Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “DIGESTIVE SYSTEM”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Transarterial Hepatic Yttrium-90 Radioembolization in Patients with Unresectable Intrahepatic Cholangiocarcinoma: Factors Associated with Prolonged Survival

Introduction: In unresectable intrahepatic cholangiocarcinoma (ICC), systemic chemotherapy often is viewed as the only option, although efficacy is limited. Radioembolization (RE) using yttrium-90 ({sup 90}Y) microspheres is an accepted therapy for patients with hepatocellular-carcinoma or metastatic liver tumors. However, there are limited data on the value of RE in patients with ICC and few data on factors influencing prognosis. The purpose of our retrospective analysis was to establish which factors influenced time-to-progression (TTP) and overall survival (OS). Methods: Patients with unresectable ICC were treated with {sup 90}Y resin-microspheres and assessed at 3-monthly intervals. Radiologic response was evaluated by using Response Criteria in Solid Tumors (RECIST). Baseline characteristics, biochemical/clinical toxicities, and response were examined for impact on TTP and OS. Results: Thirty-four treatments were administered to 33 patients without major complications. By RECIST, 12 patients had a partial response, 17 had stable disease, and 5 had progressive disease after 3 months. The median OS was 22 months posttreatment and 43.7 months postdiagnosis. Median TTP was 9.8 months. Survival and TTP were significantly prolonged in patients with ECOG 0 (vs. ECOG 1 or 2; median OS: 29.4, 10, and 5.1 months; TTP: 17.5, 6.9, and 2.4 months), tumor burden {<=}25% (OS: 26.7 vs. 6 months; TTP: 17.5 vs. 2.3 months), or tumor response (PR or SD vs. PD; OS: 35.5, 17.7 vs. 5.7 months; TTP: 31.9, 9.8 vs. 2.5 months), respectively (P < 0.001). Conclusions: Radioembolization is an effective and safe option for patients with unresectable ICC. Predictors for prolonged survival are performance status, tumor burden, and RECIST response.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

A Comparison Between Electronic Portal Imaging Device and Cone Beam CT in Radiotherapy Verification of Nasopharyngeal Carcinoma

The demand of greater accuracy in intensity-modulated radiotherapy (IMRT) has driven the development of more advanced verification systems. The purpose of this study is to investigate the differences in verification accuracy in terms of the position error detected between cone-beam computed tomography (CBCT) and electronic portal imaging device (EPID) in the IMRT of nasopharyngeal carcinoma (NPC). Two groups of NPC patients (n = 22 and n = 28) verified by CBCT (G1-CB), EPID (G1-EP), and EPID (G2-EP) only, respectively, were recruited. The positional errors between the G1-CB group and the G2-EP group were compared. In addition, the magnitudes of the position errors of EPID taken in the same session of the CBCT, but after necessary corrections (G1-EP), were analyzed. In the CBCT group, 455 CBCT images (G1-CB) and 206 EPID images (G1-EP) were collected, whereas 319 EPID images (G2-EP) for the EPID group, were recorded. The median position errors detected in CBCT were between 0.80 and 0.90 mm in the antero-posterior (A-P), left-right (L-R), and supero-inferior (S-I) directions, whereas those of the EPID were all 0.50 mm. The magnitude of position deviation detected by the CBCT was higher than that of the EPID and their differences were extremely significant (p < 0.001). The frequencies in the G2-EP group with position errors greater than the tolerance (2 mm) were 32, 42, and 27 in the A-P, L-R, and S-I directions, respectively, which accounted for 16.5%, 21.6%, and 13.9% of the total number of EPID. There was difference in verification capability between the CBCT and EPID when applied to IMRT of NPC patients. Because an average of 1 of 6 verifications in EPID was inferior to that of the CBCT, verification by CBCT is recommended.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Efficacy of perfusion CT in differentiating of pancreatic ductal adenocarcinoma from mass-forming chronic pancreatitis and characterization of isoattenuating pancreatic lesions

Purpose: Multidetector computed tomography (MDCT) is routinely used in the diagnosis of pancreatic ductal adenocarcinoma (PDAC), but it may be inadequate in some cases, especially mass-forming chronic pancreatitis (MFCP) and isoattenuating pancreatic lesions. Perfusion CT (pCT) may help resolve this problem. The aim of this study was to evaluate whether pCT could help differentiating PDAC from MFCP and in characterization of isoattenuating pancreatic lesions. Materials and methods: This prospective study included 89 cases of pancreatic lesions detected by MDCT and further analyzed with pCT. Sixty-one cases with final pathological diagnosis PDAC and 12 cases with MFCP were included from the study. Blood volume (BV), blood flow (BF), mean transit time (MTT), and permeability surface area product (PS) maps were obtained. Perfusion values obtained from the lesions and normal parenchyma were compared. Results: Compared with normal parenchyma, BV, BF, PS were lower and MTT was longer in PDAC and MFCP (p < 0.05). Compared with MFCP, BV, BF, PS were lower and MTT was longer in PDAC (p < 0.001). Compared with normal parenchyma, BV, BF, PS were lower and MTT was longer in isoattenuating lesions, (p < 0.001). Cutoff values of 7.60 mL/100 mL, 64.43 mL/100 mL/min, 28.08 mL/100 mL/min for BV, BF, PS, respectively, provided 100% sensitivity and specificity and 7.47 s for MTT provided 98.3% sensitivity, 80% specificity for distinguishing PDAC from MFCP. Conclusion: pCT is a useful technology that can be helpful in overcoming the limitations of routine MDCT in diagnosing PDAC and characterization of isoattenuating lesions.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

The LACSEMS: what radiologists need to know

Endoscopic drainage is increasingly used in lieu of percutaneous or surgical drainage of pancreatitis-related fluid collections. The lumen-apposing, covered, self-expanding, metallic stent (LACSEMS) is a newly produced stent for the transmural drainage of such fluid collections. The use of LACSEMS devices requires close coordination between knowledgeable radiologic and gastrointestinal providers. We review pancreatitis-related fluid collections and show examples from our experience with LACSEMS and the appropriate case selection, planning, deployment, and follow-up for this novel device.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Interobserver agreement of computed tomography reporting standards for chronic pancreatitis

Aim: To assess the interobserver agreement of computed tomography (CT) reporting standards for chronic pancreatitis (CP). Subjects and methods: Retrospective analysis of CT of 47 patients (33 males and 11 females, age range 36 to 56 years) with CP who presented with abdominal pain (n = 41), steatorrhea (n = 37), and glucose intolerance (n = 31). The patients underwent CT study using a 16-multidetector CT scanner with a pancreatic protocol including a nonenhanced scan followed by pancreatic phase at 35 s and portal venous phase at 65 s after intravenous injection of nonionic contrast medium. Image analysis was performed by two radiologists according to reporting standards for CP. Results: There was excellent interobserver agreement (84.8 %) between the two reviewers in CT reporting standards for CP (K = 0.80, 95 % CI 0.75–0.85, P = 0.001). There was good interobserver agreement for pancreatic duct (PD) caliber (K = 0.71, 95 % CI 0.56–0.87, P = 0.001), PD contour (K = 0.76, 95 % CI 0.61–0.91, P = 0.001), PD stricture (K = 0.070, 95 % CI 0.53–0.88, P = 0.001), and distribution of findings (K = 0.69, 95 % CI 0.51–0.86, P = 0.001). There was excellent interobserver agreement for intraductal calculi (K = 0.84, 95 % CI 0.68–0.98, P = 0.001), pancreatic calcifications (K = 0.86, 95 % CI 0.84–0.98, P = 0.001), and pancreatic diameter (K = 0.87, 95 % CI 0.75–0.99, P = 0.001). Conclusion: CT reporting standards for CP is a reliable method for diagnosis of patients with CP.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Long-Term Follow-Up of the Percutaneous Treatment of Hydatid Cyst in the Adrenal Gland: A Case Report and Review of the Literature

Although the most involved organs are liver and lung, hydatid cysts occur in adrenal glands, rarely, and constitute only 0.5% of hydatid cysts. Herein, we demonstrate and discuss, for the first time in the literature to the best of our knowledge, the radiological features of adrenal hydatid disease and evaluate the long-term results (57 months of follow-up) of the percutaneous treatment of hydatid cyst in the adrenal gland in a patient.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Interval Biliary Stent Placement Via Percutaneous Ultrasound Guided Cholecystostomy: Another Approach to Palliative Treatment in Malignant Biliary Tract Obstruction

Percutaneous cholecystostomy is a minimally invasive procedure for providing gallbladder decompression, often in critically ill patients. It can be used in malignant biliary obstruction following failed endoscopic retrograde cholangiopancreatography when the intrahepatic ducts are not dilated or when stent insertion is not possible via the bile ducts. In properly selected patients, percutaneous cholecystostomy in obstructive jaundice is a simple, safe, and rapid option for biliary decompression, thus avoiding the morbidity and mortality involved with percutaneous transhepatic biliary stenting. Subsequent use of a percutaneous cholecystostomy for definitive biliary stent placement is an attractive concept and leaves patients with no external drain. To the best of our knowledge, it has only been described on three previous occasions in the published literature, on each occasion forced by surgical or technical considerations. Traditionally, anatomic/technical considerations and the risk of bile leak have precluded such an approach, but improvements in catheter design and manufacture may now make it more feasible. We report a case of successful interval metal stent placement via percutaneous cholecystostomy which was preplanned and achieved excellent palliation for the patient. The pros and cons of the procedure and approach are discussed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Thoracic Discitis as a Complication of Self-Expanding Metallic Stents in Esophageal Carcinoma

The role of metallic stents in the palliation of esophageal cancer is well established. Self-expanding metal stents (SEMSs) are frequently used, as they provide an effective and safe method of relieving malignant dysphagia. A number of complications are associated with the use of SEMSs, including esophageal perforation. We report a case of thoracic discitis occurring in a patient with advanced esophageal malignancy, treated with SEMSs. We propose that the likely etiology in this patient was esophageal perforation by a metallic stent.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Liver Hydatid Cyst with Transdiaphragmatic Rupture and Lung Hydatid Cyst Ruptured into Bronchi and Pleural Space

The aim of this case study is to present effectiveness of percutaneous drainage as a treatment option of ruptured lung and liver hydatid cysts. A 65-year-old male patient was admitted with complicated liver and lung hydatid cysts. A liver hydatid cyst had ruptured transdiaphragmatically, and a lung hydatid cyst had ruptured both into bronchi and pleural space. The patient could not undergo surgery because of decreased respiratory function. Both cysts were drained percutaneously using oral albendazole. Povidone-iodine was used to treat the liver cyst after closure of the diaphragmatic rupture. The drainage was considered successful, and the patient had no recurrence of signs and symptoms. Clinical, laboratory, and radiologic recovery was observed during 2.5 months of catheterization. The patient was asymptomatic after catheter drainage. No recurrence was detected during 86 months of follow-up. For inoperable patients with ruptured liver and lung hydatid cysts, percutaneous drainage with oral albendazole is an alternative treatment option to surgery. The percutaneous approach can be life-saving in such cases.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Aortoesophageal Fistula and Aortic Pseudoaneurysm Induced by Swallowed Fish Bone: A Report of Two Cases

Esophageal perforation caused by accidental swallowing of fish bones can lead to rare complications, such as aortoesophageal fistula accompanied by aortic pseudoaneurysm, which can be fatal if not properly handled. We report two rare cases of aortoesophageal fistula and aortic pseudoaneurysm caused by esophagus perforation after accidental swallow of fish bone; the patients also had purulent mediastinitis and esophagitis. The treatment of aortic pseudoaneurysm was successful in both cases, with one patient undergoing surgical resection and aortic neoplasty and the other patient undergoing endovascular stent graft placement. Long-term antibiotic treatment was administered to both patients after surgery. There were no postsurgical complications, and the patients recovered without incident.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Radiologic-Pathologic Correlation of Hepatocellular Carcinoma Treated with Chemoembolization

To correlate posttreatment radiologic and pathologic findings in patients who underwent transarterial chemoembolization before transplantation or resection. Thirty-five patients with postchemoembolization follow-up imaging underwent liver transplantation/resection. Pre- and posttreatment contrast-enhanced magnetic resonance imaging were used to evaluate radiologic findings. Imaging characteristics using World Health Organization (WHO) and European Association for the Study of the Liver (EASL) criteria after treatment were evaluated. Treated lesions were examined by pathology (gold standard) for the assessment of necrosis. Radiologic findings on magnetic resonance imaging were correlated to pathologic findings to assess the predictability by imaging of actual necrosis. Kappa ({kappa}) statistics were used to determine intermethod agreement between WHO and EASL criteria. Fourteen (40%) of 35 lesions had biopsy-proven hepatocellular carcinoma. Thirteen (37%) of 35 target lesions showed complete pathologic necrosis. Complete pathologic necrosis was seen in 35% of lesions with pretreatment size <3 cm. Complete pathologic necrosis was seen in 1 (100%) of 1, 6 (67%) of 9, 6 (33%) of 18, and 0 (0%) of 7 of the lesions that exhibited complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD) by WHO criteria, respectively. Complete pathologic necrosis was seen in 9 (82%) of 11, 4 (36%) of 11, 0 (0%) of 8, and 0 (0%) of 5 of the lesions that showed CR, PR, SD, or PD by EASL criteria, respectively. EASL CR and WHO response were shown to have {>=}85% specificity for predicting complete pathologic necrosis. The {kappa} coefficient for agreement between WHO and EASL was 0.29. EASL and WHO criteria had minimal intermethod agreement. EASL CR and WHO response were able to predict pathologic necrosis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Refractory Cystobiliary Fistula Secondary to Percutaneous Treatment of Hydatid Cyst: Treatment with N-Butyl 2-Cyanoacrylate Embolization

A 27-year-old female with a type 2 hydatid cystic lesion in the liver according to the Gharbi classification (CE 3A according to the WHO classification) was referred for percutaneous treatment after albendazole treatment for 1 year. A catheterization technique was performed but hypertonic saline and alcohol were not given into the cavity due to cystobiliary leakage. During the 4-month follow-up period, sequential cavitography revealed biliary fistula, and bile-stained drainage had not been ceased despite the sphincterotomy, nasobiliary drainage catheter, and plastic stent. Since the patient refused to surgery, we embolized the biliary fistula using N-butyl 2-cyanoacrylate for the first time in the literature. At the 3-month follow-up, the patient's course was uneventful and ultrasound, multidetector-row CT, and MRI examinations revealed no collection in or adjacent to the cavity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Stenting of the Lower Gastrointestinal Tract: Current Status

Colon obstruction due to colorectal cancer is a major surgical emergency. Patients with acute bowel obstruction are usually poor surgical candidates with 10-20% operative mortality and 40-50% operative morbidity rates. Colorectal stenting is an image-guided, minimally invasive procedure, and typical indications include either palliation of inoperable malignant disease or temporary bowel decompression as a bridge to surgery. Colorectal stenting allows the patient to recover before definite elective surgical resection, reducing perioperative morbidity and mortality, overall hospital stay, and associated health care costs. Palliative stenting improves quality of life compared to surgery. A concise review is provided of contemporary stenting practice of the lower gastrointestinal tract, the colon in particular, and both palliative and preoperative adjuvant procedures are evaluated in terms of relevant patient oncology, insertion technique, available stent designs, technical and clinical outcomes, associated complications, and cost-benefit analysis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Transcatheter Arterial Chemoembolization for Liver Cancer: Is It Time to Distinguish Conventional from Drug-Eluting Chemoembolization?

Conventional transcatheter arterial chemoembolization and chemoembolization with drug-eluting beads are increasingly being performed interchangeably in many institutions throughout the world. As both therapies continue to being tested in many phase II and III studies and in combination with other therapies, especially targeted agents, for treatment of primary and metastatic liver cancer, it is imperative to review their current status and evaluate their impact on patient survival. This review critically assesses patient selection, indications, contraindications, techniques, materials, safety, and clinical outcomes of patients treated with conventional chemoembolization and chemoembolization with drug-eluting beads.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Management of Transjugular Intrahepatic Portosystemic Shunt (TIPS)-associated Refractory Hepatic Encephalopathy by Shunt Reduction Using the Parallel Technique: Outcomes of a Retrospective Case Series

Purpose: To investigate the reproducibility and technical and clinical success of the parallel technique of transjugular intrahepatic portosystemic shunt (TIPS) reduction in the management of refractory hepatic encephalopathy (HE). Materials and Methods: A 10-mm-diameter self-expanding stent graft and a 5-6-mm-diameter balloon-expandable stent were placed in parallel inside the existing TIPS in 8 patients via a dual unilateral transjugular approach. Changes in portosystemic pressure gradient and HE grade were used as primary end points. Results: TIPS reduction was technically successful in all patients. Mean {+-} standard deviation portosystemic pressure gradient before and after shunt reduction was 4.9 {+-} 3.6 mmHg (range, 0-12 mmHg) and 10.5 {+-} 3.9 mmHg (range, 6-18 mmHg). Duration of follow-up was 137 {+-} 117.8 days (range, 18-326 days). Clinical improvement of HE occurred in 5 patients (62.5%) with resolution of HE in 4 patients (50%). Single episodes of recurrent gastrointestinal hemorrhage occurred in 3 patients (37.5%). These were self-limiting in 2 cases and successfully managed in 1 case by correction of coagulopathy and blood transfusion. Two of these patients (25%) died, one each of renal failure and hepatorenal failure. Conclusion: The parallel technique of TIPS reduction is reproducible and has a high technical success rate. A dual unilateral transjugular approach is advantageous when performing this procedure. The parallel technique allows repeat bidirectional TIPS adjustment and may be of significant clinical benefit in the management of refractory HE.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Percutaneous Cholecystostomy as a First-Line Therapy in Chronic Hemodialysis Patients with Acute Cholecystitis with Midterm Follow-up

Purpose: The purpose of this article was to share midterm results of percutaneous cholecystostomy (PC) as a first-line therapy in chronic hemodialysis patients with acute cholecystitis. Methods: Fourteen chronic hemodialysis patients with acute cholecystitis underwent PC between March 2007 and May 2009 at our institute. On preoperative assessment, the patients were classified into the ASA score by the anesthesiology team. All patients were class IV because of severe underlying comorbidities. The patients were referred to interventional radiology unit for PC by consensus of the multidisciplinary team. Results: The PC was technically successful in all the patients without minor or major complications related to the procedure. Clinical symptoms in three patients who presented with sepsis and multiorgan failure did not resolve after PC, and these patients died following urgent surgery, including open cholecystectomy and common bile duct exploration. A new cholecystitis attack was detected in one patient in the acalculous group at the sixth month of the follow-up period. The mean catheterization time was 31.7 (range, 28-41) days. The mean follow-up time was 13.3 (range 4-21) months. Conclusions: The PC may come into consideration as a first-line treatment modality in the management of acute cholecystitis in poor surgical candidate chronic hemodialysis patients. This is the first report focusing on the midterm results of PC as a first-line therapy in hemodialysis patients with acute cholecystitis who could be operated on.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Embolization of Hepatic Arteriovenous Shunt with Absolute Ethanol in a Patient with Hepatocellular Carcinoma

We report a 76-year-old man who had hepatocellular carcinoma (HCC) with arteriovenous shunting (AVS). Transcatheter chemoembolization (TACE) was selected as treatment because of poor pulmonary function. To prevent pulmonary embolism caused by the flow of embolic materials through the AVS, we performed embolization of the AVS with absolute ethanol under flow control by balloon catheters. Subsequently, we could perform TACE for HCC safely.

62 RADIOLOGY AND NUCLEAR MEDICINE↗