共查询到20条相似文献,搜索用时 31 毫秒
1.
Steven Schalekamp Bram van Ginneken Louis Meiss Liesbeth Peters-Bax Lorentz G.B.A. Quekel Miranda M. Snoeren Audrey M. Tiehuis Rianne Wittenberg Nico Karssemeijer Cornelia M. Schaefer-Prokop 《European journal of radiology》2013
Objectives
To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs.Materials and methods
Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis.Results
ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03).Conclusion
Bone suppressed images improve radiologists’ detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity. 相似文献2.
Christopher Herzog J. Matthias Kerl Salvatore De Rosa Tuna Tekin Eike Boehme Sven Liem Miriam Scheuchenzuber He-Ri Kim Ralf W. Bauer Justin R. Silverman Peter L. Zwerner Hanns Ackermann Thomas J. Vogl U. Joseph Schoepf 《European journal of radiology》2013
Purpose
To assess the influence of experience and training on the proficiency in coronary CT angiography (CCTA) interpretation of practitioners with different levels of experience.Methods and materials
Nine radiologist and cardiologist observers with varying prior CCTA experience ranging from novice to expert independently analyzed two case series of 50 catheter-correlated CCTA studies for coronary artery stenosis (0%, ≤49%, 50–74%, 75–99%, or 100%). Results of the first case series were unblinded and presented along with catheter angiography results to each reader before proceeding to the second series. Diagnostic accuracy on a per-segment basis was compared for all readers and both case series, respectively.Results
Correlation coefficients between CCTA and catheter angiography initially ranged between good (r = 0.87) and poor (r = 0.26), depending on reader experience, and significantly (p < 0.05) improved in the second case series (range: r = 0.42 to r = 0.91). Diagnostic accuracy was significantly (p < 0.05) higher for more experienced readers (range: 96.5–97.8%) as compared to less experienced observers (range: 90.7–93.6%). After completion of the second case series for less experienced readers sensitivity and PPV significantly (p < 0.05) improved (range: 62.7–67.8%/51.4–84.1%), but still remained significantly (p < 0.05) lower as compared to more experienced observers (range: 89.8–93.3%/80.6–93.3%).Conclusion
The level of experience appears to be a strong determinant of proficiency in CCTA interpretation. Limited one-time training improves proficiency in novice readers, but not to clinically satisfactory levels. 相似文献3.
Laila A. Mohsen Ehab A.A. GawadMohamed A. Ibrahiem 《The Egyptian Journal of Radiology and Nuclear Medicine》2014
Objective
To evaluate whether a simple semi-quantitative method aided by software enhanced visualization can be reliable enough for the quantification of emphysema during the daily workload.Patients and methods
Thirty patients with COPD were included. Patients had a standard non enhanced MDCT study of the chest using a 16 slice machine. The images were evaluated visually and scored. This scoring was repeated after applying a density mask. Three radiologists evaluated the images on separate occasions. Repeatability was also tested. The CT emphysema index and the mean lung attenuation were calculated. The extent of airway disease was not assessed.Results
Kappa test between the 3 readers revealed slight agreement (k = 0.122, p = 0.001) before the density mask and substantial agreement (k = 0.75, p < 0.0005) after its application. A high degree of repeatability was found. The median visual score after density mask application, showed a stronger correlation to the emphysema index (r = 0.81, p < 0.0005) than before.Conclusion
We present a simple visual score for quantitation of emphysema, that when combined with a simple density mask, the inter-rater agreement and repeatability of scoring are markedly improved. This method appears to be fast and easy to perform. 相似文献4.
A. Christe L. Leidolt A. Huber P. Steiger Z. Szucs-Farkas J.E. Roos J.T. Heverhagen L. Ebner 《European journal of radiology》2013
Objectives
To find the best pairing of first and second reader at highest sensitivity for detecting lung nodules with CT at various dose levels.Materials and methods
An anthropomorphic lung phantom and artificial lung nodules were used to simulate screening CT-examination at standard dose (100 mAs, 120 kVp) and 8 different low dose levels, using 120, 100 and 80 kVp combined with 100, 50 and 25 mAs. At each dose level 40 phantoms were randomly filled with 75 solid and 25 ground glass nodules (5–12 mm). Two radiologists and 3 different computer aided detection softwares (CAD) were paired to find the highest sensitivity.Results
Sensitivities at standard dose were 92%, 90%, 84%, 79% and 73% for reader 1, 2, CAD1, CAD2, CAD3, respectively. Combined sensitivity for human readers 1 and 2 improved to 97%, (p1 = 0.063, p2 = 0.016). Highest sensitivities – between 97% and 99.0% – were achieved by combining any radiologist with any CAD at any dose level. Combining any two CADs, sensitivities between 85% and 88% were significantly lower than for radiologists combined with CAD (p < 0.03).Conclusions
Combination of a human observer with any of the tested CAD systems provide optimal sensitivity for lung nodule detection even at reduced dose at 25 mAs/80 kVp. 相似文献5.
Fabian Bamberg Christopher L. Schlett Quynh A. Truong John T. Nagurney Udo Hoffmann 《European journal of radiology》2010,74(1):182-188
Objective
We aimed to determine predictors of image quality in consecutive patients who underwent coronary computed tomography (CT) for the evaluation of acute chest pain.Method and materials
We prospectively enrolled patients who presented with chest pain to the emergency department. All subjects underwent contrast-enhanced 64-slice coronary multi-detector CT. Two experienced readers determined overall image quality on a per-patient basis and the prevalence and characteristics of non-evaluable coronary segments on a per-segment basis.Results
Among 378 subjects (143 women, age: 52.9 ± 11.8 years), 345 (91%) had acceptable overall image quality, while 33 (9%) had poor image quality or were unreadable. In adjusted analysis, patients with diabetes, hypertension and a higher heart rate during the scan were more likely to have exams graded as poor or unreadable (odds ratio [OR]: 2.94, p = 0.02; OR: 2.62, p = 0.03; OR: 1.43, p = 0.02; respectively). Of 6253 coronary segments, 257 (4%) were non-evaluable, most due to severe calcification in combination with motion (35%). The presence of non-evaluable coronary segments was associated with age (OR: 1.08 annually, 95%-confidence interval [CI]: 1.05-1.12, p < 0.001), baseline heart rate (OR: 1.35 per 10 beats/min, 95%-CI: 1.11-1.67, p = 0.003), diabetes, hypertension, and history of coronary artery disease (OR: 4.43, 95%-CI: 1.93-10.17, p < 0.001; OR: 2.27, 95-CI: 1.01-4.73, p = 0.03; OR: 5.12, 95%-CI: 2.0-13.06, p < 0.001; respectively).Conclusion
Coronary CT permits acceptable image quality in more than 90% of patients with chest pain. Patients with multiple risk factors are more likely to have impaired image quality or non-evaluable coronary segments. These patients may require careful patient preparation and optimization of CT scanning protocols. 相似文献6.
Alexandra R. Morgan Geoff J.M. Parker Caleb Roberts Giovanni A. Buonaccorsi Niall C. Maguire Penny L. Hubbard Cristinacce Dave Singh Jørgen Vestbo Leif Bjermer Jonas Jögi Ziad Taib Janeli Sarv Piet L.B. Bruijnzeel Lars E. Olsson Eva Bondesson Ulf Nihlén Deirdre M. McGrath Simon S. Young John C. Waterton Lars H. Nordenmark 《European journal of radiology》2014
Objectives
Oxygen-enhanced MRI (OE-MRI) biomarkers have potential value in assessment of COPD, but need further evaluation before treatment-induced changes can be interpreted. The objective was to evaluate how OE-MRI parameters of regional ventilation and oxygen uptake respond to standard pharmacological interventions in COPD, and how the response compares to that of gold standard pulmonary function tests.Materials and methods
COPD patients (n = 40), mean FEV1 58% predicted normal, received single-dose inhaled formoterol 9 μg, or placebo, followed by 8 weeks treatment bid with a combination of budesonide and formoterol Turbuhaler® 320/9 μg or formoterol Turbuhaler®. OE-MRI biomarkers were obtained, as well as X-ray computed tomography (CT) biomarkers and pulmonary function tests, in a two-center study. An ANCOVA statistical model was used to assess effect size of intervention measurable in OE-MRI parameters of lung function.Results
OE-MRI data were successfully acquired at both study sites. 8-week treatment with budesonide/formoterol significantly decreased lung wash-out time by 31% (p < 0.01), decreased the change in lung oxygen level upon breathing pure oxygen by 13% (p < 0.05) and increased oxygen extraction from the lung by 58% (p < 0.01). Single-dose formoterol increased both lung wash-out time (+47%, p < 0.05) and lung oxygenation time (+47%, p < 0.05). FEV1 was improved by single-dose formoterol (+12%, p < 0.001) and 8 weeks of budesonide/formoterol (+ 18%, p < 0.001), consistent with published studies.Conclusions
In COPD, OE-MRI parameters showed response to both single-dose bronchodilatory effects of a β2-agonist, formoterol, and 8-week treatment with an inhaled corticosteroid, budesonide, and the measurements are feasible in a small-scale multi-center trial setting. 相似文献7.
Marcos Paulo Ferreira Botelho Rishi AgrawalFernanda Dias Gonzalez-Guindalini Eric M. HartSuresh K. Patel Hüseyin Gürkan TöreVahid Yaghmai 《European journal of radiology》2013
Objective
To evaluate the effect of different acquisition parameters and reconstruction algorithms in lung lesions conspicuity in chest MDCT.Methods
An anthropomorphic chest phantom containing 6 models of lung disease (ground glass opacity, bronchial polyp, solid nodule, ground glass nodule, emphysema and tree-in-bud) was scanned using 80, 100 and 120 kVp, with fixed mAs ranging from 10 to 110. The scans were reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Three blinded thoracic radiologists reviewed the images and scored lesions conspicuity and overall image quality. Image noise and radiation dose parameters were recorded.Results
All acquisitions with 120 kVp received a score of 3 (acceptable) or higher for overall image quality. There was no significant difference between IR and FBP within each setting for overall image quality (p > 0.05), even though image noise was significantly lower using IR (p < 0.0001). When comparing specific lower radiation acquisition parameters 100 kVp/10 mAs [Effective Dose (ED): 0.238 mSv] vs 120 kVp/10 mAs (ED: 0.406 mSv) vs 80 kVp/40 mAs (ED: 0.434 mSv), we observed significant difference in lesions conspicuity (p < 0.02), as well as significant difference in overall image quality, independent of the reconstruction algorithm (p < 0.02), with higher scores on the 120 kV/10 mAs setting. Tree-in-bud pattern, ground glass nodule and ground glass opacity required lower radiation doses to get a diagnostic score using IR when compared to FBP.Conclusion
Designing protocols for specific lung pathologies using lower dose acquisition parameters is feasible, and by applying iterative reconstruction, radiologists may have better diagnostic confidence to evaluate some lesions in very low dose settings, preserving acceptable image quality. 相似文献8.
Sherine G. Moftah Warawut Sukkasem Eric J. Stern 《The Egyptian Journal of Radiology and Nuclear Medicine》2014
Purpose
To demonstrate the spectrum of incidental findings on chest CT scans and to evaluate the clinical impact of significant different abnormalities on patient management.Materials and methods
This retrospective study included incidental findings on chest CT scans from an adult patient population, performed at the University of Washington, within a 10 month period. After exclusion of repetitive findings, 113 patients (50 males and 63 females, age 18–96 years, mean = 57.3 years) demonstrated 163 uniquely different findings. We determined the clinical significance according to the need for further workup and/or therapy. The gold standard for diagnosis was either by pathologic proof, follow up CT, or other imaging modalities.Results
38 different findings were judged clinically significant (10.4%) requiring further workup and/or therapy in 9.6% and 7.1%, respectively. The anatomic site of disease was: intra-thoracic (n = 27, 71.1%), extra-thoracic (n = 5, 13.1%), lower neck (n = 3, 7.9%), and upper abdomen (n = 3, 7.9%). They included 12 unique malignant pathologies (31.6%), and 26 non-malignant findings (68.4%).Conclusion
The clinically significant different incidental abnormalities on chest CT scans represented 10.4% of all incidental findings, 3.3% were due to malignancies. The clinical impact of incidental abnormalities on chest CT may be of utmost importance on patient care. 相似文献9.
Bone images from dual-energy subtraction chest radiography in the detection of rib fractures 总被引:1,自引:0,他引:1
Objective
To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures.Materials and methods
In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference.Results
The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p = 0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p = 0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p < 0.001).Conclusions
Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures. 相似文献10.
Amir M. Owrangi Brandon Entwistle Andrew Lu Jack Chiu Nabil Hussain Roya Etemad-Rezai Grace Parraga 《European journal of radiology》2013
Objective
We developed a semi-automated tool to quantify emphysema from thoracic X-ray multi-detector (64-slice) computed tomography (CT) for training purposes and multi-reader studies.Materials and Methods
Thoracic X-ray CT was acquired in 93 ex-smokers, who were evaluated by six trainees with little or no expertise (trainees) and a single experienced thoracic radiologist (expert). A graphic user interface (GUI) was developed for emphysema quantification based on the percentile of lung where a score of 0 = no abnormalities, 1 = 1–25%, 2 = 26–50%, 3 = 51–75% and 4 = 76–100% for each lung side/slice. Trainees blinded to subject characteristics scored randomized images twice; accuracy was determined by comparison to expert scores, density histogram 15th percentile (HU15), relative area at −950 HU (RA950), low attenuation clusters at −950 HU (LAC950), −856 HU (LAC856) and the diffusing capacity for carbon monoxide (DLCO%pred). Intra- and inter-observer reproducibility was evaluated using coefficients-of-variation (COV), intra-class (ICC) and Pearson correlations.Results
Trainee–expert correlations were significant (r = 0.85–0.97, p < 0.0001) and a significant trainee bias (0.15 ± 0.22) was observed. Emphysema score was correlated with RA950 (r = 0.88, p < 0.0001), HU15 (r = −0.77, p < 0.0001), LAC950 (r = 0.76, p < 0.0001), LAC856 (r = 0.74, p = 0.0001) and DLCO%pred (r = −0.71, p < 0.0001). Intra-observer reproducibility (COV = 4–27%; ICC = 0.75–0.94) was moderate to high for trainees; intra- and inter-observer COV were negatively and non-linearly correlated with emphysema score.Conclusion
We developed a GUI for rapid and interactive emphysema scoring that allows for comparison of multiple readers with clinical and radiological standards. 相似文献11.
Yoshiharu Ohno Mizuho Nishio Hisanobu Koyama Takeshi Yoshikawa Sumiaki Matsumoto Daisuke Takenaka Shinichiro Seki Maho Tsubakimoto Kazuro Sugimura 《European journal of radiology》2013
Purpose
The purpose of this study was to compare diagnostic capabilities for assessment of recurrence in non-small cell lung cancer (NSCLC) patients by contrast-enhanced whole-body MRI (CE-WB-MRI) with and without CE-Quick 3D and double RF fat suppression technique (DFS), FDG-PET/CT and conventional radiological examinations.Materials and methods
A total of 134 pathologically proven and completely resected NSCLC patients (78 males, 56 females; mean age: 72 years) underwent FDG-PET/CT, CE-WB-MRI with and without Quick 3D and DFS at 3 T as well as conventional radiological examinations. The probability of recurrence was assessed with a 5-point scoring system on a per-patient basis, and final diagnosis was made by consensus between two readers. The capability for overall recurrence assessment by all the methods was compared by means of ROC analysis and their sensitivity, specificity and accuracy by means of McNemar's test.Results
Although areas under the curve did not show any significant differences, specificity (100%) and accuracy (95.5%) of CE-WB-MRI with CE-Quick 3D and DFS were significantly higher than those of FDG-PET/CT (specificity: 93.6%, p = 0.02; accuracy: 89.6%, p = 0.01) and conventional radiological examinations (specificity: 92.7%, p = 0.01; accuracy: 91.0%, p = 0.03). In addition, specificity of CE-WB-MRI without CE-Quick 3D and DFS (100%) was significantly higher than that of FDG-PET/CT (p = 0.02) and conventional radiological examinations (p = 0.01).Conclusion
Specificity and accuracy of CE-WB-MRI with CE-Quick 3D and DFS for assessment of recurrence in NSCLC patients are at least as high as, or higher than those of others. 相似文献12.
Katsutoshi Ando Kazunori Tobino Masatoshi Kurihara Hideyuki Kataoka Tokuhide Doi Yoshito Hoshika Kazuhisa Takahashi Kuniaki Seyama 《European journal of radiology》2012
Backgrounds
Lymphangioleiomyomatosis (LAM) is a destructive lung disease that share clinical, physiologic, and radiologic features with chronic obstructive pulmonary disease (COPD). This study aims to identify those features that are unique to LAM by using quantitative CT analysis.Methods
We measured total cross-sectional areas of small pulmonary vessels (CSA) less than 5 mm2 and 5–10 mm2 and calculated percentages of those lung areas (%CSA), respectively, in 50 LAM and 42 COPD patients. The extent of cystic destruction (LAA%) and mean parenchymal CT value were also calculated and correlated with pulmonary function.Results
The diffusing capacity for carbon monoxide/alveolar volume (DLCO/VA %predicted) was similar for both groups (LAM, 44.4 ± 19.8% vs. COPD, 45.7 ± 16.0%, p = 0.763), but less tissue damage occurred in LAM than COPD (LAA% 21.7 ± 16.3% vs. 29.3 ± 17.0; p < 0.05). Pulmonary function correlated negatively with LAA% (p < 0.001) in both groups, yet the correlation with %CSA was significant only in COPD (p < 0.001). When the same analysis was conducted in two groups with equal levels of LAA% and DLCO/VA %predicted, %CSA and mean parenchymal CT value were still greater for LAM than COPD (p < 0.05).Conclusions
Quantitative CT analysis revealing a correlation between cystic destruction and CSA in COPD but not LAM indicates that this approach successfully reflects different mechanisms governing the two pathologic courses. Such determinations of small pulmonary vessel density may serve to differentiate LAM from COPD even in patients with severe lung destruction. 相似文献13.
Thomas Henzler Joachim Gruettner Mathias Meyer Baerbel Rothhaar Paul Apfaltrer Franz Metzger Martin Borggrefe U. Joseph Schoepf Stefan O. Schoenberg Christian Fink 《European journal of radiology》2013
Objective
To evaluate the economic impact of integrating coronary CT angiography (cCTA) or whole chest “triple-rule-out” CTA (TRO-CTA) in the work-up of patients with acute chest pain.Materials and methods
100 consecutive emergency department patients with acute chest pain and an intermediate cardiac risk for ACS underwent cCTA or TRO-CTA (cCTA group). Diagnostic performance, rate and length of hospitalization, hospital costs, hospital reimbursement and hospital profit were analyzed. All findings were compared to those of 100 different patients with acute chest pain that were evaluated with a standard of care (SOC) diagnostic algorithm (SOC group) that did not include cCTA. Diagnostic performance (“safety”) of both algorithms was defined as the absence of major adverse cardiac events (MACE) over a 90-day follow-up period.Results
In the cCTA group 60/100 patients were safely discharged at the same day. 19/100 patients were hospitalized due to significant coronary stenosis on cCTA, which was confirmed by invasive coronary catheterization (ICC) in 17/19 patients. Relevant non-coronary disease that led to hospitalization were found in 21 patients of the cCTA group. In the SOC group all patients were hospitalized. 87 of these hospitalized patients underwent ICC for exclusion of coronary artery stenosis. A significant coronary artery stenosis was found in only 25 of these patients. Within the cCTA group no patient suffered from MACE over the 90-day follow-up period. In the SOC group 2 patients were rehospitalized during the 90-day follow-up period due to recurrent chest pain and 1 patient because of a pseudoaneurym of the left femoral artery after ICC. The median hospital costs per patient were significantly lower in the cCTA group than in the SOC group (428.9€ vs. 1575.0€, p < 0.001). The median reimbursement of the cCTA group was less compared to the SOC group (589.8€ vs. 2412.1€, p < 0.001) and patients in the cCTA group gained less profit than patients in the SOC group (57.0€ vs. 448.4€, p < 0.001).Conclusion
Integrating cCTA or TRO-CTA in a SOC algorithm can safely reduce the number of hospitalized patients and reduce total health care costs. 相似文献14.
Joachim Böttcher Andreas Hansch Alexander Pfeil Peter Schmidt Ansgar Malich Albrecht Schneeweiss Martin H. Maurer Florian Streitparth Ulf K. Teichgräber Diane M. Renz 《European journal of radiology》2013
Objective
To compare the diagnostic efficacy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) vs. multidetector computed tomography (MDCT) for the detection and classification of focal liver lesions, differentiated also for lesion entity and size; a separate analysis of pre- and postcontrast images as well as T2-weighted MRI sequences of focal and exclusively solid lesions was integrated.Methods
Twenty-nine patients with 130 focal liver lesions underwent MDCT (64-detector-row; contrast medium iopromide; native, arterial, portalvenous, venous phase) and MRI (1.5-T; dynamic and tissue-specific phase 20 min after application of Gd-EOB-DTPA). Hepatic lesions were verified against a standard of reference (SOR). CT and MR images were independently analysed by four blinded radiologists on an ordinal 6-point-scale, determining lesion classification and diagnostic confidence.Results
Among 130 lesions, 68 were classified as malignant and 62 as benign by SOR. The detection of malignant and benign lesions differed significantly between combined and postcontrast MRI vs. MDCT; overall detection rate was 91.5% for combined MRI and 80.4% for combined MDCT (p < 0.05). Considering all four readers together, combined MDCT achieved sensitivity of 66.2%, specificity of 79.0%, and diagnostic accuracy of 72.3%; combined MRI reached superior diagnostic efficacy: sensitivity 86.8%, specificity 94.4%, accuracy 90.4% (p < 0.05). Differentiated for lesion size, in particular lesions <20 mm revealed diagnostic benefit by MRI. Postcontrast MRI also achieved higher overall sensitivity, specificity, and accuracy compared to postcontrast MDCT for focal and exclusively solid liver lesions (p < 0.05).Conclusion
Combined and postcontrast Gd-EOB-DTPA-enhanced MRI provided significantly higher overall detection rate and diagnostic accuracy, including low inter-observer variability, compared to MDCT in a single centre study. 相似文献15.
Daniel J. Hou David K. Tso Chris Davison Joao Inacio Luck J. Louis Savvakis Nicolaou Anja J. Reimann 《European journal of radiology》2013
Objectives/Purpose
Aim of this study was to retrospectively compare the image quality and the radiation dose of an ultra high pitch CT scan for the evaluation of pulmonary embolism and visualization of cardiac structures in comparison to our institution's standard pulmonary embolism protocol.Method and materials
The study cohort consisted of 115 consecutive patients, 57 underwent CT pulmonary angiography on a dual source 128 slice scanner (Siemens Somatom Definition FLASH) via an ultra high pitch mode (Pitch 2.8) while 58 were scanned on a dual source 64 slice scanner (Siemens Somatom Definition Dual Source) with standard pitch (Pitch 0.9). Qualitative image assessment was determined by two blinded radiologists with 3 and 15 years’ experience in chest and cardiac CT. Quantitative image assessment was determined by the signal to noise ratio (SNR) and contrast to noise ratio (CNR). Effective radiation dose was calculated via the product of the dose length product.Results
For the ultra high pitch protocol, 14% (8/57) were positive for pulmonary embolus compared to 13.7% (8/58) for the standard pitch group. 98.2% of the ultra high pitch scans were diagnostic for pulmonary embolus vs. 94.8% of the standard protocol. Visualization of cardiac structures was significantly improved with the ultra high pitch protocol (p < 0.0001). Significantly more lung parenchymal motion was observed on the standard protocol (p < 0.0001). The mean pulmonary vessel attenuation, SNR, and CNR were not significantly different. The mean effective dose was lower for the ultra high pitch studies (4.09 mSv ± 0.78 vs. 7.72 mSv ± 2.60, p < 0.0001).Conclusion
Ultra high pitch CT imaging for pulmonary embolus is a technique which has potential to assess motion free evaluation of most cardiac structures and proximal coronary arteries at lower radiation doses. 相似文献16.
Olivio F. Donati Roger Hunziker Michael A. Fischer Dimitri A. Raptis Stefan Breitenstein Michael A. Patak 《European journal of radiology》2014
Purpose
To evaluate the added value of hepatospecific phase in Gd-EOB-DTPA enhanced magnetic resonance imaging (MRI) in patients with primary tumors in non-cirrhotic liver.Methods
Twenty-nine patients (median, 39 years; range, 18–81 years; 11 male) underwent preoperative Gd-EOB-DTPA enhanced MRI including hepatospecific phase after 10 and 20 min of contrast injection at four institutions in Europe, North America and New Zealand. Images were evaluated by three different readers (R1–R3) who characterized liver tumors with and without consultation of the hepatospecific phase images. Confidence in diagnosis was scored on a visual analog scale from 1 to 10. Histopathology (adenoma, n = 5; focal nodular hyperplasia, n = 11 and hepatocellular carcinoma, n = 13) in all patients served as the standard of reference. Differences were evaluated using the McNemar and Wilcoxon signed rank test.Results
Without hepatospecific phase images available, 22 (76%), 19 (66%) and 19 (66%) of 29 tumors were characterized correctly by the three readers respectively. Mean confidence in diagnosis was 6.1, 5.7 and 5.8. With the hepatospecific phase included, characterization of liver tumors did not change significantly with 21 (72%), 23 (79%) and 19 (66%) of 29 tumors diagnosed correctly (p > 0.05). According confidence ratings increased to 6.3, 6.5 and 7.7, respectively. Increase in diagnostic confidence was significant for R2 and R3 (p < 0.05) and independent of reader's experience.Conclusion
The additional hepatospecific phase in Gd-EOB-DTPA enhanced MRI did not significantly increase diagnostic accuracy in characterization of primary tumors in the non-cirrhotic liver. However, 2/3 readers showed a significant increase in diagnostic confidence after consultation of the hepatospecific phase. 相似文献17.
Jingyun Shi Gerald Schmid-Bindert Christian Fink Sonja Sudarski Paul Apfaltrer Lothar R. Pilz Bo Liu Ulrike Haberland Ernst Klotz Caicun Zhou Stefan O. Schoenberg Thomas Henzler 《European journal of radiology》2013
Objective
To evaluate dynamic volume perfusion CT (dVPCT) tumor baseline characteristics of three different subtypes of lung cancer in untreated patients.Materials and methods
173 consecutive patients (131 men, 42 women; mean age 61 ± 10 years) with newly diagnosed lung cancer underwent dVPCT prior to biopsy. Tumor permeability, blood flow (BF), blood volume (BV) and mean transit time (MTT) were quantitatively assessed as well as tumor diameter and volume. Tumor subtypes were histologically determined and compared concerning their dVPCT results. dVPCT results were correlated to tumor diameter and volume.Results
Histology revealed adenocarcinoma in 88, squamous cell carcinoma in 54 and small cell lung cancer (SCLC) in 31 patients. Tumor permeability was significantly differing between adenocarcinoma, squamous cell carcinoma and SCLC (all p < 0.05). Tumor BF and BV were higher in adenocarcinomathan in SCLC (p = 0.001 and p = 0.0002 respectively). BV was also higher in squamous cell carcinoma compared to SCLC (p = 0.01). MTT was not differing between tumor subtypes. Regarding all tumors, tumor diameter did not correlate with any of the dVPCT parameters, whereas tumor volume was negatively associated with permeability, BF and BV (r = −0.22, −0.24, −0.24, all p < 0.05). In squamous cell carcinoma, tumor diameter und volume correlated with BV (r = 0.53 and r = −0.40, all p < 0.05). In SCLC, tumor diameter und volume correlated with MTT (r = 0.46 and r = 0.39, all p < 0.05). In adenocarcinoma, no association between morphological and functional tumor characteristics was observed.Conclusions
dVPCT parameters are only partially related to tumor diameter and volume and are significantly differing between lung cancer subtypes. 相似文献18.
Shinichiro Seki Hisanobu Koyama Yoshiharu Ohno Mizuho Nishio Daisuke Takenaka Yoshimasa Maniwa Tomoo Itoh Yoshihiro Nishimura Kazuro Sugimura 《European journal of radiology》2014
Purpose
To evaluate and compare the capability of diffusion-weighted MR imaging (DWI) and CT for assessment of management needs for anterior mediastinal solitary tumors.Materials and methods
Thirty-five patients with pathologically confirmed anterior mediastinal tumors were enrolled. The tumors were divided into two groups according to need for management: tumors not needing further intervention or treatment (group A; thymoma type A, AB and B1) and tumors needing further intervention and treatment (group B; other thymoma types and malignancies). The apparent diffusion coefficient (ADC) of each tumor was measured, and probabilities of malignancy and need for further intervention and treatment were visually assessed on CT. The differences in ADCs between group A and B and between malignancies and thymomas in group B were evaluated with the Mann–Whitney's U-test. Feasible threshold values for differentiation of group B from group A and distinguishing malignancies from thymomas assessed as group B were determined by the ROC-based positive test, and McNemar's test was used for comparing diagnostic capabilities of DWI with those of CT.Results
ADCs for the two groups were significantly different (p < 0.001). Application of the threshold value for differentiation of group B from A showed no significant difference (p > 0.05). Application of the feasible threshold value for distinguishing malignant from thymomas assessed as group B showed that specificity (76.9%) and accuracy (85.2%) of DWI were significantly better than those of visual score (p < 0.05).Conclusion
DWI has useful potential for the assessment of management needs for anterior mediastinum solitary tumors as well as CT. 相似文献19.
Achim Eller Wolfgang Wuest Michael Scharf Michael Brand Stephan Achenbach Michael Uder Michael M. Lell 《European journal of radiology》2013
Objectives
To evaluate an automated attenuation-based kV-selection in computed tomography of the chest in respect to radiation dose and image quality, compared to a standard 120 kV protocol.Materials and methods
104 patients were examined using a 128-slice scanner. Fifty examinations (58 ± 15 years, study group) were performed using the automated adaption of tube potential (100–140 kV), based on the attenuation profile of the scout scan, 54 examinations (62 ± 14 years, control group) with fixed 120 kV. Estimated CT dose index (CTDI) of the software-proposed setting was compared with a 120 kV protocol. After the scan CTDI volume (CTDIvol) and dose length product (DLP) were recorded. Image quality was assessed by region of interest (ROI) measurements, subjective image quality by two observers with a 4-point scale (3 – excellent, 0 – not diagnostic).Results
The algorithm selected 100 kV in 78% and 120 kV in 22%. Overall CTDIvol reduction was 26.6% (34% in 100 kV) overall DLP reduction was 22.8% (32.1% in 100 kV) (all p < 0.001). Subjective image quality was excellent in both groups.Conclusion
The attenuation based kV-selection algorithm enables relevant dose reduction (∼27%) in chest-CT while keeping image quality parameters at high levels. 相似文献20.
Nicola Sverzellati Giorgia Randi Paolo Spagnolo Alfonso Marchianò Mario Silva Jan-Martin Kuhnigk Carlo La Vecchia Maurizio Zompatori Ugo Pastorino 《European journal of radiology》2013