Non-detection Rate Research Articles

Lessons Learned and Outcomes from Risk-Based Modernisation of Post-Mortem Inspection and Disposition Criteria of Beef, Sheep, Goat, and Pig Carcasses in Australia.

The lessons learned from reviewing national risk assessments to modernise the Australian Standard for the post-mortem inspection and disposition judgement of beef, sheep, goat, and pig carcases are discussed. The initial risk profiles identified priorities for quantitative assessments. Broadly, the main difficulty encountered was the paucity of quantified performance for the current inspection. Resolving this involved acquiring gross abnormality data representing regional production/proportional abattoir volumes, the range of gross abnormalities appearing nationally, proportional occurrence at carcase sites, and seasonality to enable the comparison of procedures. The methodologies followed the Codex Alimentarius Commission's risk assessment guidelines and are fully documented in the associated publications. The evidence and discussion are provided for the associated challenges experienced, including preventing contamination, the use of food chain information to support amendment, inspection as a part of industry Quality Assurance programmes, and opportunities to improve inspector training. The criteria considered by the Competent Authority for the determination of the equivalence of alternative post-mortem inspection techniques included comparisons of public health risk, non-detection rates for gross abnormalities, and microbial contamination resulting from inspection activities, as appropriate. Most of the gross abnormalities detected arose from animal health and welfare conditions affecting wholesomeness and did not present as food safety hazards. The non-detection rates between the current and alternative inspection (observation) were negligible. A quantitative risk assessment for Cysticercus bovis was conducted. Carcases with multiple gross abnormalities predominantly reflected historic infections (prior septicaemia), where trimming achieved wholesomeness unless they were cachexic.

Sufficient Reduction Method for Bivariate Zero-Inflated Poisson Process

The sufficient reduction (SR) method was developed for detecting a mean shift in a bivariate zero-inflated Poisson process. The derived sequence of statistics from the reduction was monitored with the EWMA and EWMA-SN charts for monitoring a mean shift in a process. The detection performance was compared against other SR methods developed for a Poisson process and evaluated via the simulations under the different shift sizes and proportions of zero in the process. The results showed that the presence of zeros in the process influenced the performance of SR methods by delaying shift detection and reducing the detection accuracy, especially when shift size was small. The proposed method with the EWMA chart gave the shortest delay for detecting a small to moderate shift and gave the highest true alarm rate and the lowest non-detection rate for detecting a small shift compared to other methods.

Rate of Missed Intracranial Colloid Cysts on MRI and CT.

Intracranial colloid cysts of the third ventricle are rare; however, they may be symptomatic. They can create a mass effect on the foramina of Monro, resulting in acute hydrocephalus. Colloid cysts are detectable on CT and MRI but are commonly missed. In this paper, we investigate the rate of missed colloid cysts on MRI and/or CT imaging within our multihospital metropolitan medical group. A retrospective, institutional review board-approved search of the network-wide picture archiving and communication system (PACS) from January 1, 2010, to October 31, 2020, was performed to identify reports including a "colloid cyst" in MRI brain or CT head imaging. Results without imaging and/or surgical confirmation of intracranial colloid cysts were excluded, rendering 229 cases. A PACS review of these cases was performed by two neuroradiologists to determine instances where the cyst had previously been imaged but not diagnosed on either CT or MRI. Two hundred twenty-nine subjects had confirmed colloid cysts through imaging and/or surgical reports. Of these, 46 had prior imaging depicting a colloid cyst either on CT and/or MRI without mention on the interpretative report, resulting in a non-detection rate of 20.1%. Intracranial colloid cysts can be missed at a considerably high rate, which is concerning given their clinically unpredictable nature and ability to cause significant morbidity and mortality. As such, it is important to take a proactive approach to searching for these cysts as part of a regular imaging search pattern and to continue to determine new methods of increasing detection sensitivity.

Statistical methods for handling nondetected results in food chemical monitoring data to improve food risk assessments.

Chemical risk assessment is important for risk management, and estimates of chemical exposure must be as accurate as possible. Chemical concentrations in food below the limit of detection are known as nondetects and result in left-censored data. During statistical analysis, the method used for handling values below the limit of detection is important. Many risk assessors employ widely used substitution methods to treat left-censored data, as recommended by international organizations. The National Institute of Food and Drug Safety Evaluation of South Korea also recommends these methods, which are currently used for chemical exposure assessments. However, these methods have statistical limitations, and international organizations recommend more advanced alternative statistical approaches. In this study, we assessed the validity of currently used statistical methods for handling nondetects. To identify the most suitable statistical method for handling nondetection, we created virtual data and conducted simulation studies. Based on both simulation and case studies, the Maximum Likelihood Estimation (MLE) and Robust Regression on Order Statistics (ROS) methods were found to be the best options. The statistical values obtained from these methods were similar to those obtained from the commonly used 1/2 Limit of Detection (LOD) substitution method for nondetection treatment. In three case studies, we compared the various methods based on the root mean squared error. The data for all case studies were from the same source, to avoid heterogeneity. Across various sample sizes and nondetection rates, the mean and 95th percentile values for all treatment methods were similar. However, "lognormal maximum likelihood estimation" method was not suitable for estimating the mean. Risk assessors should consider statistical processing of monitoring data to reduce uncertainty. Currently used substitution methods are effective and easy to apply to large datasets with nondetection rates <80%. However, advanced statistical methods are required in some circumstances, and national guidelines are needed regarding their use in risk assessments.

Grayscale ultrasound feature typing of metastatic ovarian tumors, particularly signet-ring cell carcinoma

To describe grayscale ultrasound (US) features of metastatic ovarian tumors (MOTs) based on origin of the primary tumor in a large sample size study. This retrospective cross-sectional single-center study included 112 patients with 190 histopathologically confirmed MOTs. Among the patients, 102 collectively had 144 masses, which were detected via US. The clinical data and static US images of MOTs were collected. The MOTs were mostly bilateral (78.9%) but had a lower rate of bilaterality when detected by US (55.6%). Breast cancer metastasis had the highest nondetection rate (69.6%), because its focal metastasis could only be recognized using histology or immunohistochemistry. The stomach was the most common origin of metastasis (45.3% and 50.7% detected via pathology and US, respectively). The US images were classified into three subtypes: multilocular solid (Type A), purely solid (Type B), and solid with several round or oval cysts (Type C). The MOTs that originated from the colon mostly belonged to Type A (65.1%) and closely mimicked primary epithelial ovarian tumor morphologically. The MOTs that originated from the stomach predominantly belonged to Types B (31.5%) and C (57.5%). Signet-ring cell carcinoma (SRCC) corresponded to Types B and C regardless of origin. The developed novel typing method provides more vivid images for classifying MOTs compared with existing typing methods. Given that no specific sonographic parameters have been established to distinguish MOTs from primary invasive ovarian tumors, these images may be helpful in diagnosing these masses.

Statistical Methods for Handling Nondetected Results in Food Chemical Monitoring Data to Improve Food Risk Assessments

Chemical risk assessment is important for risk management, and estimates of chemical exposure must be as accurate as possible. Chemical concentrations in food below the limit of detection are known as nondetects and result in leftcensored data. During statistical analysis, the method used for handling values below the limit of detection is important. Many risk assessors employ widely used substitution methods to treat left-censored data, as recommended by international organizations. The National Institute of Food and Drug Safety Evaluation of South Korea also recommend these methods, which are currently used for chemical exposure assessments. However, these methods have statistical limitations, and international organizations recommend more advanced alternative statistical approaches. In this study, we assessed the validity of currently used statistical methods for handling nondetects. The best method was determined based on a simulation study. In three case studies, we compared the various methods based on the root mean squared error. The data for all case studies were from the same source, to avoid heterogeneity. Across various sample sizes and nondetection rates, the mean and 95th percentile values for all treatment methods were similar. However, “log normal maximum likelihood estimation” method was not suitable for estimating the mean. Risk assessors should consider statistical processing of monitoring data to reduce uncertainty. Currently used substitution methods are effective and easy to apply to large data sets with nondetection rates &lt; 80%. However, advanced statistical methods are required in some circumstances, and national guidelines are needed regarding their use in risk assessments.

Maintaining Antiviral Efficacy after Switching to Generic Entecavir 1 mg for Antiviral-resistant Chronic Hepatitis B

Other SectionsAbstractINTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONACKNOWLEDGEMENTFinancial supportConflict of interestFiguresTablesReferences

Sentinel Lymph Node Biopsy for Early Stage Endometrial and Cervical Cancer Performed By Surgeons in Training

Study Objective The aim of this study was to evaluate the results of the sentinel lymph node (SLN) biopsy performed by doctors in training. Design Prospective single-armed interventional study. Setting All sequential patients treated in a referral cancer center, from 2016 to 2020. IRB approved. Patients or Participants 126 patients, over 18y.o., with a prior diagnosis of initial endometrial (EC) or cervical (CC) cancer. Interventions Patients were submitted to SLN biopsy performed by surgical oncology residents or gynecologic oncology fellows, under direct supervision of a qualified preceptor. SLN was detected with blue dye with or without scintigraphy. Measurements and Main Results Patients underwent surgery by laparotomy - 22 surgeries (17.46%), by laparoscopy - 86 (81.13%) and by robotic - 18 (16.98%). SLN detection rate was 84.1% (n=106), bilateral in 53% (n=67) and mostly in younger patients (59.7% under 60y.o., p=0.022). There was a higher failure rate (non or unilateral detection) among older than 60y.o. (p=0.0075, CI:0.1656-0.7928, OR:0.3664). Among non-smokers, there was a greater bilateral detection of LNS (60.3%), and, among smokers, more cases of detection failure (59.4%). In 3 cases, the SLN was not identified, and there were positive pelvic nodes in the lymphadenectomy. There were no cases with positive nodes at lymphadenectomy with a negative SLN (false-negative). Mean surgical time was 217min and mean blood loss 116cc. Four patients had grade 3 complications, and none died. Conclusion We have demonstrated that residents and fellows can safely perform SLN biopsy for initial CC and EC under the direct supervision of a trained surgeon. Detection rates were aligned to the literature, and there were no false negatives. Lymph node positivity, age over 60y.o. and smoking were associated with a higher SLN non-detection rate.

Contributions of Liquid-Based (Papanicolaou) Cytology and Human Papillomavirus Testing in Cotesting for Detection of Cervical Cancer and Precancer in the United States.

ObjectivesGiven the recent debate challenging the contribution of cytology in cervical screening, we evaluated results of liquid-based cytology (LBC) and human papillomavirus (HPV) testing in cotesting preceding cervical cancer (CxCa) and precancer diagnoses in a national, heterogeneous population.MethodsWe assessed the results of cotesting, performed by Quest Diagnostics, in 13,633,071 women 30 years and older, tested 2010 to 2018. Cotest results preceding CxCa or precancer diagnoses were analyzed and stratified by histopathology.ResultsAmong all screening results, 1,615 cotests preceded 1,259 CxCa diagnoses, and 11,164 cotests preceded 8,048 cervical precancer diagnoses. More women who were subsequently diagnosed with CxCa within 1 year were identified by the LBC result than by the HPV result (85.1%, 1,015/1,193 vs 77.5%, 925/1,193). Among all women with CxCa, the overall rate of nondetection was 13.1% (212/1,615) for cotesting results (LBC negative/HPV negative) and this rate increased substantially when testing exceeded 12 months compared to within 1 year prediagnosis of either CxCa or precancer.ConclusionsAnalysis of 9-year cotest results from a national reference laboratory confirms the value of LBC element in cotesting. This supports that LBC/HPV cotesting enhances screening for the identification of CxCa in women 30 years and older, more so than LBC or HPV alone within cotesting.

Validation of a 2-gene mRNA urine test for the detection of ≥GG2 prostate cancer in an opportunistic screening population.

A 2-gene urine-based molecular test that targets messenger RNAs known to be overexpressed in aggressive prostate cancer (PCa) has been described as a helpful method for detecting clinically significant prostate cancer (grade group [GG] ≥2). We performed an external validation of this test in men undergoing initial prostate biopsy (Bx) within a Spanish opportunistic screening scenario. We analyzed archived samples from 492 men who underwent prostate Bx in an opportunistic screening scenario, with prostate-specific antigen (PSA) 3 to 10 ng/mL and/or suspicious digital rectal exploration (DRE) and without previous multi-parametric magnetic resonance imaging (mpMRI). Urinary biomarker measurements were combined with clinical risk factors to determine a risk score, and accuracy for GG ≥ 2 PCa detection was compared with PCA3, European randomized screening in prostate cancer (ERSPC), and prostate biopsy collaborative group (PBCG) risk calculators in a validation workup that included calibration, discrimination, and clinical utility analysis. In our cohort, the detection rates for GG1 and GG ≥ 2 PCa were 20.3% and 14.0%, respectively. The median PSA level was 3.9 ng/mL and 13.4% of subjects had suspicious DRE findings. The median risk score for men with GG ≥ 2 PCa was 21 (interquartile range: 14-28), significantly higher than benign+GG1 PCa (10, 6-18), P < .001, achieving the highest area under the curve among the models tested, 0.749 (95% confidence interval: 0.690-0.807). The urine test was well-calibrated, while ERSPC showed a slight underestimation and PBCG a slight overestimation of risk. Assuming a GG2 non-detection rate of 11% without using mpMRI, use of the urinary biomarker-based clinical model could have helped avoid 37.2% of excess biopsies while delaying the diagnosis of eight patients (1.6% of the entire cohort) with GG ≥ 2 PCa. In this first evaluation in an opportunistic screening population, the urinary biomarker-based test improved the detection of clinically significant PCa. Facing men with elevated PSA and/or suspicious DRE, it could be a useful tool to help avoid excess initial Bx and to identify patients most likely to benefit from Bx.

Symbolic regression of uncertainty-resilient inferential sensors for fault diagnostics

An algorithm is presented for the design of inferential sensors for fault diagnostics in thermal management systems. The algorithm uses input and output sensed system information to improve the detection and isolation of a fault by generating inferential sensors that augment the measured information to: (i) reduce the evidence of uncertainty in the inferred variables, and thus decrease false alarm and nondetection rates; and (ii) provide distinguishable responses to faults, and thus reduce reduce the rate of misdiagnoses. The novelty of the algorithm is its use of genetic programming to evolve explainable inferential sensors that maximize information criteria specific to fault diagnostics. The chosen criteria: (i) least squares regression; and (ii) Ds -optimality (calculated from the Fisher Information Matrix), leverage symbolic mathematics and automatic differentiation to obtain parametric sensitivities of the measured outputs and inferential sensors. The algorithm is included in a standard work for fault diagnostics, where its effectiveness is assessed through k-NN classification and illustrated in an application to an aircraft cross-flow plate-fin heat exchanger.

Effectiveness of cold coagulation in treating high-grade cervical intraepithelial neoplasia: the human papillomavirus evidence of cure

We retrospectively analysed post-treatment human papillomavirus (HPV) results in women treated for cervical intraepithelial neoplasia (CIN) to establish if ‘virological cure’ rates achieved by cold coagulation matched those for large-loop excision of the transformation zone (LLETZ) in the treatment of CIN. The main outcome measure was the rate of non-detection of HPV at 6- and 18-month follow-up. HPV was not detected in 82.0% and 86.0% of women at 6- and 18-month follow-up, respectively. In women with high-grade CIN (CIN 2 or worse), there was no difference in HPV non-detection rates among the two treatment methods at six-month (81.8% for cold coagulation vs. 84.0% for LLETZ, χ2=0.23, p value=.632), and 18-month follow-up (83.3% for cold coagulation vs. 89.2% for LLETZ, χ2=1.46, p value=.227). Cervical cold coagulation provides a high ‘virological cure’ rate for all grades of CIN, equivalent to that seen with LLETZ.Impact StatementWhat is already known on this subject? It is well established that CIN cure rates after treatment with cold coagulation are comparable to those of excisional methods and are over 90% on cytological follow-up post-treatment. Furthermore, there are no demonstrable adverse effects on fertility and delivery in pregnancies conceived after cold coagulation according to long-term follow-up studies. In contrast, there is a positive correlation between treatment with LLETZ and the risk of subsequent subfertility and adverse pregnancy outcomes.What the results of this study add? This study provides evidence that cold coagulation achieves similar cure rates to that of LLETZ not only in cytology but also in HPV test of cure. This finding is significant as we are moving to a primary HPV cervical screening programme.What the implications are of these findings for clinical practice and/or further research? A negative high-risk HPV test provides a greater reassurance of a low risk of CIN 3 or cancer than a negative cytology result. Therefore, given parity to LLETZ in ‘virological cure’ rate and having no known adverse effects on fertility and pregnancy, cold coagulation should be used to treat most cases of CIN, especially in women of reproductive age.

An analysis of SPECT/CT non-visualization of sentinel lymph nodes in renal tumors

BackgroundSentinel lymph node biopsy (SLNB) after intratumoral injection of 99mTc labeled nanocolloid and imaging with scintigraphy and SPECT/CT in renal tumors is feasible. However, sentinel lymph node (SN) non-detection rate with scintigraphy and SPECT/CT is high. The aim of the study was to determine factors affecting non-visualization (NV) of SN imaging in renal tumors. Seventy-eight patients with cT1–3 renal tumors received intratumoral injection of 225 MBq 99mTc-labeled nanocolloid 1 day before (partial) nephrectomy. Radiotracer injection was followed by anterioposterior and lateral scintigraphy in combination with SPECT/CT 20 min and 2–4 h after. Surgical treatment of the tumor with sentinel lymph node biopsy by aid of γ-probe and-camera was performed the next day. Scintigraphy and SPECT/CT images were evaluated and patient, tumor, and procedure characteristics were collected for 73 eligible patients used in uni- and multivariable analysis of a potential association with NV.ResultsA total of 80 (mean 1.1, IQR 0–2, max 6) sentinel lymph nodes in 46 patients were detected with scintigraphy and SPECT/CT. Preoperative visualization rate and intraoperative detection rate was 63% [95% CI 50–73%] and 61% [95% CI 49–72%], respectively. In uni- and multivariable analysis, the only factor associated with non-visualization was age, showing higher odds of non-visualization with higher age.ConclusionOur study demonstrated that non-visualization of SNs in renal tumors is relatively high and is associated with patient age. Furthermore, kidneys and also its tumors are highly vascularized which may cause a wash-out effect that could be identified with decreased kidney-liver ratios. However, in our data, the effect was statistically inconclusive. Further studies are needed to improve visualization and standardize the procedure of SLNB in renal tumors. The percentage of NV limits the use of SLNB for research and clinical purposes in renal cancer.

Efficacy and safety of sofosbuvir plus ribavirin for Korean patients with hepatitis C virus genotype 2 infection: A retrospective multi-institutional study.

Background/AimsSofosbuvir plus ribavirin is a standard treatment for patients infected with chronic hepatitis C virus (HCV) genotype 2 in Korea. The purpose of this study was to examine the efficacy and safety of this treatment in Korean patients with chronic HCV genotype 2 infection.MethodsWe retrospectively analyzed clinical data of patients treated with sofosbuvir plus ribavirin for chronic HCV genotype 2 from May 2016 to December 2017 at eight hospitals located in the Daejeon-Chungcheong area.ResultsA total of 172 patients were treated with sofosbuvir plus ribavirin. Of them, 163 patients completed the treatment, and 162 patients were tested for sustained virologic response 12 weeks after treatment discontinuation (SVR12). Mean age was 59.6±12.3 years (27–96), and 105 (64.4%) patients were female. Of the total patients, 49 (30.1%) were diagnosed with cirrhosis, and 31 of them were treated for 16 weeks. Sofosbuvir plus ribavirin was the first-line treatment for 144 (88.3%) patients. Eleven (6.7%) patients were intolerant to previous interferon-based treatment. Eight (5.0%) patients relapsed after interferon-based treatment. HCV RNA non-detection rate at 4, 8, and 12 weeks was 97.5%, 99.1%, and 99.3%, respectively, and SVR12 was 98.8% (161/163). During treatment, 18 (11.0%) patients had to reduce their administrated dose of ribavirin because of anemia. One patient stopped the treatment because of severe anemia. Other adverse events, including dizziness, indigestion, and headache, were found in 26 (16.0%) patients.ConclusionsA 12-16 week treatment with sofosbuvir plus ribavirin is remarkably effective and well tolerated in Korean patients with chronic HCV genotype 2 infection.

Optimal Variable Transmission for Distributed Local Fault Detection Incorporating RA and Evolutionary Optimization

Determining the variable transmission structure is the key step in designing a distributed monitoring scheme for multiunit processes. This paper proposes randomized algorithm (RA) integrated with evolutionary optimization-based data-driven distributed local fault detection scheme to achieve efficient monitoring of multiunit chemical processes. First, the RA is employed to generate faulty validation data. Second, evolutionary optimization-based variable transmission structure determination is performed to achieve the minimal non-detection rate by selecting transferred variables. Then, a principal component analysis (PCA) or kernel PCA monitoring model is established for each operation unit to identify the status of the unit. Last, a comprehensive index is developed to identify the status of the entire process. The established local monitors consider the relationship with other units but avoid introducing redundant information, thereby exhibiting superior monitoring performance. Case studies on two numerical examples, including a linear and a nonlinear case and the Tennessee Eastman benchmark process, are provided. Comparative results of traditional local or global monitoring methods verify the efficiency of the proposed monitoring scheme.

Diagnostic accuracy of non-contrast abdominal CT scans performed as follow-up for patients with an established cancer diagnosis: a retrospective study

Objectives: To determine the accuracy and non-detection rate of cancer related findings (CRFs) on follow-up non-contrast-enhanced CT (NECT) versus contrast-enhanced CT (CECT) images of the abdomen in patients with a known cancer diagnosis.Methods: A retrospective review of 352 consecutive CTs of the abdomen performed with and without IV contrast between March 2010 and October 2014 for follow-up of cancer was included. Two radiologists independently assessed the NECT portions of the studies. The reader was provided the primary cancer diagnosis and access to the most recent prior NECT study. The accuracy and non-detection rates were determined by comparing our results to the archived reports as a gold standard.Results: A total of 383 CRFs were found in the archived reports of the 352 abdominal CTs. The average non-detection rate for the NECTs compared to the CECTs was 3.0% (11.5/383) with an accuracy of 97.0% (371.5/383) in identifying CRFs. The most common findings missed were vascular thrombosis with a non-detection rate of 100%. The accuracy for non-vascular CRFs was 99.1%.Conclusion: Follow-up NECT abdomen studies are highly accurate in the detection of CRFs in patients with an established cancer diagnosis, except in cases where vascular involvement is suspected.

Influence of previous breast surgery in sentinel lymph node biopsy in patients with breast cancer.

The aim of this study was to review the feasibility of selective sentinel lymph node biopsy in patients with previous surgery for breast cancer, as well as to examine the factors that may interfere with sentinel node detection. A retrospective review was performed on 91 patients with breast cancer and previous breast surgery, and who underwent sentinel lymph node biopsy. Patients were divided into two groups according to their previous treatment: aesthetic breast surgery in 30 patients (group I) and breast-conserving surgery in 61 (group II). Lymphoscintigraphy was performed after an intra-tumour injection in 21 cases and a peri-areolar injection in 70 cases. An analysis was made of lymphatic drainage patterns and overall sentinel node detection according to clinical, pathological and surgical variables. The overall detection of the sentinel lymph node in the lymphoscintigraphy was 92.3%, with 7.7% of extra-axillary drainages. The identification rate was similar after aesthetic breast surgery (93.3%) and breast-conserving surgery (91.8%). Sentinel lymph nodes were found in the contralateral axilla in two patients (2.2%), and they were included in the histopathology study. The non-identification rate in the lymphoscintigraphy was 7.7%. There was a significantly higher non-detection rate in the highest histological grade tumours (28.6% grade III, 4.5% grade I and 3.6% grade II). Sentinel lymph node biopsy in patients with previous breast surgery is feasible and deserves further studies to assess the influence of different aspects in sentinel node detection in this clinical scenario. A high histological grade was significantly associated with a lower detection.

Influence of previous breast surgery in sentinel lymph node biopsy in patients with breast cancer

AimThe aim of this study was to review the feasibility of selective sentinel lymph node biopsy in patients with previous surgery for breast cancer, as well as to examine the factors that may interfere with sentinel node detection. Material and methodsA retrospective review was performed on 91 patients with breast cancer and previous breast surgery, and who underwent sentinel lymph node biopsy. Patients were divided into two groups according to their previous treatment: esthetic breast surgery in 30 patients (group I) and breast-conserving surgery in 61 (group II). Lymphoscintigraphy was performed after an intra-tumor injection in 21 cases and a peri-areolar injection in 70 cases. An analysis was made of lymphatic drainage patterns and overall sentinel node detection according to clinical, pathological and surgical variables. ResultsThe overall detection of the sentinel lymph node in the lymphoscintigraphy was 92.3%, with 7.7% of extra-axillary drainages. The identification rate was similar after esthetic breast surgery (93.3%) and breast-conserving surgery (91.8%). Sentinel lymph nodes were found in the contralateral axilla in two patients (2.2%), and they were included in the histopathology study. The non-identification rate in the lymphoscintigraphy was 7.7%. There was a significantly higher non-detection rate in the highest histological grade tumors (28.6% grade III, 4.5% grade I and 3.6% grade II). ConclusionSentinel lymph node biopsy in patients with previous breast surgery is feasible and deserves further studies to assess the influence of different aspects in sentinel node detection in this clinical scenario. A high histological grade was significantly associated with a lower detection.

Incidental extracerebral findings on brain nonenhanced magnetic resonance imaging: frequency, nondetection rate, and clinical importance.

This study aims to elucidate the frequency, nondetection rate, and clinical importance of incidental extracerebral findings (IECFs) on brain nonenhanced magnetic resonance imaging (MRI). A total of 8284 brain MRIs performed between January 1, 2015 and December 31, 2015 were evaluated for the presence of IECFs and the distribution of IECFs was analyzed. IECFs were categorized as E1 (clinically unimportant, e.g., sinus mucosal thickening); E2 (likely unimportant, e.g., pharyngeal mucosal symmetrical thickening); and E3 (potentially important, e.g., pharyngeal mucosal asymmetrical thickening). The nondetection rate was determined by comparing the results of the structured approach with the initial MRI reports. The medical records were examined for patients with E3 IECFs to assess clinical importance and outcome of these lesions. A total of 5992 IECFs were found in 4469 of the 8284 patients (54.0%). E1 findings constituted 82.2% (4924/5992) of all IECFs; E2 constituted 16.6% (995/5992) and E3 constituted 1.2% (73/5992). Overall IECFs and E1 findings were significantly more common in male patients (P<0.05). Statistically significant difference was also seen between the different age groups (P<0.001). The nondetection rate was 56.9% (3409/5992) for overall IECFs and 32.9% (24/73) for E3 IECFs. Of the 73 patients with E3 IECFs, 34 (46.6%) received final diagnosis and appropriate treatment during the study period. IECFs are prevalent in clinical patients on brain MR images with a nondetection rate of 32.9% for potentially important (E3) findings. The reporting of IECFs according to clinical importance is helpful for patients' management.

Extraspinal Incidental Findings at Lumbar Spine Magnetic Resonance Imaging in Two Hospitals: Prevalence and Clinical Importance

Objective: To assess the importance of incidental extraspinal findings on Magnetic Resonance Imaging of the lumbar spine in two hospital facilities. Materials and Methods: It was a descriptive and retrospective study from November 2015 to March 2016. The records of patients who had done a Magnetic Resonance Imaging (MRI) scan of the lumbar spine were re-read in search of incidental findings. The incidental findings found were classified using Colonography Reporting and Data System(C-RADS) classification of extracolonic lesions to assess clinical significance. The prevalence of incidental findings was calculated for each facility, as well as the distribution according to age, the organs involved and the clinical importance. A non-detection rate was calculated by confronting the findings of the study with the original reports. Results: The prevalence of incidental findings was respectively 33% (19 out of 36) in Jordan Medical Center (JMC) in Yaounde and 27.74% (106 out of 292) in Jacques Monod Hospital. The extraspinal incidental findings were classified mainly as extracolonic 2 (E2): 58% in each facility. The percentage detection of incidental findings was 5% at JMS and 1.7% at Jacques Monod Hospital. Conclusion: Extraspinal incidental findings are frequent in both hospitals. However, the rate of detection remains very low.