The detection of surface patterns by flexible spectral imaging color enhancement without magnification for diagnosis of colorectal polyps

Purpose

Flexible spectral imaging color enhancement (FICE), or image-enhanced endoscopy, can enhance visualization of surface and vascular patterns of colorectal polyps. Resolution of FICE has recently been improved. We evaluated diagnostic accuracy for neoplastic and non-neoplastic colorectal polyp differentiation with detection of surface patterns by FICE without magnification.

Methods

Retrospective analysis of 151 colorectal polyps evaluated by FICE without magnification was performed. Neoplastic surface patterns were defined as tubular and oval pit. We aimed to determine sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy in correlating diagnosis by FICE without magnification with histology. Moreover, findings were compared to those of white-light endoscopy (WL) and chromoendoscopy (CHR).

Results

Of the 151 colorectal polyps, 95 were identified as neoplastic and 56 were identified as non-neoplastic. FICE without magnification had a sensitivity of 89.4%, specificity of 89.2%, PPV of 93.4%, NPV of 83.3%, and accuracy of 89.4%. The accuracy of FICE value was higher than that of WL (sensitivity of 74.7%, specificity of 73.2%, PPV of 82.5%, NPV of 63.0%, and accuracy of 74.1%) and was worse than that of CHR (sensitivity of 96.8%, specificity of 89.2%, PPV of 93.9%, NPV of 96.1%, and accuracy of 94.7%). Imaging evaluation was validated by inter-/intra-observer measurements, demonstrating consistent results.

Conclusions

The detection of surface patterns by FICE without magnification is useful for differential diagnosis of colorectal polyps. We believe that FICE without magnification is more convenient and easier method than CHR.     

Use of a T cell interferon gamma release assay in the investigation for suspected active tuberculosis in a low prevalence area

Background

In settings with low background prevalence of tuberculosis (TB) infection, interferon-γ release assays (IGRA) could be useful for diagnosing active TB. This study aims to evaluate the performance of QuantiFERON^®-TB Gold (QFT-G) in the investigation for suspected active TB, with particular attention to patients originating in high-incidence countries. Furthermore, factors associated with QFT-G results in patients with active TB were assessed.

Methods

From patients investigated for clinically suspected active TB, blood was obtained for QFT-G testing, in addition to routine investigations. Positive (PPV) and negative (NPV) predictive values for QFT-G were calculated, comparing patients with confirmed TB and those with other final diagnoses. QFT-G results in TB patients originating from countries with intermediate or high TB incidence were compared with QFT-G results from a control group of recently arrived asymptomatic immigrants from high-incidence countries. Factors associated with QFT-G outcome in patients with confirmed TB were assessed.

Results

Among 141 patients, 41/70 (58.6%) with confirmed TB had a positive QFT-G test, compared to 16/71 (22.6%) patients with other final diagnoses, resulting in overall PPV of 71.9% and NPV of 67.6%. For patients with pulmonary disease, PPV and NPV were 61.1% and 67.7%, respectively, and 90.5% and 66.7% for subjects with extrapulmonary manifestations. Comparing patients from high-incidence countries with controls yielded a PPV for active TB of 76.7%, and a NPV of 82.7%. Patients with confirmed TB and positive QFT-G results were characterized by a lower median peripheral white blood cell count (5.9 × 10⁹/L vs. 8.8 × 10⁹/L; P < 0.001) and a higher median body mass index (22.7 vs. 20.7; P = 0.043) as compared to QFT-G-negative TB patients.

Conclusion

The overall PPV and NPV of QFT-G for identifying active TB were unsatisfactory, especially for pulmonary disease. Thus, the usefulness of QFT-G for this purpose is questionable. However, a high PPV was observed for extrapulmonary TB and QFT-G might be considered in the diagnostic process in this situation. The PPV and NPV for identifying active TB among persons originating from regions with high-and intermediate TB incidence was similar to that observed in subjects originating in the low-incidence region.     

The diagnostic accuracy and strength of agreement between endoscopic ultrasound and histopathology in the staging of ampullary tumors

Aim

Ampullary tumors are rare. Reports on ampullary tumor staging are heterogeneous and combine both periampullary and ampullary tumors. This study assessed the performance of endoscopic ultrasound (EUS) in the local staging of ampullary tumors only.

Methods

Data were collected retrospectively. We included patients with an ampullary tumor who underwent EUS and surgical resection. Tumor (T) and nodal (N) TNM staging for EUS and histopathological (HP) staging were compared.

Results

From 2009 to 2010, a total of 79 patients with ampullary tumors were identified. Of these, 26 had both EUS and Whipple??s surgery and were included (28 did not undergo resection, 13 had palliative surgery only and 12 had resection without EUS). For T staging by HP, there were 2 (7.7?%) T1, 11 (42.3?%) T2, 12 (46.2?%) T3 and 1 (3.8?%) T4 tumors. The accuracy of EUS T staging was 73.1?% with a Kappa value of 0.564 (p?<?0.0001). The sensitivity, specificity, positive predictive value (PPV), negative predictive values (NPV) of EUS, respectively were 50.0?%, 91.7?%, 33.3?% and 95.7?% for T1 tumors; 81.8?%, 80.0?%, 75.0?% and 85.7?% for T2; 75.0?%, 92.9?%, 90.0?% and 81.3?% for T3 tumors. For N staging by HP, 17 (65.4?%) were N0 and 9 (34.6?%) N1. The N staging diagnostic accuracy was 80.8?% with a Kappa value of 0.586 (p?=?0.003). The sensitivity, specificity, PPV, NPV for N0 disease were 82.4?%, 77.8?%, 87.5?% and 70.0?%, respectively while for N1 they were 77.8?%, 82.4?%, 70.0?% and 87.5?%, respectively.

Conclusions

EUS had a moderate strength of agreement with histopathology for both T and N staging, and a high diagnostic accuracy for nodal staging.     

A Cross-Sectional Study Examining Australian General Practitioners’ Identification of Overweight and Obese Patients

BACKGROUND

Overweight and obese patients attempt weight loss when advised to do so by their physicians; however, only a small proportion of these patients report receiving such advice. One reason may be that physicians do not identify their overweight and obese patients.

OBJECTIVES

We aimed to determine the extent that Australian general practitioners (GP) recognise overweight or obesity in their patients, and to explore patient and GP characteristics associated with non-detection of overweight and obesity.

METHODS

Consenting adult patients (n?=?1,111) reported weight, height, demographics and health conditions using a touchscreen computer. GPs (n?=?51) completed hard-copy questionnaires indicating whether their patients were overweight or obese. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for GP detection, using patient self-reported weight and height as the criterion measure for overweight and obesity. For a subsample of patients (n?=?107), we did a sensitivity analysis with patient-measured weight and height. We conducted an adjusted, multivariable logistic regression to explore characteristics associated with non-detection, using random effects to adjust for correlation within GPs.

RESULTS

Sensitivity for GP assessment was 63 % [95 % CI 57–69 %], specificity 89 % [95 % CI 85–92 %], PPV 87 % [95 % CI 83–90 %] and NPV 69 % [95 % CI 65–72 %]. Sensitivity increased by 3 % and specificity was unchanged in the sensitivity analysis. Men (OR: 1.7 [95 % CI 1.1–2.7]), patients without high blood pressure (OR: 1.8 [95 % CI 1.2–2.8]) and without type 2 diabetes (OR: 2.4 [95 % CI 1.2–8.0]) had higher odds of non-detection. Individuals with obesity (OR: 0.1 [95 % CI 0.07–0.2]) or diploma-level education (OR: 0.3 [95%CI 0.1–0.6]) had lower odds of not being identified. No GP characteristics were associated with non-detection of overweight or obesity.

CONCLUSIONS

GPs missed identifying a substantial proportion of overweight and obese patients. Strategies to support GPs in identifying their overweight or obese patients need to be implemented.     

Inflammatory low back pain: High negative predictive value of contrast‐enhanced color Doppler ultrasound in the detection of inflamed sacroiliac joints

Objective

To determine the value of microbubble contrast agents for color Doppler ultrasound (CDUS) compared with magnetic resonance imaging (MRI) in the detection of active sacroiliitis.

Methods

An observational case‐control study of 103 consecutive patients (206 sacroiliac [SI] joints) with inflammatory low back pain according to the Calin criteria and 30 controls (60 SI joints) without low back pain was conducted at the University Hospital of Innsbruck. All patients and controls underwent unenhanced and contrast‐enhanced CDUS and MRI of the SI joints. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of unenhanced and contrast‐enhanced CDUS were evaluated.

Results

Forty‐three patients (41%) with 70 of 206 SI joints (34%) and none of the controls nor the 60 control SI joints demonstrated active sacroiliitis on MRI. Unenhanced CDUS showed a sensitivity of 17%, a specificity of 96%, a PPV of 65%, and an NPV of 72%; contrast‐enhanced CDUS showed a sensitivity of 94%, a specificity of 86%, a PPV of 78%, and an NPV of 97%. Detection of vascularity in the SI joint was increased by contrast administration (P < 0.0001). Clustered receiver operating curve analysis demonstrated that enhanced CDUS (A_z = 0.89) was significantly better than unenhanced CDUS (A_z = 0.61) for the diagnosis of active sacroiliitis verified by MRI (P < 0.0001; 2‐sided test).

Conclusion

Microbubble contrast‐enhanced CDUS is a sensitive technique with a high NPV for detection of active sacroiliitis compared with MRI.

     

Accuracy of routinely collected comorbidity data in patients undergoing colectomy: a retrospective study

Objectives

This paper aimed to determine the baseline accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of routinely collected comorbidity data in patients undergoing any types of colectomy.

Methods

All patients aged >18 who underwent right hemicolectomy, left hemicolectomy, sigmoid colectomy, subtotal colectomy, or total colectomy between 1 January 2015 and 1 November 2016 were identified. The following comorbidities were considered: hypertension, ischemic heart disease (IHD), diabetes, asthma, chronic obstructive pulmonary disease (COPD), cerebrovascular disease (CVD), chronic kidney disease (CKD), and hypercholesterolemia. The comorbidity data from clinical notes were compared with corresponding data in hospital episode statistics (HES) database in order to calculate accuracy, sensitivity, specificity, PPV, and NPV of HES codes for comorbidities. In order to assess the agreement between clinical notes and HES data, we also calculated Cohen’s kappa index value as a more robust measure of agreement.

Results

Overall, 267 patients comprising 2136 comorbidity codes were included. Overall, HES codes for comorbidities in patients undergoing colectomy had substandard accuracy 94% (kappa 0.542), sensitivity (39%), and NPV (89%). The HES codes were 100% specific with PPV of 100%. The results were consistent when individual comorbidities were analyzed separately.

Conclusions

Our results demonstrated that HES comorbidity codes in patients undergoing colectomy are specific with good positive predictive value; however, they have substandard accuracy, sensitivity, and negative predictive value. Better documentation of comorbidities in admission clerking proforma may help to improve the quality of source documents for coders, which in turn may improve the accuracy of coding.

     

Diagnostic value of biochemical markers (NashTest) for the prediction of non alcoholo steato hepatitis in patients with non-alcoholic fatty liver disease

Background

Liver biopsy is considered the gold standard for assessing histologic lesions of non-alcoholic fatty liver disease (NAFLD). The aim was to develop and validate a new biomarker of non alcoholic steato hepatitis (NASH) the NashTest (NT) in patients with NAFLD.

Methods

160 patients with NAFLD were prospectively included in a training group, 97 were included in a multicenter validation group and 383 controls. Histological diagnoses used Kleiner et al's scoring system, with 3 classes for NASH: "Not NASH", "Borderline", "NASH"). The area under the ROC curves (AUROC), sensitivity (Se), specificity (Sp), and positive and negative predictive values (PPV, NPV) were assessed.

Results

NT was developed using patented algorithms combining 13 parameters: age, sex, height, weight, and serum levels of triglycerides, cholesterol, alpha2macroglobulin, apolipoprotein A1, haptoglobin, gamma-glutamyl-transpeptidase, transaminases ALT, AST, and total bilirubin. AUROCs of NT for the diagnosis of NASH in the training and validation groups were, respectively, 0.79 (95%CI 0.69–0.86) and 0.79 (95%CI 0.67–0.87; P = 0.94); for the diagnosis of borderline NASH they were: 0.69 (95%CI 0.60–0.77) and 0.69 (95%CI 0.57–0.78; P = 0.98) and for the diagnosis of no NASH, 0.77 (95%CI 0.68–0.84) and 0.83 (95%CI 0.67–0.90; P = 0.34). When the two groups were pooled together the NashTest Sp for NASH = 94% (PPV = 66%), and Se = 33% (NPV = 81%); for borderline NASH or NASH Sp = 50% (PPV = 74%) and Se = 88% (NPV = 72%).

Conclusion

In patients with non-alcoholic fatty liver disease, NashTest, a simple and non-invasive biomarker reliably predicts the presence or absence of NASH.     

Modified STOP-BANG questionnaire to predict obesity hypoventilation syndrome in obese subjects with obstructive sleep apnea

Purpose

The STOP-BANG questionnaire (SBQ) has never been studied in the context of its ability to predict obesity hypoventilation syndrome (OHS). Our aim was to evaluate the predictive performance of the original and modified SBQs for OHS in obese subjects with obstructive sleep apnea (OSA).

Methods

Demographics, polysomnographic data, body mass index (BMI), Epworth Sleepiness Scale (ESS) scores, arterial blood gases, spirometric measurements, and SBQ scores were recorded. The modified SBQ was created by dividing BMI into ranges and adding the serum bicarbonate ranges.

Results

The study included 196 obese subjects, of whom 17 had normal polysomnography. Of the remaining subjects, 105 had pure OSA and 74 had OHS with OSA. Both the original and modified SBQs scores were higher for the OHS subjects than for those with pure OSA (p?<?0.001). An original SBQ score of ≥6 gave a satisfactory discrimination for OHS diagnosis (sensitivity 71.6 %, specificity 59.1 %, positive predictive value (PPV) 55.2 %, and negative predictive value (NPV) 74.7 %). The diagnostic OR for an original SBQ score of ≥6 for predicting OHS was 3.7. The sensitivity and NPV were increased for the modified SBQ (sensitivity 89.2 %, specificity 47.6 %, PPV 54.6 %, NPV 86.2 %), and the OR was 7.5. Both the original and modified SBQ scores were moderately correlated with ESS, AHI, ODI, lowest SpO₂, and sleep time spent with SpO₂ <90 %.

Conclusions

The modified SBQ can be used to screen for OHS in obese subjects.

     

Liver stiffness measurement by acoustic radiation force impulse is useful in predicting the presence of esophageal varices or high-risk esophageal varices among patients with HCV-related cirrhosis

Background

Screening and periodic surveillance for esophageal varices (EVs) by esophagogastroduodenoscopy (EGD) are recommended for cirrhotic patients. We investigated non-invasive liver stiffness measurement using acoustic radiation force impulse (ARFI) for the diagnosis of EV presence and high-risk EVs among patients with HCV-related cirrhosis.

Methods

Among 181 consecutive patients with HCV-related cirrhosis, we studied 135 patients who had received EGD and ARFI. Serum fibrosis markers [platelet count, FIB-4, and aspartate aminotransferase-to-platelet ratio index (APRI)] were measured in a training set of 92 patients and compared with ARFI in the diagnostic performance for EV presence and high-risk EVs. Furthermore, the obtained optimal cutoff values of ARFI were prospectively examined in a validation set of 43 patients.

Results

In the training set, the ARFI value increased with the EV grade (p < 0.001). The ARFI value for high-risk EVs was significantly higher than that for low-risk EVs (p < 0.001). AUROC values for diagnosis of EV presence and high-risk EVs by ARFI were 0.890 and 0.868, which had the highest diagnostic performance among factors including serum fibrosis markers. The optimal cutoff value of ARFI for EV presence was 2.05 m/s with good sensitivity (83 %), specificity (76 %), PPV (78 %), and NPV (81 %), and that for high-risk EVs was 2.39 m/s with good sensitivity (81 %), specificity (82 %), PPV (69 %), and NPV (89 %). These cutoff values obtained in the training cohort also showed excellent performance in the validation set.

Conclusions

Liver stiffness measurement by ARFI is useful in predicting EV presence or high-risk EVs among patients with HCV-related cirrhosis.     

Role of surface electrocardiogram precordial leads in localizing different anatomic sites of ectopic atrial tachycardia arising from lower right atrium in pediatric population

Background

The study was designed to examine P wave morphology (PWM) in precordial leads (V₁–V₆) during ectopic atrial tachycardia (EAT) originating from low right atrium (RA) to identify the anatomic sites of these foci in children.

Methods

Twenty‐three consecutive pediatric patients (56% females, mean age 8.5 ± 2.5) with EAT originating from the low RA underwent detailed atrial endocardial activation mapping and radiofrequency ablation. PWM during EAT was analyzed using standard 12‐lead ECG in relation to successful ablation sites in RA.

Results

Ectopic atrial tachycardia originated from coronary sinus ostium (CSo) in 12 patients, nonseptal tricuspid annulus (TA) in five, lower crista terminalis (CT) in three and lower free wall in three. In lead V₁, PWM showed a positive pattern during EAT originating from CSo (8/12) [91.7% sensitivity, 100% specificity, 100% positive predictive value (PPV), 100% negative predictive value (NPV)]. A negative pattern was observed in EAT originating from lower free wall (1/3) and nonseptal TA (5/5) [50% sensitivity, 100% specificity, 100% PPV, 75% NPV], while isoelectric pattern was in EAT originating from lower CT (3/3) [100% sensitivity, 100% specificity, 100% PPV, 100% NPV]. In leads V₃–V₆, PWM showed a negative pattern in at least two consecutive leads during EAT from CSo (12/12), nonseptal TA (5/5) and lower free wall (3/3) while it was positive in EAT originating from lower CT (3/3) [100% sensitivity, 95% specificity, 75% PPV and 100% NPV].

Conclusions

P wave morphology in precordial leads can help differentiate the anatomic sites of EAT from lower RA with high PPVs and NPVs.

     

The Validity of HCC Diagnosis Codes in Chronic Hepatitis B Patients in the Veterans Health Administration

Background

Administrative databases that include diagnostic codes are valuable sources of information for research purposes.

Aim

To validate diagnostic codes for hepatocellular carcinoma (HCC) in chronic hepatitis B patients.

Methods

We conducted a retrospective study of patients with chronic HBV seen in the national Veterans Administration (VA). HCC cases were identified by the presence of ICD-9 code 155.0. We randomly selected 200 HBV controls without this code as controls. We manually reviewed the electronic medical record (EMR) of all cases and controls to determine HCC status. We calculated the positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity for the HCC code. We conducted an implicit review of the false-positive cases to determine possible reasons for the miscoding.

Results

Of the 8350 patients with HBV, 416 had an ICD-9 code for HCC. Of these 416, 332 patients had confirmed HCC and 61 did not; HCC status was indeterminate for 23 patients. Of the 200 controls, none had HCC confirmed in the EMR. The PPV ranged from 85.3 to 80.0% and specificity ranged from 99.2 to 99.0% based on classification of indeterminate cases as true versus false positives, respectively. The NPV, sensitivity, and specificity were 100%. Two-thirds of false-positive cases were diagnosed with HCC prematurely as a workup of liver mass and latter imaging and/or biopsy were not diagnostic for HCC.

Conclusion

The diagnostic code of HCC in chronic HBV patients in the VHA data is predictive of the presence of HCC in medical records and can be used for epidemiological and clinical research.

     

Administrative billing codes accurately identified occurrence of electrical cardioversion and ablation/maze procedures in a prospective cohort study of atrial fibrillation patients

Background

Administrative billing codes for electrical cardioversion and ablation/maze procedures may be useful for atrial fibrillation (AF) research if the codes are accurate relative to medical record documentation.

Hypothesis

Administrative billing codes accurately identify occurrence of electrical cardioversion and ablation/maze procedures in AF patients.

Methods

We studied adults ages 30 to 84 who experienced new‐onset AF between October 2001 and December 2004 in Group Health Cooperative (acquired by Kaiser Permanente in 2017), an integrated healthcare system in Washington state and northern Idaho. Using medical record review as the gold standard, we calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for 3 administrative billing codes for electrical cardioversion and 3 codes for AF ablation/maze procedures.

Results

Of 1953 study participants, during a mean (SD) of 1.5 (0.7) years of follow‐up after AF onset, 470 (24%) experienced electrical cardioversion and 44 (2%) experienced ablation/maze procedures, according to medical record review. For electrical cardioversion, individual codes had 7.7% to 76.4% sensitivity, >99% specificity, 83.7% to 96.5% PPV, and 77.3% to 93.0% NPV. Considering any of 3 codes (code 1 or code 2 or code 3) improved sensitivity to 84.9%. For ablation/maze, individual codes had 18.2% to 47.7% sensitivity, >99% specificity, 66.7% to 95.5% PPV, and >98% NPV. Considering any of 3 codes improved sensitivity to 84.1%.

Conclusions

Administrative billing data accurately identified electrical cardioversion and ablation/maze procedures and can be used instead of medical record review. Our findings apply to healthcare settings with available administrative billing databases.

     

Superiority of the DNA Amplification Assay for the Diagnosis of C. difficile Infection: A Clinical Comparison of Fecal Tests

Background

Clostridium difficile infection (CDI) is a major infectious concern, accounting for substantial morbidity and resource utilization. Advances in microbiological and molecular techniques have resulted in an increasing number of testing options for CDI. A glutamate dehydrogenase (GDH) enzyme immunoassay (EIA) and a DNA amplification (DNA-A) test for the diagnosis of CDI have recently become commercially available.

Aims

The aim of this prospective study was to compare the test performance characteristics of the traditional diagnostic modality for CDI diagnosis, the toxin A/B (TOX) EIA, with those of the GDH EIA and DNA-A test, utilizing enriched toxigenic culture (TGC) as the gold standard. Clinical variables predictive of CDI were also studied.

Methods

Participants fulfilled one or more criteria placing them at increased risk for CDI. Each stool sample was tested by each of the methods mentioned above. Clinical data parameters were collected via a 12-month review of the electronic medical record prior to the index date of the first stool test.

Results

A total of 272 stool samples from 144 admissions of 139 patients were evaluated for CDI. The sensitivity and positive predictive value (PPV) of the TOX EIA were 86.1 and 58.4?%, respectively, whereas the sensitivity and PPV of the GDH EIA and DNA-A test were 100?%. 1.8?% of the GDH tests yielded inconclusive results. Using TGC as the gold standard, nosocomial exposure with emphasis on nursing home residence, history of previous CDI, and female gender were predictive of CDI.

Conclusions

Test performance characteristics of the DNA-A test and GDH EIA were superior to those of the traditional TOX EIA. The GDH test is limited by inconclusive test results and requires a multi-step diagnostic algorithm. Therefore, the DNA-A test should be implemented as the diagnostic method of choice for CDI. CDI clinical predictors are important for diagnostic decision-making.     

The clinical utility of tuberculin skin test and interferon-γ release assay in the diagnosis of active tuberculosis among young adults: a prospective observational study

Background

The roles of the tuberculin skin test (TST) and QuantiFERON^®-TB Gold In-Tube assay (QFT-IT) in the diagnosis of active tuberculosis (TB) are not clear in young adults. We evaluated the diagnostic accuracy of the TST and QFT-IT in smear-negative TB among young adults with no underlying disease.

Methods

We prospectively enrolled 166 young participants 20-29 years of age with suspected active TB in a military hospital of South Korea. The TST and QFT-IT were performed for all participants.

Results

Of the 143 patients included in the analysis, active TB was diagnosed in 100 (69.9%). There were 141 male patients, none of whom had immunosuppressive disease. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TST were 94% (95% CI, 87-98%), 88% (95% CI, 74-96%), 95% (95% CI, 88-98%), and 86% (95% CI, 72-94%), respectively. The sensitivity, specificity, PPV, and NPV of the QFT-IT were 93% (95% CI, 86-97%), 95% (95% CI, 81-99%), 98% (95% CI, 92-99%), and 84% (95% CI, 69-93%), respectively. No significant differences were found between the TST and QFT-IT in any statistic.

Conclusions

Both the TST and QFT-IT showed high sensitivity and specificity in differentiating active TB from other diseases. The diagnostic accuracy of these two tests did not differ significantly when applied to this clinical population of young, immunocompetent adults in whom neonatal BCG vaccination was common, there was no history of previous TB and in whom suspicion of TB was high.

Trial registration

ClinicalTrials.gov: NCT00982969

     

Diagnostic value of FDG-PET/CT for lateral pelvic lymph node metastasis in rectal cancer treated with preoperative chemoradiotherapy

Background

The aim of this study was to elucidate the diagnostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography (PET)–computed tomography (CT) for lateral pelvic lymph node (LPN) metastasis in rectal cancer treated with preoperative chemoradiotherapy (CRT).

Methods

Eighteen rectal cancer patients with enlarged (≥?8 mm) LPNs were treated with CRT followed by total mesorectal excision with LPN dissection during 2012–2015. After CRT, LPN maximum standard uptake values (SUVmax) were measured using PET/CT and long diameters of LPNs were measured using CT or magnetic resonance imaging (MRI). LPN size and SUVmax were compared with pathological status in the resected specimen. Radiologically identified nodes were matched with surgically resected nodes by separate examination of 4 lymph nodal regions: internal iliac, obturator, external iliac and common iliac lymph nodes.

Results

In total, 34 LPNs were located by CT or MRI. Metastatic LPNs were significantly larger than non-metastatic LPNs (size, mean?±?standard deviation: 13.0?±?8.3 vs. 4.9?±?3.5 mm, p?<?0.01). SUVmax was determinable for 28 of the LPNs, among which metastatic LPNs were found to have significantly higher SUVmax than non-metastatic LPNs (mean?±?standard deviation: 2.2?±?1.3 vs. 1.2?±?0.3, p?<?0.01). Receiver operating characteristic analysis suggested optimal cutoff values of size?=?12 mm which had an accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 82.1, 70.6, 100, 100, and 68.8%, respectively. An SUVmax?=?1.6 had an accuracy, sensitivity, specificity, PPV, and NPV of 85.7, 76.5, 100, 100, and 73.3%, respectively. When LPNs that were?≥?12 mm in size and/or had an SUV?≥?1.6, the accuracy, sensitivity, specificity, PPV, and NPV were 92.9, 88.2, 100, 100, and 84.6%, respectively.

Conclusions

After CRT, PET/CT alone or in combination with CT and MRI can predict the presence of metastatic LPN with a high degree of accuracy. PET/CT may be useful in selecting patients with rectal cancer who would benefit from LPN dissection in addition to TME. These results need to be confirmed by larger studies.

     

Diagnostic value of biochemical markers (FibroTest-FibroSURE) for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease

Background

Liver biopsy is considered as the gold standard for assessing non-alcoholic fatty liver disease (NAFLD) histologic lesions. The aim of this study was to determine the diagnostic utility of non-invasive markers of fibrosis, validated in chronic viral hepatitis and alcoholic liver disease (FibroTest, FT), in patients with NAFLD.

Methods

170 patients with suspected NAFLD were prospectively included in a reference center (Group 1), 97 in a multicenter study (Group 2) and 954 blood donors as controls. Fibrosis was assessed on a 5 stage histological scale validated by Kleiner et al from F0 = none, F1 = perisinusoidal or periportal, F2 = perisinusoidal and portal/periportal, F3 = bridging and F4 = cirrhosis. Histology and the biochemical measurements were blinded to any other characteristics. The area under the ROC curves (AUROC), sensitivity (Se), specificity (Sp), positive and negative predictive values (PPV, NPV) were assessed.

Results

In both groups FT has elevated and not different AUROCs for the diagnosis of advanced fibrosis (F2F3F4): 0.86 (95%CI 0.77–0.91) versus 0.75 (95%CI 0.61–0.83; P = 0.10), and for F3F4: 0.92 (95%CI 0.83–0.96) versus 0.81 (95%CI 0.64–0.91; P = 0.12) in Group1 and Group 2 respectively. When the 2 groups were pooled together a FT cutoff of 0.30 had a 90% NPV for advanced fibrosis (Se 77%); a FT cutoff of 0.70 had a 73% PPV for advanced fibrosis (Sp 98%).

Conclusion

In patients with NAFLD, FibroTest, a simple and non-invasive quantitative estimate of liver fibrosis reliably predicts advanced fibrosis.     

A dynamic estimation of the daily cumulative cases during infectious disease surveillance: application to dengue fever

Background

To control multidrug resistant tuberculosis (MDR-TB), the drug susceptibility profile is needed to guide therapy. Classical drug susceptibility testing (DST) may take up to 2 to 4 months. The GenoType^® MTBDR plus test is a commercially available line-probe assay that rapidly detects Mycobacterium tuberculosis (MTB) complex, as well as the most common mutations associated with rifampin and isoniazid resistance. We assessed sensitivity and specificity of the assay by using a geographically representative set of MTB isolates from the South of Vietnam.

Methods

We re-cultured 111 MTB isolates that were MDR, rifampin-resistant or pan-susceptible according to conventional DST and tested these with the GenoType^® MTBDR plus test.

Results

By conventional DST, 55 strains were classified as MDR-TB, four strains were rifampicin mono-resistant and 52 strains were susceptible to all first-line drugs. The sensitivity of the GenoType^® MTBDR plus was 93.1% for rifampicin, 92.6% for isoniazid and 88.9% for the combination of both; its specificity was 100%. The positive predictive value of the GenoType^® MTBDR plus test for MDR-TB was 100% and the negative predictive value 90.3%.

Conclusions

We found a high specificity and positive predictive value of the GenoType^® MTBDR plus test for MDR-TB which merits its use in the MDR-TB treatment program in Vietnam.     

Algorithm to determine the outcome of patients with acute liver failure: a data-mining analysis using decision trees

Background

We established algorithms to predict the prognosis of acute liver failure (ALF) patients through a data-mining analysis, in order to improve the indication criteria for liver transplantation.

Methods

The subjects were 1,022 ALF patients seen between 1998 and 2007 and enrolled in a nationwide survey. Patients older than 65?years, and those who had undergone liver transplantation and received blood products before the onset of hepatic encephalopathy were excluded. Two data sets were used: patients seen between 1998 and 2003 (n=698), whose data were used for the formation of the algorithm, and those seen between 2004 and 2007 (n=324), whose data were used for the validation of the algorithm. Data on a total of 73 items, at the onset of encephalopathy and 5?days later, were collected from 371 of the 698 patients seen between 1998 and 2003, and their outcome was analyzed to establish decision trees. The obtained algorithm was validated using the data of 160 of the 324 patients seen between 2004 and 2007.

Results

The outcome of the patients at the onset of encephalopathy was predicted through 5 items, and the patients were classified into 6 categories with mortality rates between 23% and89%. When the prognosis of the patients in the categories with mortality rates greater than 50% was predicted as “death”, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the algorithm were 79, 78, 81, 83, and 75%, respectively. Similar high values were obtained when the algorithm was employed in the patients for validation. The outcome of the patients 5?days after the onset of encephalopathy was predicted through 7 items, and a similar high accuracy was found for both sets of patients.

Conclusions

Novel algorithms for predicting the outcome of ALF patients may be useful to determine the indication for liver transplantation.     

Prediction of lateral pelvic lymph node metastasis from lower rectal cancer using magnetic resonance imaging and risk factors for metastasis: Multicenter study of the Lymph Node Committee of the Japanese Society for Cancer of the Colon and Rectum

Purpose

The goal of the study was to examine prediction of lateral pelvic lymph node (LPLN) metastasis from lower rectal cancer using a logistic model including risk factors for LPLN metastasis and magnetic resonance imaging (MRI) clinical LPLN (cLPLN) status, compared to prediction based on MRI alone.

Methods

The subjects were 272 patients with lower rectal cancer who underwent MRI prior to mesorectal excision combined with LPLN dissection (LPLD) at six institutes. No patients received neoadjuvant therapy. Prediction models for right and left pathological LPLN (pLPLN) metastasis were developed using cLPLN status, histopathological grade, and perirectal lymph node (PRLN) status. For evaluation, data for patients with left LPLD were substituted into the right-side equation and vice versa.

Results

Left LPLN metastasis was predicted using the right-side model with accuracy of 86.5%, sensitivity 56.4%, specificity 92.7%, positive predictive value (PPV) 61.1%, and negative predictive value (NPV) 91.2%, while these data using MRI cLPLN status alone were 80.4, 76.9, 81.2, 45.5, and 94.5%, respectively. Similarly, right LPLN metastasis was predicted using the left-side equation with accuracy of 83.8%, sensitivity 57.8%, specificity 90.4%, PPV 60.5%, and NPV 89.4%, and the equivalent data using MRI alone were 78.4, 68.9, 80.8, 47.7, and 91.1%, respectively. The AUCs for the right- and left-side equations were significantly higher than the equivalent AUCs for MRI cLPLN status alone.

Conclusions

A logistic model including risk factors for LPLN metastasis and MRI findings had significantly better performance for prediction of LPLN metastasis compared with a model based on MRI findings alone.

     

Transperineal ultrasound compared to evacuation proctography for diagnosing enteroceles and intussusceptions

Introduction

This study concerns the level of agreement between transperineal ultrasound and evacuation proctography for diagnosing enteroceles and intussusceptions.

Method

In a prospective observational study, 50 consecutive women who were planned to have an evacuation proctography underwent transperineal ultrasound too. Sensitivity, specificity, positive (PPV) and negative predictive value, as well as the positive and negative likelihood ratio of transperineal ultrasound were assessed in comparison to evacuation proctography. To determine the interobserver agreement of transperineal ultrasound, the quadratic weighted kappa was calculated. Furthermore, receiver operating characteristic curves were generated to show the diagnostic capability of transperineal ultrasound.

Results

For diagnosing intussusceptions (PPV 1.00), a positive finding on transperineal ultrasound was predictive of an abnormal evacuation proctography. Sensitivity of transperineal ultrasound was poor for intussusceptions (0.25). For diagnosing enteroceles, the positive likelihood ratio was 2.10 and the negative likelihood ratio, 0.85. There are many false-positive findings of enteroceles on ultrasonography (PPV 0.29). The interobserver agreement of the two ultrasonographers assessed as the quadratic weighted kappa of diagnosing enteroceles was 0.44 and that of diagnosing intussusceptions was 0.23.

Conclusion

An intussusception on ultrasound is predictive of an abnormal evacuation proctography. For diagnosing enteroceles, the diagnostic quality of transperineal ultrasound was limited compared to evacuation proctography.