Ultra-high-resolution photon-counting detector CT in evaluating coronary stent patency: a comparison to invasive coronary angiography.

OBJECTIVES: To determine the diagnostic accuracy of ultra-high-resolution photon-counting detector CT angiography (UHR PCD-CTA) for evaluating coronary stent patency compared to invasive coronary angiography (ICA). METHODS: Consecutive, clinically referred patients with prior coronary stent implantation were prospectively enrolled between August 2022 and March 2023 and underwent UHR PCD-CTA (collimation, 120 × 0.2 mm). Two radiologists independently analyzed image quality of the in-stent lumen using a 5-point Likert scale, ranging from 1 ("excellent") to 5 ("non-diagnostic"), and assessed all coronary stents for the presence of in-stent stenosis (≥ 50% lumen narrowing). The diagnostic accuracy of UHR PCD-CTA was determined, with ICA serving as the standard of reference. RESULTS: A total of 44 coronary stents in 18 participants (mean age, 83 years ± 6 [standard deviation]; 12 women) were included in the analysis. In 3/44 stents, both readers described image quality as non-diagnostic, whereas reader 2 noted a fourth stent to have non-diagnostic image quality. In comparison to ICA, UHR PCD-CTA demonstrated a sensitivity, specificity, and accuracy of 100% (95% CI [confidence interval] 47.8, 100), 92.3% (95% CI 79.1, 98.4), and 93.2% (95% CI 81.3, 98.6) for reader 1 and 100% (95% CI 47.8, 100), 87.2% (95% CI 72.6, 95.7), and 88.6% (95% CI 75.4, 96.2) for reader 2, respectively. Both readers observed a 100% negative predictive value (36/36 stents and 34/34 stents). Stent patency inter-reader agreement was 90.1%, corresponding to a substantial Cohen's kappa value of 0.72. CONCLUSIONS: UHR PCD-CTA enables non-invasive assessment of coronary stent patency with high image quality and diagnostic accuracy. CLINICAL RELEVANCE STATEMENT: Ultra-high-resolution photon-counting detector CT angiography represents a reliable and non-invasive method for assessing coronary stent patency. Its high negative predictive value makes it a promising alternative over invasive coronary angiography for the rule-out of in-stent stenosis. KEY POINTS: • CT-based evaluation of coronary stent patency is limited by stent-induced artifacts and spatial resolution. • Ultra-high-resolution photon-counting detector CT accurately evaluates coronary stent patency compared to invasive coronary angiography. • Photon-counting detector CT represents a promising method for the non-invasive rule-out of in-stent stenosis.

Value of virtual non-contrast images to identify uncomplicated cystic renal lesions: photon-counting detector CT vs. dual-energy integrating detector CT.

PURPOSE: To investigate the value of photon-counting detector CT (PCD-CT) derived virtual non-contrast (VNC) reconstructions to identify renal cysts in comparison with conventional dual-energy integrating detector (DE EID) CT-derived VNC reconstructions. MATERIAL AND METHODS: We prospectively enrolled consecutive patients with simple renal cysts (Bosniak classification-Version 2019, density ≤ 20 HU and/or enhancement ≤ 20 HU) who underwent multiphase (non-contrast, arterial, portal venous phase) PCD-CT and for whom non-contrast and portal venous phase DE EID-CT was available. Subsequently, VNC reconstructions were calculated for all contrast phases and density as well as contrast enhancement within the cysts were measured and compared. MRI and/or ultrasound served as reference standards for lesion classification. RESULTS: 19 patients (1 cyst per patient; age 69.5 ± 10.7 years; 17 [89.5%] male) were included. Density measurements on PCD-CT non-contrast and VNC reconstructions (arterial and portal venous phase) revealed no significant effect on HU values (p = 0.301). In contrast, a significant difference between non-contrast vs. VNC images was found for DE EID-CT (p = 0.02). For PCD-CT, enhancement for VNC reconstructions was < 20 HU for all evaluated cysts. DE EID-CT measurements revealed an enhancement of > 20 HU in five lesions (26.3%) using the VNC reconstructions, which was not seen with the non-contrast images. CONCLUSION: PCD-CT-derived VNC images allow for reliable and accurate characterization of simple cystic renal lesions similar to non-contrast scans whereas VNC images calculated from DE EID-CT resulted in substantial false characterization. Thus, PCD-CT-derived VNC images may substitute for non-contrast images and reduce radiation dose and follow-up imaging.

Evaluating the association of childhood sexual abuse with the development of irritable bowel syndrome later in life: A systematic review.

Objective: To review available medical literature to elucidate the association between childhood sexual abuse and the development of irritable bowel syndrome later in life. METHODS: This systematic review was conducted from January to August 2022 and comprised a literature search on Medline (via PubMed), Scopus, Embase, Web of Science, and Google Scholar databases for relevant studies published between 2001 and 2021. The Newcastle-Ottawa scale was used to determine the quality of the studies. Data on the prevalence of irritable bowel syndrome were meta-analysed using a Mantel-Haenszel random-effects model in RevMan 5.4.1. RESULTS: Of the 7 observational studies analyzed in detail, 5 (71.4%) had a case-control design, and 2 (28.6%) were crosssectional studies. Overall, there were 3156 subjects. The prevalence of irritable bowel syndrome in the childhood sexual abuse group was 51.86% (334/644), while it was 36.74% (923/2512) in the non-childhood sexual abuse group. The pooled odds ratio, indicating the association between childhood sexual abuse and irritable bowel syndrome, was 1.87 (95% confidence interval: 1.56-2.26). The study quality was rated as good in 3 (42.8%) cases, fair in 3 (42.8%), and poor in 1 (14.3%). Conclusion: Childhood sexual abuse was found to be significantly associated with the development of irritable bowel syndrome later in life, further strengthening the argument that childhood sexual abuse can lead to long-term detriments extending into adulthood. However, there was no existing literature found that stratified other aspects of irritable bowel syndrome, including symptom severity and childhood sexual abuse being the exclusive cause of irritable bowel syndrome.

Accuracy of Ultrahigh-Resolution Photon-counting CT for Detecting Coronary Artery Disease in a High-Risk Population.

Background Recently introduced photon-counting CT may improve noninvasive assessment of patients with high risk for coronary artery disease (CAD). Purpose To determine the diagnostic accuracy of ultrahigh-resolution (UHR) coronary CT angiography (CCTA) in the detection of CAD compared with the reference standard of invasive coronary angiography (ICA). Materials and Methods In this prospective study, participants with severe aortic valve stenosis and clinically indicated CT for transcatheter aortic valve replacement planning were consecutively enrolled from August 2022 to February 2023. All participants were examined with a dual-source photon-counting CT scanner using a retrospective electrocardiography-gated contrast-enhanced UHR scanning protocol (tube voltage, 120 or 140 kV; collimation, 120 × 0.2 mm; 100 mL of iopromid; no spectral information). Subjects underwent ICA as part of their clinical routine. A consensus assessment of image quality (five-point Likert scale: 1 = excellent [absence of artifacts], 5 = nondiagnostic [severe artifacts]) and a blinded independent reading for the presence of CAD (stenosis ≥50%) were performed. UHR CCTA was compared with ICA using area under the receiver operating characteristic curve (AUC). Results Among 68 participants (mean age, 81 years ± 7 [SD]; 32 male, 36 female), the prevalence of CAD and prior stent placement was 35% and 22%, respectively. The overall image quality was excellent (median score, 1.5 [IQR, 1.3-2.0]). The AUC of UHR CCTA in the detection of CAD was 0.93 per participant (95% CI: 0.86, 0.99), 0.94 per vessel (95% CI: 0.91, 0.98), and 0.92 per segment (95% CI: 0.87, 0.97). Sensitivity, specificity, and accuracy, respectively, were 96%, 84%, and 88% per participant (n = 68); 89%, 91%, and 91% per vessel (n = 204); and 77%, 95%, and 95% per segment (n = 965). Conclusion UHR photon-counting CCTA provided high diagnostic accuracy in the detection of CAD in a high-risk population, including subjects with severe coronary calcification or prior stent placement. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Williams and Newby in this issue.

Application of p and n-Type Silicon Nanowires as Human Respiratory Sensing Device.

Accurate and fast breath monitoring is of great importance for various healthcare applications, for example, medical diagnoses, studying sleep apnea, and early detection of physiological disorders. Devices meant for such applications tend to be uncomfortable for the subject (patient) and pricey. Therefore, there is a need for a cost-effective, lightweight, small-dimensional, and non-invasive device whose presence does not interfere with the observed signals. This paper reports on the fabrication of a highly sensitive human respiratory sensor based on silicon nanowires (SiNWs) fabricated by a top-down method of metal-assisted chemical-etching (MACE). Besides other important factors, reducing the final cost of the sensor is of paramount importance. One of the factors that increases the final price of the sensors is using gold (Au) electrodes. Herein, we investigate the sensor's response using aluminum (Al) electrodes as a cost-effective alternative, considering the fact that the electrode's work function is crucial in electronic device design, impacting device electronic properties and electron transport efficiency at the electrode-semiconductor interface. Therefore a comparison is made between SiNWs breath sensors made from both p-type and n-type silicon to investigate the effect of the dopant and electrode type on the SiNWs respiratory sensing functionality. A distinct directional variation was observed in the sample's response with Au and Al electrodes. Finally, performing a qualitative study revealed that the electrical resistance across the SiNWs renders greater sensitivity to breath than to dry air pressure. No definitive research demonstrating the mechanism behind these effects exists, thus prompting our study to investigate the underlying process.

Effect of preoperative intravenous steroids on seroma formation after modified radical mastectomy.

OBJECTIVE: To analyse the efficacy of preoperative intravenous injection of 120mg of methylprednisolone acetate steroid on the formation of seroma after modified radical mastectomy in breast cancer patients. Method: The case-control study was conducted at Ward 3, Surgical Unit 1, Department of General Surgery, Jinnah Postgraduate Medical Centre, Karachi, from November 2020 to April 2021, and comprised female patients with biopsy-proven carcinoma of breast who were scheduled for elective definitive breast cancer surgery. The subjects were randomised into treatment group A and control group B. Group A was given a single dose of intravenous injection methylprednisolone acetate 120mg half-an-hour before surgery, while group B underwent similar surgery without the said injection. Seroma was graded using the Common Terminology Criteria for Adverse Events v3.0. The groups were compared for age, total drainage, duration of drainage, seroma grading and wound status. Data was analysed using SPSS 25. RESULTS: Of the 60 patients, there were 30(50%) in each of the two groups. The age difference between groups was non-significant (p=0.346). There was a significant difference in the mean total drainage volume and mean duration of drainage between the groups (p=0.001). Seroma formation, seroma grading and wound status were not significantly different between the groups (p>0.05). The efficacy in treatment was high in group A (odds ratio: 2.78; 95% confidence interval: 0.65-13.94). CONCLUSIONS: A single preoperative dose of Injection methylprednisolone acetate was effective in terms of post-mastectomy outcomes.

Evaluating the safety and efficacy of daprodustat for anemia of chronic kidney disease: a meta-analysis of randomized clinical trials.

PURPOSE: Anemia of chronic kidney disease (CKD) has traditionally been treated with recombinant human erythropoietin (rhEPO). Recently, daprodustat, a hypoxia-inducible factor prolyl-hydroxylase inhibitor, has also been shown to increase hematocrit. It remains unclear whether daprodustat or rhEPO should be the treatment of choice for anemia of CKD. We aimed to assess the efficacy and cardiovascular safety of daprodustat versus rhEPO in CKD patients. METHODS: Online databases were queried in April 2022 for articles comparing the efficacy and safety of daprodustat in DD-CKD and NDD-CKD subgroups. Results from trials were pooled using a random-effects model. RESULTS: Data on 8245 CKD patients from eight clinical trials were included. Our results show that in comparison to rhEPO, daprodustat maintained the same efficacy in increasing hemoglobin levels in both the DD-CKD (MD: 0.10; 95% CI [- 0.13,0.34]; p = 0.50) and NDD-CKD (MD: - 0.01; 95% CI [- 0.38,0.35]; p = 0.95) subgroups. Daprodustat significantly lowered hepcidin levels and significantly increased TIBC in both subgroups. Additionally, daprodustat significantly reduced the incidence of major adverse cardiovascular events (MACE) (RR: 0.89; 95% CI: 0.89-0.98; p = 0.02) and its myocardial infarction (MI) component (RR: 0.74; 95% CI: 0.59-0.92; p = 0.006) in the DD-CKD subgroup. CONCLUSION: Daprodustat has similar efficacy compared to rhEPO for the treatment of anemia of CKD. On treatment, the reduced experience of MACE was reported in DD-CKD patients as compared to rhEPO. Furthermore, effects on iron metabolism varied by parameter, with daprodustat being superior to rhEPO in some cases and inferior in others.

Piezoresistance Characterization of Silicon Nanowires in Uniaxial and Isostatic Pressure Variation.

Silicon nanowires (SiNWs) are known to exhibit a large piezoresistance (PZR) effect, making them suitable for various sensing applications. Here, we report the results of a PZR investigation on randomly distributed and interconnected vertical silicon nanowire arrays as a pressure sensor. The samples were produced from p-type (100) Si wafers using a silver catalyzed top-down etching process. The piezoresistance response of these SiNW arrays was analyzed by measuring their I-V characteristics under applied uniaxial as well as isostatic pressure. The interconnected SiNWs exhibit increased mechanical stability in comparison with separated or periodic nanowires. The repeatability of the fabrication process and statistical distribution of measurements were also tested on several samples from different batches. A sensing resolution down to roughly 1m pressure was observed with uniaxial force application, and more than two orders of magnitude resistance variation were determined for isostatic pressure below atmospheric pressure.

Clinical presentation, diagnostic features on cardiac magnetic resonance imaging and outcome of patients with cardiac amyloidosis presenting to a tertiary care setting.

Cardiac amyloidosis is a rare disease which is under diagnosed in this region. This study was aimed to assess the clinical presentation, cardiac magnetic resonance (CMR) imaging findings and prognosis of patients with cardiac amyloidosis in Pakistani population presenting to a tertiary care setting. A total of eight patients were included with the confirmed diagnosis of cardiac amyloidosis on CMR, after reviewing the CMR data of Aga Khan University Hospital from January 2011 to August 2019. Mean age was 51±11.5 years with the majority (75%) being male. All patients presented with heart failure. Suboptimal myocardial nulling on late gadolinium images was the most common finding on CMR. Late gadolinium enhancement was diffuse transmural in 5 patients (62.5%) and diffuse sub-endocardial in 3 patients (37.5%). On a mean follow up of 14±10 months, 3 patients (37.5%) died while 7 patients (87.5%) had hospital admissions due to heart failure.

Positional syncope occurring just at the right time in a patient with a permanent pacemaker: A case report.

We present an unusual case of positional syncope occurring years after pacemaker implantation. Syncope was caused by a pacemaker lead fracture, which resulted from subclavian crush syndrome. The syncope occurred incidentally during hospital admission and was timely diagnosed using an integrated approach of history taking, examination findings, device interrogation and radiographic parameters. The patient subsequently underwent lead and device alteration which led to resolution of her symptoms.

Frequency and Association of Stress Levels with Modes of Commuting Among Medical Students of a Developing Country.

INTRODUCTION: This study aimed at determining the frequency and association of stress levels with modes of transportation and was likely to reveal the contributing transportation-related factors for stress in medical students. METHODS: This was a questionnaire-based, cross-sectional study that included undergraduate medical students of a public sector medical university in Karachi, Pakistan. A total of 573 students participated voluntarily, of which 300 were provided a manual questionnaire and 273 filled it online. The reliability of the questionnaire was assessed using Cronbach's alpha at 0.791. The collected data were analysed using IBM SPSS Statistics for Windows, version 21.0. RESULTS: Out of 573 participants, 99.3% (n = 298) of students filled the questionnaire manually, whereas 100% of students filled the questionnaire online. Almost two-thirds of students used university transport; more than 90% lived more than 5 km from the university and 56% had a traveling time of more than an hour. Approximately 15.4% of students reported physical trauma and some form of harassment. Sheldon Cohen's stress scale surprisingly revealed 90% of students to be within the moderate-to-high stress category. Risk factors were associated with stress levels and significant associations were observed with noise exposure (P = 0.023) and sleep quality (P = 0.001). The most common reported stressors associated with commuting included overcrowding, long travel, and air and noise pollution. Noise pollution was the main predictor of stress among commuters. CONCLUSION: Poor transportation has adverse effects on health and academic performance. Administration in their respective jurisdictions is needed to investigate this matter to make commuting a routine rather than a hassle.

Scalpel versus diathermy of midline skin incisions: comparison of mean pain scores on second post-operative day.

OBJECTIVE: To determine the mean post-operative pain in scalpel versus diathermy opening of midline laparotomies. METHODS: The randomised controlled study was conducted at Civil Hospital and Dow University of Health Sciences, Karachi, from May to November 2010, and comprised patients undergoing midline laparotomy. Patients were equally divided into two groups; those who received incision with diathermy were placed in group A, and those who received incision with scalpel in group B. Mean post-operative pain scores were recorded using numerical analogue scale on second post-operative day. SPSS 16 was used for statistical analysis. RESULTS: Of the 58 patients, there were 29(50%) in each group. The overall mean age of the patients was 31.8±12.8 years. Besides, 40(68.9%) patients were male. The mean post-operative pain scores at 48 hours in diathermy group was 1.48±0.68 while in scalpel group it was 2.17±0.46 (p<0.05). CONCLUSIONS: The use of diathermy for midline laparotomy incision had significant advantage over scalpel in reducing pain on second post-operative day.

A Microwave Ring-Resonator Sensor for Non-Invasive Assessment of Meat Aging.

The assessment of moisture loss from meat during the aging period is a critical issue for the meat industry. In this article, a non-invasive microwave ring-resonator sensor is presented to evaluate the moisture content, or more precisely water holding capacity (WHC) of broiler meat over a four-week period. The developed sensor has shown significant changes in its resonance frequency and return loss due to reduction in WHC in the studied duration. The obtained results are also confirmed by physical measurements. Further, these results are evaluated using the Fricke model, which provides a good fit for electric circuit components in biological tissue. Significant changes were observed in membrane integrity, where the corresponding capacitance decreases 30% in the early aging (0D-7D) period. Similarly, the losses associated with intracellular and extracellular fluids exhibit changed up to 42% and 53%, respectively. Ultimately, empirical polynomial models are developed to predict the electrical component values for a better understanding of aging effects. The measured and calculated values are found to be in good agreement.

Presentation delay in breast cancer patients and its association with sociodemographic factors in North Pakistan.

BACKGROUND: There is strong evidence that delayed diagnosis of breast cancer is associated with poor survival. The objectives were to determine the frequency of breast cancer patients with delayed presentation, the reasons of delay and its association with different socio-demographic variables in our settings. METHODS: We interviewed 315 histologically confirmed breast cancer patients. Delay was defined as more than 3 months from appearance of symptoms to the consultation from doctor. Questions were asked from each patient which could reflect their understanding about the disease and which could be the likely reasons for their delayed presentation. RESULTS: A total of 39.01% (n=123) of patients presented late and out of those, 40.7% wasted time using alternative medicines; 25.2% were not having enough resources; 17.1% presented late due to painless lump; 10.6% felt shyness and 6.5% presented late due to other reasons. Higher age, negative family history, <8 school years of education and low to middle socio-economic status were significantly associated with delayed presentation (P<0.05). Education and socioeconomic status were two independent variables related to the delayed presentation after adjustment for others [odds ratios (OR) of 2.26, 2.29 and 95% confidence intervals (CI) was 1.25-4.10, 1.06-4.94 respectively]. CONCLUSIONS: Significant percentage of women with breast cancer in North Pakistan is experiencing presentation delay due to their misconceptions about the disease. Coordinated efforts with public health department are needed to educate the focused groups and mitigating the barriers identified in the study. Long term impact will be reduced overall burden of the disease in the region.