Evolution of type II endoleaks based on different ultrasound-identified patterns.

OBJECTIVE: The objective of this study was to delineate the specific types of waveforms that exist in type II endoleaks (T2ELs) and their effect on aneurysm sac size. METHODS: Patients who underwent an endovascular aneurysm repair and were diagnosed with a T2EL were included in the study. The flow velocity characteristics of the T2ELs were evaluated in detail with duplex ultrasound. Four different flow patterns were identified: high resistance, low flow; low resistance, low flow; low resistance, high flow; and to-fro flow. The type and number of vessels involved, time at detection, evolution, and need for treatment were recorded. The aneurysm sac diameter was monitored with duplex ultrasound. A computed tomography scan was always performed at baseline within 1 month of the procedure and repeated only when symptoms developed or there were changes in the ultrasound examination findings, such as sac enlargement. RESULTS: Of 382 patients who underwent endovascular aneurysm repair in our institution, 56 (14.65%) were found to have a T2EL. There were 52 male and four female patients with a mean age of 74 years (61-86 years). The T2EL was diagnosed within the first month in 32 patients; 9 patients were diagnosed at 3 months, 5 patients at 6 months, 3 patients at 9 months, and 7 patients at 1 year or later. There were 43 patients who had a T2EL involving one vessel; two vessels were involved in 11 patients and three vessels were involved in two patients. During follow-up, several changes were observed for the different types of T2EL. High-resistance, low-flow endoleak was detected in 14 patients; of those, 13 were occluded and 1 converted to high flow. Low-resistance, low-flow endoleak was detected in seven patients; of those, 5 were occluded, 1 remained stable, and 1 converted to high flow with sac enlargement requiring treatment. Low-resistance, high-flow endoleak was found in 13 patients; of those, 8 were occluded, 3 remained stable, and 2 had sac enlargement requiring treatment; 1 patient presented with rupture. Finally, to-fro flow was identified in the majority of the patients (22); of those, 14 occluded, 3 remained stable, and 5 had sac enlargement requiring treatment; 2 patients presented with rupture. No deaths due to T2EL were encountered. CONCLUSIONS: Most of the T2ELs resulted in spontaneous occlusion and were not associated with sac enlargement. A low-resistance, high-flow or to-fro flow T2EL has higher chances of sac enlargement, rupture, and requiring reintervention.

Prospective determination of candidates for thrombolysis in patients with acute proximal deep vein thrombosis.

PURPOSE: To prospectively determine the distribution, extent, and age of venous thrombosis in patients presenting with acute signs and symptoms of venous thromboembolism and identify candidates for thrombolysis. MATERIALS AND METHODS: Five hundred seventy-six consecutive patients (281 male, 295 female; mean age 58) referred for lower extremity deep vein thrombosis (DVT) assessment between November 2007 and April 2008 were included in the study. Documented cases of DVT were categorized by age (acute, chronic, and acute on chronic), anatomic location, and extent. Patients with iliofemoral and femoropopliteal DVT were evaluated for thrombolysis using standard criteria. RESULTS: DVT was found in 19% of patients (112/576). Of these, 31 patients (27.7%, 31/112) had isolated calf DVT, 61 patients (54.5%, 61/112) had proximal vein thrombosis extending into the femoropopliteal venous segments, and 20 patients (17.9%, 20/112) presented with iliofemoral DVT. Using standard criteria, 12 patients were selected as potential candidates for pharmacomechanical thrombolysis (PhMT). This equated to an incidence of 2% (12/576) in the population studied, 11% of patients (12/112) with DVT, 26.1% of patients (12/46) presenting with acute proximal DVT, and 20% of patients (4/20) with iliofemoral DVT. CONCLUSION: The incidence of potential candidates for thrombolysis is low. These data should be considered when recruiting centers to participate in ongoing clinical trials assessing the efficacy of these techniques.

A Task-dependent Investigation on Dose and Texture in CT Image Reconstruction.

Localizing and characterizing clinically-significant lung nodules, a potential precursor to lung cancer, at the lowest achievable radiation dose is demanded to minimize the stochastic radiation effects from x-ray computed tomography (CT). A minimal dose level is heavily dependent on the image reconstruction algorithms and clinical task, in which the tissue texture always plays an important role. This study aims to investigate the dependence through a task-based evaluation at multiple dose levels and variable textures in reconstructions with prospective patient studies. 133 patients with a suspicious pulmonary nodule scheduled for biopsy were recruited and the data was acquired at120kVp with three different dose levels of 100, 40 and 20mAs. Three reconstruction algorithms were implemented: analytical filtered back-projection (FBP) with optimal noise filtering; statistical Markov random field (MRF) model with optimal Huber weighting (MRF-H) for piecewise smooth reconstruction; and tissue-specific texture model (MRF-T) for texture preserved statistical reconstruction. Experienced thoracic radiologists reviewed and scored all images at random, blind to the CT dose and reconstruction algorithms. The radiologists identified the nodules in each image including the 133 biopsy target nodules and 66 other non-target nodules. For target nodule characterization, only MRF-T at 40mAs showed no statistically significant difference from FBP at 100mAs. For localizing both the target nodules and the non-target nodules, some as small as 3mm, MRF-T at 40 and 20mAs levels showed no statistically significant difference from FBP at 100mAs, respectively. MRF-H and FBP at 40 and 20mAs levels performed statistically differently from FBP at 100mAs. This investigation concluded that (1) the textures in the MRF-T reconstructions improves both the tasks of localizing and characterizing nodules at low dose CT and (2) the task of characterizing nodules is more challenging than the task of localizing nodules and needs more dose or enhanced textures from reconstruction.

A Feasibility Study of Extracting Tissue Textures From a Previous Full-Dose CT Database as Prior Knowledge for Bayesian Reconstruction of Current Low-Dose CT Images.

Markov random field (MRF) has been widely used to incorporate a priori knowledge as penalty or regularizer to preserve edge sharpness while smoothing the region enclosed by the edge for pieces-wise smooth image reconstruction. In our earlier study, we proposed a type of MRF reconstruction method for low-dose CT (LdCT) scans using tissue-specific textures extracted from the same patient's previous full-dose CT (FdCT) scans as prior knowledge. It showed advantages in clinical applications. This paper aims to remove the constraint of using previous data of the same patient. We investigated the feasibility of extracting the tissue-specific MRF textures from an FdCT database to reconstruct a LdCT image of another patient. This feasibility study was carried out by experiments designed as follows. We constructed a tissue-specific MRF-texture database from 3990 FdCT scan slices of 133 patients who were scheduled for lung nodule biopsy. Each patient had one FdCT scan (120 kVp/100 mAs) and one LdCT scan (120 kVp/20 mAs) prior to biopsy procedure. When reconstructing the LdCT image of one patient among the 133 patients, we ranked the closeness of the MRF-textures from the other 132 patients saved in the database and used them as the a prior knowledge. Then, we evaluated the reconstructed image quality using Haralick texture measures. For any patient within our database, we found more than eighteen patients' FdCT MRF texures can be used without noticeably changing the Haralick texture measures on the lung nodules (to be biopsied). These experimental outcomes indicate it is promising that a sizable FdCT texture database could be used to enhance Bayesian reconstructions of any incoming LdCT scans.

Endovascular covered stenting for visceral artery pseudoaneurysm rupture: report of 2 cases and a summary of the disease process and treatment options.

We present 2 cases of hemorrhage from a visceral artery pseudoaneurysm, managed successfully with endovascular covered stent placement. The first case was a 59-year-old man, 3 months after a laparoscopic distal pancreatectomy for adenoma, presenting with diffuse abdominal pain. The patient was evaluated with a computed tomography scan revealing a splenic artery pseudoaneurysm (PA) bleeding into a pancreatic pseudocyst. He was emergently taken to the angiography suite where a covered stent was deployed at the level of splenic artery PA. The second case was a 52-year-old woman with recurrent left retroperitoneal mass 5 years after distal pancreatectomy and splenectomy for a nonfunctional neuroendocrine tumor. She underwent resection of the mass in the left upper quadrant. Postoperative course was complicated by hematoma, abscess formation, reexploration, and repair of the duodenotomy and the portal vein. Subsequently, she was noted to have intermittent gastrointestinal hemorrhage, which prompted an angiogram revealing a hepatic artery PA that was repaired with a covered balloon-expandable stent. A completion angiogram was obtained in each case demonstrating exclusion of the PA. Our experience with these 2 cases supports the notion that endovascular covered stenting is a safe and effective therapy for exclusion of visceral artery aneurysm.

Renal Artery Pseudoaneurysm in Kawasaki Disease.

Whereas coronary aneurysms are commonly associated with Kawasaki disease, involvement of the renal vasculature is exceedingly rare. Genitourinary involvement in patients with Kawasaki disease is typically limited to sterile pyuria and proteinuria. In this case, a 13-year-old girl who presented with right flank pain and microhematuria was found to have an intraparenchymal hemorrhagic mass on computerized tomography scan. Renal arteriography confirmed the diagnosis of pseudoaneurysm in a lower pole segmental artery branch and complete occlusion was achieved with endovascular embolization.

Endovascular repair of an arteriovenous fistula from a ruptured hypogastric artery aneurysm--a case report.

A spontaneous ilioiliac arteriovenous fistula secondary to rupture of a hypogastric artery aneurysm is an unusual occurrence. A case of an endovascular repair of this challenging problem is reported.

Preliminary outcomes of the Lake Erie College of Osteopathic Medicine's 3-year Primary Care Scholar Pathway in osteopathic predoctoral education.

CONTEXT: In 2007, the Lake Erie College of Osteopathic Medicine initiated its Primary Care Scholar Pathway (PCSP), a 3-year osteopathic predoctoral education curriculum. OBJECTIVE: To assess preliminary outcomes of the PCSP curriculum. METHODS: Scores for the Comprehensive Osteopathic Medical Licensing Examination (COMLEX-USA) Levels 1 and 2-Cognitive Evaluation (CE) and pass rates for Level 2-Performance Evaluation (PE) were obtained for individuals who graduated from the PCSP program in 2010, 2011, and 2012. Scores for Levels 1 and 2-CE were compared with national mean scores. Acceptance rates for residency programs were also recorded. RESULTS: Nineteen PCSP graduates were included in the study: 3 graduated in 2010, 6 graduated in 2011, and 10 graduated in 2012. Scores for PCSP students were not significantly different than national average scores for COMLEX-USA Levels 1 and 2-CE (P>.05). All 19 PCSP graduates passed the COMLEX-USA Level 2-PE on the first attempt, and all graduates were accepted into primary care residency programs. CONCLUSION: The COMLEX-USA scores of PCSP graduates were similar to national mean scores, suggesting that it is possible for osteopathic medical students to attain the same level of education as students of 4-year programs in less time. A 3-year osteopathic predoctoral education curriculum would allow students to complete their education at a reduced cost. This potential reduction in debt burden could encourage more students to pursue a primary care career and thus could help address the shortage of primary care physicians in the United States.