An average enumeration method of hyperspectral imaging data for quantitative evaluation of medical device surface contamination

We propose a quantification method called Mapped Average Principal component analysis Score (MAPS) to enumerate the contamination coverage on common medical device surfaces. The method was adapted from conventional Principal Component Analysis (PCA) on non-overlapped regions of a full frame hyperspectral image to resolve the percentage of contamination from the substrate. The concept was proven by using a controlled contamination sample with artificial test soil and color simulating organic mixture, and was further validated using a bacterial system including biofilm on stainless steel surface. We also validate the results of MAPS with other statistical spectral analysis including Spectral Angle Mapper (SAM). The proposed method provides an alternative quantification method for hyperspectral imaging data, which can be easily implemented by basic PCA analysis.OCIS codes: (110.4234) Multispectral and hyperspectral imaging, (170.3880) Medical and biological imaging     

MR image overlay guidance: system evaluation for preclinical use

Purpose

A clinical augmented reality guidance system was developed for MRI-guided musculoskeletal interventions Magnetic Resonance Image Overlay System (MR-IOS). The purpose of this study was to assess MRI compatibility, system accuracy, technical efficacy, and operator performance of the MR-IOS.

Methods and materials

The impact of the MR-IOS on the MR environment was assessed by measuring image quality with signal-to-noise ratio (SNR) and signal intensity uniformity with the system in various on/off states. The system accuracy was assessed with an in-room preclinical experiment by performing 62 needle insertions on a spine phantom by an expert operator measuring entry, depth, angle, and target errors. Technical efficacy and operator performance were tested in laboratory by running an experiment with 40 novice operators (20 using freehand technique versus 20 MR-IOS-guided) with each operator inserting 10 needles into a geometric phantom. Technical efficacy was measured by comparing the success rates of needle insertions between the two operator groups. Operator performance was assessed by comparing total procedure times, total needle path distance, presumed tissue damage, and speed of individual insertions between the two operator groups.

Results

The MR-IOS maximally altered SNR by 2% with no perceptible change in image quality or uniformity. Accuracy assessment showed mean entry error of 1.6 ± 0.6 mm, depth error of 0.7 ± 0.5 mm, angle error of 1.5 ± 1.1°, and target error of 1.9 ± 0.8 mm. Technical efficacy showed a statistically significant difference (p = 0.031) between success rates (freehand 35.0% vs. MR-IOS 80.95%). Operator performance showed: mean total procedure time of 40.3 ± 4.4 (s) for freehand and 37.0 ± 3.7 (s) for MR-IOS (p = 0.584), needle path distances of 152.6 ± 15.0 mm for freehand and 116.9 ± 8.7 mm for MR-IOS (p = 0.074), presumed tissue damage of 7,417.2 ± 955.6 mm² for freehand and 6062.2 ± 678.5 mm² for MR-IOS (p = 0.347), and speed of insertion 5.9 ± 0.4 mm/s for freehand and 4.3 ± 0.3 mm/s for MR-IOS (p = 0.003).

Conclusion

The MR-IOS is compatible within a clinical MR imaging environment, accurate for needle placement, technically efficacious, and improves operator performance over the unassisted insertion technique. The MR-IOS was found to be suitable for further testing in a clinical setting.     

Reliability of Blood Pressure Parameters for Dry Weight Estimation in Hemodialysis Patients

Chronic volume overload resulting from interdialytic weight gain and inadequate fluid removal plays a significant role in poorly controlled high blood pressure. Although bioimpedance has been introduced as an accurate method for assessing hydration status, the instrument is not available in general hemodialysis (HEMO) centers. This study was conducted to explore the correlation between hydration status measured by bioimpedance and blood pressure parameters in chronic HEMO patients. Multifrequency bioimpedance analysis was used to determine pre‐ and post‐dialysis hydration status in 32 stable HEMO patients. Extracellular water/total body water (ECW/TBW) determined by sum of segments from bioimpedance analysis was used as an index of hydration status. The mean age was 57.9 ± 16.4 years. The mean dry weight and body mass index were 57.7 ± 14.5 kg and 22.3 ± 4.7 kg/m², respectively. Pre‐dialysis ECW/TBW was significantly correlated with only pulse pressure (r = 0.5, P = 0.003) whereas post‐dialysis ECW/TBW had significant correlations with pulse pressure, systolic blood pressure, and diastolic blood pressure (r = 0.6, P = 0.001, r = 0.4, P = 0.04, r = ?0.4, and P = 0.02, respectively). After dialysis, the mean values of ECW/TBW, systolic blood pressure, mean arterial pressure, and pulse pressure were significantly decreased. ECW/TBW was used to classify the patients into normohydration (≤0.4) and overhydration (>0.4) groups. Systolic blood pressure, mean arterial pressure, and pulse pressure significantly reduced after dialysis in the normohydration group but did not significantly change in the overhydration group. Pre‐dialysis pulse pressure, post‐dialysis pulse pressure, and post‐dialysis systolic blood pressure in the overhydration group were significantly higher than normohydration group. Due to the simplicity and cost, blood pressure parameters, especially pulse pressure, might be a simple reference for clinicians to determine hydration status in HEMO patients.     

Congenital Coronary Artery Fistula in Children: A Review of 28 Cases with Clinical and Imaging Outcomes

Background: Congenital coronary artery fistula (CCAF) is a rare anomaly. Treatment strategies tend to close the defect with a symptomatic and significant shunt, primarily based on expert consensus and case series. Results for long-term follow-up in children are limited Methods: We conducted a retrospective study to assess clinical and imaging outcomes of children with CCAF at Siriraj Hospital, Thailand during 2000–2020. Patients with single ventricle were excluded. Treatment strategies [surgical closure (SC), and percutaneous closure (PC)] were classified and the clinical outcomes at the follow-up in 2021, including coronary thrombosis, myocardial ischemia, and the results of cardiovascular imaging were reviewed. Results: Twenty-eight children with CCAF were included in the study. The median age at diagnosis was 2.5 years (2 days–18 years). Presenting symptoms were audible murmur (82%) and heart failure (35%). Most of fistulae arose from the right coronary artery (12/28) and exited at the right atrium (11/28). In recent visits (0.5–14 years follow-up), six patients with asymptomatic small CCAF were managed by watchful follow-up without complications. PC was primarily treated in 11 children: 7 underwent successful procedures; 1 had a residual shunt and required re-intervention; 1 had ischemic symptoms immediately after the procedure with left coronary occlusion that required device removal plus SC and 2 were technically unable to place the device, requiring SC. Four patients were waiting for interventions (1 PC and 3 SC). Cardiovascular imaging surveillance that followed closure demonstrated asymptomatic thrombus formation in three patients (1 PC and 2 SC). No mortality presented. Conclusion: CCAF with significant shunt is indicated to close either SC or PC. Ischemic events are rare but have been reported after closure. In addition, thrombus formation should be watched for post-intervention. Surveillance with cardiovascular imaging is recommended after defect closure (ideally 1–5 years post closure), or at interval follow-ups in patients with symptoms to evaluate possible recanalization, thrombus, or ischemia. Life-long clinical and echocardiographic follow-up is warranted. Watchful follow-up is acceptable for hemodynamically insignificant fistula without complication in the series.     

Effect of Obesity in Persistent or Remission in Postmenopausal Women with Atypical Cervical Cytology

Objectives: To determine the effects of obesity in pre and postmenopausal women diagnosed with atypical squamous cells of undetermined significance (ASC-US) (in cases of remission, persistence, and progression of disease) after initial management and follow-up within 2 years to inform proper management for postmenopausal Thai women. Methods: This retrospective study was conducted at Bhumibol Adulyadej Hospital, Thailand between January 2013 and October 2018. Medical records of 506 patients whose cervical cytology reported of ASC-US were reviewed. Prevalence of silent high grade cervical intraepithelial neoplasia (CIN2/3) was evaluated. Cervical cytology after completed follow-up within 2 years were determined. Results: During the study period, there were 506 cases of ASC-US cytology reported. One quarter of cases were of post-menopausal status. Prevalence of CIN 2/3 in ASC-US cytology in pre and postmenopausal women were 9.9 and 7.2%, respectively. At 2-year follow-up appointments, around 90% of patients who completed follow-up remained in remission of the disease in both age groups. Menopausal status, body mass index (BMI), sexual activity, number of sexual partners, parity, smoking and hormone replacement therapy were not correlating factors to remission. Obese postmenopausal women had a lower remission rate of CIN, but this finding was not statistically significant. Conclusion: Obesity was not found to correlate strongly with the progression or remission of CIN. Obese postmenopausal women may still be affected by a persistence of the disease. Continuing cervical cytology monitoring should be recommended for such patients. Silent high grade cervical intraepithelial neoplasia (CIN2/3) in ASC-US cytology in this study were high. Colposcopy should be recommended for diagnosis and follow-up in this setting.     

Intravenous carbetocin versus intravenous oxytocin for preventing atonic postpartum hemorrhage after normal vaginal delivery in high-risk singleton pregnancies: a triple-blind randomized controlled trial

Purpose

To compare the effectiveness of intravenous carbetocin to that of intravenous oxytocin for prevention of atonic postpartum hemorrhage (PPH) after vaginal delivery in high-risk singleton pregnancies.

Methods

This triple-blind randomized controlled trial included singleton pregnant women who delivered at Siriraj Hospital between August 2016 and January 2017 and who were 20 years or older, had a gestational age of at least 34 weeks, had a vaginal delivery, and had at least one risk factor for atonic postpartum hemorrhage. Immediately after vaginal delivery, participants were randomly assigned to receive either 5 U of oxytocin or 100 mcg of carbetocin intravenously. Postpartum blood loss was measured objectively in mL using a postpartum drape with a calibrated bag.

Results

A total of 174 and 176 participants constituted the oxytocin and carbetocin groups, respectively. The baseline characteristics were comparable between the groups. The carbetocin group had less postpartum blood loss (146.7?±?90.4 vs. 195.1?±?146.2 mL; p?<?0.01), a lower incidence of atonic PPH (0 vs. 6.3%; p?<?0.01), less usage of additional uterotonic drugs (9.1 vs. 27.6%; p?<?0.01), and a lower incidence of postpartum anemia (Hb?≤?10 g/dL) (9.1 vs. 18.4%; p?<?0.05) than the oxytocin group. No significant differences regarding side effects were evident between the groups.

Conclusions

Intravenous carbetocin is more effective than intravenous oxytocin for the prevention of atonic PPH among singleton pregnancies with at least one risk factor for PPH.

Clinical trial registration

TCTR20160715004.

     

Cytotoxic effects of Thai noni juice product ethanolic extracts against cholangiocarcinoma cell lines

Objective: To investigate the cytotoxic activity and molecular mechanism(s) of two Thai noni juice (TNJ) products ethanolic extracts against cholangiocarcinoma ...     

Effective Bilirubin Reduction by Single-Pass Albumin Dialysis in Liver Failure

Albumin dialysis is widely accepted as a liver-support technique for patients with liver failure. The Molecular Adsorbent Recirculating System, the widely accepted albumin dialysis technique, has limited use in developing countries because of its technical difficulties and high cost. Therefore, we assessed the efficacy of the more practical modality, the single-pass albumin dialysis (SPAD), in terms of bilirubin reduction, as a marker of albumin-bound toxins removal, as well as the patient outcomes. Twelve acute or acute-on-chronic patients with liver failure who had hyperbilirubinemia (total bilirubin > 20 mg/dL) were treated with SPAD by using 2% human serum albumin dialysate for 6 h. SPAD treatment significantly improved the levels of total bilirubin, conjugated bilirubin, urea, and creatinine ( P  < 0.001 for all parameters). The reduction ratios of these four parameters were 22.9 ± 3.8%, 20.9 ± 5%, 19.0 ± 4.1%, and 27.7 ±  3.2%, respectively. No significant difference was observed between serum ammonia before and after treatment. No significant changes in mean arterial pressures were noted during the maneuver, representing cardiovascular tolerability. No treatment-related complications were found. The 15-day in-hospital survival was 16.7%. However, a subgroup of the patients who had moderate severity showed 100% 15-day-survival rate (2 of 2 patients). In conclusion, SPAD is salutarily effective in reducing bilirubin in patients with liver failure. The procedure is safe and simply set up.