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1.
Anaesthesia ; 77(10): 1089-1096, 2022 10.
Article in English | MEDLINE | ID: mdl-36006056

ABSTRACT

A model to classify the difficulty of videolaryngoscopic tracheal intubation has yet to be established. The videolaryngoscopic intubation and difficult airway classification (VIDIAC) study aimed to develop one based on variables associated with difficult videolaryngoscopic tracheal intubation. We studied 374 videolaryngoscopic tracheal intubations in 320 adults scheduled for ear, nose and throat or oral and maxillofacial surgery, for whom airway management was expected to be difficult. The primary outcome was whether an anaesthetist issued a 'difficult airway alert' after videolaryngoscopy. An alert was issued after 183 (49%) intubations. Random forest and lasso regression analysis selected six intubation-related variables associated with issuing an alert: impaired epiglottic movement; increased lifting force; direct epiglottic lifting; vocal cords clearly visible; vocal cords not visible; and enlarged arytenoids. Internal validation was performed by a 10-fold cross-validation, repeated 20 times. The mean (SD or 95%CI) area under the receiver operating characteristic curve was 0.92 (0.05) for the cross validated coefficient model and 0.92 (0.89-0.95) for a simplified unitary score (VIDIAC score with component values of -1 or 1 only). The calibration belt for the coefficient model was consistent with observed alert probabilities, from 0% to 100%, while the unitary VIDIAC score overestimated probabilities < 20% and underestimated probabilities > 70%. Discrimination of the VIDIAC score for patients more or less likely to be issued an alert was better than discrimination by the Cormack-Lehane classification, with mean (95%CI) areas under the receiver operating characteristic curve of 0.92 (0.89-0.95) vs. 0.75 (0.70-0.80), respectively, p < 0.001. Our model and score can be used to calculate the probabilities of difficult airway alerts after videolaryngoscopy.


Subject(s)
Laryngoscopes , Laryngoscopy , Adult , Airway Management , Epiglottis , Humans , Intubation, Intratracheal/adverse effects , Laryngoscopy/adverse effects
2.
Pharmazie ; 77(1): 2-5, 2022 01 03.
Article in English | MEDLINE | ID: mdl-35045917

ABSTRACT

To assess the toxic potential of the alkaloids, a quantification method is necessary. An ion pair extraction method was used for quantitative fluorometric determination of vincamine, protopine and all contained alkaloids in the mother tinctures of Vinca minor and Fumaria officinalis. The non-fluorescent alkaloids were transformed into an ion pair with sodium-9,10-dimethoxy-anthracene-sulfonate and then fluorometrically determined and quantified in this study. The applicable ion pair was extracted in a suitable organic solvent, where dichloromethane has proven to be beneficial. Conditions for the ion pairing and fluorometric quantification are given. The recovery rate was used to investigate the quality of determinability and the influence of the mother tincture matrix. The method was applied to determine the concentration of protopine in the range 0.1 - 15 µg/ml and of vincamine in the range of 0.5 - 20 µg/ml. The limit of detection was < 0.3 µg/ml, and the limit of quantification < 0.9 µg/ml for both alkaloids.


Subject(s)
Alkaloids , Fumaria , Vinca , Vincamine , Female , Humans , Mothers
3.
Ultrasound Obstet Gynecol ; 58(2): 201-206, 2021 08.
Article in English | MEDLINE | ID: mdl-32959919

ABSTRACT

OBJECTIVE: To compare the perinatal outcome of monochorionic twin pregnancies with twin-twin transfusion syndrome (TTTS), according to the disease severity, defined using Quintero staging, after treatment with fetoscopic laser surgery. METHODS: This was a single-center study of 1020 consecutive cases with severe TTTS, which were treated with fetoscopic laser surgery. During the study period from January 1995 to March 2013, the participants were included at a mean ± SD gestational age of 20.8 ± 2.2 weeks. Perinatal survival analysis, including the rates of double survival and survival of at least one fetus, was undertaken according to the Quintero staging system. For blockwise comparisons of data, the whole population was divided into five chronologically consecutive study subgroups of 200 patients in each of the first four subgroups and 220 in the last one. RESULTS: For the entire study population with known outcome (n = 1019), the rate of pregnancy with double fetal survival was 69.0% (127/184) in Stage-I, 71.4% (257/360) in Stage-II, 55.4% (236/426) in Stage-III and 51.0% (25/49) in Stage-IV TTTS cases. At least one twin survived in 91.3% (168/184) of pregnancies with Stage-I, 89.7% (323/360) of those with Stage-II, 83.1% (354/426) of those with Stage-III and 77.6% (38/49) of those with Stage-IV TTTS. The rates of double survival and survival of at least one fetus were both significantly higher in Stage-II TTTS compared with those in Stage-III TTTS cases (P < 0.001 and P = 0.011, respectively). Survival rates between pregnancies with Stage-I vs Stage-II TTTS and between those with Stage-III vs Stage-IV TTTS were not significantly different. Therefore, we combined pregnancies with Stage-I or Stage-II TTTS, and those with Stage-III or Stage-IV TTTS. The double survival rate was 70.6% (384/544) in combined Stage-I and Stage-II vs 54.9% (261/475) in combined Stage-III and Stage-IV TTTS cases (P < 0.001). At least one twin survived in 90.3% (491/544) of pregnancies with Stage-I or Stage-II TTTS vs 82.5% (392/475) in those with Stage-III or Stage-IV TTTS (P < 0.001). The double survival rate increased between the first and the last consecutive study subgroups from 59.8% (55/92) to 75.0% (96/128) (adjusted odds ratio (aOR)linear trend , 1.26 (95% CI, 1.01-1.56); P = 0.037) in pregnancies with Stage-I or Stage-II TTTS and from 41.7% (45/108) to 62.0% (57/92) (aORlinear trend , 1.21 (95% CI, 0.98-1.50); P = 0.082) in those with Stage-III or Stage-IV TTTS. Double survival rate was the lowest for Stage-III cases in which the donor twin was affected by severely abnormal Doppler findings (45.4% (64/141)). CONCLUSIONS: Double survival and survival of at least one fetus in monochorionic twin pregnancies with TTTS were related significantly to Quintero stage. However, our data show that the differentiation between Stages I vs II and Stages III vs IV does not have any significant prognostic implication for perinatal survival. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Subject(s)
Fetofetal Transfusion/diagnosis , Pregnancy, Twin , Female , Fetofetal Transfusion/diagnostic imaging , Fetofetal Transfusion/mortality , Fetofetal Transfusion/surgery , Fetoscopy , Germany , Gestational Age , Humans , Infant, Newborn , Laser Therapy , Pregnancy , Prospective Studies , Retrospective Studies , Survival Analysis , Treatment Outcome
4.
Eur Arch Otorhinolaryngol ; 276(4): 1183-1189, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30725209

ABSTRACT

PURPOSE: Tumor volume in locally advanced head and neck squamous cell carcinomas (LAHNSCC) treated by induction chemotherapy (ICT) and followed by radiochemotherapy (RCT) was measured. The presence of potential correlation of initial tumor volume and volume reduction after ICT and RCT with remission status, overall survival (OS) and disease-free survival (DFS) were investigated. Furthermore, reliability of approximation of the tumor volume relying on its diameter to manual three-dimensional measurement was assessed. METHODS: Data of patients with LAHNSCC treated by ICT consisting of docetaxel, cisplatin, and 5-fluorouracil (TPF) followed by definite RCT were retrospectively analyzed. The tumor volume was calculated slice-by-slice in contrast-enhanced CT or MRI before and after ICT as well as after complete treatment. The volume was compared to radiologic remission status, correlated with OS and DFS, and to volume estimation using tumor diameter. RESULT: 65 patients were included. Primary tumor volume did not correlate with complete remission rate (CR) after ICT and RCT, OS or DFS. The change in tumor volume between baseline imaging and post-RCT had a significant impact on OS (p = 0.026) and DFS (p = 0.028). The agreement between tumor volume and radiologic remission was 72.14%. CONCLUSION: The initial tumor volume had no influence on CR, OS or DFS. A severe response to ICT did not predict a powerful RCT outcome. The change in tumor volume post-RCT had an impact on OS and DFS. Tumor volume estimation using its diameter seems to be a reliable method.


Subject(s)
Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/therapy , Induction Chemotherapy , Squamous Cell Carcinoma of Head and Neck/pathology , Squamous Cell Carcinoma of Head and Neck/therapy , Tumor Burden , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Chemoradiotherapy , Cisplatin/administration & dosage , Disease-Free Survival , Docetaxel/administration & dosage , Female , Fluorouracil/administration & dosage , Head and Neck Neoplasms/mortality , Humans , Male , Middle Aged , Remission Induction , Reproducibility of Results , Retrospective Studies , Squamous Cell Carcinoma of Head and Neck/mortality , Taxoids/administration & dosage , Young Adult
5.
J Clin Monit Comput ; 33(3): 531-539, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30073445

ABSTRACT

Medication errors occur frequently and are a risk to patient safety. To reduce mistakes in the medication process in emergencies, a mobile app has been developed supporting the calculation of doses and administration of drugs. A simulation study was performed to validate the app as a tool to reduce medication errors. This was a randomised crossover study conducted in the Academic Hospital. The participants included were residents and attendings in anaesthesiology. 74 Participants performed four simulation scenarios in which they had to calculate and administer drugs for emergencies. Two scenarios were performed with the app ("app scenarios") and the other two scenarios were performed without the use of the app ("control scenarios"). The order of drugs, simulation patients and usage of aid were randomized. The accuracy of administered drug doses were measured. Medications were categorised as either "accurate" ([Formula: see text]% of target dosage) or "wrong" (less than 50% or more than 200% of target dosage). The dosage calculated and the dosage administered were documented separately to differentiate between calculation and handling errors. During app scenarios, there were no "wrong" dosages, whereas 6.8 (95% CI 2.7-10.8%) of dosages in control scenarios were evaluated as "wrong". The probability of giving an "accurate" dosage was increased from 77.7 (70.9-84.5%) in control scenarios to 93.9 (90-97.8%) in app scenarios. Calculation errors were the main cause for wrong dosing. The app is an appropriate and feasible tool to reduce calculation and handling errors and may increase patient safety.


Subject(s)
Emergencies , Medication Errors/prevention & control , Mobile Applications , Patient Safety , Administration, Intravenous , Adult , Computer Simulation , Cross-Over Studies , Emergency Service, Hospital , Feasibility Studies , Female , Humans , Male , Manikins , Reproducibility of Results , Smartphone , Young Adult
6.
Clin Radiol ; 73(7): 675.e9-675.e15, 2018 07.
Article in English | MEDLINE | ID: mdl-29576224

ABSTRACT

AIM: To compare standard (SD-) and reduced-dose computed tomography (RD-CT) in combination with iterative reconstruction (IR) in emergency patients with suspected lumbar spine fracture. MATERIAL AND METHODS: Forty emergency patients with suspected lumbar spinal disorder who underwent RD-CT and 40 body mass index-matched patients undergoing SD-CT were enrolled in this retrospective study. Raw data for RD-CT were reconstructed using two increasing IR levels (IRL) 4 and 6, while SD-CT was reconstructed with IRL3. Two radiologists assessed image quality, image noise, and reader confidence in interpreting findings of spinal fractures in a blinded manner. RESULTS: Effective radiation dose was reduced by 50% using RD-CT. Overall subjective image quality (SIQ) was high for both protocols and slightly superior in the RD-CT protocol for both IRL compared to SD-CT. The detection rate of spinal disorders was high for both protocols with a high interobserver agreement. CONCLUSION: RD-CT with higher levels of IR results in substantial dose reduction of 50% in lumbar spine CT while maintaining an excellent subjective image quality resulting in a high diagnostic confidence.


Subject(s)
Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/injuries , Multidetector Computed Tomography/methods , Radiation Dosage , Radiographic Image Interpretation, Computer-Assisted/methods , Spinal Fractures/diagnostic imaging , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies
7.
Ultrasound Obstet Gynecol ; 50(6): 728-735, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28477345

ABSTRACT

OBJECTIVE: To investigate the growing experience and learning curve of fetoscopic laser coagulation of the placental vascular anastomoses in severe mid-trimester twin-twin transfusion syndrome (TTTS) and its influence on perinatal outcome in a single-center setting. METHODS: Between January 1995 and March 2013 we performed laser therapy in 1020 consecutive pregnancies with TTTS between 15.1 and 27.4 weeks' gestation. We compared perinatal outcome in blocks of five sequential groups of 200 cases, taking into account several covariates in order to adjust for case mix and to demonstrate learning curves and success rates. RESULTS: The percentage of pregnancies with survival of both fetuses increased from 50.0% (n = 100) in the first 200 cases to 69.5% (n = 153) in the last 220 cases (P = 0.018 for trend) and the overall survival rate for both fetuses in the complete series of 1019 cases with known outcome was 63.3% (n = 645). The survival rate of at least one fetus increased from 80.5% (161/200) in the first group to 91.8% (202/220) in the last group (P = 0.072 for trend) and the overall survival rate of at least one fetus in the complete series was 86.7% (883/1019). In the total population, the mean gestational age at delivery of pregnancies with at least one liveborn neonate was 33.7 ± 3.2 weeks, with a mean interval of 12.9 ± 4.0 weeks between intervention and delivery. Among the first two groups, 124 pregnancies had anterior placentae and were treated with a 0° fetoscope. These cases had the poorest overall outcome, with a double-twin survival rate of 44.4% (55/124), which increased to 65.1% (207/318; P = 0.001) after the introduction of a 30° fetoscope for cases with anterior placenta. The success rate for double-twin survival reached a plateau of 69% at 600 procedures, a rate equalled by a new operator who was trained hands-on and performed 174 of the last 400 procedures. CONCLUSIONS: We report the largest single-center experience of laser coagulation in TTTS. We observed a continuous increase in double-twin survival rate owing to the growing experience based on the learning curve and refinements in fetoscopic instruments and techniques. These data provide strong arguments for the centralization of minimally invasive intrauterine surgery in specialized high-volume centers. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Fetofetal Transfusion/surgery , Fetoscopy , Laser Coagulation , Pregnancy, Twin , Adult , Feasibility Studies , Female , Fetofetal Transfusion/mortality , Fetoscopy/education , Fetoscopy/mortality , Gestational Age , Humans , Infant, Newborn , Laser Coagulation/education , Laser Coagulation/mortality , Learning Curve , Placenta/blood supply , Pregnancy , Pregnancy Outcome , Survival Rate , Twins
8.
Clin Res Cardiol ; 106(1): 38-48, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27435077

ABSTRACT

BACKGROUND: The use of non-vitamin K antagonists (NOACs), uninterrupted (uVKA) and interrupted vitamin K antagonists (iVKA) are common periprocedural oral anticoagulation (OAC) strategies for atrial fibrillation (AF) ablation. Comparative data on complication rates resulting from OAC strategies for solely persistent AF (persAF) undergoing ablation are sparse. Thus, we sought to determine the impact of these OAC strategies on complication rates among patients with persAF undergoing catheter ablation. METHODS: Consecutive patients undergoing persAF ablation were included. Depending on preprocedural OAC, three groups were defined: (1) NOACs (paused 48 h preablation), (2) uVKA, and (3) iVKA with heparin bridging. A combined complication endpoint (CCE) composed of bleeding and thromboembolic events was analyzed. RESULTS: Between 2011 and 2014, 1440 persAF ablation procedures were performed in 1092 patients. NOACs were given in 441 procedures (31 %; rivaroxaban 57 %, dabigatran 33 %, and apixaban 10 %), uVKA in 488 (34 %), and iVKA in 511 (35 %). Adjusted CCE rates were 5.5 % [95 % confidence interval (CI) (3.1-7.8)] in group 1 (NOACs), 7.5 % [95 % CI (5.0-10.1)] in group 2 (uVKA), and 9.9 % [95 % CI (6.6-13.2)] in group 3. Compared to group 1, the combined complication risk was almost twice as high in group 3 [odd's ratio (OR) 1.9, 95 % CI (1.0-3.7), p = 0.049)]. The major complication rate was low (0.9 %). Bleeding complications, driven by minor groin complications, are more frequent than thromboembolic events (n = 112 vs. 1, p < 0.0001). CONCLUSIONS: Patients undergoing persAF ablation with iVKA anticoagulation have an increased risk of complications compared to NOACs. Major complications, such as thromboembolic events, are generally rare and are exceeded by minor bleedings.


Subject(s)
Anticoagulants/administration & dosage , Atrial Fibrillation/surgery , Catheter Ablation/adverse effects , Length of Stay , Postoperative Hemorrhage/chemically induced , Thromboembolism/prevention & control , Administration, Oral , Aged , Anticoagulants/adverse effects , Atrial Fibrillation/blood , Atrial Fibrillation/diagnosis , Drug Administration Schedule , Female , Humans , Linear Models , Male , Middle Aged , Odds Ratio , Perioperative Care , Postoperative Hemorrhage/blood , Retrospective Studies , Risk Assessment , Risk Factors , Thromboembolism/blood , Thromboembolism/etiology , Time Factors , Treatment Outcome , Vitamin K/antagonists & inhibitors
9.
Br J Anaesth ; 116(2): 289-94, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26787800

ABSTRACT

BACKGROUND: The oesophageal leak pressure is defined as the pressure which breaks the seal between the cuff of a supraglottic airway and the peri-cuff mucosa, allowing penetration of fluid into the pharynx and the oral cavity. As a consequence, a decrease in this variable increases the risk of reflux and can lead to pulmonary aspiration. The aim of this study was to analyse the effects of cuff overinflation and pressure on the neck on the oesophageal leak pressure of seven supraglottic airways. METHODS: Three laryngeal masks, two laryngeal tubes, and two oesophageal-tracheal tubes were tested in an experimental setting. In five human cadavers, we simulated a sudden increase in oesophageal pressure. To measure baseline values (control), we used an intracuff pressure as recommended by the manufacturer. The first intervention included overinflation of the cuff by applying twice the amount of pressure recommended. A second intervention was defined as external pressure on the neck. RESULTS: The oesophageal leak pressure was decreased for laryngeal masks (control, 28 cm H2O; overinflation, 9 cm H2O; pressure on the neck, 8 cm H2O; P<0.01) and for laryngeal tubes (control, 68 cm H2O; overinflation, 37 cm H2O; pressure on the neck, 39 cm H2O; P<0.01) and was unaffected for oesophageal-tracheal tubes (control, 126 cm H2O; overinflation/pressure on the neck, 130 cm H2O; n.s.). CONCLUSION: Cuff overinflation and pressure on the neck can enhance the risk of gastro-oesophageal reflux when using supraglottic airways. Therefore, both manoeuvres should be avoided in clinical practice.


Subject(s)
Intubation, Intratracheal/instrumentation , Laryngeal Masks/adverse effects , Neck , Respiratory Aspiration/prevention & control , Aged , Aged, 80 and over , Cadaver , Female , Humans , Male , Pressure
10.
Clin Exp Metastasis ; 31(7): 817-27, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25098566

ABSTRACT

Gastroenteropancreatic neuroendocrine tumors (NETs) often present as liver metastasis from a carcinoma of unknown primary. We recently showed that primary NETs from the pancreas, small intestine and stomach as well as their respective liver metastases differ from each other by the expression profile of the three genes CD302, PPWD1 and ABHB14B. The gene and protein expression of CD302, PPWD1, and ABHB14B was studied in abdominal NET metastases to identify the site of the respective primary tumors. Cryopreserved tissue from NET metastases collected in different institutions (group A: 29, group B: 50, group C: 132 specimens) were examined by comparative genomic hybridization (Agilent 105 K), gene expression analysis (Agilent 44 K) (groups A and B) and immunohistochemistry (group C). The data were blindly evaluated, i.e. without knowing the site of the primary. Gene expression analysis correctly revealed the primary in the ileum in 94 % of the cases of group A and in 58 % of group B. A pancreatic primary was predicted in 83 % (group A) and 20 % (group B), respectively. The combined sensitivity of group A and B was 75 % for ileal NETs and 38 % for pancreatic NETs. Immunohistochemical analysis of group C revealed an overall sensitivity of 80 %. Gene and protein expression analysis of CD302 and PPWD1 in NET metastases correctly identifies the primary in the pancreas or the ileum in 80 % of the cases, provided that the tissue is well preserved. Immunohistochemical profiling revealed CD302 as the best marker for ileal and PPWD1 for pancreatic detection.


Subject(s)
Endocrine Glands/pathology , Neoplasm Metastasis , Neoplasms/pathology , Female , Gene Expression Profiling , Humans , Male , Neoplasms/genetics
11.
Eur J Dent Educ ; 18(3): 128-34, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24283462

ABSTRACT

INTRODUCTION: The Internet represents the central communication medium in higher education. University applicants, students, teachers and scientists use the Internet when seeking information on medicine. The homepages of dental schools are not just sources of information, but also a means of presenting the school. No comparative studies have been undertaken concerning the content and extent of their Internet sites so far. METHODS: Based on the literature and assessments of medical school websites, 136 criteria were defined within the setting of a Delphi procedure and drawn upon for a standardised evaluation of the websites of all 30 German dental schools. Structure and extent of the content of the websites were evaluated. Possible influencing factors, such as financial resources and number of applicants, were investigated. RESULTS: The results yielded by the homepages varied considerably. The best Internet site received 84% of the possible points, the poorest 38%. On average, 62% of the criteria were fulfilled. Influencing factors, such as the amount of funding by the particular state government, could not be detected. Two-thirds of the dental schools addressed students, three-fourth teachers and scientists as target groups. More than 50% did not address applicants. Specific requirements regarding barrier-free accessibility of information were hardly met. CONCLUSIONS: Individual faculties already have homepages of a high quality; for others, there is a need for improvement. General recommendations for university websites should be discussed at the European level to ensure a uniform standard of quality. The criteria presented here offer faculties the possibility to reflect upon their own Internet sites.


Subject(s)
Internet , Schools, Dental , Access to Information , Germany , Humans
12.
Rofo ; 185(8): 741-8, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23900941

ABSTRACT

OBJECTIVES: To intraindividually evaluate the potential of 4th generation iterative reconstruction (IR) on brain CT with regard to subjective and objective image quality. METHODS: 31 consecutive raw data sets of clinical routine native sequential brain CT scans were reconstructed with IR level 0 (= filtered back projection), 1, 3 and 4; 3 different brain filter kernels (smooth/standard/sharp) were applied respectively. Five independent radiologists with different levels of experience performed subjective image rating. Detailed ROI analysis of image contrast and noise was performed. Statistical analysis was carried out by applying a random intercept model. RESULTS: Subjective scores for the smooth and the standard kernels were best at low IR levels, but both, in particular the smooth kernel, scored inferior with an increasing IR level. The sharp kernel scored lowest at IR 0, while the scores substantially increased at high IR levels, reaching significantly best scores at IR 4. Objective measurements revealed an overall increase in contrast-to-noise ratio at higher IR levels, which was highest when applying the soft filter kernel. The absolute grey-white contrast decreased with an increasing IR level and was highest when applying the sharp filter kernel. All subjective effects were independent of the raters' experience and the patients' age and sex. CONCLUSION: Different combinations of IR level and filter kernel substantially influence subjective and objective image quality of brain CT.


Subject(s)
Brain Diseases/diagnostic imaging , Brain/diagnostic imaging , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Adult , Aged , Aged, 80 and over , Artifacts , Basal Ganglia Cerebrovascular Disease/diagnostic imaging , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/secondary , Cerebral Cortex/diagnostic imaging , Cerebral Infarction/diagnostic imaging , Female , Humans , Image Enhancement/standards , Image Processing, Computer-Assisted/standards , Intracranial Hemorrhages/diagnostic imaging , Male , Middle Aged , Observer Variation , Radiography , Radiology Information Systems , Reference Values , Sensitivity and Specificity , Skull Base/diagnostic imaging , Stroke/diagnostic imaging , Young Adult
13.
Rofo ; 185(9): 824-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23857073

ABSTRACT

PURPOSE: To evaluate a novel algorithm for correcting beam hardening artifacts caused by metal implants in computed tomography performed on a C-arm angiography system equipped with a flat panel (FP-CT). MATERIALS AND METHODS: 16 datasets of cerebral FP-CT acquisitions after coil embolization of brain aneurysms in the context of acute subarachnoid hemorrhage have been reconstructed by applying a soft tissue kernel with and without a novel reconstruction filter for metal artifact correction. Image reading was performed in multiplanar reformations (MPR) in average mode on a dedicated radiological workplace in comparison to the preinterventional native multisection CT (MS-CT) scan serving as the anatomic gold standard. Two independent radiologists performed image scoring following a defined scale in direct comparison of the image data with and without artifact correction. For statistical analysis, a random intercept model was calculated. RESULTS: The inter-rater agreement was very high (ICC = 86.3 %). The soft tissue image quality and visualization of the CSF spaces at the level of the implants was substantially improved. The additional metal artifact correction algorithm did not induce impairment of the subjective image quality in any other brain regions. CONCLUSION: Adding metal artifact correction to FP-CT in an acute postinterventional setting helps to visualize the close vicinity of the aneurysm at a generally consistent image quality.


Subject(s)
Algorithms , Artifacts , Cerebral Angiography/methods , Embolization, Therapeutic/methods , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Metals , Prostheses and Implants , Subarachnoid Hemorrhage/diagnostic imaging , Subarachnoid Hemorrhage/therapy , Tomography, X-Ray Computed/methods , Acute Disease , Adult , Aged , Female , Humans , Male , Middle Aged , Multidetector Computed Tomography/methods , Observer Variation , Sensitivity and Specificity
14.
Rofo ; 185(8): 749-57, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23749649

ABSTRACT

PURPOSE: To determine the image quality of an iterative reconstruction (IR) technique in low-dose MDCT (LDCT) of the chest of immunocompromised patients in an intraindividual comparison to filtered back projection (FBP) and to evaluate the dose reduction capability. MATERIALS AND METHODS: 30 chest LDCT scans were performed in immunocompromised patients (Brilliance iCT; 20-40 mAs; mean CTDIvol: 1.7 mGy). The raw data were reconstructed using FBP and the IR technique (iDose4™, Philips, Best, The Netherlands) set to seven iteration levels. 30 routine-dose MDCT (RDCT) reconstructed with FBP served as controls (mean exposure: 116 mAs; mean CDTIvol: 7.6 mGy). Three blinded radiologists scored subjective image quality and lesion conspicuity. Quantitative parameters including CT attenuation and objective image noise (OIN) were determined. RESULTS: In LDCT high iDose4™ levels lead to a significant decrease in OIN (FBP vs. iDose7: subscapular muscle 139.4 vs. 40.6 HU). The high iDose4™ levels provided significant improvements in image quality and artifact and noise reduction compared to LDCT FBP images. The conspicuity of subtle lesions was limited in LDCT FBP images. It significantly improved with high iDose4™ levels (> iDose4). LDCT with iDose4™ level 6 was determined to be of equivalent image quality as RDCT with FBP. CONCLUSION: iDose4™ substantially improves image quality and lesion conspicuity and reduces noise in low-dose chest CT. Compared to RDCT, high iDose4™ levels provide equivalent image quality in LDCT, hence suggesting a potential dose reduction of almost 80%.


Subject(s)
Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Multidetector Computed Tomography/methods , Opportunistic Infections/diagnostic imaging , Pneumonia/diagnostic imaging , Radiation Dosage , Adult , Aged , Aged, 80 and over , Algorithms , Anthropometry , Artifacts , Female , Humans , Image Enhancement/standards , Image Processing, Computer-Assisted/standards , Male , Middle Aged , Observer Variation , Young Adult
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