Diagnostic Accuracy Parameters Research Articles

Preclinical study of diagnostic performances of contrast-enhanced spectral mammography versus MRI for breast diseases in China.

PurposeTo evaluate diagnostic performances of CESM for breast diseases with comparison to breast MRI in China.Materials and methodsSixty-eight patients with 77 breast lesions underwent MR and CESM. Two radiologists interpreted either MRI or CESM images, separately and independently. BI-RADS 1–3 and BI-RADS 4–5 were classified into the suspicious benign and suspicious malignant groups. Diagnostic accuracy parameters were calculated. Receiver operating characteristic (ROC) curves were constructed for the two modalities. The agreement and correlation between maximum lesion diameter based on CESM and MRI, or CESM and pathology were analyzed.ResultsDiagnostic accuracy parameters for CESM were sensitivity 95.8 %, specificity 65.5 %, PPV 82.1 %, NPV 90.5 % and accuracy 84.4 %. The diagnostic accuracy parameters for breast MRI were sensitivity 93.8 %, specificity 82.8 %, PPV 88.2 %, NPV 92.3 %and accuracy 89.6 %. Area under the curve (AUC) of ROC was 0.96 for breast MRI and 0.88 for CESM. The Bland–Altman plots showed a mean difference of 0.7 mm with 95 % limits of agreement of 11.4 mm in tumor diameter measured using CESM and breast MRI. The differences of size measurement between CESM and breast MRI were significant, whereas no difference was observed between CESM and pathology as well as between breast MRI and pathology. The better correlation with pathological results was found in CESM than breast MRI.ConclusionOur study demonstrates that CESM possesses better diagnostic performances than breast MRI in terms of diagnostic sensitivity and lesion size assessment. And CESM is a good alternative method of screening breast cancer in high-risk people.

Diagnostic one-stop-shop in suspected coronary artery disease gets closer. Coronary computed tomography angiography based fractional flow reserve.

Diagnostic one-stop-shop in suspected coronary artery disease gets closer. Coronary computed tomography angiography based fractional flow reserve.

Feasibility and Diagnostic Accuracy of Ischemic Stroke Territory Recognition Based on Two-Dimensional Projections of Three-Dimensional Diffusion MRI Data.

This study was conducted to assess the feasibility and diagnostic accuracy of brain artery territory recognition based on geoprojected two-dimensional maps of diffusion MRI data in stroke patients. In this retrospective study, multiplanar diffusion MRI data of ischemic stroke patients was used to create a two-dimensional map of the entire brain. To guarantee correct representation of the stroke, a computer-aided brain artery territory diagnosis was developed and tested for its diagnostic accuracy. The test recognized the stroke-affected brain artery territory based on the position of the stroke in the map. The performance of the test was evaluated by comparing it to the reference standard of each patient’s diagnosed stroke territory on record. This study was designed and conducted according to Standards for Reporting of Diagnostic Accuracy (STARD). The statistical analysis included diagnostic accuracy parameters, cross-validation, and Youden Index optimization. After cross-validation on a cohort of 91 patients, the sensitivity of this territory diagnosis was 81% with a specificity of 87%. With this, the projection of strokes onto a two-dimensional map is accurate for representing the affected stroke territory and can be used to provide a static and printable overview of the diffusion MRI data. The projected map is compatible with other two-dimensional data such as EEG and will serve as a useful visualization tool.

Apparent diffusion coefficient measurement covering complete tumor area better predicts rectal cancer response to neoadjuvant chemoradiotherapy.

AimTo determine the impact of two apparent diffusion coefficient (ADC) measurement techniques on diffusion-weighted magnetic resonance images (DW MRI) on the assessment of rectal cancer response to neoadjuvant chemoradiotherapy (CRT).MethodsADC values were measured prospectively with two different techniques – the first, which measures ADCs in the most cellular tumor parts, and the second, which measures the entire tumor area, in 58 patients with locally advanced rectal cancer on pre-CRT and post-CRT image sets. Areas under the receiver operating characteristic curves (AUCs) and parameters of diagnostic accuracy were calculated for pre- and post-CRT ADC values and numeric and percent ADC change for each technique to determine their performance in tumor response evaluation using histopathological tumor-regression grade as the reference standard.ResultsThe second technique yielded higher AUCs (0.935 vs 0.704, P < 0.001), percent-change (0.828 vs 0.636, P < 0.001), and numeric-change (0.866 vs 0.653, P < 0.001) than the first technique for post-CRT ADC. Accuracies for post-CRT ADC assessment were 62% for the first and 88% for the second technique (cut-off values: 0.98 and 1.29 × 10−3 mm2/s, respectively) and for ADC change assessment, both numeric and percent, 59% and 74%, respectively (cut-off values: increase of 0.18 and 0.28 × 10−3 mm2/s; increase of 24% and 37%, respectively).ConclusionsThe type of measurement technique significantly affected ADC results. ADC measurements covering a larger area better predicted tumor response to therapy. Post-CRT ADCs, regardless of the measurement technique, and numeric ADC change measured in the whole tumor volume accurately identified non-complete responders. Post-CRT ADCs measured in the entire tumor area yielded the highest accuracy level in tumor response evaluation.

Is the Short Form of the Mini-Mental State Examination (MMSE) a better screening instrument for dementia in older primary care patients than the original MMSE? Results of the German study on ageing, cognition, and dementia in primary care patients (AgeCoDe).

The aim of the study was to investigate the psychometric properties of a Short Form of the Mini-Mental State Examination (SMMSE) for the screening of dementia in older primary care patients. Data were obtained from a large longitudinal cohort study of initially nondemented individuals recruited via primary care chart registries and followed at 18-month intervals. Item and scale parameters for MMSE and SMMSE scores were analyzed and cross-validated for 2 follow-up assessments (n1 = 2,657 and n2 = 2,274). Binary logistic regression and receiver-operating-characteristic (ROC) curve analyses were conducted in order to assess diagnostic accuracy parameters for MMSE and SMMSE scores. Cross-sectional differentiation between dementia-free and dementia patients yielded moderate to good results for MMSE and SMMSE scores. With regard to most diagnostic accuracy parameters, SMMSE scores did not outperform the MMSE scores. The current study provides first evidence regarding the psychometric properties of the SMMSE score in a sample of older primary care patients. However, our findings do not confirm previous findings that the SMMSE is a more accurate screening instrument for dementia than the original MMSE. Further studies are needed in order to assess and to develop short, reliable and valid instruments for routine cognitive screening in clinical practice and primary care settings.

A Randomised Assessment of Trainee Doctors' Understanding and Interpretation of Diagnostic Test Results.

Doctors are unfamiliar with diagnostic accuracy parameters despite routine clinical use of diagnostic tests to estimate disease probability. Trainee doctors completed a questionnaire exploring their understanding of diagnostic accuracy parameters; ability to calculate post-test probability of a common surgical condition (appendicitis) and their perceptions on training in this area. To determine whether the method of information provision altered interpretation, trainees were randomised to receive diagnostic test information in three ways: positive test only; positive test with specificity and sensitivity; positive test with positive likelihood ratio in layman terms. 326 candidates were recruited across 30 training sessions. Trainees scored a median of three out of seven in questions concerning knowledge of diagnostic accuracy parameters. This was affected neither by training level (P = 0.737) nor by experience in acute general surgery (P = 0.738). 30 (11.8%) candidates correctly estimated post-test probability; with 86.6% overestimating this value. Neither level of training (P = 0.180) nor experience (P = 0.242) influenced the accuracy of the estimate. Provision of the ultrasound scan results in different ways was not associated with likelihood of a correct response (P = 0.857). This study highlights the deficiencies in trainee doctors' understanding and application of diagnostic tests results. Most trainees over-estimated disease probability, increasing the risk of unnecessary intervention and treatment.

Prediction models for neonatal health care-associated sepsis: a meta-analysis.

Blood culture is the gold standard to diagnose bloodstream infection but is usually time-consuming. Prediction models aim to facilitate early preliminary diagnosis and treatment. We systematically reviewed prediction models for health care-associated bloodstream infection (HABSI) in neonates, identified superior models, and pooled clinical predictors. LibHub, PubMed, and Web of Science. The studies included designed prediction models for laboratory-confirmed HABSI or sepsis. The target population was a consecutive series of neonates with suspicion of sepsis hospitalized for ≥ 48 hours. Clinical predictors had to be recorded at time of or before culturing. Methodologic quality of the studies was assessed. Data extracted included population characteristics, total suspected and laboratory-confirmed episodes and definition, clinical parameter definitions and odds ratios, and diagnostic accuracy parameters. The systematic search revealed 9 articles with 12 prediction models representing 1295 suspected and 434 laboratory-confirmed sepsis episodes. Models exhibit moderate-good methodologic quality, large pretest probability range, and insufficient diagnostic accuracy. Random effects meta-analysis showed that lethargy, pallor/mottling, total parenteral nutrition, lipid infusion, and postnatal corticosteroids were predictive for HABSI. Post hoc analysis with low-gestational-age neonates demonstrated that apnea/bradycardia, lethargy, pallor/mottling, and poor peripheral perfusion were predictive for HABSI. Limitations include clinical and statistical heterogeneity. Prediction models should be considered as guidance rather than an absolute indicator because they all have limited diagnostic accuracy. Lethargy and pallor and/or mottling for all neonates as well as apnea and/or bradycardia and poor peripheral perfusion for very low birth weight neonates are the most powerful clinical signs. However, the clinical context of the neonate should always be considered.

C-reactive protein and white blood cell count as triage test between urgent and nonurgent conditions in 2961 patients with acute abdominal pain.

The purpose of this article is to assess the diagnostic accuracy of C-reactive protein (CRP) and white blood cell (WBC) count to discriminate between urgent and nonurgent conditions in patients with acute abdominal pain at the emergency department, thereby guiding the selection of patients for immediate diagnostic imaging.Data from 3 large published prospective cohort studies of patients with acute abdominal pain were combined in an individual patient data meta-analysis. CRP levels and WBC counts were compared between patients with urgent and nonurgent final diagnoses. Parameters of diagnostic accuracy were calculated for clinically applicable cutoff values of CRP levels and WBC count, and for combinations.A total of 2961 patients were included of which 1352 patients (45.6%) had an urgent final diagnosis. The median WBC count and CRP levels were significantly higher in the urgent group than in the nonurgent group (12.8 ×109/L; interquartile range [IQR] 9.9–16) versus (9.3 ×109/L; IQR 7.2–12.1) and (46 mg/L; IQR 12–100 versus 10 mg/L; IQR 7–26) (P < 0.001).The highest positive predictive value (PPV) (85.5%) and lowest false positives (14.5%) were reached when cutoff values of CRP level >50 mg/L and WBC count >15 ×109/L were combined; however, 85.3% of urgent cases was missed.A high CRP level (>50 mg/L) combined with a high WBC count (>15 ×109/L) leads to the highest PPV. However, this applies only to a small subgroup of patients (8.7%). Overall, CRP levels and WBC count are insufficient markers to be used as a triage test in the selection for diagnostic imaging, even with a longer duration of complaints (>48 hours).

The Supine Internal Rotation Test: A Pilot Study Evaluating Tibial Internal Rotation in Grade III Posterior Cruciate Ligament Tears.

Background:Biomechanical studies have reported that the posterior cruciate ligament (PCL) functions as a restraint against excessive tibial internal rotation at higher degrees of knee flexion.Purpose:To investigate the use of a supine internal rotation (IR) test for the diagnosis of grade III PCL injuries. The hypothesis was that internal rotation would be greater in patients with grade III PCL injuries compared with other knee injuries and that the supine IR test would demonstrate excellent diagnostic accuracy.Study Design:Cohort study (diagnosis); Level of evidence, 2.Methods:A consecutive series of 309 patients underwent arthroscopic and/or open knee ligament reconstruction surgery. Seven patients were excluded based on the inability to perform a side-to-side comparison of internal rotation. Tibial internal rotation was assessed bilaterally on 302 patients during examination under anesthesia by a single orthopaedic surgeon measuring tibial tubercle excursion (mm) while applying internal rotation torque. Internal rotation was graded from 0 to 4 at 60°, 75°, 90°, 105°, and 120° of knee flexion. Data were collected and stored prospectively. The optimal threshold for the supine IR test was chosen based on maximization of the Youden index. Diagnostic accuracy parameters were calculated. Multiple logistic regression models were constructed to assess the influence of other knee pathologies on diagnostic accuracy.Results:Examination of the 22 PCL-deficient knees demonstrated an increase in tibial internal rotation at 60°, 75°, 90°, 105°, and 120° of knee flexion. The supine IR test had a sensitivity of 95.5%, a specificity of 97.1%, a positive predictive value of 72.4%, and a negative predictive value of 99.6% for the diagnosis of grade III PCL injuries. Posterolateral corner injury had a significant interaction with the supine IR test, increasing its sensitivity and decreasing its specificity.Conclusion:PCL-deficient knees demonstrated an increase in the side-to-side difference in tibial internal rotation compared with other knee pathologies. The supine IR test offers high sensitivity and specificity for grade III PCL injuries and may represent a useful adjunct for diagnosing PCL injuries.

Endoscopic Ultrasonography for Tumor Node Staging and Vascular Invasion in Pancreatic Cancer: A Meta-Analysis

Background/Aims: The accurate staging of pancreatic cancer (PanCa) is crucial in the development of a stage-specific treatment plan for PanCa patients. We aimed to perform a meta-analysis of endoscopic ultrasonography (EUS) in the tumor node (TN) staging and evaluation of vascular invasion in PanCa. Methods: A meta-analysis of diagnostic accuracy parameters was performed to evaluate the EUS-based TN staging, and vascular invasion by PanCa was compared to the results of intraoperative staging or to the histopathology of resected specimens. Results: Twenty studies with 726 PanCa cases were identified from 281 articles. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were 0.72, 0.90, 6.27, 0.28, and 24.69, respectively, for T1-2 staging and 0.90, 0.72, 3.58, 0.16, and 24.69, respectively, for T3-4 staging. The overall sensitivity, specificity, PLR, NLR, and DOR were 0.62, 0.74, 2.54, 0.51, and 6.67, respectively, for N staging (positive vs. negative) and 0.87, 0.92, 7.16, 0.20, and 56.19, respectively, for vascular invasion. The area under the curve was 0.90, 0.90, 0.79, and 0.94 for T1-2 staging, T3-4 staging, N staging, and vascular invasion, respectively. Conclusions: EUS is a reliable and accurate diagnostic tool for the TN staging and evaluation of vascular invasion in PanCa. The nodal staging accuracy using EUS is less satisfactory. i 2014 S. Karger AG, Basel

INCLEN Diagnostic Tool for Autism Spectrum Disorder (INDT-ASD): development and validation.

To develop and validate INCLEN Diagnostic Tool for Autism Spectrum Disorder (INDT-ASD). Diagnostic test evaluation by cross sectional design. Four tertiary pediatric neurology centers in Delhi and Thiruvanthapuram, India. Children aged 2-9 years were enrolled in the study. INDT-ASD and Childhood Autism Rating Scale (CARS) were administered in a randomly decided sequence by trained psychologist, followed by an expert evaluation by DSM-IV TR diagnostic criteria (gold standard). Psychometric parameters of diagnostic accuracy, validity (construct, criterion and convergent) and internal consistency. 154 children (110 boys, mean age 64.2 mo) were enrolled. The overall diagnostic accuracy (AUC=0.97, 95% CI 0.93, 0.99; P<0.001) and validity (sensitivity 98%, specificity 95%, positive predictive value 91%, negative predictive value 99%) of INDT-ASD for Autism spectrum disorder were high, taking expert diagnosis using DSM-IV-TR as gold standard. The concordance rate between the INDT-ASD and expert diagnosis for 'ASD group' was 82.52% [Cohen's k=0.89; 95% CI (0.82, 0.97); P=0.001]. The internal consistency of INDT-ASD was 0.96. The convergent validity with CARS (r = 0.73, P= 0.001) and divergent validity with Binet-Kamat Test of intelligence (r = -0.37; P=0.004) were significantly high. INDT-ASD has a 4-factor structure explaining 85.3% of the variance. INDT-ASD has high diagnostic accuracy, adequate content validity, good internal consistency high criterion validity and high to moderate convergent validity and 4-factor construct validity for diagnosis of Autistm spectrum disorder.

Diagnostic accuracy of level 3 portable sleep tests versus level 1 polysomnography for sleep-disordered breathing: a systematic review and meta-analysis.

Greater awareness of sleep-disordered breathing and rising obesity rates have fueled demand for sleep studies. Sleep testing using level 3 portable devices may expedite diagnosis and reduce the costs associated with level 1 in-laboratory polysomnography. We sought to assess the diagnostic accuracy of level 3 testing compared with level 1 testing and to identify the appropriate patient population for each test. We conducted a systematic review and meta-analysis of comparative studies of level 3 versus level 1 sleep tests in adults with suspected sleep-disordered breathing. We searched 3 research databases and grey literature sources for studies that reported on diagnostic accuracy parameters or disease management after diagnosis. Two reviewers screened the search results, selected potentially relevant studies and extracted data. We used a bivariate mixed-effects binary regression model to estimate summary diagnostic accuracy parameters. We included 59 studies involving a total of 5026 evaluable patients (mostly patients suspected of having obstructive sleep apnea). Of these, 19 studies were included in the meta-analysis. The estimated area under the receiver operating characteristics curve was high, ranging between 0.85 and 0.99 across different levels of disease severity. Summary sensitivity ranged between 0.79 and 0.97, and summary specificity ranged between 0.60 and 0.93 across different apnea-hypopnea cut-offs. We saw no significant difference in the clinical management parameters between patients who underwent either test to receive their diagnosis. Level 3 portable devices showed good diagnostic performance compared with level 1 sleep tests in adult patients with a high pretest probability of moderate to severe obstructive sleep apnea and no unstable comorbidities. For patients suspected of having other types of sleep-disordered breathing or sleep disorders not related to breathing, level 1 testing remains the reference standard.

Radiological Support for Diagnosis of Acute Appendicitis: Use, Effectiveness and Clinical Repercussions

ObjectiveThe aim of this study is to analyze the increasing need of radiological support in the diagnosis of acute appendicitis (AA), the clinical repercussions associated, and the parameters of diagnostic accuracy of ultrasound and computed tomography (CT) scan for AA. Materials and methodsObservational and analytical study. Cohort, patients operated on for suspected AA at a tertiary referral hospital. Pregnancy and <14 years were exclusion criteria. Study group: January 2010–December 2011 (n1=419). Control group: set of patients aged 18–65 years old operated between October 2001 and September 2003 (n2=237). Variables analyzed in both groups: (1) percentage of radiological support for diagnosis of acute appendicitis; (2) sensitivity and positive predictive value (PPV) of ultrasound and CT scan; (3) rate of surgical explorations with negative result or with diagnosis other than acute appendicitis. Statistical analysis: SPSS software, χ2 test, statistical significance accepted with P<05, 95% confidence interval (95% CI) for the odds ratio (OR). ResultsAge, gender, percentage of atypical locations and gangrenous/perforated episodes were similar in both groups. The number of radiological examinations needed for diagnosis was significantly higher in the study group (78.8% vs 30.4%, P<000). Sensitivity was significantly superior for CT than for ultrasound scan (97% vs 86%), but PPV was similar in both tests (92% vs 94%). Surgical exploration percent values with diagnosis of acute appendicitis were significantly higher in the study group (94.5% vs 88.6%; P<006, OR 2.2; 95% CI: 1.25–4). ConclusionsCT and ultrasound scan are excellent diagnostic tools for acute appendicitis, and have contributed to a significant increase in surgical explorations with correct diagnosis.

Ability of FDG‐PET/CT in the detection of gallbladder cancer

To assess the value of FDG-PET/CT in the evaluation of gallbladder carcinomas (GBC). A prospective cohort of patients with suspicion of or confirmed GBC was studied with FDG-PET/CT. Diagnostic accuracy parameters were calculated in comparison with pathology and/or the clinical course of patients. Clinical impact of PET/CT imaging was estimated. Forty-nine patients were enrolled (34 malignant tumors, 15 benign lesions; 37 staging, 12 restaging). Overall diagnostic accuracy was 95.9% for the diagnosis of the primary lesion, 85.7% for lymph node involvement and 95.9% for metastatic disease. Mean SUVmax in malignant gallbladder lesions was 7.92 ± 6.25 Analysis of ROC curves showed a SUVmax cut-off value of 3.62 for malignancy (S: 78.1%; Sp: 88.2%). Diagnostic accuracy in the restaging group reached 100%. FDG-PET/CT changed the management of 22.4% of the population. Diagnosis of malignancy or benignity of suspicious gallbladder lesions is accurately made with FDG PET/CT, allowing a precise staging of GBC due to its ability to identify unsuspected metastatic disease. SUVmax has a complementary role in addition to visual analysis.

Evaluation of incomplete multiple diagnostic tests, with an application in the colon cancer family registry study

Accurate diagnosis of a molecularly defined subtype of cancer is often an important step toward its effective control and treatment. For the diagnosis of some subtypes of a cancer, a gold standard with perfect sensitivity and specificity may be unavailable. In those scenarios, tumor subtype status is commonly measured by multiple imperfect diagnostic markers. Additionally, in many such studies, some subjects are only measured by a subset of diagnostic tests and the missing probabilities may depend on the unknown disease status. In this paper, we present statistical methods based on the EM algorithm to evaluate incomplete multiple imperfect diagnostic tests under a missing at random assumption and one missing not at random scenario. We apply the proposed methods to a real data set from the National Cancer Institute (NCI) colon cancer family registry on diagnosing microsatellite instability for hereditary non-polyposis colorectal cancer to estimate diagnostic accuracy parameters (i.e. sensitivities and specificities), prevalence, and potential differential missing probabilities for 11 biomarker tests. Simulations are also conducted to evaluate the small-sample performance of our methods.

Agreement of glaucoma specialists and experienced optometrists in gonioscopy and optic disc evaluation

PurposeTo compare the diagnostic performance of glaucoma specialists and experienced optometrists in gonioscopy and optic disc assessment. MethodsThis study was done to validate the diagnostic performance of two experienced optometrists for using their skills of detecting glaucoma using gonioscopy and optic disc assessment in a major epidemiological study, the L V Prasad Eye Institute Glaucoma Epidemiology and Molecular Genetics Study (LVPEI-GLEAMS). Gonioscopic findings for 150 eyes were categorized as 0, 1 and 2 for open angle, primary angle closure suspect (PACS) and primary angle closure (PAC) respectively. Optic disc findings for 200 eyes were categorized as 0, 1 and 2 for normal, suspects and glaucomatous respectively. Weighted kappa (κ) and diagnostic accuracy parameters were calculated. Two optometrists (#1 and #2) participated in the study. ResultsAgreement between glaucoma specialists and optometrist for interpretation of gonioscopy to discriminate PACS and PAC from open angles and for interpretation of optic disc to discriminate glaucomatous and suspicious discs from normal, the kappa (κ) was 0.92 and 0.84 and 0.90 and 0.89 for optometrists #1 and #2 respectively. Sensitivities and specificities were above 90% for gonioscopy. Optic disc evaluation had specificities greater than 95% to discriminate normal from glaucomatous discs while the sensitivities were 83% and 93% for optometrists #1 and #2 respectively. ConclusionAgreement between optometrists and glaucoma specialists, in diagnostic performance of gonioscopy and optic assessment was excellent with high sensitivity and specificity. Hence, we conclude that the experienced optometrists can detect glaucoma accurately in the LVPEI-GLEAMS.

Additional value of adenosine-stress dynamic CT myocardial perfusion imaging in the reclassification of severity of coronary artery stenosis at coronary CT angiography

To assess the additional value of adenosine-stress dynamic computed tomography (CT) perfusion (ASDCTP) imaging compared with coronary CT angiography (CCTA) alone to detect significant coronary artery stenosis for each threshold of 50% and 70% diameter stenosis. The study included 34 patients (65±11 years, 79% men) with suspected coronary artery diseases who underwent ASDCTP imaging using a 128-section dual-source CT (DSCT) and invasive coronary angiography (ICA). Two investigators classified coronary artery stenosis on CCTA as severe or not. If appropriate image quality could not be acquired due to artefacts, the segment was classified as a lesion with significant stenosis. After the interpretation of ASDCTP imaging, the degree of stenosis was reclassified. All parameters of diagnostic accuracy were calculated before and after ASDCTP analysis for detection of significant coronary artery stenosis with ICA as the reference standard. The diagnostic accuracy parameters per vessel for the detection of ≥50% stenosis before and after ASDCTP analysis changed as follows: sensitivity, from 80% to 83%; specificity, from 83% to 98%; positive predictive value (PPV), from 87% to 98%; and negative predictive value (NPV), from 75% to 80%. The addition of ASDCTP resulted in reclassification from one class of stenosis severity to another in a significant number of vessels with threshold of 50% stenosis [net reclassification improvement (NRI), 0.176; p<0.01]. Conversely, the addition of ASDCTP did not result in significant reclassification of stenosis severity in vessels with threshold of 70% stenosis (NRI, 0.034; p=0.51). ASDCTP imaging provides incremental value in the detection of significant coronary artery stenosis using a threshold of 50%.

Diagnostic accuracy of multidetector computed tomography coronary angiography in 330 consecutive patients referred for balloon-expandable transcatheter aortic valve implantation

Purpose: The aim of this study was to assess the evaluability and diagnostic accuracy of the multidetector computed tomography (MDCT) coronary angiography in patients referred for transcatheter aortic valve implantation (TAVI). MDCT is playing an increasingly role in patients scheduled for TAVI, providing detailed anatomic assessment of the aortic root and valve annulus and of iliofemoral access. However, the diagnostic performance of MDCT coronary angiography has not been well investigated. Methods: 330 consecutive patients scheduled for invasive coronary angiography (ICA) and 64-slice MDCT for the screening protocol before TAVI were enrolled (42 patients with previous coronary artery bypass graft (CABG), 49 with previous coronary stenting, 233 without previous revascularizations). All MDCT coronary angiography were performed using the same data set dedicated to the standard MDCT evaluation of aortic annulus, obtained with retrospective ECG triggering. Coronary arteries evaluability by MDCT coronary angiography and its diagnostic accuracy parameters in comparison with ICA as gold standard were evaluated. Results: In the remaining 325 patients, the mean HR during the scan was 61±9 bpm. The MDCT evaluability of native coronary arteries was 95.6%. The leading cause of unevaluability was the beam-hardening artifact due to large coronary calcifications (109 cases), followed by slice misalignments (56 cases) due to HR variability or premature heart beats during the scan and motion artifacts (40 cases). In the segment-based analysis, sensibility, specificity, positive predictive value, negative predictive value and accuracy were 91%, 99.2%, 83.4%, 99.6% and 98.8%, respectively. MDCT correctly assessed the patency of all CABG, without graft classified as non evaluable. The MDCT evaluability of coronary stents was 82.1%. In the segment-based analysis, MDCT showed sensibility, specificity, positive predictive value, negative predictive value and accuracy for the detection of ≥ 50% luminal narrowing of 94.1%, 86.7%, 66.7%, 98.1% and 88.3%, respectively. Conclusions: MDCT coronary angiography allows to correctly rule out the presence of significant coronary stenosis in patients referred for TAVI, demonstrating and excellent negative predictive value also in patients with previous CABG or stents.

Empleo, eficacia y repercusión clínica del apoyo radiológico al diagnóstico de la apendicitis aguda

ObjectiveThe aim of this study is to analyze the increasing need of radiological support in the diagnosis of acute appendicitis (AA), the clinical repercussions associated, and the parameters of diagnostic accuracy of ultrasound and computed tomography (CT) scan for AA. Material and methodsObservational and analytical study. Cohort, patients operated on for suspected AA at a tertiary referral hospital. Pregnancy and <14 years were exclusion criteria. Study group: January 2010-December 2011 (n1=419). Control group: set of patients aged 18 to 65 years old operated between October 2001-September 2003 (n2=237). Variables analyzed in both groups: 1) percentage of radiological support for diagnosis of acute appendicitis; 2) sensitivity and positive predictive value (PPV) of ultrasound and CT scan; 3) rate of surgical explorations with negative result or with diagnosis other than acute appendicitis. Statistical analysis: SPSS software, χ2 test, statistical significance accepted with P<.05, 95% confidence interval (95% CI) for the odds ratio (OR). ResultsAge, gender, percentage of atypical locations and gangrenous/perforated episodes were similar in both groups. The number of radiological examinations needed for diagnosis was significantly higher in the study group (78.8% vs. 30.4%, P<.0,000). Sensitivity was significantly superior for CT than for ultrasound scan (97% vs. 86%), but PPV was similar in both tests (92% vs. 94%). Surgical exploration percent values with diagnosis of acute appendicitis was significantly higher in the study group (94.5% vs. 88.6%; P<.006, OR 2.2; CI 95% 1.25-4). ConclusionsCT and ultrasound scan are excellent diagnostic tools for acute appendicitis, and have contributed to a significant increase in surgical explorations with correct diagnosis.

PTU-033 Meta-Analysis of Flexible Spectral Imaging Colour Enhancement (Fice) in Detection and Characterization of Colorectal Polyps

IntroductionSeveral endoscopic innovations have been developed recently to improve detection and characterization of colorectal polyps. Flexible spectral imaging colour enhancement (FICE) is a form of image enhanced endoscopy which enhances...