195 research outputs found
Double-contrast magnetic resonance imaging of hepatocellular carcinoma after transarterial chemoembolization
Background: The purpose of this study was to assess the accuracy of double-contrast magnetic resonance (MR) imaging for the treatment response evaluation of hepatocellular carcinoma (HCC) in cirrhotic liver after transarterial chemoembolization (TACE). Methods: Twenty-two patients with 30 HCC nodules treated by TACE underwent double-contrast MR imaging 1month after treatment. MR images were obtained before and after the sequential administration of superparamagnetic iron oxide (SPIO) and gadopentetate dimeglumine contrast agent within the same imaging session. Two observers retrospectively assessed all treated nodules for evidence of residual viable tumor after TACE. The diagnostic performance of gadolinium-enhanced, SPIO-enhanced, and double-contrast enhanced images was calculated. Histopathological and angiographical findings served as standard of reference. Receiver operating characteristic curves and areas under the curves (A z) were calculated. Results: Double-contrast technique (A z=0.95) was significantly (p=0.036) more accurate than SPIO-enhanced technique (A z=0.92) and gadolinium-enhanced technique (p=0.005) (A z=0.81) in viable tumor detection after TACE. Double-contrast technique was significantly more sensitive (92%) than SPIO-enhanced technique (80%) and gadolinium-enhanced technique (68%). Kappa values for interobserver agreement ranged from 0.67 to 0.87 and were significantly different from zero (all p<0.001). Conclusions: Compared to gadolinium-enhanced and SPIO-enhanced techniques, double-contrast technique significantly improves the detection of viable tumor in HCC after TAC
Splenic duplication: a rare cause of acute upper gastrointestinal bleeding
Acute gastrointestinal bleeding represents a common medical emergency. We report the rare case of acute upper gastrointestinal bleeding caused by varices in the gastric fundus secondary to splenic duplication. Splenic duplication has been only rarely reported in the literature, and no case so far has described the associated complication of gastrointestinal bleeding, caused by venous drainage of the upper spleen via varices in the gastric fundus. We describe the imaging findings from endoscopy, endosonography, computed tomography (CT), flat-panel CT, and angiography in this rare condition and illustrate the effective role of intra-arterial embolizatio
Efficiency evaluation of leaded glasses and visors for eye lens dose reduction during fluoroscopy guided interventional procedures
PURPOSE
Fluoroscopy guided interventional procedures guarantee high benefits for patients, but are associated with high levels of radiation exposure for the medical staff. Their increasing use and complexity results in even higher radiation exposures, with a risk to exceed the annual dose limit of 20Â mSv for the eye lens. The aim of the study was to evaluate the potential dose reduction of eye lens exposure for lead glasses and for two types of visors (half and full), used by physicians performing interventional procedures.
METHODS
Eye lens dose measurements were carried out on an anthropomorphic phantom simulating a physician performing a fluoroscopy guided interventional procedure. Dose reduction factors were calculated using high sensitivity thermoluminescent dosimeters. Moreover, a spatial dose distribution was generated for the two visors.
RESULTS
The dose reduction coefficient was found to be 1.6 for the glasses, 1.2 for the half visor and 4.5 for the full visor.
CONCLUSIONS
Optimal radiation protection requires a combination of different radiation protection equipment. Full visors that cover all the face of the operator are recommended, as they absorb scattered radiation reaching the eyes from all directions. Full visors should be prioritized over radiation protection glasses for cases where other protective equipment such as ceiling shielding cannot be used
Success Rate and Long-Term Effects of Embolization of Pelvic Arteries for the Treatment of Postpartum Hemorrhage
Introduction: Postpartum hemorrhage (PPH) is the leading cause of peripartal maternal mortality and accounts for 25% of all maternal deaths worldwide. The most common reasons of PPH are uterine atony, retained placenta, or placenta accreta spectrum. Treatment of PPH depends on the etiology and corresponds to a stepwise approach, which follows the German, Austrian and Swiss guideline for the diagnosis and therapy of PPH in Switzerland. In severe ongoing PPH, hysterectomy has been the ultima ratio for many decades. Nowadays, interventional embolization of the pelvic arteries (PAE) has become a popular alternative. Besides being a highly effective minimally invasive method, PAE avoids hysterectomy with consecutively reduced morbidity and mortality. However, data on the long-term effects of PAE on fertility and menstrual cycle are scarce. Methods: We performed a monocentric study consisting of a retro- and a prospective part including all women who had undergone a PAE between 2012 and 2016 at University Hospital Zurich. Descriptive characteristics of patients and efficacy of PAE defined as cessation of bleeding were analyzed retrospectively. In the prospective part, all patients were contacted for a follow-up questionnaire regarding menstruation and fertility after embolization. Results: Twenty patients with PAE were evaluated. Our data showed a success rate of PAE in 95% of patients with PPH; only 1 patient needed a second, then successful, PAE. No patient needed a hysterectomy or any other surgical intervention. In our study, an association between mode of delivery and identified etiology of PPH is observed. After spontaneous delivery (n = 6), the main reason of severe PPH was retained placenta (n = 4), while after cesarean section (n = 14), uterine atony was identified in most cases (n = 8). Regarding menstruation after embolization, all women reported regular menstruation after the breastfeeding period (100%). The majority reported a regular pattern with a shorter or similar duration (73%) and lower or similar intensity (64%). Dysmenorrhea decreased in 67% of patients. Four patients planned another pregnancy, of whom only one had become pregnant with assisted reproductive technology and ended up in a miscarriage. Discussion: Our study confirms the efficacy of PAE in PPH, thus obviating complex surgical interventions and associated morbidity. The success of PAE does not depend on the primary cause of PPH. Our results may encourage the prompt decision to perform PAE in the management of severe PPH in case of failure of conservative management and help physicians in the post-interventional counseling regarding menstruation patterns and fertility
Hybrid-repair of thoraco-abdominal or juxtarenal aortic aneurysm: what the radiologist should know
Purpose: Endovascular aneurysm repair of the infrarenal or thoracic aorta has been shown to be a less invasive alternative to open surgery. A combined aneurysm of the thoracic and abdominal aorta is complex and challenging; the involvement of renal and/or visceral branches requires new treatment methods. Methods: A hybrid approach is currently an accepted alternative to conventional surgery. Renal and/or visceral revascularisation enables subsequent stent-graft placement into the visceral portion of the aorta. Results: Knowledge of the surgical procedure and a precise assessment of the vascular morphology are crucial for pre-procedural planning and for detection of post-procedural complications. Multi-detector computed tomography angiography (MDCTA) combined with two- and three-dimensional (2D and 3D) rendering is useful for pre-interventional planning and for the detection of post-procedural complications. Three-dimensional rendering allows proper anatomical analyses, influencing interventional strategies and resulting in a better outcome. Conclusions: With the knowledge of procedure-specific MDCTA findings in various vascular conditions, the radiologist and surgeon are able to perform an efficient pre-interventional planning and follow-up examination. Based on our experience with this novel technique of combined open and endovascular aortic aneurysm treatment, this pictorial review illustrates procedure-specific imaging findings, including common and rare complications, with respect to 2D and 3D post-processing technique
Transvenous Biopsy of Cavo-Atrial Tumors with the Quick-Core Needle
A variant application of the renal Quick-Core needle in 3 patients with cavo-atrial tumors is reported. In all 3 patients either a transjugular or transfemoral venous biopsy approach with this device yielded sufficient tissue for histological diagnosis at the first attempt. Bioptic diagnoses were confirmed either by surgery or radiological and clinical response to a specific chemotherapy. There were no procedure-related complication
Maximum Diameter Measurements of Aortic Aneurysms on Axial CT Images After Endovascular Aneurysm Repair: Sufficient for Follow-up?
Purpose: To assess the accuracy of maximum diameter measurements of aortic aneurysms after endovascular aneurysm repair (EVAR) on axial computed tomographic (CT) images in comparison to maximum diameter measurements perpendicular to the intravascular centerline for follow-up by using three-dimensional (3D) volume measurements as the reference standard. Materials and Methods: Forty-nine consecutive patients (73±7.5years, range 51-88years), who underwent EVAR of an infrarenal aortic aneurysm were retrospectively included. Two blinded readers twice independently measured the maximum aneurysm diameter on axial CT images performed at discharge, and at 1 and 2years after intervention. The maximum diameter perpendicular to the centerline was automatically measured. Volumes of the aortic aneurysms were calculated by dedicated semiautomated 3D segmentation software (3surgery, 3mensio, the Netherlands). Changes in diameter of 0.5cm and in volume of 10% were considered clinically significant. Intra- and interobserver agreements were calculated by intraclass correlations (ICC) in a random effects analysis of variance. The two unidimensional measurement methods were correlated to the reference standard. Results: Intra- and interobserver agreements for maximum aneurysm diameter measurements were excellent (ICC=0.98 and ICC=0.96, respectively). There was an excellent correlation between maximum aneurysm diameters measured on axial CT images and 3D volume measurements (r=0.93, P<0.001) as well as between maximum diameter measurements perpendicular to the centerline and 3D volume measurements (r=0.93, P<0.001). Conclusion: Measurements of maximum aneurysm diameters on axial CT images are an accurate, reliable, and robust method for follow-up after EVAR and can be used in daily routin
Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT
This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleedin
Prophylactic Insertion of Optional Vena Cava Filters in High-Risk Trauma Patients
Background:: Vena cava interruption is a form of pulmonary embolism prophylaxis that is being used in high-risk patients who do not tolerate pharmacologic prophylaxis. Retrievable prophylactic vena cava filters (VCFs) are of particular interest for severely injured patients where the necessity for VCF is often only temporary. Methods:: In a single-institution case series of consecutive patients who received prophylactic VCFs after polytrauma, between 04/1998 and 07/2004, the demographic data, injury pattern and complications were analysed. Results:: Ninety-five prophylactic VCFs were placed in polytrauma patients (median ISS of 38). Median age was 38 years (range 16-80 years). Median delay between trauma and filter placement was 1 day (range 0-31 days). No complication was seen related to filter insertion or retrieval. Sixty-five VCFs (68.4%) were retrieved after 4-25 days (median 13 days). One filter migration (1.1%) was observed. Retrieval failed in two patients (3.0%). A total of 30 VCFs (31.6%) were left permanently. One non-fatal PE (1.1%) occurred 21 days after filter retrieval despite prophylaxis with LMWH. DVT developed in two patients (2.1%) including one vena caval occlusion (1.1%). Overall mortality was 7.4%. Conclusions:: Early prophylactic placement of VCF in a high-risk trauma patient should be considered when anticoagulation is contraindicated. Filter insertion and retrieval is safe with a low complication rat
MR-guided cholecystostomy: Assessment of biplanar, real-time needle tracking in three pigs
Purpose: To demonstrate the feasibility of magnetic resonance (MR)-guided cholecystostomy using active, real-time, biplanar MR tracking in animal experiments. Methods: Experiments were performed on three fully anesthetized pigs in an interventional MR system (GE open). The gallbladder was displayed in two orthogonal planes using a heavily T2-weighted fast spin-echo sequence. These "cholangio roadmaps” were displayed on LCD monitors positioned in front of the interventionalist. A special coaxial MR-tracking needle, equipped with a small receive-only coil at its tip, was inserted percutaneously into the gallbladder under continuous, biplanar MR guidance. The MR-tracking sequence allowed sampling of the coil (needle tip) position every 120 msec. The position of the coil was projected onto the two orthogonal "cholangio roadmap” images. Results: Successful insertion of the needle was confirmed by aspiration of bile from the gallbladder. The process of aspiration and subsequent instillation of Gd-DTPA into the gallbladder was documented with fast gradient-recalled echo imaging. Conclusion: Biplanar, active, real-time MR tracking in combination with "cholangio roadmaps” allows for cholecystostomies in an interventional MRI environmen
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