Combined radiomics-clinical model to predict malignancy of vertebral compression fractures on CT.

OBJECTIVES: To develop and validate a combined radiomics-clinical model to predict malignancy of vertebral compression fractures on CT. METHODS: One hundred sixty-five patients with vertebral compression fractures were allocated to training (n = 110 [62 acute benign and 48 malignant fractures]) and validation (n = 55 [30 acute benign and 25 malignant fractures]) cohorts. Radiomics features (n = 144) were extracted from non-contrast-enhanced CT images. Radiomics score was constructed by applying least absolute shrinkage and selection operator regression to reproducible features. A combined radiomics-clinical model was constructed by integrating significant clinical parameters with radiomics score using multivariate logistic regression analysis. Model performance was quantified in terms of discrimination and calibration. The model was internally validated on the independent data set. RESULTS: The combined radiomics-clinical model, composed of two significant clinical predictors (age and history of malignancy) and the radiomics score, showed good calibration (Hosmer-Lemeshow test, p > 0.05) and discrimination in both training (AUC, 0.970) and validation (AUC, 0.948) cohorts. Discrimination performance of the combined model was higher than that of either the radiomics score (AUC, 0.941 in training cohort and 0.852 in validation cohort) or the clinical predictor model (AUC, 0.924 in training cohort and 0.849 in validation cohort). The model stratified patients into groups with low and high risk of malignant fracture with an accuracy of 98.2% in the training cohort and 90.9% in the validation cohort. CONCLUSIONS: The combined radiomics-clinical model integrating clinical parameters with radiomics score could predict malignancy in vertebral compression fractures on CT with high discriminatory ability. KEY POINTS: • A combined radiomics-clinical model was constructed to predict malignancy of vertebral compression fractures on CT by combining clinical parameters and radiomics features. • The model showed good calibration and discrimination in both training and validation cohorts. • The model showed high accuracy in the stratification of patients into groups with low and high risk of malignant vertebral compression fractures.

CDISC-compliant clinical trial imaging management system with automatic verification and data Transformation: Focusing on tumor response assessment data in clinical trials.

OBJECTIVE: Major issues in imaging data management of tumor response assessment in clinical trials include high human errors in data input and unstandardized data structures, warranting a new breakthrough IT solution. Thus, we aim to develop a Clinical Data Interchange Standards Consortium (CDISC)-compliant clinical trial imaging management system (CTIMS) with automatic verification and transformation modules for implementing the CDISC Study Data Tabulation Model (SDTM) in the tumor response assessment dataset of clinical trials. MATERIALS AND METHODS: In accordance with various CDISC standards guides and Response Evaluation Criteria in Solid Tumors (RECIST) guidelines, the overall system architecture of CDISC-compliant CTIMS was designed. Modules for standard-compliant electronic case report form (eCRF) to verify data conformance and transform into SDTM data format were developed by experts in diverse fields such as medical informatics, medical, and clinical trial. External validation of the CDISC-compliant CTIMS was performed by comparing it with our previous CTIMS based on real-world data and CDISC validation rules by Pinnacle 21 Community Software. RESULTS: The architecture of CDISC-compliant CTIMS included the standard-compliant eCRF module of RECIST, the automatic verification module of the input data, and the SDTM transformation module from the eCRF input data to the SDTM datasets based on CDISC Define-XML. This new system was incorporated into our previous CTIMS. External validation demonstrated that all 176 human input errors occurred in the previous CTIMS filtered by a new system yielding zero error and CDISC-compliant dataset. The verified eCRF input data were automatically transformed into the SDTM dataset, which satisfied the CDISC validation rules by Pinnacle 21 Community Software. CONCLUSIONS: To assure data consistency and high quality of the tumor response assessment data, our new CTIMS can minimize human input error by using standard-compliant eCRF with an automatic verification module and automatically transform the datasets into CDISC SDTM format.

Temporary percutaneous radiologic gastrojejunostomy with single gastropexy.

BACKGROUND: Although the effectiveness of percutaneous radiologic gastrojejunostomy (PRGJ) has been reported, a detailed description of the indications and clinical effectiveness of temporary PRGJ is still limited. PURPOSE: To evaluate the clinical effectiveness and technical feasibility of temporary PRGJ using the modified Chiba-needle technique with single gastropexy. MATERIAL AND METHODS: Temporary PRGJ using the modified Chiba-needle technique with single gastropexy was performed in 27 consecutive patients (19 men, 8 women; mean age = 61 years; age range = 32-77 years) for esophageal perforation (n = 18) or postoperative gastroparesis (n = 9). Outcomes analyzed included the technical and clinical success, procedure-related complications, and the tube indwelling period. RESULTS: Technical and clinical success was achieved in all 27 patients. All the tubes were electively removed 19-364 days (mean indwelling period = 104 days) after confirmation of the possibility of oral intake. Asymptomatic pneumoperitoneum occurred in 2/27 (7.4%) patients as minor complications and was resolved spontaneously by the time of the one-week follow-up. There were no major complications. During the follow-up period, a total of 11 tube changes were performed in seven patients for an elective tube change within a six-month interval (n = 5) or because of tube occlusion (n = 6). CONCLUSION: Temporary PRGJ using the modified Chiba-needle technique with a single gastropexy was clinically effective and technically feasible in patients with esophageal perforation or gastroparesis. It can provide adequate enteral nutrition during its temporary placement.

Percutaneous antegrade removal of foreign bodies in the urinary tract: a 20-year, single-center experience.

BACKGROUND: While removing urinary tract foreign bodies is mostly performed through retrograde cystoscopy, antegrade removal using interventional procedures is reported less frequently. PURPOSE: To evaluate the safety and effectiveness of percutaneous antegrade removal of urinary tract foreign bodies. MATERIAL AND METHODS: A total of 14 consecutive patients (age range 9-80 years) who percutaneous antegrade removal of urinary tract foreign bodies between January 2001 and March 2020 were reviewed. Detailed removal procedures and complications were reviewed retrospectively. RESULTS: Types of foreign bodies were sheared percutaneous nephrostomy (PCN) catheters (n = 5), sheared double J stents (n = 3), migrated ureteral catheters (n = 3), embolization coils (n = 2), and a 0.018-inch guide wire (n = 1). The mean and median indwelling times (range 0-306 days) of the foreign bodies were 58.3 and 1.5 days, respectively. Computed tomography (CT) scans were conducted in six patients, and the extent and nature of the foreign bodies were well-visualized on CT scans. The removal access was new PCN access (n = 8), the tract missing PCN catheter (n = 3), pre-existing PCN access (n = 2), and percutaneous dissection (n = 1). The removal success rate was 92.9% (13/14) with either a simple (n = 8) or modified (n = 4; combination of a snare and guide wire is used) snare technique or a direct forceps grasp (n = 1). The mean procedure time for successful cases was 14.2 min (range 7-25 min). Procedure-related hematoma with (n = 2) or without (n = 1) renal pelvis injury occurred in three patients, which were all self-limited within one week. CONCLUSION: Percutaneous antegrade removal is safe and effective for urinary tract foreign bodies.

Tract ablation after radiofrequency ablation to prevent viable tumor cell adhesion to the needle electrode.

PURPOSE: To evaluate whether the additive needle tract ablation (TA) can reduce adherent cells on the needle tract after radiofrequency ablation (RFA) in a preclinical HCC mouse model. METHODS: Hep3B-Luc cells were engrafted in the Balb/c-nude mice. Nineteen mice were randomly assigned into three groups: the needle only group (needle placement only without performing RFA), the RFA only group (needle placement with active RFA treatment), and the RFA-TA group (needle placement with active RFA treatment and additive tract ablation). The 17-gauge needle with a 10-mm active tip was used. After RFA and TA, the viability of adherent tumor cells on the RFA needle was evaluated with bioluminescence imaging (BLI) and live-cell counting. RESULTS: We observed that RFA-TA group had the lowest BLI values compared with other groups (needle only group, 11.2 ± 6.4 million; RFA only group, 13.6 ± 9.1 million; RFA-TA group, 1.11 ± 0.8 million, p = 0.001). Live cell counting with acridine orange/propidium iodide staining also confirmed that the counted viable cell numbers in RFA-TA group were lowest compared to the other groups (needle only group, 14.8 ± 4.5; RFA only group, 643.8 ± 131.9; RFA-TA group, 1.5 ± 0.9, p < 0.001). CONCLUSIONS: The additive tract ablation can significantly reduce the number of viable tumor cells adherent to the RFA needle, which can prevent needle tract seeding after RFA procedure.

Gadoxetate-enhanced dynamic contrast-enhanced MRI for evaluation of liver function and liver fibrosis in preclinical trials.

BACKGROUND: To facilitate translational drug development for liver fibrosis, preclinical trials need to be run in parallel with clinical research. Liver function estimation by gadoxetate-enhanced dynamic contrast-enhanced MRI (DCE-MRI) is being established in clinical research, but still rarely used in preclinical trials. We aimed to evaluate feasibility of DCE-MRI indices as translatable biomarkers in a liver fibrosis animal model. METHODS: Liver fibrosis was induced in Sprague-Dawley rats by thioacetamide (200 mg, 150 mg, and saline for the high-dose, low-dose, and control groups, respectively). Subsequently, DCE-MRI was performed to measure: relative liver enhancement at 3-min (RLE-3), RLE-15, initial area-under-the-curve until 3-min (iAUC-3), iAUC-15, and maximum-enhancement (Emax). The correlation coefficients between these MRI indices and the histologic collagen area, indocyanine green retention at 15-min (ICG-R15), and shear wave elastography (SWE) were calculated. Diagnostic performance to diagnose liver fibrosis was also evaluated by receiver-operating-characteristic (ROC) analysis. RESULTS: Animal model was successful in that the collagen area of the liver was the largest in the high-dose group, followed by the low-dose group and control group. The correlation between the DCE-MRI indices and collagen area was high for iAUC-15, Emax, iAUC-3, and RLE-3 but moderate for RLE-15 (r, - 0.81, - 0.81, - 0.78, - 0.80, and - 0.51, respectively). The DCE-MRI indices showed moderate correlation with ICG-R15: the highest for iAUC-15, followed by iAUC-3, RLE-3, Emax, and RLE-15 (r, - 0.65, - 0.63, - 0.62, - 0.58, and - 0.56, respectively). The correlation coefficients between DCE-MRI indices and SWE ranged from - 0.59 to - 0.28. The diagnostic accuracy of RLE-3, iAUC-3, iAUC-15, and Emax was 100% (AUROC 1.000), whereas those of RLE-15 and SWE were relatively low (AUROC 0.777, 0.848, respectively). CONCLUSION: Among the gadoxetate-enhanced DCE-MRI indices, iAUC-15 and iAUC-3 might be bidirectional translatable biomarkers between preclinical and clinical research for evaluating histopathologic liver fibrosis and physiologic liver functions in a non-invasive manner.

In Vivo Fluorescence Microendoscopic Monitoring of Stent-Induced Fibroblast Cell Proliferation in an Esophageal Mouse Model.

PURPOSE: To evaluate the feasibility of self-expanding metal stent (SEMS) placement and fluorescence microendoscopic monitoring for determination of fibroblast cell proliferation after stent placement in an esophageal mouse model. MATERIALS AND METHODS: Twenty fibroblast-specific protein (FSP)-1 green fluorescent protein (GFP) transgenic mice were analyzed. Ten mice (Group A) underwent SEMS placement, and fluoroscopic and fluorescence microendoscopic images were obtained biweekly until 8 weeks thereafter. Ten healthy mice (Group B) were used for control esophageal values. RESULTS: SEMS placement was technically successful in all mice. The relative average number of fibroblast GFP cells and the intensities of GFP signals in Group A were significantly higher than in Group B after stent placement. The proliferative cellular response, including granulation tissue, epithelial layer, submucosal fibrosis, and connective tissue, was increased in Group A. FSP-1-positive cells were more prominent in Group A than in Group B. CONCLUSIONS: SEMS placement was feasible and safe in an esophageal mouse model, and proliferative cellular response caused by fibroblast cell proliferation after stent placement was longitudinally monitored using a noninvasive fluorescence microendoscopic technique. The results have implications for the understanding of proliferative cellular response after stent placement in real-life patients and provide initial insights into new clinical therapeutic strategies for restenosis.

Radiation-induced esophageal strictures treated with fluoroscopic balloon dilation: clinical outcomes and factors influencing recurrence in 62 patients.

Background Balloon dilation is safe and effective for the treatment of radiation-induced esophageal stricture (RIES), with favorable short-term and mid-term outcomes; however, few reports of long-term outcomes exist. Few studies have evaluated factors associated with recurrence after balloon dilation. Purpose To evaluate the long-term outcome of balloon dilation in patients with RIES and to identify factors associated with stricture recurrence. Material and Methods The medical records of 62 consecutive patients who had undergone fluoroscopic balloon dilation for RIES at our institution between December 1998 and June 2016 were reviewed. Results One hundred and twenty balloon dilation sessions were performed in 62 patients (mean = 1.9 sessions per patient). Clinical success was achieved in 53 (86%) patients after single (n = 37) or multiple (n = 16) dilation sessions. Complications occurred in 27% of the dilation sessions. The primary patency rates at one, two, three, and five years were 60%, 56%, 52%, and 52%, respectively. Secondary patency rates at one, two, three, and five years were 87%, 85%, 85%, and 80%, respectively. Multivariate logistic regression analysis identified an interval from radiation therapy (RT) to stricture of ≥6 months (hazard ratio [HR] = 0.205; P < 0.001), strictures located at the cervical esophagus (HR = 5.846; P < 0.001), and stricture length of ≥2 cm (HR = 2.923; P = 0.006) as significant predictors of recurrence. Conclusion Despite the high incidence of ruptures and recurrences, fluoroscopic balloon dilation is valuable as an initial therapeutic option for patients with RIES.

Incidence and management of oesophageal ruptures following fluoroscopic balloon dilatation in children with benign strictures.

OBJECTIVES: The purpose of this study is to investigate the incidence and management of oesophageal ruptures following fluoroscopic balloon dilatation (FBD) in children with benign oesophageal strictures. METHODS: Sixty-two children with benign oesophageal strictures underwent FBDs. Oesophageal rupture was categorized as intramural (type 1), transmural (type 2), or transmural with free leakage (type 3). The possible risk factors for oesophageal ruptures were analyzed. RESULTS: One hundred and twenty-nine FBDs were performed in these patients. The oesophageal rupture rate was 17.1 % (22/129). The majority (21/22) of ruptures were type 1 and type 2, both were treated conservatively. Only one patient had a type 3 rupture and underwent oesophagoesophagostomy. The patient gender, age, and the length and cause of the stricture showed no significant effect on the rupture (P > 0.05). However, for the patients ≤2 years old, the initial balloon with a diameter ≥10 mm showed a higher oesophageal rupture rate than those <10 mm during the first session (P = 0.03). CONCLUSIONS: Although the oesophageal rupture rate in children was 17.1 %, the type 3 rupture rate was 0.8 %, which usually requires aggressive treatment. For children ≤2 years old, the initial balloon diameter should be <10 mm in the first session for decreasing the risk of oesophageal rupture. KEY POINTS: • The oesophageal rupture rate following balloon dilatation in children was 17.1 %. • The incidence of transmural rupture with free leakage is very low. • Only transmural rupture with free leakage needs aggressive treatment. • For children ≤2 years, the initial balloon diameter should be <10 mm.

Fluoroscopic removal of retrievable self-expandable metal stents in patients with malignant oesophageal strictures: Experience with a non-endoscopic removal system.

OBJECTIVES: To evaluate clinical outcomes of fluoroscopic removal of retrievable self-expandable metal stents (SEMSs) for malignant oesophageal strictures, to compare clinical outcomes of three different removal techniques, and to identify predictive factors of successful removal by the standard technique (primary technical success). METHODS: A total of 137 stents were removed from 128 patients with malignant oesophageal strictures. Primary overall technical success and removal-related complications were evaluated. Logistic regression models were constructed to identify predictive factors of primary technical success. RESULTS: Primary technical success rate was 78.8 % (108/137). Complications occurred in six (4.4 %) cases. Stent location in the upper oesophagus (P=0.004), stricture length over 8 cm (P=0.030), and proximal granulation tissue (P<0.001) were negative predictive factors of primary technical success. If granulation tissue was present at the proximal end, eversion technique was more frequently required (P=0.002). CONCLUSIONS: Fluoroscopic removal of retrievable SEMSs for malignant oesophageal strictures using three different removal techniques appeared to be safe and easy. The standard technique is safe and effective in the majority of patients. The presence of proximal granulation tissue, stent location in the upper oesophagus, and stricture length over 8 cm were negative predictive factors for primary technical success by standard extraction and may require a modified removal technique. KEY POINTS: • Fluoroscopic retrievable SEMS removal is safe and effective. • Standard removal technique by traction is effective in the majority of patients. • Three negative predictive factors of primary technical success were identified. • Caution should be exercised during the removal in those situations. • Eversion technique is effective in cases of proximal granulation tissue.

Fluoroscopic-guided stent placement in failed tentative endoscopic approaches to malignant gastroduodenal obstructions.

Background Fluoroscopic or endoscopic placement of metallic stents is used as a safe, non-surgical, palliative treatment option for malignant gastroduodenal obstructions. However, endoscopic stent placement is not always feasible, due to the tight or tortuous stricture of the obstructed area and insufficient visualization of the stomach due to remnant food material. Purpose To assess the technical feasibility and clinical outcomes of fluoroscopic-guided stent placement in malignant gastroduodenal obstructions following the technical failure of endoscopic stent placement. Material and Methods In all, 19 patients (14 men, 5 women; age range, 36-85 years) were referred due to technical failures of tentative endoscopic stent placement. Indications were failure to pass the guide wire through the obstruction (n = 13), failure to reach the stricture lesion due to short endoscope (n = 5), and acute angulation of the stricture lesion (n = 1). Data were retrospectively collected regarding the technical and clinical success of the fluoroscopy, the dysphagia score before and after stent placement, and major complications and their management. Results Fluoroscopic stent placement was technically successful in 15/19 patients (79%). Failures were due to complete obstruction (n = 3) and acute angulation of the stricture lesion (n = 1). Clinical success was achieved in all 15 patients with successful stent placement. The dysphagia score significantly improved after stent placement ( P < 0.001). Complications occurred in 4/15 patients (27%), including tumor overgrowth (n = 2), stent collapse (n = 1), and jaundice (n = 1). Conclusion Fluoroscopic stent placement in malignant gastroduodenal obstructions following a technical failure of endoscopic stent placement is technically feasible and has an acceptable clinical outcome.

Overlapping self-expandable metallic stent for palliation of a long (>10 cm) malignant gastroduodenal obstruction.

Background Self-expandable metallic stent (SEMS) placement is a well-established palliative treatment approach for malignant gastroduodenal obstruction. In patients with a long (>10 cm) stricture, multiple stents placed in an overlapping fashion are often required. Purpose To investigate the outcomes of overlapping SEMS placement for the palliative treatment of malignant gastroduodenal obstruction in patients with a long (>10 cm) stricture. Material and Methods The medical records of 40 patients who underwent fluoroscopic overlapping SEMS placement for malignant gastroduodenal obstruction due to a long (>10 cm) stricture were reviewed. Results The technical and clinical success rates were 100% and 65.0%, respectively. The mean length of the stricture was 17.0 ± 4.7 cm and the mean number of stents placed in each patient was 2.2 ± 0.5. Metastatic cancer (odds ratio [OR], 0.315; P = 0.018), Eastern Cooperative Oncology Group (ECOG) score ≥3 (OR, 0.018; P = 0.006), and carcinomatosis with ascites (OR, 0.025; P = 0.017) were independent predictors of poor clinical success. The rates of minor and major complications were 27.5% and 2.5%, respectively. The median stent patency and survival were 33 days (interquartile range [IQR], 19-60 days) and 35 days (IQR, 19-73 days), respectively. An ECOG score ≥3 was an independent predictor of a poor survival outcome (hazard ratio, 4.681; P < 0.001). Conclusion Overlapping SEMS placement may be safe and effective for the palliative treatment of malignant gastroduodenal obstruction in patients with a long (>10 cm) stricture.

Tuberculous Tracheobronchial Strictures Treated with Balloon Dilation: A Single-Center Experience in 113 Patients during a 17-year Period.

PURPOSE: To evaluate the safety and effectiveness of balloon dilation in the treatment of tuberculous tracheobronchial strictures (TTBSs) in a series of 113 patients at a single institution. MATERIALS AND METHODS: The institutional review board approved the study and waived the requirement to obtain informed consent. Between 1997 and 2014, under bronchoscopic and fluoroscopic guidance, a total of 167 balloon dilation sessions were performed in 113 consecutive patients (14 male and 99 female patients; mean age, 37 years [age range, 17-73 years]), with a range of one to eight sessions per patient (mean, 1.5 sessions). Outcomes were number and/or frequency of balloon dilations, technical success, primary and secondary clinical success, improvement in respiratory status, airway patency rate, and alternative treatment after balloon dilation. A two-tailed paired t test and the Kaplan-Meier method were used to evaluate the improvement in respiratory status and airway patency rate after balloon dilation, respectively. RESULTS: Dilation was successful in 82 patients (73%) after single (n = 67) or multiple (n = 15) balloon dilations, with a mean follow-up of 30.3 months. Clinical failure occurred in 31 patients (27%). In these 31 patients, symptoms recurred 1 day to 113 months (mean, 13 months) after repeat balloon dilations. These 31 patients required alternative treatment, including temporary stent placement (n = 12), cutting balloon dilation (n = 12), radiation-eluting balloon dilation (n = 3), and surgery (n = 4). Before, immediately after, and 1 month after the procedure, pulmonary function test results showed significant improvements in mean forced vital capacity (P < .001), forced expiratory volume in 1 second (P = .001), forced expiratory flow in the midexpiratory phase (P = .020), and peak expiratory flow (P = .005). CONCLUSION: Balloon dilation of TTBSs is a safe, minimally invasive primary treatment that relieved symptoms in a large percentage of patients (73%). In patients with TTBSs refractory to balloon dilation, temporary stent placement, cutting balloon dilation, or radiation-eluting balloon dilation can be an alternative treatment.

Migration of retrievable expandable metallic stents inserted for malignant esophageal strictures: incidence, management, and prognostic factors in 332 patients.

OBJECTIVE: The purpose of this study was to evaluate the incidence, prognostic factors, and secondary management of stent migration in patients with malignant esophageal strictures. MATERIALS AND METHODS: A retrospective study was performed in a single tertiary referral university hospital to identify the incidence, management, and prognostic factors for stent migration in 332 consecutive patients with placement of a retrievable expandable metallic stent. Stent migration was classified into four patterns as locations of a migrated stent: pattern I, partially migrated in the proximal direction; pattern II, partially migrated in the distal direction; pattern III, completely migrated into the stomach; and pattern IV, completely migrated into the bowel. RESULTS: Stent migration occurred in 42 (12.6%) of 332 patients. Migration was partial (n = 21) or complete (n = 21), and nine (21%), 12 (29%), 11 (26%), and 10 (24%) patients had patterns I, II, III, and IV, respectively. Multivariate analysis identified the following prognostic factors: esophagogastric junction strictures caused by cancer of the gastric cardia (odds ratio 1.330; p = 0.004), patients who underwent anticancer treatment after stent placement (17.514; p < 0.001), and patients with a longer survival time (1.994; p < 0.001). Secondary management was needed for 33 of 42 patients. The strictures in the remaining nine patients improved throughout follow-up. CONCLUSION: Stent migration occurs most commonly in patients with cancer of the gastric cardia, patients with longer survival time, and those who underwent anticancer treatment after stent placement. Stent migration is successfully managed by further intervention. Accurate knowledge of the pattern of stent migration is important for successful management.

Full-thickness esophageal perforation after fluoroscopic balloon dilation: incidence and management in 820 adult patients.

OBJECTIVE: The purpose of this study is to investigate the incidence, management, and outcomes of esophageal perforation after fluoroscopic balloon dilation in 820 adult patients with esophageal diseases. MATERIALS AND METHODS: Between December 1990 and April 2014, a total of 820 adult patients (age range, 21-93 years) underwent 1869 fluoroscopic balloon dilation sessions (mean, 2.3 sessions/patient; range, 1-29 sessions/patient) for esophageal diseases. We retrospectively reviewed the prospectively collected medical records and images of these patients and collected the data of patients who developed esophageal perforations after fluoroscopic balloon dilation. RESULTS: During this period, 12 patients (six men and six women; mean age, 51 years; age range, 28-69 years) developed perforations. The perforation rate was 1.5% per patient and 0.6% per dilation. Among the first eight patients, four who were treated with surgery had perforations 2 cm or larger, and the other four who underwent fasting, parenteral alimentation, and treatment with antibiotics had perforations smaller than 2 cm. The last four patients underwent stent placement immediately after the diagnosis, regardless of the perforation's size. The median hospital stay was 11.5 days. CONCLUSION: Fluoroscopic balloon dilation of esophageal diseases is a safe procedure with a low perforation rate. A perforation size greater than 2 cm is considered large and requires aggressive treatment. Although the number of patients with esophageal perforation we treated is relatively small and further clinical trials are needed, temporary stent placement seems to be an initial choice in the management of esophageal perforations after fluoroscopic balloon dilation.

Preliminary Results of Percutaneous Radiologic Gastrostomy in a Pediatric Population: A Modified Chiba-Needle Puncture Technique With Single Gastropexy.

OBJECTIVE: The purpose of this study was to evaluate the technical feasibility, safety, and clinical effectiveness of percutaneous radiologic gastrostomy using a modified Chiba-needle puncture technique with single gastropexy in pediatric patients. MATERIALS AND METHODS: From July 2006 to December 2013, percutaneous radiologic gastrostomy was performed in 12 children (median age, 21 months; range, 6-46 months). Their stomachs were punctured using a 21-gauge Chiba needle. A single Cope gastrointestinal suture anchor was used for gastropexy, and a tube was inserted through the same tract as the anchor using a 12- or 14-French Dawson-Mueller pigtail drainage catheter. We then evaluated the technical success of the procedure, the number of puncture attempts using a 21-gauge Chiba needle, the procedure time, complications, and treatment of complications. RESULTS: Percutaneous radiologic gastrostomy was technically successful in all patients. Only a single puncture attempt was required in 10 patients (83%); two attempts were needed in two patients (17%). The average procedure time was 10 minutes 25 seconds (range, 5 minutes 5 seconds to 25 minutes 24 seconds). Pneumoperitoneum requiring tube exchange occurred in two of the 12 patients (17%). Two patients experienced pain immediately after the procedure. Three patients who had esophagogastric reflux after percutaneous radiologic gastrostomy underwent conversion percutaneous radiologic gastrojejunostomy. CONCLUSION: Percutaneous radiologic gastrostomy using a modified Chiba-needle technique with single gastropexy in pediatric patients is technically feasible and safe.

Polydioxanone biodegradable stent placement in a canine urethral model: analysis of inflammatory reaction and biodegradation.

PURPOSE: To investigate the inflammatory reaction and perform quantitative analysis of biodegradation after placement of a polydioxanone (PDO) biodegradable stent in a canine urethral model. MATERIALS AND METHODS: PDO biodegradable stents were placed in the proximal and distal urethra of nine male mongrel dogs. The dogs were euthanized 4 weeks (group A; n = 3), 8 weeks (group B; n = 3), or 12 weeks (group C; n = 3) after stent placement. The luminal diameter of the stent-implanted urethra was assessed by follow-up retrograde urethrography, and histologic findings were obtained after the dogs were killed. Stents were removed after euthanasia, and their surface morphology and molecular weight were evaluated. Hematologic examination was performed to evaluate inflammatory reaction. RESULTS: Stent placement was technically successful in all dogs. The average luminal diameter gradually decreased. The average number of epithelial layers (2.93 vs 4.42; P < .001), the average thickness of papillary projection (0.80 mm vs 1.28 mm; P < .001), and the average thickness of submucosal fibrosis (0.34 mm vs 0.49 mm ; P < .001) were significantly increased in group B versus group A. There were no significant differences between group B and group C. The average inflammatory cell infiltration did not differ significantly in the three groups. Molecular weight losses were 54% in group A and 84% in group B. In group C, PDO stents were completely decomposed. CONCLUSIONS: An experimental study in a canine urethral model has demonstrated acceptable inflammatory reaction with gradually increasing granulation tissue but no luminal obstruction within 12 weeks.

Whole Process of Standardization of Diffusion-Weighted Imaging: Phantom Validation and Clinical Application According to the QIBA Profile.

Background: To use the apparent diffusion coefficient (ADC) as reliable biomarkers, validation of MRI equipment performance and clinical acquisition protocols should be performed prior to application in patients. This study aims to validate various MRI equipment and clinical brain protocols for diffusion weighted imaging (DWI) using commercial phantom, and confirm the validated protocols in patients' images. Methods: The performance of four different scanners and clinical brain protocols were validated using a Quantitative Imaging Biomarker Alliance (QIBA) diffusion phantom and cloud-based analysis tool. We evaluated the performance metrics regarding accuracy and repeatability of ADC measurement using QIBA profile. The validated clinical brain protocols were applied to 17 patients, and image quality and repeatability of ADC were assessed. Results: The MRI equipment performance of all four MRI scanners demonstrated high accuracy in ADC measurement (ADC bias, -2.3% to -0.4%), excellent linear correlation to the reference ADC value (slope, 0.9 to 1.0; R2, 0.999-1.000), and high short-term repeatability [within-subject-coefficient-of-variation (wCV), 0% to 0.3%]. The clinical protocols were also validated by fulfilling QIBA claims with high accuracy (ADC bias, -3.1% to -0.7%) and robust repeatability (wCV, 0% to 0.1%). Brain DWI acquired using the validated clinical protocols showed ideal image quality (mean score ≥ 2.9) and good repeatability (wCV, 1.8-2.2). Conclusions: The whole process of standardization of DWI demonstrated the robustness of ADC with high accuracy and repeatability across diverse MRI equipment and clinical protocols in accordance with the QIBA claims.

Automated segmentation of the fractured vertebrae on CT and its applicability in a radiomics model to predict fracture malignancy.

Although CT radiomics has shown promising results in the evaluation of vertebral fractures, the need for manual segmentation of fractured vertebrae limited the routine clinical implementation of radiomics. Therefore, automated segmentation of fractured vertebrae is needed for successful clinical use of radiomics. In this study, we aimed to develop and validate an automated algorithm for segmentation of fractured vertebral bodies on CT, and to evaluate the applicability of the algorithm in a radiomics prediction model to differentiate benign and malignant fractures. A convolutional neural network was trained to perform automated segmentation of fractured vertebral bodies using 341 vertebrae with benign or malignant fractures from 158 patients, and was validated on independent test sets (internal test, 86 vertebrae [59 patients]; external test, 102 vertebrae [59 patients]). Then, a radiomics model predicting fracture malignancy on CT was constructed, and the prediction performance was compared between automated and human expert segmentations. The algorithm achieved good agreement with human expert segmentation at testing (Dice similarity coefficient, 0.93-0.94; cross-sectional area error, 2.66-2.97%; average surface distance, 0.40-0.54 mm). The radiomics model demonstrated good performance in the training set (AUC, 0.93). In the test sets, automated and human expert segmentations showed comparable prediction performances (AUC, internal test, 0.80 vs 0.87, p = 0.044; external test, 0.83 vs 0.80, p = 0.37). In summary, we developed and validated an automated segmentation algorithm that showed comparable performance to human expert segmentation in a CT radiomics model to predict fracture malignancy, which may enable more practical clinical utilization of radiomics.

Prediction of the Acuity of Vertebral Compression Fractures on CT Using Radiologic and Radiomic Features.

RATIONALE AND OBJECTIVES: To develop and validate prediction models to differentiate acute and chronic vertebral compression fractures based on radiologic and radiomic features on CT. MATERIALS AND METHODS: This study included acute and chronic compression fractures in patients who underwent both spine CT and MRI examinations. For each fractured vertebra, three CT findings ([1] cortical disruption, [2] hypoattenuating cleft or sclerotic line, and [3] relative bone marrow attenuation) were assessed by two radiologists. A radiomic score was built from 280 radiomic features extracted from non-contrast-enhanced CT images. Weighted multivariable logistic regression analysis was performed to build a radiologic model based on CT findings and an integrated model combining the radiomic score and CT findings. Model performance was evaluated and compared. Models were externally validated using an independent test cohort. RESULTS: A total to 238 fractures (159 acute and 79 chronic) in 122 patients and 58 fractures (39 acute and 19 chronic) in 32 patients were included in the training and test cohorts, respectively. The AUC of the radiomic score was 0.95 in the training and 0.93 in the test cohorts. The AUC of the radiologic model was 0.89 in the training and 0.83 in the test cohorts. The discriminatory performance of the integrated model was significantly higher than the radiologic model in both the training (AUC, 0.97; p<0.01) and the test (AUC, 0.95; p=0.01) cohorts. CONCLUSION: Combining radiomics with radiologic findings significantly improved the performance of CT in determining the acuity of vertebral compression fractures.