CT Texture analysis and CT scores for characterization of fluid collections.

BACKGROUND: Texture analysis derived from Computed tomography (CT) might be able to better characterize fluid collections undergoing CT-guided percutaneous drainage treatment. The present study tested, whether texture analysis can reflect microbiology results in fluid collections suspicious for septic focus. METHODS: Overall, 320 patients with 402 fluid collections were included into this retrospective study. All fluid collections underwent CT-guided drainage treatment and were microbiologically evaluated. Clinically, serologically parameters and conventional imaging findings as well as textures features were included into the analysis. A new CT score was calculated based upon imaging features alone. Established CT scores were used as a reference standard. RESULTS: The present score achieved a sensitivity of 0.78, a specificity of 0.69, area under curve (AUC 0.82). The present score and the score by Gnannt et al. (AUC 0.81) were both statistically better than the score by Radosa et al. (AUC 0.75). Several texture features were statistically significant between infected fluid collections and sterile fluid collections, but these features were not significantly better compared with conventional imaging findings. CONCLUSIONS: Texture analysis is not superior to conventional imaging findings for characterizing fluid collections. A novel score was calculated based upon imaging parameters alone with similar diagnostic accuracy compared to established scores using imaging and clinical features.

Endoscopic Necrosectomy of Walled-Off Necrosis following Severe Pancreatitis Using a Hot AxiosTM Stent - A Case Series.

BACKGROUND: Walled-off necrosis is a common complication of severe pancreatitis. Guidelines recommend endoscopic transgastric necrosectomy as therapy of choice. Different endoscopic approaches are possible. METHODS: We retrospectively analyzed our series of 9 patients where necrosectomy was performed after application of a lumen-apposing metal stent (LAMS) delivered using a Hot AxiosTM Stent device. RESULTS: In all 9 cases, the walled-off necrosis resolved completely. Necrosectomy was performed through the LAMS (mean: 5.7 times). Endoscopic necrosectomy was repeated every 3rd-7th day using 10- or 15-mm snares. There were no major complications. Especially, no early or delayed bleeding was seen. CONCLUSION: The Hot AxiosTM Stent device is a safe method for necrosectomy of walled-off necrosis. It enables puncture, drainage, and LAMS insertion in a single delivery, followed by several courses of necrosectomy if needed without stent exchange.

Treatment of Acute Hemoptysis by Bronchial Artery Embolization with the Liquid Embolic Agent Ethylene Vinyl Alcohol Copolymer.

PURPOSE: To determine the technical and clinical success of bronchial artery embolization (BAE) with the liquid embolic agent ethylene vinyl alcohol (EVOH) copolymer in patients with acute hemoptysis. MATERIALS AND METHODS: Thirty-four patients (25 male; mean age, 58 y; range, 13-78 y) who underwent BAE with EVOH were retrospectively reviewed. Reasons for acute hemoptysis included lung cancer (44%), pulmonary metastases (12%), bronchiectasis (21%), arteriovenous malformation (5%), tuberculosis (6%), aspergilloma (3%), acute respiratory distress syndrome (3%), anticoagulant overdose (3%), and scar tissue (3%). Technical and clinical success of BAE were retrospectively assessed. RESULTS: Embolization was technically successful in 94% of patients. Additional embolization material was needed in 4 patients (12%). The immediate clinical success rate was 94% (32 of 34); in 2 patients (6%), hemoptysis recurred immediately after the intervention or could not be stopped. Periinterventional minor complications included headache (n = 1), fever (n = 1), and acute renal failure (n = 1). During follow-up (mean, 8.8 mo), 5 patients had a recurrence of hemoptysis (15%). CONCLUSIONS: The use of EVOH copolymer for BAE in patients with acute hemoptysis is technically successful and safe and has a good clinical outcome with a low number of recurrences.

Ethanol-Gel Sclerotherapy of Venous Malformations: Effectiveness and Safety.

OBJECTIVE: In the treatment of venous malformations, ethanol may be administered in a gelified form to increase local effects and reduce systemic ones. The purpose of this prospective study was to evaluate the efficacy and safety of a commercially available viscous ethanol gel in the treatment of venous malformations. SUBJECTS AND METHODS: Thirty-one patients (mean age, 23.4 years; age range, 6.6-46.5 years) with venous malformations were prospectively scheduled for two ethanol-gel sclerotherapy sessions. Venous malformations were located at the lower extremity (n = 18), the upper extremity (n = 9), and the face (n = 4). Questionnaires to assess pain, clinical examinations, professional photographs, and contrast-enhanced MRI of the venous malformations were performed before and after therapy to measure therapy-induced changes. Two experienced radiologists blinded to the examination date and clinical status compared photographs and MR images before and after treatment. RESULTS: A mean of 4.2 mL of ethanol gel were administered per session. The technical success rate was 100%. Clinical success, defined as improvement or resolution of symptoms, was noted in 81% of patients. Mean pain score decreased, and the difference was statistically significant (3.9 vs 3.1, p = 0.005). In 54 treatment sessions where follow-up was available, four minor complications occurred. Comparison of photographs and MR images before and after treatment showed improvement in 35% and 93% of patients, respectively. CONCLUSION: Ethanol gel is an effective and safe sclerosing agent in the treatment of venous malformations.

Degradable starch microspheres versus ethiodol and doxorubicin in transarterial chemoembolization of hepatocellular carcinoma.

PURPOSE: To compare outcomes of transarterial chemoembolization with degradable starch microspheres (DSMs) and conventional transarterial chemoembolization with doxorubicin and Ethiodol in patients with unresectable intermediate-stage hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 69 patients underwent 169 chemoembolization procedures with Ethiodol (n = 35) or DSMs (n = 34) as the embolic agent. The same chemotherapeutic agent was used for all patients (50 mg doxorubicin). The primary endpoint was patient survival, and secondary endpoints were local tumor response and incidence of therapy-associated complications with conventional or DSM chemoembolization. Tumor response was evaluated by consensus reading by two radiologists in accordance with modified Response Evaluation Criteria In Solid Tumors. Mean survival was calculated according to Kaplan-Meier analysis, and differences in survival curves were assessed by univariate log-rank test. The statistical significance of quantitative variables was determined by parameter-free Wilcoxon-Mann-Whitney U test. RESULTS: The study groups were similar with regard to demographic data and disease stage. For the DSM chemoembolization group, the objective response rate (ie, complete or partial response) was 44.1%, and the rate of stable disease was 38.2%. The respective rates for the conventional chemoembolization group were 48.6% and 31.4%. Mean survival (P = .337) and complications did not significantly differ between groups (P = .907; P = 1.000). CONCLUSIONS: DSM chemoembolization represents an alternative method of HCC treatment with a safety profile similar to that of conventional transarterial chemoembolization. Regarding local tumor response and overall survival, results of DSM chemoembolization were similar to those of conventional chemoembolization.

Significance of Postprocedural Contrast Medium Injection after CT-Guided Abscess Drainage.

The aim was to evaluate the additive clinical value of an additional post-procedural control-scan after CT-guided percutaneous abscess drainage (PAD) placement with contrast medium (CM) via the newly placed drain. All CT-guided PADs during a 33-month period were retrospectively analyzed. We analyzed two subgroups, containing patients with and without surgery before intervention. Additionally, radiological records were reevaluated, concerning severe inflammatory response syndrome (SIRS) during the intervention. A total of 499 drainages were placed under CT-guidance in 352 patients. A total of 197 drainages were flushed with CM directly after the intervention, and 51 (26%) showed an additional significant finding. An immediate change of therapy was found in 19 cases (9%). The subgroup that underwent surgery (120 CM-drainages; 32 (27%) additional findings; 13 (11%) immediate changes of therapy) showed no statistically significant difference compared to the subgroup without surgery (77 CM-drainages; 19 (25%) additional findings; 5 (6%) immediate changes of therapy). SIRS occurred in 2 of the 197 flushed drainages (1%) after CM application. An additional scan with CM injection via the newly placed drain revealed clinically significant additional information in almost 26% of the drainages reviewed in this study. In 9% of the cases this information led to an immediate change of therapy. Risks for SIRS are low.

Right portal vein ligation combined with in situ splitting induces rapid left lateral liver lobe hypertrophy enabling 2-staged extended right hepatic resection in small-for-size settings.

OBJECTIVE: To evaluate a new 2-step technique for obtaining adequate but short-term parenchymal hypertrophy in oncologic patients requiring extended right hepatic resection with limited functional reserve. BACKGROUND: Patients presenting with primary or metastatic liver tumors often face the dilemma that the remaining liver tissue may not be sufficient. Preoperative portal vein embolization has thus far been established as the standard procedure for achieving resectability. METHODS: Two-staged hepatectomy was performed in patients who preoperatively appeared to be marginally resectable but had a tumor-free left lateral lobe. Marginal respectability was defined as a left lateral lobe to body weight ratio of less than 0.5. In the first step, surgical exploration, right portal vein ligation (PVL), and in situ splitting (ISS) of the liver parenchyma along the falciform ligament were performed. Computed tomographic volumetry was performed before ISS and before completion surgery. RESULTS: The study included 25 patients with primary liver tumors (hepatocellular carcinoma: n = 3, intrahepatic cholangiocarcinoma: n = 2, extrahepatic cholangiocarcinoma: n = 2, malignant epithelioid hemangioendothelioma: n = 1, gallbladder cancer: n = 1 or metastatic disease [colorectal liver metastasis]: n = 14, ovarian cancer: n = 1, gastric cancer: n = 1). Preoperative CT volumetry of the left lateral lobe showed 310 mL in median (range = 197-444 mL). After a median waiting period of 9 days (range = 5-28 days), the volume of the left lateral lobe had increased to 536 mL (range = 273-881 mL), representing a median volume increase of 74% (range = 21%-192%) (P < 0.001). The median left lateral liver lobe to body weight ratio was increased from 0.38% (range = 0.25%-0.49%) to 0.61% (range = 0.35-0.95). Ten of 25 patients (40%) required biliary reconstruction with hepaticojejunostomy. Rapid perioperative recovery was reflected by normalization of International normalized ratio (INR) (80% of patients), creatinine (84% of patients), nearly normal bilirubin (56% of patients), and albumin (64% of patients) values by day 14 after completion surgery. Perioperative morbidity was classified according to the Dindo-Clavien classification of surgical complications: grade I (12 events), grade II (13 events), grade III (14 events, III a: 6 events, III b: 8 events), grade IV (8 events, IV a: 3 events, IV b: 5 events), and grade V (3 events). Sixteen patients (68%) experienced perioperative complications. Follow-up was 180 days in median (range: 60-776 days) with an estimated overall survival of 86% at 6 months after resection. CONCLUSIONS: Two-step hepatic resection performing surgical exploration, PVL, and ISS results in a marked and rapid hypertrophy of functional liver tissue and enables curative resection of marginally resectable liver tumors or metastases in patients that might otherwise be regarded as palliative.

Retrospective evaluation of early thrombosis in transjugular intrahepatic portosystemic polytetrafluoroethylene-coated shunts under 2-day postinterventional heparinization.

The development of acute thrombosis within the TIPS tract may be prevented by prophylactic anticoagulation; however, there is no evidence of the correct anticoagulation regimen after TIPS placement. The purpose of this single-center retrospective study was to evaluate the short-term occlusion rate of transjugular intrahepatic portosystemic shunts (TIPSs) with polytetrafluorethylene (PTFE)-coated stents under consequent periprocedural full heparinization (target partial thromboplastin time [PTT]: 60-80 s). We analyzed TIPS placements that were followed up over a six-month period by Doppler ultrasound in 94 patients and compared the study group of 54 patients who received intravenous periprocedural full heparinization (target PTT: 60-80 s) without any other anticoagulation to patients with prolonged anticoagulation medication. The primary endpoint was TIPS patency after six months. The primary patency rate was 88.3% overall, and in the study group, 90.7%, with an early thrombosis rate of 3.2% (study group: 1.9%) and a primary assisted patency rate of 95.7% (study group: 96.3%). In the study group, one case of TIPS thrombosis occurred on the 23rd day after TIPS placement. Two patients underwent reintervention because of stenosis or buckling. Moreover, the target PTT was not attained in 8 of the 54 patent TIPSs. Four patients had an increased portosystemic pressure gradient, without stenosis, and the flow rate was corrected by increasing the TIPS diameter by dilation. Two-day heparinization seems sufficient to avoid early TIPS thrombosis over a six-month period.

The Liver Maximum Capacity Test (LiMAx) Is Associated with Short-Term Survival in Patients with Early Stage HCC Undergoing Transarterial Treatment.

Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are recommended to treat patients with early or intermediate hepatocellular carcinoma (HCC). The liver maximum capacity test (LiMAx) has been supposed to predict the risk of post-interventional liver failure. We investigated the correlation of LiMAx with short-term survival as primary endpoint and the occurrence of adverse events after therapy as secondary endpoint. Our study cohort prospectively included 69 patients receiving TACE (n = 57) or TARE (n = 12). LiMAx test and serological analyses were performed on the day before and 4 weeks after treatment. Hepatic and extrahepatic complications were monitored for 4 weeks. The LiMAx results were not associated with altered liver function and the occurrence of adverse events. The survival rates of patients with BCLC A with LiMAx ≤ 150 µg/kg/h were lower after 30 days (75.0 ± 15.3% vs. 100%, p = 0.011), 90 days (62.5 ± 17.7% vs. 95.8 ± 4.1%, p = 0.011) and 180 days (50.0 ± 17.7% vs. 95.8 ± 4.1%, p = 0.001) compared to those with higher LiMAx levels. The LiMAx test is not suitable to predict liver function abnormalities or the occurrence of complications 4 weeks after therapy but enables the identification of patients with early stage HCC and reduced short-term survival after treatment.

Impact of low dose settings on radiation exposure during pediatric fluoroscopic guided interventions.

PURPOSE: To evaluate the effects of lowering the detector entrance exposure in children undergoing interventional radiology procedures. MATERIALS AND METHODS: The study retrospectively investigated radiation dose levels in pediatric patients aged 0-18 years before (n = 39) and after (n = 26) lowering detector entrance dose, undergoing embolization of peripheral Arteriovenous malformations, Portal Vein Interventions or Percutaneous Transhepatic Cholangio Drainage (PTCD) between 2014 and 2017. Patient characteristics, fluoroscopy time, protocols used as well as resulting Skin Dose and Dose Area Product (DAP) were compared in each cohort. Image quality was assessed by two independent readers. RESULTS: The two patient cohorts did not differ in terms of patient demographics. Similarly, fluoroscopy time did not differ before and after implementation of the low dose settings. An overall reduction of skin dose of 75.1% for AVM embolizations, 80.5% for Portal Vein Interventions and 85.3% for PTCD placement was observed. The DAP decrease was 82.5% for AVM embolizations, 72.2% for Portal Vein Interventions and 79.8% for PTCD placement. Image quality was generally considered to be good with an insignificant difference between pre and post implementation of the low dose approach and good agreement between the two readers. Manual inroom-switching to higher dose levels was possible, however this was not performed more frequently after implementation of the low dose settings. CONCLUSION: Lowering the detector entrance dose in pediatric interventional radiology procedures results in a significant decrease of the radiation dose burden.

Direct Effective Dose Calculations in Pediatric Fluoroscopy-Guided Abdominal Interventions with Rando-Alderson Phantoms - Optimization of Preset Parameter Settings.

OBJECTIVE: The aim of the study was to calculate the effective dose during fluoroscopy-guided pediatric interventional procedures of the liver in a phantom model before and after adjustment of preset parameters. METHODS: Organ doses were measured in three anthropomorphic Rando-Alderson phantoms representing children at various age and body weight (newborn 3.5kg, toddler 10kg, child 19kg). Collimation was performed focusing on the upper abdomen representing mock interventional radiology procedures such as percutaneous transhepatic cholangiography and drainage placement (PTCD). Fluoroscopy and digital subtraction angiography (DSA) acquisitions were performed in a posterior-anterior geometry using a state of the art flat-panel detector. Effective dose was directly measured from multiple incorporated thermoluminescent dosimeters (TLDs) using two different parameter settings. RESULTS: Effective dose values for each pediatric phantom were below 0.1mSv per minute fluoroscopy, and below 1mSv for a 1 minute DSA acquisition with a frame rate of 2 f/s. Lowering the values for the detector entrance dose enabled a reduction of the applied effective dose from 12 to 27% for fluoroscopy and 22 to 63% for DSA acquisitions. Similarly, organ doses of radiosensitive organs could be reduced by over 50%, especially when close to the primary x-ray beam. CONCLUSION: Modification of preset parameter settings enabled to decrease the effective dose for pediatric interventional procedures, as determined by effective dose calculations using dedicated pediatric Rando-Alderson phantoms.

Measuring leg length and offset with an imageless navigation system during total hip arthroplasty: is it really accurate?

BACKGROUND: A novel imageless measurement algorithm to assess leg length (LL) and offset (OS) changes during total hip arthroplasty (THA) has been established, the purpose of this study was to describe the process and establish whether or not it is accurate. METHODS: THA was performed on 17 cadaver hip specimens. LL and OS changes were determined intra-operatively, using an imageless navigation system. Pre- and postoperatively, all specimens had a computed tomography scan (CT) and the LL and OS changes were analysed by two blinded investigators. RESULTS: With mean differences of less than 1 mm (LL, 0.74; SD, 2.4 mm; OS, 0.89; SD, 1.8 mm) supported by substantial significant correlations [r = 0.83 (LL) and r = 0.92 (OS)] imageless navigation values demonstrated a high accuracy when compared to CT measurements. CONCLUSIONS: Intra-operative LL and OS measures are reliable and accurate when using an imageless calculation algorithm which stores the position of the femoral reference frame in relation to the pelvic coordinate system before and after reconstruction.