment that correlated inversely with the DeltaR2* values (r = -0.83). Moreover, tumor perfusion measurements corroborated the MR results, indicating a significant reduction in tissue perfusion after VTA treatment (mean tissue fluorescence, 570.4 arbitrary units [au] per gram +/- 27 vs 161.7 au/g +/- 17; P < .05). CONCLUSION: USPIO-enhanced MR imaging enables early monitoring of antiangiogenic treatment of tumors.

Assessment of bone marrow angiogenesis in patients with acute myeloid leukemia by using contrast-enhanced MR imaging with clinically approved iron oxides: initial experience.

PURPOSE: To prospectively assess bone marrow (BM) angiogenesis in patients with acute myeloid leukemia (AML) by using iron oxide-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: The study was institutional ethics committee approved. Informed signed consent was obtained from each study participant. The requirement for informed consent for use of data from a reference database was waived. Eleven patients (seven women, four men; mean age, 53 years+/-4.40 [standard deviation]) with an initial diagnosis of AML were enrolled in the study and underwent T2*-weighted two-echo echo-planar MR imaging of the pelvis before and after intravenous injection of a clinically approved iron oxide blood-pool contrast agent. Six healthy control subjects (one woman, five men; mean age, 35 years+/-2.31) were examined with the same MR protocol. The iron oxide-induced change in R2* relaxation rate (DeltaR2*) was calculated, and the vascular volume fraction (VVF) of the BM was derived by dividing the DeltaR2* of the BM by the DeltaR2* of the muscle. Parametric DeltaR2* maps were calculated to visualize vessel distribution. Patients underwent BM biopsy for correlative determination of microvessel density (MVD) and vascular endothelial growth factor (VEGF). Differences in DeltaR2*, VVF, VEGF, and MVD were compared by using the Wilcoxon rank sum test. RESULTS: DeltaR2* maps showed prominent areas of highly vascularized BM in the patients with AML, whereas the control subjects had moderately vascularized BM with homogeneous vessel distribution. Quantitative analysis revealed VVF values to be significantly higher in patients with AML than in control subjects: The mean VVF in the pelvis was 9.18%+/-1.54 for patients versus 3.91%+/-0.61 for control subjects (P=.010). In accordance with MR results, MVD (P=.009) and VEGF expression (P=.017) were significantly elevated in the AML group compared with values in the control group. CONCLUSION: Iron oxide-enhanced MR imaging enables assessment of BM angiogenesis in patients with AML.

Cell tagging with clinically approved iron oxides: feasibility and effect of lipofection, particle size, and surface coating on labeling efficiency.

PURPOSE: To evaluate the effect of lipofection, particle size, and surface coating on labeling efficiency of mammalian cells with superparamagnetic iron oxides (SPIOs). MATERIALS AND METHODS: Institutional Review Board approval was not required. Different human cell lines (lung and breast cancer, fibrosarcoma, leukocytes) were tagged by using carboxydextran-coated SPIOs of various hydrodynamic diameters (17-65 nm) and a dextran-coated iron oxide (150 nm). Cells were incubated with increasing concentrations of iron (0.01-1.00 mg of iron [Fe] per milliliter), including or excluding a transfection medium (TM). Cellular iron uptake was analyzed qualitatively at light and electron microscopy and was quantified at atomic emission spectroscopy. Cell visibility was assessed with gradient- and spin-echo magnetic resonance (MR) imaging. Effects of iron concentration in the medium and of lipofection on cellular SPIO uptake were analyzed with analysis of variance and two-tailed Student t test, respectively. RESULTS: Iron oxide uptake increased in a dose-dependent manner with higher iron concentrations in the medium. The TM significantly increased the iron load of cells (up to 2.6-fold, P < .05). For carboxydextran-coated SPIOs, larger particle size resulted in improved cellular uptake (65 nm, 4.37 microg +/- 0.08 Fe per 100 000 cells; 17 nm, 2.14 microg +/- 0.06 Fe per 100 000 cells; P < .05). Despite larger particle size, dextran-coated iron oxides did not differ from large carboxydextran-coated particles (150 nm, 3.81 microg +/- 0.46 Fe per 100 000 cells; 65 nm, 4.37 microg +/- 0.08 Fe per 100 000 cells; P > .05). As few as 10 000 cells could be detected with clinically available MR techniques by using this approach. CONCLUSION: Lipofection-based cell tagging is a simple method for efficient cell labeling with clinically approved iron oxide-based contrast agents. Large particle size and carboxydextran coating are preferable for cell tagging with endocytosis- and lipofection-based methods.

Fast interactive real-time magnetic resonance imaging of cardiac masses using spiral gradient echo and radial steady-state free precession sequences.

RATIONALE AND OBJECTIVES: Cardiac and respiratory controlled MR-imaging is the gold standard for imaging of cardiac masses. However, this technique may be limited in patients with dyspnoe or arrhythmia. The aim of this study was the evaluation of an interactive MR-approach for the detection and localization of cardiac masses. METHODS: Interactive real-time spiral gradient-echo (spiralGE) and radial steady-state-free-precession (radialSSFP) MR-imaging was performed during free-breathing and without cardiac triggering in 15 patients with 14 intracardiac or paracardiac masses. Standard cardiac triggered segmented k-space breath-hold steady-state-free-precession cine MR-imaging was used as the reference MR-imaging technique. Two groups of investigators blinded to clinical data were ask to rank image quality and to identify cardiac masses on real-time MR-images. RESULTS: Image quality was superior using radialSSFP when compared with spiralGE. Using radialSSFP all masses were correctly detected while 6 of 14 masses were missed on spiralGE. Mean real-time MR-imaging time was less than 3 minutes for both techniques. CONCLUSION: Interactive real-time radialSSFP MR-imaging allows for accurate and fast detection of cardiac masses without the need of cardiac or respiratory triggering.