Radiopaque marker colonic transit study in the pediatric population BSPGHAN Motility Working Group consensus statement.

Functional constipation (FC) is a common condition in childhood in the United Kingdom and worldwide. Various radiological approaches have been established for diagnostic purposes. The radiopaque marker study (ROMS) is universally accepted and used to assess colonic transit time (CTT) in children with FC. Despite being widely used, there is a lack of standardization with various technical protocols, reproducibility of different populations, the purpose for using investigation, variance in the number of markers used, the amount of study days and calculations, the need to empty the colon before performing the test, and whether to perform on medication or off, or the use of specific diets. As part of the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) motility working group (MWG), we decided to explore further into the evidence, in order to provide guidance regarding the use of ROMS in dealing with FC in the pediatric population.

Ultrasonographic appearance of retained surgical sponges and gauzes in the acute postoperative period: a phantom and cadaveric study.

Retained surgical sponges or gauzes (RSS) are an uncommon complication of exploratory laparotomy surgery and pose a clinically significant risk to the patient. The purpose of this two-part, prospective, descriptive study was to describe the previously uncharacterized ultrasonographic appearance of RSS in phantom and cadaveric models of the acute postoperative period (24-48 h). For the first part of the study, a gelatin phantom containing a woven gauze with a radiopaque marker (radiopaque gauze), a woven gauze with no marker (nonradiopaque gauze), and a laparotomy sponge with a radiopaque marker (radiopaque sponge) was evaluated with ultrasonography. For the second part of the study, a total of 23 gauzes and sponges (of the aforementioned three types) were placed within the peritoneal cavity of 20 cadavers in one of three randomized locations during an exploratory laparotomy laboratory. The cadavers were imaged with ultrasonography 17 h later and still images and video clips were reviewed. The retained surgical sponges and gauzes in the gelatin phantom displayed multiple hyperechoic layers and variable degrees of distal acoustic shadowing. In cadavers, 100% (23/23) of the retained surgical sponges and gauzes displayed a single hyperechoic layer of variable thickness and distal acoustic shadowing. In 95.6% (22/23) retained sponges and gauzes, there was a thin hypoechoic layer noted superficially to the hyperechoic layer. An improved understanding of the ultrasonographic appearance of retained sponges or gauzes in the acute postoperative period may assist in the identification of these objects.

Rare complications of Guideplus guide-extension catheter during complex percutaneous coronary intervention.

Guide-extension catheters (GECs) are effective in providing reinforced backup support and coaxial alignment, leading to successful complex percutaneous coronary intervention (PCI). However, several GEC-associated complications have been reported, including coronary injuries, thrombotic events, and GEC fractures. The Guideplus GEC (Guideplus II ST; Nipro, Osaka, Japan) has a higher crossability due to its unique hydrophilic-coated soft cylinder, which is frequently used in complex PCI for diffuse, tortuous, and heavily calcified lesions. We describe two cases of Guideplus GEC-associated complications during complex PCI: Case 1 with a radiopaque marker dislodgement and Case 2 with a stent dislodgment. In both cases, the Guideplus GEC was used within 7-Fr guiding catheters, employing the mother-and-child technique. A large inner-catheter gap between these catheters caused by a positioning bias due to arterial bends (the aortic arch in Case 1 and brachiocephalic arterial bends in Case 2) may have caused these complications due to its interference with coronary devices (the trapping balloon in Case 1, and the scoring balloon in Case 2). Early cognition and management of these potential Guideplus GEC-associated complications are important to prevent further deterioration. Learning objectives: The Guideplus guide-extension catheter (GEC) with a hydrophilic-coated soft cylinder can deliver coronary devices to complex lesions owing to its high crossability. However, delivering coronary devices with the Guideplus GEC should be carefully performed because a large inner-catheter gap between Guideplus GEC and a guiding catheter may occur if a proximal port of the Guideplus GEC is located at an arterial bend. In such settings, Guideplus GEC-associated complications must be carefully observed, including radiopaque marker dislodgement and stent dislodgement.

Density map estimation with convolutional neural networks to count radiopaque markers on colonic transit studies.

BACKGROUND: A radiopaque marker study measures colonic transit time for work-up of primary constipation. It requires the patient to ingest multiple tiny radiopaque markers, which the radiologist must count manually on follow-up abdominal radiographs. Counting these markers is tedious but cognitively simple. OBJECTIVE: To develop a convolutional neural network (CNN) capable of counting the number of radiopaque markers on abdominal radiographs. MATERIALS AND METHODS: The image archive at a large tertiary children's hospital was searched to identify abdominal radiographs performed in children for the indication of a radiopaque marker study. To establish the ground truth, a radiologist manually labeled the coordinates of the radiopaque markers in each radiograph and thereby generated a density map for that radiograph. A CNN was trained to estimate this density map from its corresponding abdominal radiograph. Spatially integrating the output density map provided an estimate of the number of markers in the radiograph. To assess model accuracy, mean absolute error and root mean square error were calculated. RESULTS: The study cohort consisted of 436 radiographs (mean number of markers per radiograph: 34). This cohort was randomly divided into training, validation and testing sets consisting of 306, 65 and 65 radiographs, respectively. Based on the testing set, the CNN accurately estimated the number of markers in each radiograph with mean absolute error=2.6 markers and root mean square error=3.9 markers. CONCLUSION: The proposed CNN generated promising results in counting the number of radiopaque markers on abdominal radiographs and offers the potential of automating the interpretation of colonic transit studies.

Self-Radiopaque Markers Guiding Physician-Modified Fenestration (S-Fenestration) in Aortic Arch Endovascular Repair.

Backgrounds and Objectives: Thoracic endovascular aortic repair (TEVAR) has currently become the "first-line choice" for descending aortic pathologies. For pathologies located at the aortic arch, TEVAR with physician-modified fenestration (PMF) has been gained popularity as an alternative choice. However, stent fenestration is an experience-dependent technique and comes with possible adverse events such as misalignment. This study aims to introduce the self-radiopaque PMF (SF), which uses the radiopaque marker as a guiding indicator. Methods: This is a single-center retrospective study of 125 patients who underwent the SF-TEVAR in Second Xiangya Hospital from December 2015 to December 2020. Data include basic clinical information and technique records of SF-TEVAR with follow-up results. Results: According to the SF-TEVAR protocol, we have performed the procedures on 125 patients and obtained an instant success rate of 98.4%. A total of 140 aortic stent-grafts and 44 bridging stents have been implanted in this study. The operation time is 64.6 ± 19.3 min, X-ray exposure time (from first digital subtraction angiography (DSA) to last DSA) is 25.6 ± 14.3 min, and contrast volume is 82.2 ± 22.6 ml. The success rate of PMF alignment is 98.4%. One bailout stent-graft was implanted into the left subclavian artery (LSA) by the chimney technique (0.8%). One fenestration was successfully and immediately corrected after misalignment (0.8%). Large simultaneous fenestration was performed in six patients (4.8%) for the left common carotid artery (LCCA) and LSA and in two patients (1.6%) for IA, LCCA, and LSA. One hundred twenty-two out of 125 patients' LSAs have been kept patent by the technique during the follow-up. The bridging stent group consists of 44 patients who received LSA stents, while the non-bridging stent group includes the other 81 patients. Type I endoleak has occurred in seven patients (5.6%) 1 week after the procedure. During follow-up (23 ± 18 months), survival rate is 95.7% and branch artery patent rate is 97.4%. Conclusions: The SF-TEVAR technique, which utilizes the radiopaque marker in stent-graft as an indication for PMF in TEVAR, seems a likely safe, effective, and efficient procedure that brings acceptable survival rate and branch artery patency rate. SF-TEVAR serves as a progressive alternative method to keep the branch artery patent in aortic arch endovascular reconstruction.

Comparison of resection margin status after single or double radiopaque marker insertion for tumor localization in breast cancer patients receiving neoadjuvant chemotherapy.

PURPOSE: Insertion of radiopaque markers is helpful for tumor localization in patients receiving neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS). The aim of this retrospective study was to investigate the pathologic margin status in patients with single or double marker insertion. METHODS: We reviewed the records of 130 patients with marker insertion prior to NAC followed by BCS from January 2016 to September 2019. Under ultrasonography guidance, single or double markers were inserted to localize a tumor in the breast. The incidence of additional resection after frozen biopsy and re-excision after permanent pathologic diagnosis was analyzed. RESULTS: In a total of 130 patients, 104 had a single marker in the center of the tumor and 26 had double markers at the periphery of the tumor before NAC. Among 69 patients with residual invasive tumors after NAC, there was no difference in the additional resection rate after frozen biopsy (single vs. double markers; 14.3% vs. 38.5%, P = .059) or the re-excision rate after final pathologic diagnosis (0% vs. 7.7%, P = .188). After propensity score matching for tumor size and subtypes, the two groups showed no differences in the additional resection rate after frozen biopsy (7.7% vs. 19.2%, P = .139) or the re-excision rate (0% vs. 3.8%, P = .308). After a median follow-up of 19 months (range 8-48 months), local recurrence-free survival did not differ between the two groups (log-rank P = .456). CONCLUSIONS: Number of inserted markers for tumor localization did not affect the pathologic margin status after BCS.

Can the radiopaque marker in surgical swabs scratch orthopaedic implant surfaces?

AIMS: To determine whether the radiopaque marker strip, which is woven in surgical swabs, causes measureable wear on metal implants at pressures typically used to wipe off fluid from their surface. MATERIALS AND METHODS: Finger pressure used to wipe a surface was measured and used as a reference pressure for further testing. A tribological wear rig was then used to analyse the wear caused on polished titanium plates by a cobalt chromium pin (the control test), the pin covered by a surgical swab and the pin covered by a radiopaque marker strip. RESULTS: It was found that the cotton part or the radiopaque marker of surgical swabs on polished medical grade titanium plates caused no significant wear. In contrast severe scratching was observed from the cobalt chromium pin on its own. CONCLUSION: To our knowledge, this is the first study in the literature analysing the wear caused by the surgical swabs and radiopaque strip on metal implants. The results suggest that surgical swabs are safe to use on metallic implants at pressures typical of a wiping motion.

[Automated Detection of Radiopaque Markers in Chest and Abdomen Radiography].

We aimed to develop a computerized method for the detection of radiopaque markers, such as R and L in chest and abdomen radiography by using the generalized Hough transform and the template matching. To develop the computerized method, we used 200 chest and abdomen images in our institution as training cases. First, two template images for R and L markers were created with the same exposure condition as a chest X-ray. Following various image processing, such as edge detection, thinning and Hough transformed, a look-up table that consisted of distance and direction pairs was built for the generalized Hough transform. All training images were preprocessed with median filter, edge detection, binarization, thinning, back ground removal and labeling. For candidates of markers that were detected as true positive or false positive, their vote and cross-correlation were calculated with the generalized Hough transform. To evaluate this proposed method, a validation test was performed with another database that consisted of 800 chest and abdomen images by use of Mahalanobis distance based on vote and cross-correlation in statistics. The precision of detecting the radiopaque markers for 800 test images was 99.9%. In addition, this method worked out well for some specific images in which markers were overlapped with a human body.

External radiopaque marking of Gillies posterior zygomatic arch osteotomy in reduction malarplasty.

Although the Gillies (temporal) approach to reduction malarplasty helps preserve supportive soft tissue and avoid facial scars, the osteotomy site is difficult to gauge when using this blind technique. Our experience with external radiopaque marking of the zygomatic arch to guide this process is presented herein. This retrospective review included all patients who underwent reduction malarplasty (as above) at our clinic between August 2013 and September 2015. Procedures entailed L-shaped osteotomy only (no segmental excision) of the zygomatic body by the intraoral route, and posterior zygomatic arch osteotomy by the Gillies approach, guided by external radiopaque markings. Patient characteristics, surgical outcomes, and complications were analyzed to assess the merits of this strategy. Postoperative results were evaluated by both the patients and the surgeon. Most patients expressed satisfaction during the follow-up period (range, 3-27 months). Posterior osteotomies were properly performed as planned, with no major complications (i.e., malunion or nonunion, cheek drooping, or facial nerve injury), although minor complications were recorded in three instances. Use of external radiopaque markings provides guidance during malarplasty by the Gillies approach and may help avoid procedural complications.

Fully automated tracking of cardiac structures using radiopaque markers and high-frequency videofluoroscopy in an in vivo ovine model: from three-dimensional marker coordinates to quantitative analyses.

PURPOSE: Recently, algorithms were developed to track radiopaque markers in the heart fully automated. However, the methodology did not allow to assign the exact anatomical location to each marker. In this case study we describe the steps from the generation of three-dimensional marker coordinates to quantitative data analyses in an in vivo ovine model. METHODS: In one adult sheep, twenty silver balls were sutured to the right side of the heart: 10 to the tricuspid annulus, one to the anterior tricuspid leaflet and nine to the epicardial surface of the right ventricle. In addition, 13 cylindrical tantalum markers were implanted into the left ventricle. Data were acquired with a biplanar X-ray acquisition system (Neurostar R, Siemens AG, 500 Hz). Radiopaque marker coordinates were determined fully automated using novel tracking algorithms. RESULTS: The anatomical marker locations were identified using a 3-dimensional model of a single frame containing all tracked markers. First, cylindrical markers were manually separated from spherical markers, thus allowing to distinguish right from left heart markers. The fast moving leaflet marker was identified by using video loops constructed of all recorded frames. Rotation of the 3-dimensional model allowed the identification of the precise anatomical position for each marker. Data sets were then analyzed quantitatively using customized software. CONCLUSIONS: The method presented in this case study allowed quantitative data analyses of radiopaque cardiac markers that were tracked fully automated with high temporal resolution. However, marker identification still requires substantial manual work. Future improvements including the implication of marker identification algorithms and data analysis software could allow almost real-time quantitative analyses of distinct cardiac structures with high temporal and spatial resolution.

Transmural penetration of sigmoid colon and rectum by retained surgical sponge after hysterectomy.

Gossypiboma is a surgical sponge that is retained in the body after the operation. A 39-year-old female presented with vague lower abdominal pain, fever, and rectal discharge 15 mo after hysterectomy. The sponge remaining in the abdomen had no radiopaque marker. Therefore a series of radiographic evaluations was fruitless. The surgical sponge was found in the rectosigmoid colon on colonoscopy. The sponge penetrated the sigmoid colon and rectum transmurally, forming an opening on both sides. The patient underwent low anterior resection and was discharged without postoperative complications.

Clinical pharmacology of daikenchuto assessed by transit analysis using radiopaque markers in patients with colon cancer undergoing open surgery: a multicenter double-blind randomized placebo-controlled study (JFMC39-0902 additional study).

BACKGROUND: This exploratory trial was conducted to investigate whether daikenchuto accelerates the recovery of gastrointestinal function in patients undergoing open surgery for sigmoid or rectosigmoid cancer. METHODS: Eighty-eight patients who underwent colectomy at one of the 11 clinical trial sites in Japan from January 2009 to June 2011 were registered in the study. Patients received either placebo or daikenchuto (15.0 g/day, 5 g three times a day) from postoperative day 2 to postoperative day 8. The study end points included the gastrointestinal tract transit time evaluated with radiopaque markers and the time to first flatus. The safety profile of daikenchuto was also evaluated until postoperative day 8. RESULTS: Seventy-one patients (daikenchuto, n = 38; placebo, n = 33) were statistically analyzed. Although the number of radiopaque markers in the anal side of the small intestine at 6 h was significantly greater in the daikenchuto group than in the placebo group (15.19 vs 10.06, p = 0.008), the total transit analysis results and the mean time to first flatus did not differ significantly between the two groups. CONCLUSIONS: Daikenchuto has a positive effect on the resolution of delayed gastric emptying, but has a limited effect on the resolution of postoperative paralytic ileus after open surgery in patients with sigmoid or rectosigmoid cancer. Daikenchuto may contribute to early oral intake in the postoperative course.

Automatic detection of selective arterial devices for advanced visualization during abdominal aortic aneurysm endovascular repair.

Here we address the automatic segmentation of endovascular devices used in the endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) that deform vascular tissues. Using this approach, the vascular structure is automatically reshaped solving the issue of misregistration observed on 2D/3D image fusion for EVAR guidance. The endovascular devices we considered are the graduated pigtail catheter (PC) used for contrast injection and the stent-graft delivery device (DD). The segmentation of the DD was enhanced using an asymmetric Frangi filter. The segmented geometries were then analysed using their specific features to remove artefacts. The radiopaque markers of the PC were enhanced using a fusion of Hessian and newly introduced gradient norm shift filters. Extensive experiments were performed using a database of images taken during 28 AAA-EVAR interventions. This dataset was divided into two parts: the first half was used to optimize parameters and the second to compile performances using optimal values obtained. The radiopaque markers of the PC were detected with a sensitivity of 88.3% and a positive predictive value (PPV) of 96%. The PC can therefore be positioned with a majority of its markers localized while the artefacts were all located inside the vessel lumen. The major parts of the DD, the dilatator tip and the pusher surfaces, were detected accurately with a sensitivity of 85.9% and a PPV of 88.7%. The less visible part of the DD, the stent enclosed within the sheath, was segmented with a sensitivity of 63.4% because the radiopacity of this region is low and uneven. The centreline of the DD in this stent region was alternatively traced within a 0.74 mm mean error. The automatic segmentation of endovascular devices during EVAR is feasible and accurate; it could be useful to perform elastic registration of the vascular lumen during endovascular repair.

Evaluation of constipation.

The evaluation of the chronically constipated patient is multifaceted and challenging. Many clinicians define constipation according to the latest Rome III diagnostic criteria for functional gastrointestinal disorders. Female sex, older age, low fiber diet, a sedentary life style, malnutrition, polypharmacy, and a lower socioeconomic status have all been identified as risk factors for functional constipation. In elderly patients, it is important to rule out a colonic malignancy as the cause of constipation. The initial evaluation of the constipated patient includes a detailed history to elicit symptoms distinguishing slow transit constipation from obstructive defecation. Slow transit and obstructive defecation are the two major subtypes of functional constipation. In addition, the clinician should identify any secondary causes of constipation. The office examination of the constipated patient includes an abdominal, perineal, and a rectal exam. Many patients improve with lifestyle modification. When dietary interventions and lifestyle modifications fail, many diagnostic studies are available to further evaluate the constipated patient. Sitzmark transit study, nuclear scintigraphic defecography, electromyography, anorectal manometry, balloon expulsion test, paradoxical puborectalis contraction, cinedefecography, and dynamic magnetic resonance imaging defecography have all been used to diagnose the underlying causes of functional constipation.

Use of locally innovated radiopaque markers (MAKKO pills) for colonic transit study

Locally made radiopaque markers for colonic transit study are presented, specifically on how they were made, and how they compared radiographically with markers available abroad. These markers were produced using locally available materials like barium powder, a feeding tube, cyanoacrylate, and emptied drug capsules. They were then ingested and monitored by X-ray. They were found to be radiographically comparable with imported ones. No adverse events were noted when used in 5 patients: 2 patients with constipation secondary to chronic laxative abuse, 2 patients with reducible complete rectal prolapse, and 1 patient with constipation secondary to short segment Hirschsprungs' Disease. (Author)

Segmental Colon Transit Time with Radiopaque Markers in a Delayed-release Capsule / 대한소화관운동학회지

BACKGROUNDS/AIM: Scintigraphic measurement of colon transit has been proven useful clinically and in the research area, however this method requires well equipped laboratories. The aim of this study was to develop a new colon transit test using radiopaque markers instead of radiolabeled pellets in a methacrylate-coated capsule. METHODS: Ten healthy volunteers were studied. After simultaneous administration of two methacrylate-coated gelatin capsules containing activated charcoal mixed with 8 mCi of 99mTc or a commercially used radiopaque marker, scintigraphies and plain abdominal X-rays were performed. We compared colon transit profiles as the geometric center at 4, 8, 24, and 48 hours after ingestion of gelatin capsules. This new radiopaque marker test was validated with a scintigraphic method as the gold standard. RESULTS: Geometric centers (mean+/-SEM) of 99mTc-scintigraphy were 0.50+/-0.18 at 4 hours, 1.16+/-0.05 at 8 hours, 3.31+/-0.36 at 24 hours, and 4.16+/-0.29 at 48 hours. Geometric centers of the radiopaque marker method were 0.40+/-0.16, 1.13+/-0.05, 3.33+/-0.37, and 4.18+/-0.30 respectively. Transit profiles were the same with both methods and highly correlated (r=0.994, p < 0.001). The difference between the two methods against the mean for the geometric center was within 2SD. CONCLUSIONS: A colon transit test using radiopaque markers in a methacrylate-coated, delayed release capsule was inexpensive, simple, and reliable. This new test could be applicable when a gamma camera is not available.