Endoscopic extraction of vascular embolization coils that have migrated into the biliary tract in a liver transplant recipient.

Hepatic artery pseudoaneurysm (HAA) is a rare vascular complication of liver transplantation. Minimally invasive radiological interventions are generally considered before seeking surgical treatment of HAA. Coil embolization of the aneurysmal sac and or exclusion of pseudoaneurysm by deploying a stent over the aneurysm are effective interventions to control hemobilia arising from the HAA. Migration of coils inside the bile duct is a rarely reported complication in post-hepatic transplantation. Treatment options remain largely unexplored due to the rarity of its occurrence. Endoscopic retrograde cholangiographic removal of migrated vascular coils in the common bile duct following embolization of HAA has not been described in a liver transplant setting. We report a liver transplant recipient who underwent uneventful and successful endoscopic removal of migrated coils into the bile duct.

Frequency and Characteristics of Incidental Pulmonary Embolism in Cancer Patients: A Retrospective Study at a Large Oncology Center in Saudi Arabia.

INTRODUCTION: Oncology patients are predisposed to incidental-asymptomatic Pulmonary Embolism (PE) which has a substantial morbidity and mortality in untreated patients. As the cancer patients frequently undergo contrast enhanced Computed Tomography (CT) scanning for staging their primary disease, there is a higher chance of detecting unsuspected PE. METHODOLOGY: Our sample included a retrospective review of one-thousand consecutive oncology patients who had CT scan of the chest for reasons other than PE. We excluded females on oral contraceptives, patients who had a prior history of PE or deep veins thrombosis, and history of intensive care unit admission, surgery, trauma, or lower limb fractures within 6 months prior to the CT study. A positive case of incidental PE is considered if it was confirmed by CT pulmonary angiogram study within 24 hours of the staging CT or if there is an agreement for positive PE by two experienced radiologists. The overall incidence of asymptomatic PE in cancer patients, rate of incidental PE in different types and stages of cancer, and location of the PE within the pulmonary vasculature are described. DISCUSSION: The true incidence, prevalence, and mortality rates of incidental PEs in oncology patients is underestimated due to its silent nature. Since the mortality and morbidity are exceptionally high in cancer patients with incidental pulmonary embolism, staging CT chest examinations should include a meticulous search for incidental PE. CONCLUSION: The rate of pulmonary embolism in oncology patients is higher in female and in the advanced stage of the disease. There are certain tumors associated with a higher rate of incidental PEs, which may be related to tumors characteristics or to its treatment.

Implications of COVID-19 pandemic on lung cancer management: A multidisciplinary perspective.

Treatment of patients with lung cancer during the current COVID-19 pandemic is challenging. Lung cancer is a heterogenous disease with a wide variety of therapeutic options. Oncologists have to determine the risks and benefits of modifying the treatment plans of patients especially in situation where the disease biology and treatment are complex. Health care visits carry a risk of transmission of SARS-CoV-2 and the similarities of COVID-19 symptoms and lung cancer manifestations represent a dominant problem. Efforts to modify treatment of lung cancer during the current pandemic have been adapted by many healthcare institutes to reduce exposure of lung cancer patients to SARS-CoV-2. We summarized the implications of COVID-19 pandemic on the management of lung cancer from the perspective of different specialties of thoracic oncology multidisciplinary team.

Near-real-time feedback control system for liver thermal ablations based on self-referenced temperature imaging.

Our challenge was to design and implement a dedicated temperature imaging feedback control system to guide and assist in a thermal liver ablation procedure in a double-donut 0.5T open MR scanner. This system has near-real-time feedback capability based on a newly developed "self-referenced" temperature imaging method using "moving-slab" and complex-field-fitting techniques. Two phantom validation studies and one ex vivo experiment were performed to compare the newly developed self-referenced method with the conventional subtraction method and evaluate the ability of the feedback control system in the same MR scanner. The near-real-time feedback system was achieved by integrating the following primary functions: (1) imaging of the moving organ temperature; (2) on-line needle tip tracking; (3) automatic turn-on/off the heating devices; (4) a Windows operating system-based novel user-interfaces. In the first part of the validation studies, microwave heating was applied in an agar phantom using a fast spoiled gradient recalled echo in a steady state sequence. In the second part of the validation and ex vivo study, target visualization, treatment planning and monitoring, and temperature and thermal dose visualization with the graphical user interface of the thermal ablation software were demonstrated. Furthermore, MR imaging with the "self-referenced" temperature imaging method has the ability to localize the hot spot in the heated region and measure temperature elevation during the experiment. In conclusion, we have demonstrated an interactively controllable feedback control system that offers a new method for the guidance of liver thermal ablation procedures, as well as improving the ability to assist ablation procedures in an open MR scanner.

Evaluation of coronary artery bypass grafts using multidetector-row CT with Japanese patients.

PURPOSE: To evaluate the patency of coronary artery bypass grafting (CABG) with multidetector-row computed tomography (MDCT) in Japanese patients, who have narrower coronary arteries than Caucasians. MATERIALS AND METHODS: Nineteen patients (12 men and 7 women, mean age: 63 +/- 12 years) with 33 coronary bypass grafts were examined with three-dimensional volume rendering (3D-VR) and curved multiplanar reconstruction (MPR) of MDCT. All grafts were compared with those obtained with selective graft angiography. RESULTS: For the 19 patients with 33 grafts, the overall sensitivity and specificity, compared with those for selective bypass angiography, were 96.7% and 100%, respectively. CONCLUSION: The patency of CABG in Japanese patients can be effectively evaluated with 3D-VR and curved MPR of MDCT.

Aortic compliance in patients with aortic regurgitation: evaluation with magnetic resonance imaging.

PURPOSE: To assess by means of cine magnetic resonance imaging (MRI) aortic compliance before and after aortic valve replacement (AVR with SJM valve) in patients with aortic regurgitation (AR). MATERIALS AND METHODS: Two groups (healthy controls and patients with severe isolated AR) of 10 subjects each were included in this study. Cine MRI was performed at three locations of the aorta, and aortic compliance was calculated by dividing the maximum change in the aortic area by pulse pressure. RESULTS: Cine MRI is useful to assess abnormalities of aortic compliance in patients with AR. Compared with the control group, aortic compliance in the AR group was significantly less in the ascending aorta (p<0.05), decreasing in order of aortic location. After AVR, aortic compliance improved for all locations. CONCLUSION: Cine MRI enables assessment of aortic biophysical properties such as a compliance for evaluating the progression of AR and the efficacy of treatment.

Accuracy of Canadian CT head rule in predicting positive findings on CT of the head of patients after mild head injury in a large trauma centre in Saudi Arabia.

BACKGROUND: Investigation of unjustified computed tomography (CT) scan in patients with minor head injury is lacking in Saudi Arabia. The purpose of the study was to evaluate the compliance and effectiveness of the Canadian computed tomography head rule (CCHR) in our emergency department (ED) and trauma centre and also to reduce the number of unjustified CT studies of the head in the centre. METHODS: A retrospective study of 368 ED patients with minor head injury was conducted. Patients who underwent CT scan between July 2010 and June 2011 were selected from the ED head trauma registry by systematic randomisation. The CCHR was retrospectively applied on the patients' charts to calculate the prevalence of unjustified head CT scans. A separate survey was conducted to evaluate three emergency physicians' level of awareness about the CCHR and their ability to determine the necessity of CT scans with various clinical scenarios of head injury. RESULTS: The prevalence of unjustified CT scans as per the CCHR was 61.8% (95% confidence interval (CI) 56.5-66.9%). Approximately 5% of the sample had positive CT findings with 95% CI 2.9-7.6%. The CCHR correctly identified 12 cases with positive CT findings with 66.67% sensitivity. Only 24 (6.7%) had Glasgow coma scale scores less than 15 (13/14). The Glasgow coma scale correctly identified only two cases with positive CT findings with 11.11% sensitivity. The percentage of skull fracture (0.9% vs 5%, P=0.030) was significantly lower in patients with unjustified CT scans than in patients with clinically justified CT scans. There was fair to substantial agreement between the ED physicians and the CCHR (κ=35-61%). Two ED physicians identified all cases of justified CT scan with 100% sensitivity (95% CI 71.51-100%). CONCLUSION: The level of education regarding the CCHR was found to be optimal among emergency physicians using a case-based scenario survey. The CCHR was found to have a poor compliance potential in the busy ED of our trauma centre and the prevalence of unjustified cranial CT scans remained high.

Embolic effects of superabsorbent polymer microspheres in rabbit renal model: comparison with tris-acryl gelatin microspheres and polyvinyl alcohol.

PURPOSE: We have developed a spherical embolic agent, superabsorbent polymer microspheres (SAP-MS). The aim of this study was to examine the embolic effects of SAP-MS in comparison with polyvinyl alcohol (PVA) particles and tris-acryl gelatin microsphere (Embosphere Microsphere; EM) in a rabbit renal model. MATERIALS AND METHODS: The right kidneys of nine rabbits were embolized with the given agents: PVA (180-300 microm) (n=3), EM (100-300 microm) (n=3), and SAP-MS (106-150 microm) (n=3). The embolized kidneys were evaluated by angiography and histology after one week. RESULTS: Renal artery occlusion and prominent coagulative necrosis were confirmed regardless of agent. PVA aggregated in the proximal vessels with tiny fragments migrating into glomeruli. Both EM and SAP-MS traveled distally up to the interlobular artery level, and a single particle achieved cross-sectional vessel occlusion. SAP-MS was markedly swollen, deformed, and conformed to the vessel lumen compared with the constantly spherical EM. Mild perivascular reaction was seen with both microspheres. CONCLUSION: SAP-MS resulted in targeted end-organ infarction in the rabbit renal model and showed different mechanical properties from other agents.

Evaluation of major aortopulmonary collateral arteries (MAPCAs) using three-dimensional CT angiography: two case reports.

Pulmonary atresia (PA) and ventricular septal defect (VSD) are usually associated with major aortopulmonary collateral arteries (MAPCAs). Preoperative evaluation of MAPCAs is essential for effective planning of unifocalization. Multidetector-row computed tomography (MDCT) with three-dimensional volume rendering (3D-VR) demonstrates MAPCAs as well as conventional angiography. We report two cases of PA and VSD associated with MAPCAs examined pre- and postoperatively by means of angiography and MDCT with the 3D-VR technique. MDCT with the 3D-VR technique had the potential to elucidate all MAPCAs demonstrated by invasive angiography. This technique is useful with preoperative conventional angiography as a standard examination for the planning of staged surgery.

Transarterial therapy: an evolving treatment modality of hepatocellular carcinoma.

Liver cancer is the fifth most common cancer in men, the seventh most common in women, and the third most common cause of death from cancer worldwide. Only 30-40% of liver cancer patients present early enough to undergo curative treatments such as surgery or liver transplantation. Local treatment with radiofrequency ablation or ethanol injection is often reserved for non-surgical candidates with early stages of disease. Transarterial embolization has become a widely accepted treatment for asymptomatic patients with unresectable lesions. This review discusses in details the three major forms of transarterial therapies: Bland embolization, chemoembolization, and radioembolization.

Image-guided percutaneous transthoracic biopsy in lung cancer--emphasis on CT-guided technique.

Image-guided percutaneous transthoracic core biopsy especially with CT guidance is playing an increasing role in the diagnosis and management of lung cancer. The recent advances in the specific chemotherapy and novel targeted therapy and the increasing need for specific diagnosis of tumor histopathologic subtypes have direct impact on the radiologists performing lung biopsy and important implications for the biopsy technique. Close cooperation between radiologists and referring physicians with understanding of the technical aspects of the biopsy procedure can help clinicians make appropriate referrals for this procedure and understand the significance and limitations of the results. Additionally, the appropriate management of complications can limit morbidity related to the biopsy procedure.

Hepatocellular carcinoma treated with radio frequency ablation: an early evaluation with magnetic resonance imaging.

PURPOSE: To determine the usefulness of nonenhanced T1-weighted spoiled gradient-recalled acquisition in the steady-state (SPGR) MRI in the early assessment of the efficacy of radio frequency (RF) therapy for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 23 patients with 28 HCC nodules treated with percutaneous RF ablation underwent nonenhanced MRI within two days after the RF procedure and contrast-enhanced computed tomography (CT) one week after. MR assessment of ablation efficacy according to the concentric zonal pattern on T1-weighted SPGR imaging was compared with the one-week CT and presence of local recurrence by means of follow-up study for 12 months or more. RESULTS: In 18 of 28 ablated nodules, SPGR images revealed a central hyperintense zone covering the entire tumor, CT showed a nonenhanced area covering the entire tumor, and no local recurrence was demonstrated in the follow-up studies. In nine of 28 nodules, the central hyperintense zone did not cover the entire tumor; and local recurrence was demonstrated in three nodules. In the remaining one nodule, no signal change was seen in the treated area on SPGR images and CT showed the presence of residual viable tumor. CONCLUSION: Nonenhanced T1-weighted MRI was considered useful for early assessment of the efficacy of RF therapy for HCC.