Stratified computed tomography findings improve diagnostic accuracy for appendicitis

AIM: To improve the diagnostic accuracy in patients with symptoms and signs of appendicitis, but without confirmative computed tomography (CT) findings.

Optimized protocol of multiple post-processing techniques improves diagnostic accuracy of multidetector computed tomography in assessment of small bowel obstruction compared with conventional axial and coronal reformations

BACKGROUND Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography(MDCT)examination of patients with small bowel obstruction(SBO) or other abdominal diseases. The diagnostic accuracy of MDCT for assessing SBO is expected to be further improved through the use of multiple post-processing techniques.AIM To systemically evaluate the diagnostic accuracy and efficiency of an optimized protocol using multiple post-processing techniques for MDCT assessment of SBO and secondary bowel ischemia.METHODS This retrospective cross-sectional study included 106 patients with clinically suspected SBO. Two readers applied three protocols to image post-processing and interpretation of patients' MDCT volume data. We compared the three protocols based on time spent, number of images, diagnostic self-confidence,agreement, detection rate, and accuracy of detection of SBO and secondary bowel ischemia.RESULTS Protocol 2 resulted in more time spent and number of images than protocols 1 and 3(P < 0.01), but the results of the two readers using the same protocol were not different(P > 0.05). Using protocol 3, both readers added multiple postprocessing techniques at frequencies of 29.2% and 34.9%, respectively, for obstruction cause, and 32.1% and 30.2%, respectively, for secondary bowel ischemia. Protocols 2 and 3 had higher total detection rates of obstruction cause and secondary bowel ischemia than protocol 1(P < 0.01), but no difference was detected between protocols 2 and 3(P > 0.05). The accuracy, sensitivity,specificity, positive predictive value and negative predictive value of protocols 2 and 3 were superior to those of protocol 1 for evaluating obstruction cause and secondary bowel ischemia.CONCLUSION Our optimized protocol of multiple post-processing techniques can both guarantee efficiency and improve diagnostic accuracy of MDCT for assessing SBO and secondary bowel ischemia.

Endoscopic ultrasound diagnostic gain over computed tomography and magnetic resonance cholang-iopancreatography in defining etiology of idiopathic acute pancreatitis

BACKGROUND About 10%-30%of acute pancreatitis remain idiopathic(IAP)even after clinical and imaging tests,including abdominal ultrasound(US),contrast-enhanced computed tomography(CECT)and magnetic resonance cholangiopancreatography(MRCP).This is a relevant issue,as up to 20%of patients with IAP have recurrent episodes and 26%of them develop chronic pancreatitis.Few data are available on the role of EUS in clarifying the etiology of IAP after failure of one or more cross-sectional techniques.AIM To evaluate the diagnostic gain after failure of one or more previous crosssectional exams.METHODS We retrospectively collected data about consecutive patients with AP and at least one negative test between US,CECT and MRCP,who underwent linear EUS between January 2017 and December 2020.We investigated the EUS diagnostic yield and the EUS diagnostic gain over different combinations of these crosssectional imaging techniques for the etiologic diagnosis of AP.Types and frequency of EUS diagnosis were also analyzed,and EUS diagnosis was compared with the clinical parameters.After EUS,patients were followed-up for a median of 31.5 mo to detect cases of pancreatitis recurrence.RESULTS We enrolled 81 patients(63%males,mean age 61±18,23%with previous cholecystectomy,17%with recurrent pancreatitis).Overall EUS diagnostic yield for AP etiological diagnosis was 79%(20%lithiasis,31%acute on chronic pancreatitis,14%pancreatic solid or cystic lesions,5%pancreas divisum,5%autoimmune pancreatitis,5%ductal abnormalities),while 21%remained idiopathic.US,CECT and MRCP,taken alone or in combination,led to AP etiological diagnosis in 16(20%)patients;among the remaining 65 patients,49(75%)obtained a diagnosis at EUS,with an overall EUS diagnostic gain of 61%.Sixty-eight patients had negative US;among them,EUS allowed etiological diagnosis in 59(87%).Sixty-three patients had a negative CECT;among them,47(74%)obtained diagnosis with EUS.Twenty-four had a negative MRCP;among them,20(83%)had EUS diagnosis.Twenty-one had negative CT+MRCP,of which 17(81%)had EUS diagnosis,with a EUS diagnostic gain of 63%.Patients with biliary etiology and without previous cholecystectomy had higher median values of alanine aminotransferase(154 vs 25,P=0.010),aspartate aminotransferase(95 vs 29,P=0.018),direct bilirubin(1.2 vs 0.6,P=0.015),gammaglutamyl transpeptidase(180 vs 48,P=0.006)and alkaline phosphatase(150 vs 72,P=0.015)Chronic pancreatitis diagnosis was more frequent in patients with recurrent pancreatitis at baseline(82%vs 21%,P<0.001).During the follow-up,AP recurred in 3 patients,one of which remained idiopathic.CONCLUSION EUS is a good test to define AP etiology.It showed a 63%diagnostic gain over CECT+MRCP.In suitable patients,EUS should always be performed in cases of IAP.Further prospective studies are needed.

Diagnostic capability of peripapillary retinal nerve fiber layer parameters in time-domain versus spectral-domain optical coherence tomography for assessing glaucoma in high myopia

AIM： To evaluate and compare the diagnostic capabilities of peripapillary retinal nerve fiber layer（p-RNFL） parameters of Spectralis optical coherence tomography（OCT） versus Stratus OCT to detect glaucoma in patients with high myopia. METHODS： This is a retrospective, cross-sectional study. Sixty highly myopic eyes of 60 patients were enrolled, with 30 eyes in the glaucoma group and 30 eyes in the control group. All eyes received peripapillary imaging of the optic disc using Stratus and Spectralis OCT. Areas under the receiver operating characteristic curve（AUROC） and the sensitivity at specificity of 〉80% and 〉95% for p-RNFL parameters obtained using the two devices to diagnose glaucoma were analysed and compared. RESULTS： In Spectralis OCT, p-RNFL thickness parameters with the largest AUROC were the temporal-inferior sector（0.974） and the inferior quadrant（0.951）, whereas in Stratus OCT, the best parameters were the 7-o＇clock sector（0.918） and the inferior quadrant（0.918）. Compared to the Stratus OCT parameters, the Spectralis OCT parameters demonstrated generally higher AUROC; however, the difference was not statistically significant. CONCLUSION： The best p-RNFL parameters for diagnosing glaucoma in patients with high myopia were the temporal-inferior sector on Spectralis OCT and the 7-o＇clock sector on Stratus OCT. There were no significant differences between the AUROCs for Spectralis OCT and Stratus OCT, which suggest that the glaucoma diagnostic capabilities of these two devices in patients with high myopia are similar.

Diagnostic challenges in alcohol use disorder and alcoholic liver disease

Alcohol use disorders represent a heterogeneous spectrum of clinical manifestations that have been defined by the Diagnostic and Statistical Manual of Mental Disorders-5. Excessive alcohol intake can lead to damage of various organs, including the liver. Alcoholic liver disease includes different injuries ranging from steatosis to cirrhosis and implicates a diagnostic assessment of the liver disease and of its possible complications. There is growing interest in the possible different tools for assessing previous alcohol consumption and for establishing the severity of liver injury, especially by noninvasive methods.

Diagnostic Efficacy of^(18)F-FDG PET/CT in Detecting Bone Marrow Infiltration in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma

Objective Diffuse large B-cell lymphoma(DLBCL)is often associated with bone marrow infiltration,and 2-deoxy-2-(18F)fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT)has potential diagnostic significance for bone marrow infiltration in DLBCL.Methods A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included.Bone marrow biopsy and^(18)F-FDG PET/CT examinations were performed at the time of initial diagnosis.Kappa tests were used to evaluate the agreement of^(18)F-FDG PET/CT with the gold standard,and the imaging features of DLBCL bone marrow infiltration on PET/CT were described.Results The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy(P=0.302)or between the two bone marrow biopsies(P=0.826).The sensitivity,specificity,and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923(95%CI,0.759-0.979),0.934(95%CI,0.855-0.972),and 0.857,respectively.Conclusion^(18)F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration.PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.

Radiation Dose Survey of Pediatric Chest Computed Tomography Examinations: A Local Diagnostic Reference Levels Approach to Patient Safety

Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. .

Diagnostic performance of abbreviated gadoxetic acid-enhanced magnetic resonance protocols with contrast-enhanced computed tomography for detection of colorectal liver metastases

BACKGROUND Although contrast-enhanced magnetic resonance imaging(MRI)using gadoxetic acid has been shown to have higher accuracy,sensitivity,and specificity for the detection and characterization of hepatic metastases compared with other modalities,the long examination time would limit the broad indication.Several abbreviated enhanced MRI(Ab-MRI)protocols without dynamic phases have been proposed to achieve equivalent diagnostic performance for the detection of colorectal liver metastases.However,an optimal protocol has not been established,and no studies have assessed the diagnostic performance of Ab-MRI combined with contrast-enhanced computed tomography(CE-CT),which is the preoperative imaging of colorectal cancer staging in clinical settings,to determine the best therapeutic strategy.AIM To compare the diagnostic performance of two kinds of Ab-MRI protocol with the standard MRI protocol and a combination of the Ab-MRI protocol and CE-CT for the detection of colorectal liver metastases.METHODS Study participants comprised 87 patients(51 males,36 females;mean age,67.2±10.8 years)who had undergone gadoxetic acid-enhanced MRI and CE-CT during the initial work-up for colorectal cancer from 2010 to 2021.Each exam was independently reviewed by two readers in three reading sessions:(1)Only single-shot fast spin echo(FSE)T2-weighted or fat-suppressed-FSE-T2-weighted,diffusion-weighted,and hepatobiliary-phase images(Ab-MRI protocol 1 or 2);(2)all acquired MRI sequences(standard protocol);and(3)a combination of an Ab-MRI protocol(1 or 2)and CE-CT.Diagnostic performance was then statistically analyzed.RESULTS A total of 380 Lesions were analyzed,including 195 metastases(51.4%).Results from the two Ab-MRI protocols were similar.The sensitivity,specificity,and positive and negative predictive values from Ab-MRI were non-inferior to those from standard MRI(P>0.05),while those from the combination of Ab-MRI protocol and CE-CT tended to be higher than those from Ab-MRI alone,although the difference was not significant(P>0.05),and were quite similar to those from standard MRI(P>0.05).CONCLUSION The diagnostic performances of two Ab-MRI protocols were non-inferior to that of the standard protocol.Combining Ab-MRI with CE-CT provided better diagnostic performance than Ab-MRI alone.

Multislice CT angiography in coronary artery disease: Technical developments, radiation dose and diagnostic value

Multislice computed tomography (CT) angiography has been increasingly used in the detection and diagnosis of coronary artery disease because of its rapid technical evolution from the early generation of 4-slice CT scanners to the latest models such as 64-slice, 256-slice and 320-slice CT scanners. Technical developments of multislice CT imaging enable improved diagnostic value in the detection of coronary artery disease, and this indicates that multislice CT can be used as a reliable lessinvasive alternative to invasive coronary angiography in selected patients. In addition, multislice CT angiography has played a significant role in the prediction of disease progression and cardiac events. Despite promising results reported in the literature, multislice CT has the disadvantage of having a high radiation dose which could contribute to the radiation-induced malignancy. A variety of strategies have been currently undertaken to reduce the radiation dose associated with multislice CT coronary angiography while in the meantime acquiring diagnostic images. In this article, the author will review the technical developments, radiation dose associated with multislice CT coronary angiography, and strategies to reduce radiation dose. The diagnostic and prognostic value of multislice CT angiography in coronary artery disease is briefly discussed, and future directions of multislice CT angiography in the diagnosis of coronary artery disease will also be highlighted.

Computed tomography scan imaging in diagnosing acute uncomplicated pancreatitis: Usefulness vs cost

BACKGROUND Literature has suggested that imaging is over-utilized in the diagnosis of pancreatitis. If the diagnosis of acute pancreatitis(AP) is established with abdominal pain and increased serum amylase or lipase activity without systemic signs of severe disease, computed tomography(CT) imaging may not be necessary. We hypothesize that among patients with uncomplicated acute pancreatitis(AUP), there is a significant number of unwarranted CT imaging studies. This imposes increased expenditure and cost in our healthcare system and does not improve hospital stay or management of AUP.AIM To assess the overutilization and associated cost of CT imaging among patients meeting diagnostic criteria for AUP.METHODS In this Institutional Review Board-approved retrospective, single-center study,we identified all adult patients admitted with AP from January 1, 2012 through October 1, 2017. Patients were identified via International Classification of Diseases(ICD-9) code for AP(577.0) and ICD-10 codes for different etiological AP(K85.9 unspecified, K85.0 idiopathic, K85.1 biliary, K85.2 alcohol-induced, K85.3 drug-induced, and K85.8 other). Diagnosis was confirmed by chart review using established non-imaging diagnostic criteria(presence of typical abdominal pain and elevated lipase or amylase greater than 3 times upper limit of normal).Ranson criteria and BISAP scores on presentation were calculated and patients that met scores less than or equal to 2 for both were included to suggest AUP.The utilization and cost of imaging in these patients were recorded.RESULTS Between January 2012 and October 2017, 1305 patients presented to the emergency department with AP, and 405 patients(31%) met our inclusion criteria for AUP(201 males, 204 females; mean age 49 years, range 18-98). Of those, 210 patients(51.85%) underwent CT imaging. One patient(0.47%) had evidence of pancreatic necrosis, one patient had cyst formation(0.47%), and the remaining208 patients(99.05%) had either normal CT scan imaging or findings consistent with mild AP without necrosis. The average cost of CT scan imaging was $4510 with a total cost of $947056. Median length of hospitalization stay was 3 d among both groups. Combining Ranson's Criteria and BISAP score identified AUP in our patient population with an accuracy of 99.5%.CONCLUSION CT imaging is unnecessary when AUP is diagnosed clinically and biochemically.Reducing overuse of diagnostic CT scans will decrease healthcare expenditure and radiation exposure to patients.

Diagnostic non-invasive model of large risky esophageal varices in cirrhotic hepatitis C virus patients

AIM To build a diagnostic non-invasive model for screening of large varices in cirrhotic hepatitis C virus(HCV) patients. METHODS This study was conducted on 124 post-HCV cirrhotic patients presenting to the clinics of the Endemic Medicine Department at Mansoura University Hospital for evaluation before HCV antiviral therapy: 78 were Child A and 46 were Child B(score ≤ 8). Inclusion criteria for patients enrolled in this study was presence of cirrhotic HCV(diagnosed by either biopsy or fulfillment of clinical basis). Exclusion criteria consisted of patients with other etiologies of liver cirrhosis, e.g., hepatitis B virus and patients with high MELD score on transplant list. All patients were subjected to full medical record, full basic investigations, endoscopy, and computed tomography(CT), and then divided into groups with no varices, small varices, or large risky varices. In addition, values of Fibrosis-4 score(FIB-4), aminotransferase-to-platelet ratio index(APRI), and platelet count/splenic diameter ratio(PC/SD) were also calculated.RESULTS Detection of large varies is a multi-factorial process, affected by many variables. Choosing binary logistic regression, dependent factors were either large or small varices while independent factors included CT variables such coronary vein diameter, portal vein(PV) diameter, lieno-renal shunt and other laboratory noninvasive variables namely FIB-4, APRI, and platelet count/splenic diameter. Receiver operating characteristic(ROC) curve was plotted to determine the accuracy of non-invasive parameters for predicting the presence of large esophageal varices and the area under the ROC curve for each one of these parameters was obtained. A model was established and the best model for prediction of large risky esophageal varices used both PC/SD and PV diameter(75% accuracy), while the logistic model equation was shown to be(PV diameter ×-0.256) plus(PC/SD ×-0.006) plus(8.155). Values nearing 2 or more denote large varices.CONCLUSION This model equation has 86.9% sensitivity and 57.1% specificity, and would be of clinical applicability with 75% accuracy.

Diagnostic sensitivity of imaging modalities for hepatocellular carcinoma smaller than 2 cm

AIM:To compare the imaging results with histology and to evaluate the diagnostic sensitivity of imaging modalities for hepatocellular carcinoma(HCC)smaller than 2 cm.METHODS:Nodules smaller than 2 cm(n=34)revealed by ultrasonography(US)in 29 patients with liver cirrhosis were analyzed.Histological diagnosis of HCC was performed by ultrasonographic guidance:moderately-differentiated HCC(n=24);well-differentiated HCC(n=10).The patterns disclosed by the four imaging modalities defined the conclusive diagnosis of HCC:(1)contrast-enhanced computed tomography(CECT),hypervascularity in the arterial phase and washout in the equilibrium phase;(2)Sonazoid contrast-enhanced US(CEUS),hypervascularity in the early vascular phase and defect in the Kupffer phase;(3)gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid(Gd-EOBDTPA)-enhanced magnetic resonance imaging(MRI),hypervascularity in the arterial phase and/or defect in the hepatobiliary phase;and(4)CT arterioportal angiography:hypervascularity by CT during arteriography and/ or perfusion defect by CT during arterial portography.RESULTS:Overall,the sensitivity of diagnosing HCC smaller than 2 cm was 52.9%(18/34)(95%CI:35.170.2)by CECT;67.6%(23/34)(95%CI:49.5-82.6)by Sonazoid CEUS;76.5%(26/34)(95%CI:58.8-89.3) by Gd-EOB-DTPA MRI;and 88.2%(30/34)(95%CI: 72.5-96.7)by CT arterioportal angiography.The diagnostic sensitivity of detecting moderately-differentiated HCC by CECT,Sonazoid CEUS,Gd-EOB-DTPA MRI and CT arterioportal angiography was 62.5%(15/24)(95%CI: 40.6-81.2),79.2%(19/24)(95%CI:57.8-92.9),75.0% (18/24)(95%CI:53.3-90.2)and 95.8%(23/24)(95% CI:78.9-99.9),respectively.A significant difference(P< 0.05)was observed between CECT and CT arterioportal angiography in all nodules.There was no difference between Sonazoid CEUS,Gd-EOB-DTPA MRI,and CT arterioportal angiography.The combined sensitivity of Sonazoid CEUS and Gd-EOB-DTPA MRI was 94.1%(32/34).CONCLUSION:Changing the main diagnostic modality for HCC smaller than 2 cm from CT arterioportal angiography to Sonazoid CEUS and Gd-EOB-DTPA MRI is recommended.

Diagnostic performance of OCT and OCTA in less than 60-year-old patients with early POAG:a cross-sectional study

AIM:To observe and characterize imaging features of macular and optic disc areas in less than 60-year-old patients with early primary open angle glaucoma(POAG)by optical coherence tomography(OCT)and optical coherence tomography angiography(OCTA),and to evaluate the diagnostic value of OCT and OCTA.METHODS:Totally 15 patients(23 eyes)with early POAG as observation group and 30 health people(30 eyes)as normal control group were enrolled in this cross-sectional study.OCTA-based superficial macula vessel density,superficial macula perfusion density,superficial optic disc vessel density,superficial optic disc perfusion density and spectral domain OCT(SD-OCT)-based macular area thickness,ganglion cell complex(GCC)thickness and retinal nerve fiber layer(RNFL)thickness were measured in the two groups.Independent t-test and receiver operating characteristic curve were used for analysis.Area under the receiver operating characteristic curves(AUROC)were used to measure the diagnostic utility.RESULTS:Among all the parameters,the optimal diagnostic utility parameter was the superficial vessel density in the macular area(except the center of the macula),and the AUROC reached 0.98.The diagnostic utility of macular area perfusion density(except the center of the macula)was similar to that of superficial vessel density in the macular area,and the AUROC was above 0.97.Followed by the diagnostic utility of vessel density in the optic disc area,the best parameter was the inner ring of the vessel density,and its AUROC reached 0.97.The diagnostic utility of perfusion density in the optic disc area was slightly lower than that of vessel density in the optic disc area.The best parameter was the central optic disc perfusion density,and its AUROC was 0.95.The SD-OCT-based diagnostic utility parameters were generally lower than that mentioned above,the top three parameters were the inferior RNFL thickness(AUROC=0.919),the superior(AUROC=0.919)and the inferior GCC thickness(AUROC=0.9077).CONCLUSION:The OCT-based diagnostic utility parameters are generally lower than the OCTA-based diagnostic utility parameters.OCTA has an important clinical application value in diagnosis and evaluation for less than 60-year-old patients with early POAG.

Feasibility and Diagnostic Accuracy for Assessment of Coronary Artery Stenosis of Prospectively Electrocardiogram-gated High-pitch Spiral Acquisition Mode Dual-source CT Coronary Angiography in Patients with Relatively Higher Heart Rates: in Comparison wit

Objective To prospectively investigate the diagnostic accuracy for coronary artery stenosis of prospectively electrocardiogram-triggered spiral acquisition mode (high pitch mode) dual-source computed tomography coronary angiography (CTCA) in patients with relatively higher heart rates (HR) compared with catheter coronary angiography (CCA). Methods Forty-seven consecutive patients with relatively higher HR (>65 and <100 bpm) (20 male, 27 female; age 55±10 years) who both underwent dual-source CTCA and CCA were prospectively included in this study. All patients were performed CTCA using high pitch mode setting at 20%-30% of the R-R interval for the image acquisition. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a three-point scale (1: excellent to 3: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). Considered CCA as the standard of reference, the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Radiation dose values were calculated using the dose-length product. Results Image quality was rated as being score 1 in 92.4% of segments, score 2 in 6.1% of segmentsand score 3 in 1.5% of segments. The average image quality score per segment was 1.064±0.306. The HR variability of patients with image score 1, 2 and 3 were 2.29±1.06 bpm, 5.17±1.37 bpm, 8.88±1.53 bpm, respectively. The average HR variability of patients with different image scores were significantly different (F=170.402, P=0.001). The sensitivity, specificity, positive and negative predictive values were 92.6%, 97.0%, 87.6%, 98.3%, respectively, per segment and 90.0%, 95.2%, 85.3%, 96.9%, respectively, per vessel and 100%, 63.6%, 90.0%, 100%, respectively, per patient. The effective radiation dose was on average 0.86±0.16 mSv. Conclusion In patients with HR more than 65 bpm and below 100 bpm without cardiac arrhythmia, the prospectively electrocardiogram-gated high-pitch spiral acquisition mode with image acquired timing set at 20%-30% of the R-R interval provides a high diagnostic accuracy for the assessment of coronary stenoses combined with a 1.5% of non-diagnostic coronary segments and a radiation dose below 1 mSv.

A new diagnostic model of primary open angle glaucoma based on FD-OCT parameters

AIM： To build a clinical diagnostic model of primary open angle glaucoma （POAG） using the normal probability chart of frequency-domain optical coherence tomography （FD-OCT）. METHODS： This is a cross-sectional study. Total 133 eyes from 133 healthy subjects and 99 eyes from 99 early POAG patients were included in the study. The retinal nerve fibre layer （RNFL） thickness parameters of optic nerve head （ONH） and RNFL3.45 scan were measured in one randomly selected eye of each subject using RTVue-100 FD-OCT. Then, we used these parameters to establish the diagnostic models. Four different diagnostic models based on two different area partition strategies on ONH and RNFL3.45 parameters, including ONH traditional area partition model （ONH-T）, ONH new area partition model （ONH-N）, RNFL3.45 traditional area partition model （RNFL3.45-T） and RNFL3.45 new area partition model （RNFL3.45-N）, were built and tested by cross-validation. RESULTS： The new area partition models had higher area under the receiver operating characteristic （AROC; ONH-N： 0.990; RNFL3.45-N： 0.939） than corresponding traditional area partition models （ONH-T： 0.979; RNFL3.45-T： 0.881）. There was no statistical difference among AROC of ONH-T, ONH-N, and RNFL3.45-N. Nevertheless, ONH-N was the simplest model. CONCLUSION： The new area partition models had higher diagnostic accuracy than corresponding traditional area partition models, which can improve the diagnostic ability of early POAG. In particular, the simplest ONH-N diagnostic model may be convenient for clinical application.

Diagnostic value of18F-FDG PET in the assessment of myocardial viability in coronary artery disease：A comparative study with99mTc SPECT and echocar-diography

ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography （18F-FDG PET） in the as-sessment of myocardial viability in patients with known coronary artery disease （CAD） when compared to99mTc single photon emission computed tomography （SPECT） and echocardiography, with invasive coronary angiography as the gold standard.MethodsThirty patients with diagnosed CAD met the selection criteria, with 10 of them （9 men, mean age 59.5 ± 10.5 years） undergoing all of these imaging proce-dures consisting of SPECT and PET, echocardiography and invasive angiography. Diagnostic sensitivity of these less invasive modalities for detection of myocardial viability was compared to invasive coronary angiography. Inter- and intra-observer agreement was assessed for di-agnostic performance of SPECT and PET.ResultsOf all patients with proven CAD, 50% had triple vessel disease. Diagnostic sensitivity of SPECT, PET and echocardiography was 90%, 100% and 80% at patient-based assessment, respectively. Excellent agreement was achieved between inter-observer and intra-observer agreement of the diagnostic value of SPECT and PET in myocardial viability （k= 0.9）. Conclusion18F-FDG PET has high diagnostic value in the assessment of myocardial viability in patients with known CAD when com-pared to SPECT and echocardiography. Further studies based on a large cohort with incorporation of18F-FDG PET into patient management are warranted.

Diagnostic imaging and radiation exposure in inflammatorybowel disease

Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease(IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography(CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging(MRI) and small intestine contrast enhanced ultrasonography(SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn's disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT.

Tumor-Associated Autoantibodies: Re-Optimization of EarlyCDT-Lung Diagnostic Performance and Its Application to Indeterminate Pulmonary Nodules

Background: Low-dose computed tomography (CT) screening reduces lung cancer mortality but costs are prohibitive for most healthcare budgets due to high false positive rates. An adjunctive test able to distinguish malignant from benign pulmonary nodules would be hugely beneficial. EarlyCDT-Lung measures serum autoantibodies to tumor-associated antigens and has found clinical acceptance to aid early detection of lung cancer for high risk patients. However performance was optimized for screening. The construction of a receiver-operating characteristic (ROC) curve would enable optimization of performance for alternative settings, including nodule malignancy. Methods: A Monte-Carlo search method was used to construct a ROC curve using a case-control cohort, enabling high and low specificity versions of EarlyCDT-Lung to be determined. These were used for a theoretical evaluation of a nodule cohort, and positive predictive value (PPV) was calculated under the assumption of independence of risk source. Patients or their nodules are typically classified into three risk groups: low (0% - 10%), intermediate (10% - 65%) and high (>65%) risk of malignancy. The predicted shift in risk group by application of the high and low specificity versions, along with the current commercial EarlyCDT-Lung, was then estimated. Results: The ROC curve, with an area under the curve of 0.743, was constructed. The high specificity (98%), low specificity (49%) and current commercial (91% specificity) versions of EarlyCDT-Lung re-classified 27%, 23% and 26% of intermediate nodules, respectively, to either a higher (10%, 8% and 10%) or lower (17%, 15% and 16%) risk group. Conclusion: A ROC curve was constructed to allow performance prediction of EarlyCDT-Lung at different specificities in the indeterminate nodule setting. This enabled risk re-classification of intermediate risk nodules, and could therefore facilitate alternative more appropriate intervention. We have shown how a multivariate biomarker test can add to the interpretation of pulmonary nodules and therefore aid patient management.

Hepatocellular carcinoma:State of the art diagnostic imaging

Primary liver cancer is the fourth most common malignancy worldwide,with hepatocellular carcinoma(HCC)comprising up to 90%of cases.Imaging is a staple for surveillance and diagnostic criteria for HCC in current guidelines.Because early diagnosis can impact treatment approaches,utilizing new imaging methods and protocols to aid in differentiation and tumor grading provides a unique opportunity to drastically impact patient prognosis.Within this review manuscript,we provide an overview of imaging modalities used to screen and evaluate HCC.We also briefly discuss emerging uses of new imaging techniques that offer the potential for improving current paradigms for HCC character-ization,management,and treatment monitoring.

COVID-19 imaging:Diagnostic approaches,challenges,and evolving advances

The role of radiology and the radiologist have evolved throughout the coronavirus disease-2019(COVID-19)pandemic.Early on,chest computed tomography was used for screening and diagnosis of COVID-19;however,it is now indicated for high-risk patients,those with severe disease,or in areas where polymerase chain reaction testing is sparsely available.Chest radiography is now utilized mainly for monitoring disease progression in hospitalized patients showing signs of worsening clinical status.Additionally,many challenges at the operational level have been overcome within the field of radiology throughout the COVID-19 pandemic.The use of teleradiology and virtual care clinics greatly enhanced our ability to socially distance and both are likely to remain important mediums for diagnostic imaging delivery and patient care.Opportunities to better utilize of imaging for detection of extrapulmonary manifestations and complications of COVID-19 disease will continue to arise as a more detailed understanding of the pathophysiology of the virus continues to be uncovered and identification of predisposing risk factors for complication development continue to be better understood.Furthermore,unidentified advancements in areas such as standardized imaging reporting,point-of-care ultrasound,and artificial intelligence offer exciting discovery pathways that will inevitably lead to improved care for patients with COVID-19.