Efficacy and safety of treating acute haemoptysis using glue embolization: A retrospective observational study and comparison to the literature.

INTRODUCTION: A retrospective observational study of the short-term efficacy and safety of using glue embolization, namely n-butyl-2-cyanoacrylate (NBCA), in bronchial artery embolization (BAE) and comparison with the literature. The main aim of the study is to display the safety of this embolic material through standardization of interventional procedure for consideration of NBCA as a possible primary embolic agent in cases of BAE. METHODS: A total of 35 BAE was performed in 31 patients with acute haemoptysis after failure of bronchoscopic therapy using NBCA. The mean age was 56 years with 22 male patients. Pre-interventional bronchoscopy and computed tomographic angiography were performed. In 35 cases, embolization was performed exclusively with NBCA. One patient in combination with coils and one with particles and coils. The 1:4 NBCA-to-Lipiodol mixture was most commonly used. Post-interventional bronchoscopy was performed after 24 h. RESULTS: Technical success was possible in all cases. Clinical success was achieved in 94.3%. There was a mortality rate of 6.5% within 48 h. No other embolization related major complications were noticed. A minor complication of temporary ischaemia of the bronchial mucosa. No reperfusion of the embolized vessel, however with rebleeding in four patients from different primarily not embolized bronchial arteries. CONCLUSION: Despite previous concerns about its safety based on previous reports and in line with recent studies, we conclude that NBCA is a safe and effective embolic agent to perform BAE in cases of acute haemoptysis if performed according to a clear standard operating procedure as described with a possible superiority over embolic agents. Further blinded prospective comparative studies are necessary.

Endovascular retrieval of a dislocated pushable coil in the common hepatic artery using a cerebral stent retriever.

BACKGROUND: This is case of removing a dislocated pushable coil from the common hepatic artery (CHA) as a possible complication of using pushable coils in the embolization of an upper gastrointestinal bleeding (UGIB) from the gastroduodenal artery (GDA) by using a pRESET stent retriever (Phenox, Bochum, Germany) which is utilized mainly for treatment of endovascular stroke. CASE PRESENTATION: An 88-year-old female patient was referred to our hospital to get an emergency embolization of the GDA causing an UGIB with a relevant drop of the hemoglobin level. During the routine embolization of the GDA using pushable coils, a complete dislocation of the last coil into the CHA took place leading to a relevant slowing down of the arterial blood flow to the liver. A decision was thereby made to remove the dislocated coil to avoid further possible complications which was successfully achieved. CONCLUSIONS: Various stent retrievers have been proven to be effective in removing dislocated coils during intracerebral coiling of different pathologies. This case report is to our knowledge the first case report proving the high efficacy and safety of using yet another stent retriever, namely a pRESET stent retriever in removing a fully dislocated coil in the abdominal vessels, namely in this case the CHA.

Endovascular foreign body removal of a MynxGrip polyethylene glycol (PEG) sealant embolus using a cerebral stent retriever.

BACKGROUND: This is a rare case of removing an intra-arterial foreign body represented by MynxGrip polyethylene glycol (PEG) sealant as a rare complication of using the MynxGrip™ Vascular Closure Device (AccessClosure, Inc., Mountain View, CA) using a pRESET stent retriever (Phenox, Bochum, Germany) which is utilized mainly for treatment of endovascular stroke. CASE PRESENTATION: A 60-year-old female patient suffering from intermittent claudication in the right lower limb (stage IIb according to Fontaine) due to a peripheral arterial occlusive disease was presented for an elective revascularization using balloon angioplasty of a short chronic occlusion of the right superficial femoral artery. After a successful revascularization of the right superficial femoral artery using a retrograde femoral access from the left common femoral artery, the patient suffered from an acute limb ischemia in the left foot with distal popliteal embolization with involvement of BTK (below the knee) trifurcation. This is believed to be due to an intra-arterial foreign body embolism of MynxGrip polyethylene glycol sealant as a rare complication of using the MynxGrip™ Vascular Closure Device. CONCLUSIONS: Stent retrievers have been used previously in removing dislocated coils especially in the cerebral vessels. This case report however proves a high efficacy and safety of using stent retrievers in removing different and rather unusual intra-arterial foreign bodies such as MynxGrip polyethylene glycol sealant.

Prophylactic Transcatheter Arterial Embolization After Successful Endoscopic Hemostasis in the Management of Bleeding Duodenal Ulcer.

GOALS: The aim of this study was to demonstrate the new strategy of prophylactic transcatheter arterial embolization (TAE) of the gastroduodenal artery after endoscopic hemostasis of bleeding duodenal ulcers. BACKGROUND: TAE is a well-established method for the treatment of recurrent or refractory ulcer bleeding resistant to endoscopic intervention, which increasingly replaces surgical procedures. A new approach for improving outcome and reducing rebleeding episodes is the supplemental and prophylactic TAE after successful endoscopic hemostasis. STUDY: This retrospective study included all patients (n=117) treated from 2008 to 2012 for duodenal ulcer bleeding. After initial endoscopic hemostasis, patients were assessed regarding their individual rebleeding risk. Patients with a low rebleeding risk (n=47) were conservatively treated, patients with a high risk for rebleeding (n=55) had prophylactic TAE of the gastroduodenal artery, and patients with endoscopically refractory ulcer bleeding received immediate TAE. RESULTS: The technical success of prophylactic TAE was 98% and the clinical success was 87% of cases. Rebleeding occurred in 11% of patients with prophylactic TAE and was successfully treated with repeated TAE or endoscopy. The major complication rate was 4%. Surgery was necessary in only 1 prophylactic TAE patient (0.9%) during the whole study period. Mortality associated with ulcer bleeding was 4% in patients with prophylactic TAE. CONCLUSIONS: Prophylactic TAE in patients with duodenal ulcers at high risk for rebleeding was feasible, effective at preventing the need for surgery, and had low major complication rates. Given these promising outcomes, prophylactic TAE should be further evaluated as a preventative therapy in high-risk patients.

Endovascular repair of arterial iliac vessel wall lesions with a self-expandable nitinol stent graft system.

OBJECTIVE: To assess the therapeutic outcome after endovascular repair of iliac arterial lesions (IALs) using a self-expandable Nitinol stent graft system. METHODS: Between July 2006 and March 2013, 16 patients (13 males, mean age: 68 years) with a self-expandable Nitinol stent graft. A total of 19 lesions were treated: nine true aneurysms, two anastomotic aneurysms, two dissections, one arteriovenous fistula, two type 1B endoleaks after endovascular aneurysm repair, one pseudoaneurysm, and two perforations after angioplasty. Pre-, intra-, and postinterventional imaging studies and the medical records were analyzed for technical and clinical success and postinterventional complications. RESULTS: The primary technical and clinical success rate was 81.3% (13/16 patients) and 75.0% (12/16), respectively. Two patients had technical failure due to persistent type 1A endoleak and another patient due to acute stent graft thrombosis. One patient showed severe stent graft kinking on the first postinterventional day. In two patients, a second intervention was performed. The secondary technical and clinical success rate was 87.5% (14/16) and 93.8% (15/16). The minor complication rate was 6.3% (patient with painful hematoma at the access site). The major complication rate was 6.3% (patient with ipsilateral deep vein thrombosis). During median follow-up of 22.4 months, an infection of the aneurysm sac in one patient and a stent graft thrombosis in another patient were observed. CONCLUSION: Endovascular repair of various IALs with a self-expandable Nitinol stent graft is safe and effective.

PRFS-based MR thermometry versus an alternative T1 magnitude method--comparative performance predicting thermally induced necrosis in hepatic tumor ablation.

OBJECTIVE: To compare the accuracy of a semi-quantitative proton resonance frequency shift (PRFS) thermal mapping interface and an alternative qualitative T1 thermometry model in predicting tissue necrosis in an established routine setting of MRI-guided laser ablation in the human liver. MATERIALS AND METHODS: 34 cases of PRFS-guided (GRE) laser ablation were retrospectively matched with 34 cases from an earlier patient population of 73 individuals being monitored through T1 magnitude image evaluation (FLASH 2D). The model-specific real-time estimation of necrotizing thermal impact (above 54 °C zone and T1 signal loss, respectively) was correlated in size with the resulting necrosis as shown by lack of enhancement on the first-day contrast exam (T1). Matched groups were compared using the Mann-Whitney test. RESULTS: Online PRFS guidance was available in 33 of 34 cases. Positive size correlation between calculated impact zone and contrast defect at first day was evident in both groups (p < 0.0004). The predictive error estimating necrosis was median 21% (range 1 %-52%) in the PRFS group and 61 % (range 22-84%) in the T1 magnitude group. Differences in estimating lethal impact were significant (p = 0.004), whereas the real extent of therapy-induced necrosis showed no significant difference (p > 0.28) between the two groups. CONCLUSION: PRFS thermometry is feasible in a clinical setting of thermal hepatic tumor ablation. As an interference-free MR-tool for online therapy monitoring its accuracy to predict tissue necrosis is superior to a competing model of thermally induced alteration of the T1 magnitude signal.

Potentially relevant incidental findings on research whole-body MRI in the general adult population: frequencies and management.

OBJECTIVES: To report the frequencies of potentially relevant incidental findings in the general adult population and to develop a protocol for their management in whole-body magnetic resonance imaging (wb-MRI). METHODS: A total of 2,500 adult subjects (1,271 women, 1,229 men; mean age 53 years) from the population-based Study of Health in Pomerania underwent standardised wb-MRI. Additionally, 1,129 participants received contrast-enhanced cardiac MRI, 619 men received MR angiography and 544 women received MR mammography. Two independent residents performed first-line reading. A third reader resolved disagreements. An interdisciplinary advisory board decided about disclosure. RESULTS: There were 1,330 incidental findings of potential clinical relevance in 904 subjects (36.2 %). Nine findings (0.4 %) required immediate referral. In total, 1,052 findings (79.1 %) were confirmed by the advisory board and disclosed to 787 participants (31.5 %). The abdominal organs (6.8 %), the urinary tract (6.8 %) and the skeletal system (6.0 %) were affected most often. While 383 findings (36.4 %) were indicated as benign and 62 (5.9 %) as malignant, most abnormalities, 607 (57.7 %), were of an unclear nature. CONCLUSIONS: Potentially relevant incidental findings are very common in wb-MRI research but the nature of these findings remains unclear in most cases. This requires dedicated management to protect subjects' welfare and research integrity.

R2* estimation using "in-phase" echoes in the presence of fat: the effects of complex spectrum of fat.

PURPOSE: To investigate R2* mapping robustness in the presence of fat using in-phase echoes, without and with spectral modeling of fat (single-peak and multipeak models, respectively), using varying numbers of echoes. MATERIALS AND METHODS: Data from 88 volunteers (men/women: 52/36, ages: 55.4 ± 12.2) were randomly chosen according to magnetic resonance imaging (MRI) liver fat-fraction (%), and classified into six fat-fraction groups (1: 20 cases, 0%-<10%; 2: 20 cases, 10%-<20%; 3: 20 cases, 20%-<30%; 4: 20 cases, 30%-<40%; 5: 8 cases >40% liver fat; 6: subcutaneous fat from all cases). R2* maps obtained from five in-phase echoes (echo times: 4.8-23.8 msec) were retrospectively reconstructed using single-peak and multipeak fat modeling. R2* maps were also calculated using different numbers (2-5) of echoes. RESULTS: Multipeak fat corrected R2* mapping is feasible from in-phase echoes, with noise performance comparable to single-peak R2* when using ≥ 4 echoes. Single-peak R2* showed poor robustness to varying echo time combinations in the presence of fat, where using few echoes resulted in large errors. These errors can be reduced using more echoes, or fully corrected using multipeak fat modeling. The mean R2* increased significantly with increasing fat-fraction when using single-peak R2* for any TE combination (P < 0.001), but did not vary when using multipeak R2* for any TE combination (P ≥ 0.158). CONCLUSION: R2* mapping uncorrected for spectral complexity of fat contains protocol and fat-dependent errors (lack of robustness) in tissues with high fat content. Accounting for complex fat spectrum improves robustness and accuracy of signal fitting, with modest noise performance loss.

Psychosocial consequences and severity of disclosed incidental findings from whole-body MRI in a general population study.

OBJECTIVES: Little is known about the psychosocial impact and subjective interpretation of communicated incide ntal findings from whole-body magnetic resonance imaging (wb-MRI). This was addressed with this general population study. METHODS: Data was based on the Study of Health in Pomerania (SHIP), Germany. SHIP comprised a 1.5-T wb-MRI examination. A postal survey was conducted among the first 471 participants, aged 23-84 years, who received a notification about incidental findings (response 86.0 %, n = 405). The severity of incidental findings was assessed from the participants' and radiologists' perspective. RESULTS: In total, 394 participants (97.3 %) wanted to learn about their health by undergoing wb-MRI. Strong distress while waiting for a potential notification of an incidental finding was reported by 40 participants (9.9 %), whereas 116 (28.6 %) reported moderate to severe psychological distress thereafter. Strong disagreement was noted between the subjective and radiological evaluation of the findings' severity (kappa = 0.02). Almost all participants (n = 389, 96.0 %) were very satisfied with their examination. CONCLUSIONS: Despite the high satisfaction of most participants, there were numerous adverse consequences concerning the communication of incidental findings and false expectations about the likely potential benefits of whole-body-MRI. KEY POINTS: • Disclosed incidental findings from MRI may lead to substantial psychosocial distress. • Subjective and radiological evaluations of incidental findings' severity differ strongly. • Disclosing incidental findings is strongly endorsed by study volunteers. • Study volunteers tend to have false expectations about potential benefits from MRI. • Minimizing stress in study volunteers should be a key aim in MRI research.

Normal breast parenchyma: contrast enhancement kinetics at dynamic MR mammography--influence of anthropometric measures and menopausal status.

PURPOSE: To study T1 baseline signal intensity (SI) and contrast material enhancement kinetics of normal breast parenchyma by using dynamic contrast-enhanced (DCE) magnetic resonance (MR) mammography and to determine the influence of anthropometric measures and menopausal status on the variability of these features. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. Between June 2008 and September 2011, 345 women (age range, 26-81 years; mean age, 51.3 years ± 11.6 [standard deviation]) underwent DCE MR mammography, with T1-weighted three-dimensional MR images (repetition time msec/echo time msec, 8.86/4.51; flip angle, 25°) acquired with a 1.5-T whole-body MR unit before and 1, 2, 3, 4, and 5 minutes after a gadobutrol bolus injection of 0.1 mmol per kilogram of body weight. Regions of interest were traced manually, and T1 SI of parenchyma was recorded. The influence of different predictors of T1 baseline SI and contrast enhancement was studied by using random-effects models. RESULTS: T1 baseline SI varied considerably between women, with a mean of 167.7 ± 49.2 (71.4-424.7 [range]) and 175.9 ± 48.9 (51.8-458.3) in the right and the left breast, respectively (P < .01). T1 baseline SI increased linearly with age (P < .0001) and body weight (P < .0001). After contrast material delivery, relative percentage of enhancement was 8.1%, 13.8%, 18.2%, 22.1%, and 24.6% at 1, 2, 3, 4, and 5 minutes, respectively, but varied considerably between women. Contrast enhancement was 9.3% in the lowest quintile and 47.4% in the highest. Contrast enhancement increased with body weight (P < .01) but decreased in postmenopausal women (P < .01). Women with higher baseline T1 SI tended to have a higher contrast enhancement slope. CONCLUSION: Anthropometric measures and menopausal status contribute to a large variability in contrast enhancement of normal breast parenchyma. This might influence the interpretation of contrast enhancement kinetics of breast lesions and current strategies for determining contrast medium dose for breast MR imaging.

Reproducibility of Frankfort horizontal plane on 3D multi-planar reconstructed MR images.

OBJECTIVE: The purpose of this study was to determine the accuracy and reliability of Frankfort horizontal plane identification using displays of multi-planar reconstructed MRI images, and propose it as a sufficiently stable and standardized reference plane for craniofacial structures. MATERIALS AND METHODS: MRI images of 43 subjects were obtained from the longitudinal population based cohort study SHIP-2 using a T1-weighted 3D sequence. Five examiners independently identified the three landmarks that form FH plane. Intra-examiner reproducibility and inter-examiner reliability, correlation coefficients (ICC), coefficient of variability and Bland-Altman plots were obtained for all landmarks coordinates to assess reproducibility. Intra-examiner reproducibility and inter-examiner reliability in terms of location and plane angulation were also assessed. RESULTS: Intra- and inter-examiner reliabilities for X, Y and Z coordinates of all three landmarks were excellent with ICC values ranging from 0.914 to 0.998. Differences among examiners were more in X and Z than in Y dimensions. The Bland-Altman analysis demonstrated excellent intra- as well as inter-examiner agreement between examiners in all coordinates for all landmarks. Intra-examiner reproducibility and inter-examiner reliability of the three landmarks in terms of distance showed mean differences between 1.3 to 2.9 mm, Mean differences in plane angulation were between 1.0° to 1.5° among examiners. CONCLUSION: This study revealed excellent intra-examiner reproducibility and inter-examiner reliability of Frankfort Horizontal plane through 3D landmark identification in MRI. Sufficiently stable landmark-based reference plane could be used for different treatments and studies.

A genome-wide association study identifies five loci influencing facial morphology in Europeans.

Inter-individual variation in facial shape is one of the most noticeable phenotypes in humans, and it is clearly under genetic regulation; however, almost nothing is known about the genetic basis of normal human facial morphology. We therefore conducted a genome-wide association study for facial shape phenotypes in multiple discovery and replication cohorts, considering almost ten thousand individuals of European descent from several countries. Phenotyping of facial shape features was based on landmark data obtained from three-dimensional head magnetic resonance images (MRIs) and two-dimensional portrait images. We identified five independent genetic loci associated with different facial phenotypes, suggesting the involvement of five candidate genes--PRDM16, PAX3, TP63, C5orf50, and COL17A1--in the determination of the human face. Three of them have been implicated previously in vertebrate craniofacial development and disease, and the remaining two genes potentially represent novel players in the molecular networks governing facial development. Our finding at PAX3 influencing the position of the nasion replicates a recent GWAS of facial features. In addition to the reported GWA findings, we established links between common DNA variants previously associated with NSCL/P at 2p21, 8q24, 13q31, and 17q22 and normal facial-shape variations based on a candidate gene approach. Overall our study implies that DNA variants in genes essential for craniofacial development contribute with relatively small effect size to the spectrum of normal variation in human facial morphology. This observation has important consequences for future studies aiming to identify more genes involved in the human facial morphology, as well as for potential applications of DNA prediction of facial shape such as in future forensic applications.

Effect of multipeak spectral modeling of fat for liver iron and fat quantification: correlation of biopsy with MR imaging results.

PURPOSE: To investigate the effect of the multipeak spectral modeling of fat on R2* values as measures of liver iron and on the quantification of liver fat fraction, with biopsy as the reference standard. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Patients with liver disease (n = 95; 50 men, 45 women; mean age, 57.2 years±14.1 [standard deviation]) underwent a nontargeted liver biopsy, and 97 biopsy samples were reviewed for steatosis and iron grades. MR imaging at 1.5 T was performed 24-72 hours after biopsy by using a three-echo three-dimensional gradient-echo sequence for water and fat separation. Data were reconstructed off-line, correcting for T1 and T2* effects. Fat fraction and R2* maps (1/T2*) were reconstructed and differences in R2* and steatosis grades with and without multipeak modeling of fat were tested by using the Kruskal-Wallis test. Spearman rank correlation coefficient was used to assess fat fractions and steatosis grades. Linear regression analysis was performed to compare the fat fraction for both models. RESULTS: Mean steatosis grade at biopsy ranged from 0% to 95%. Biopsy specimens in 26 of 97 patients (27%) showed liver iron (15 mild, six moderate, and five severe). In all 71 samples without iron, a strong increase in the apparent R2* was observed with increasing steatosis grade when single-peak modeling of fat was used (P=.001). When multipeak modeling was used, there were no differences in the apparent R2* as a function of steatosis grading (P=.645), and R2* values agreed closely with those reported in the literature. Good correlation between fat fraction and steatosis grade was observed (rS=0.85) both without and with spectral modeling. CONCLUSION: In the presence of fat, multipeak spectral modeling of fat improves the agreement between R2* and liver iron. Single-peak modeling of fat leads to underestimation of liver fat.

Contrast enhancement kinetics of normal breast parenchyma in dynamic MR mammography: effects of menopausal status, oral contraceptives, and postmenopausal hormone therapy.

OBJECTIVES: To investigate effects of menopausal status, oral contraceptives (OC), and postmenopausal hormone therapy (HT) on normal breast parenchymal contrast enhancement (CE) and non-mass-like enhancing areas in magnetic resonance mammography (MRM). METHODS: A total of 459 female volunteers (mean age 49.1 ± 12.5 years) underwent T1-weighted 3D MRM 1-5 min after bolus injection of gadobutrol. Quantitative analysis was performed in normal breast parenchyma by manually tracing regions of interest and calculating percentage CE. Semiquantitative analysis was performed in non-mass-like enhancing areas, and signal intensity changes were characterised by five predefined kinetic curve types. The influence of OC (n = 69) and HT (n = 24) on CE was studied using random effects models. RESULTS: Breast parenchymal enhancement was significantly higher in premenopausal than in postmenopausal women (P < 0.001). CE decreased significantly with the use of OC (P = 0.01), while HT had negligible effects (P = 0.52). Prevalence of kinetic curve types of non-mass-like enhancement differed strongly between pre- and postmenopausal women (P < 0.0001), but was similar in OC users and non-OC users (P = 0.61) as well as HT users and non-HT users (P = 0.77). CONCLUSIONS: Normal breast parenchymal enhancement and non-mass-like enhancing areas were strongly affected by menopausal status, while they were not affected by HT use and only moderately by OC use. KEY POINTS: Breast parenchymal enhancement at MR mammography is stronger in premenopausal than postmenopausal women. The prevalence of strong enhancing non-mass-like areas is greater before menopause. Such enhancing non-mass-like areas may impair lesion detection in premenopausal women. Breast parenchymal enhancement is only marginally affected by hormone use. Discontinuation of hormone use before MR mammography may be unnecessary.

Technical and clinical outcome of Talent versus Endurant endografts for endovascular aortic aneurysm repair.

OBJECTIVE: The technical evolution of endografts for the interventional management of infrarenal abdominal aortic aneurysms (AAA) has allowed a continuous expansion of indications. This study compares the established Talent endograft with its successor, the Endurant endograft, taking individual aortoiliac anatomy into account. METHODS: From June 2007 to December 2010, 35 patients with AAA were treated with a Talent endograft (33 men) and 36 patients with an Endurant endograft (34 men). Aortoiliac anatomy was evaluated in detail using preinterventional computed tomography angiography. The 30-day outcome of both groups were compared regarding technical and clinical success as well as complications including endoleaks. RESULTS: The Endurant group included more patients with unfavorable anatomy (kinking of pelvic arteries, p = 0.017; shorter proximal neck, p = 0.084). Primary technical success was 91.4% in the Talent group and 100% in the Endurant group (p = 0.115). Type 1 endoleaks occurred in 5.7% of patients in the Talent group and in 2.8% of those in the Endurant group (p = 0.614). Type 3 endoleaks only occurred in the Talent group (2.9% of patients; p = 0.493). Type 2 endoleaks were significantly less common in the Endurant group than in the Talent group (8.3% versus 28.6%; p = 0.035). Rates of major and minor complications were not significantly different between both groups. Primary clinical success was significantly better in the Endurant group (97.2%) than in the Talent group (80.0%) (p = 0.028). CONCLUSION: Endurant endografts appear to have better technical and clinical outcome in patients with difficult aortoiliac anatomy, significantly reducing the occurrence of type 2 endoleaks.

The role of the vagus nerve: modulation of the inflammatory reaction in murine polymicrobial sepsis.

The particular importance of the vagus nerve for the pathophysiology of peritonitis becomes more and more apparent. In this work we provide evidence for the vagal modulation of inflammation in the murine model of colon ascendens stent peritonitis (CASP). Vagotomy significantly increases mortality in polymicrobial sepsis. This effect is not accounted for by the dilatation of gastric volume following vagotomy. As the stimulation of cholinergic receptors by nicotine has no therapeutic effect, the lack of nicotine is also not the reason for the reduced survival rate. In fact, increased septic mortality is a consequence of the absent modulating influence of the vagus nerve on the immune system: we detected significantly elevated serum corticosterone levels in vagotomised mice 24 h following CASP and a decreased ex vivo TNF-alpha secretion of Kupffer cells upon stimulation with LPS. In conclusion, the vagus nerve has a modulating influence in polymicrobial sepsis by attenuating the immune dysregulation.

Thoracic and abdominal aortic diameter measurement by MRI using plain axial volumetric interpolated breath-hold examination in epidemiologic research: a validation study.

RATIONALE AND OBJECTIVES: This study evaluates the validity and reliability of measuring the diameters of the thoracic and abdominal aorta from plain volumetric interpolated breath-hold examination (VIBE) images. MATERIALS AND METHODS: The study included 50 male subjects from the population-based Study of Health in Pomerania. They underwent imaging of the thoracic and abdominal aorta at 1.5 Tesla using a contrast-enhanced magnetic resonance angiography (CE-MRA) and plain VIBE sequence. Diameters were measured at five predefined anatomic sites from reformatted orthogonal CE-MRA images and axial plain VIBE images. The measurements were validated using Pearson correlation and Bland-Altman analysis. The Bland-Altman method was also used to assess reliability. RESULTS: Comparison of the diameters measured from CE-MRA and VIBE images revealed strong correlation for the ascending, descending, suprarenal, and infrarenal aorta with r = 0.95 (P < .0001), r = 0.88 (P < .0001), 0.92 (P < .0001), and 0.87 (P < .0001), respectively. Measurement for the aortic arch was moderately correlated with r = 0.78 (P < .0001). Mean bias did not exceed 0.1 cm (6%). The 95% limits of agreement (LOA) were less than 0.5 cm (15%). Intra- and interobserver agreement showed a mean bias of less than 2%; the 95% LOA were less than 11%. CONCLUSIONS: Axial measurement of the diameters of the thoracic and abdominal aorta using a plain axial VIBE sequence is highly valid and reliable, making it suitable for use in epidemiologic research.

Artifacts in magnetic resonance imaging and computed tomography caused by dental materials.

BACKGROUND: Artifacts caused by dental restorations, such as dental crowns, dental fillings and orthodontic appliances, are a common problem in MRI and CT scans of the head and neck. The aim of this in-vitro study was to identify and evaluate the artifacts produced by different dental restoration materials in CT and MRI images. METHODS: Test samples of 44 materials (Metal and Non-Metal) commonly used in dental restorations were fabricated and embedded with reference specimens in gelatin moulds. MRI imaging of 1.5T and CT scan were performed on the samples and evaluated in two dimensions. Artifact size and distortions were measured using a digital image analysis software. RESULTS: In MRI, 13 out of 44 materials produced artifacts, while in CT 41 out of 44 materials showed artifacts. Artifacts produced in both MRI and CT images were categorized according to the size of the artifact. SIGNIFICANCE: Metal based restoration materials had strong influence on CT and less artifacts in MRI images. Rare earth elements such as Ytterbium trifluoride found in composites caused artifacts in both MRI and CT. Recognizing these findings would help dental materials manufacturers and developers to produce materials which can cause less artifacts in MRI and CT images.

Thermal ablation of unresectable liver tumors: factors associated with partial ablation and the impact on long-term survival.

BACKGROUND: Thermal ablation procedures, including radiofrequency ablation (RFA) or laser-induced interstitial thermotherapy (LITT), are now well established in the treatment of malignant unresectable hepatic tumors. But the impact of partial ablation (PA) on long-term survival following computed tomography (CT)-guided radiofrequency ablation and laser- induced interstitial thermotherapy of unresectable malignant liver lesions and the associated risk factors of PA remain partially unknown. MATERIAL/METHODS: This study included 254 liver tumors in 91 consecutive patients (66 men and 25 women; age 60.9 ± 10.4 years; mean tumor size 25 ± 14 mm [range 5-70 mm]) who underwent thermal ablation (RFA or LITT) between January 2000 and December 2007. Mean follow-up period was 21.1 month (range 1-69 months). Survival rate and local progression-free survival (PFS) were calculated for patients with complete ablation (CA) vs. patients with partial ablation (PA) to assess the impact on long-term survival. RESULTS: Median survival after CA was 47 months compared to 25 months after PA (P=0.04). The corresponding 5-year survival rates were 44% vs. 20%. Median PFS for CA was 11 months compared to 7 months for PA (P=0.118). The sole statistically significant risk factor for PA was tumor size (>30 mm; P=0.0003). Sustained complete ablation was achieved in 71% of lesions ≤ 30 mm vs. 47% of lesions >30 mm. CONCLUSIONS: We conclude that achievement of complete ablation is a highly important predictor of long-term survival and that tumor size is by far the most important predictor of the likelihood of achieving complete ablation.

Selective microcoil embolization of arterial gastrointestinal bleeding in the acute situation: outcome, complications, and factors affecting treatment success.

OBJECTIVES: To evaluate microcoil embolization in the interventional treatment of acute upper and lower gastrointestinal bleeding. PATIENTS AND METHODS: Forty-four patients (29 men, 15 women) with active arterial gastrointestinal bleeding were treated with microcoil embolization. The analysis included technical/clinical success, morbidity, mortality, and intervention-related mortality. Age, sex, underlying malignant disease, number of embolizations, preinterventional and postinterventional hemoglobin levels, blood products administered peri-interventionally, amount of embolization material used, duration of fluoroscopy, and use of contrast medium were evaluated for possible effects on technical and clinical success. RESULTS: The primary technical success rate of microcoil embolization for acute gastrointestinal bleeding was 88.6% with a clinical success rate of 56.8%. Minor and major complications occurred in 13.6 and 18.2% of patients, respectively. Intervention-associated mortality, due to intestinal ischemia, accounted for 4.6% of the total 18.2% mortality rate. Patients with technically successful embolization had a statistically significant increase in hemoglobin (P<0.01) after the intervention and a decrease in need for packed red blood cells, (P<0.01), fresh frozen plasma (P<0.01), and coagulation products (P<0.01). A smaller postinterventional fresh frozen plasma requirement was associated with a better clinical outcome (P=0.02). CONCLUSION: Microcoil embolization of arterial gastrointestinal bleeding in the acute situation has a high-technical success rate. The number of transfusions required before and after the intervention has no significant effect on technical success. Postinterventional fresh frozen plasma demand negatively correlates with clinical success.