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Christoph A Binkert

Publications and source records attributed to Christoph A Binkert.

At least 19 recordsLinked to original sources
PubMed2006

Bone augmentation: past, present, and future.

Painful skeletal and vertebral conditions caused by degeneration, fractures, infection, and neoplasm are common and associated with high morbidity and mortality. Since the introduction of modern orthopedic surgery these conditions have been treated with a multitude of techniques. Bone augmentation and grafting have emerged as integral parts of orthopedic reconstructive, reparative, and palliative surgery. As imaging-guided therapy has developed, image-guided procedures to achieve bone augmentation have also emerged. It is important for the radiologist to understand the materials and methods used to achieve bone augmentation. A variety of materials are available for the application of hone augmentation. Methods used to accomplish bone augmentation often are performed under image guidance. Applications in the axial skeleton include vertebroplasty, kyphoplasty (balloon-assisted vertebroplasty), sacroplasty, and acetabuloplasty. This article discusses the development, current trends, and possible future directions of bone augmentation.

Bone Transplantation↗
PubMed2006

Retrievability of the recovery vena cava filter after dwell times longer than 180 days.

PURPOSE: Permanent and optional (retrievable) inferior vena cava (IVC) filters reduce pulmonary embolism (PE) risk. Maximum safe dwell times for retrievable devices have not been defined. This retrospective multicenter analysis evaluated the feasibility of retrieval of the Bard Recovery filter after dwell times longer than 180 days. MATERIALS AND METHODS: Thirteen patients from three U.S. institutions were included. The patients ranged in age from 21 to 70 years (mean, 46.2 y); six were male, seven female. All filters were removed via the right internal jugular vein. Data were collected on filter position and condition, fluoroscopy time, complications, and IVC abnormality. RESULTS: The filter dwell times ranged from 181 to 419 days (mean, 254.2+/-79.7 d). All filters were retrieved successfully without difficulties. The mean fluoroscopy time was 5.78+/-3.39 minutes (range, 3.12-16.0 min). Two of 13 filters had a tilt of more than 10 degrees , but no filter was embedded into the IVC wall. No filter migration or thrombus within the filter was observed. On 11 of 13 venograms, the arms projected outside the IVC in a parallel fashion, likely tenting the vessel. In one case, one leg and one arm pointed outside the IVC, likely penetrating the vessel. Venographic findings after retrieval were normal in all but one patient, who had a mild narrowing of the IVC (stenosis<30%). CONCLUSION: Retrievals of the Recovery filter with dwell times beyond 180 days appear feasible and were performed without complication in this series.

Adult↗
PubMed2006

A new method for aggressive management of deep vein thrombosis: retrospective study of the power pulse technique.

Failure to treat deep vein thrombosis (DVT) is associated with significant morbidity and mortality. Anticoagulation, although effective at preventing clot progression, is not able to prevent postthrombotic syndrome. Catheter-directed thrombolysis is a more aggressive alternative, with some small studies suggesting a better long-term outcome, but the associated risks are significant, and the treatment can require 2-3 days in a monitored setting. This report describes the power pulse technique, in which mechanical thrombectomy is combined with thrombolytic agents to maximize the effectiveness of the treatment and reduce the need for prolonged infusion and its associated risks. A 24-patient retrospective study showed complete thrombus removal (>90%) in 12 patients, substantial thrombus removal (50%-90%) in seven patients, and partial thrombus removal (<50%) in five patients. All 24 patients had resolution of presenting symptoms. Only two patients required blood transfusion, and one patient experienced temporary nephropathy.

Adolescent↗
PubMed2006

Translumbar type II endoleak repair using angiographic CT.

Translumbar embolization of type II endoleaks after endovascular abdominal aneurysm repair has been proved to be effective. One challenge of this approach is the choice of the most suitable image guiding modality. For needle placement, cross-sectional imaging under computed tomographic (CT) guidance is preferable. For embolization, fluoroscopy is the modality of choice for most interventionalists. A new technology can acquire CT-like images by rotating an angiographic, flat-panel detector of a C-arm around the patient. This technology allows a combination of fluoroscopic and CT guidance within the angiographic suite. The authors describe the successful use of a combination of fluoroscopy and angiographic CT in three cases of translumbar type II endoleak embolization.

Aged↗
PubMed2006

CT features of hepatic venoocclusive disease and hepatic graft-versus-host disease in patients after hematopoietic stem cell transplantation.

OBJECTIVE: We conducted this study to evaluate whether CT scans could be used to differentiate hepatic venoocclusive disease from hepatic graft-versus-host disease in patients treated with hematopoietic stem cell transplantation. SUBJECTS AND METHODS: We retrospectively evaluated 18 patients (eight women, 10 men; mean age, 42.4 years) after hematopoietic stem cell transplantation with biopsy-proven hepatic venoocclusive disease (n = 5), hepatic graft-versus-host disease (n = 6), or both (n = 7). Two radiologists reviewed abdominal and pelvic CT scans for hepatomegaly (> 18 cm), splenomegaly (> 13 cm), size of main portal and right hepatic veins, presence of periportal edema, gallbladder wall edema, hydropic gallbladder, ascites, and small-bowel wall thickening. CT and histopathology findings were correlated using analysis of variance and Fisher-Free-man-Holton tests. RESULTS: Ascites and periportal edema were present in all five patients with venoocclusive disease, but of six patients with graft-versus-host disease, ascites was seen in two (p < 0.05) and periportal edema in only one (p < 0.05). Small-bowel wall thickening was encountered in five patients with graft-versus-host disease and in none with venoocclusive disease (p < 0.05). The right hepatic vein diameter in patients with venoocclusive disease (mean, 0.27 cm) was significantly smaller than the right hepatic vein diameter in patients with graft-versus-host disease (mean, 0.87 cm; p < 0.05). CONCLUSION: In patients treated with hematopoietic stem cell transplantation, CT findings of periportal edema, ascites, and a narrow right hepatic vein suggest venoocclusive disease rather than graft-versus-host disease. Small-bowel wall thickening suggests graft-versus-host disease.

Adult↗
PubMed2005

Inferior vena cava filter removal after 317-day implantation.

A Günther Tulip inferior vena cava (IVC) filter was placed prophylactically in a 22-year-old trauma victim with spinal injuries. Attempts to retrieve the filter at 21 and 25 days after placement were aborted as a result of clot trapped in the filter. Despite the possible risk of an IVC laceration, a third attempt was made 317 days after placement in view of the young age of the patient. The filter started collapsing into the retrieval sheath but could not easily be separated from the IVC. During attempted redeployment, the filter would not reopen. The filter was ultimately retrieved with use of additional force. A mild stenosis of the IVC was noted immediately after retrieval. However, the IVC returned to its preretrieval diameter as seen on a 3-month follow-up venogram.

Adult↗
PubMed2005

Percutaneous treatment of high-output chylothorax with embolization or needle disruption technique.

Surgical ligation of the thoracic duct is associated with a high degree of morbidity; therefore, a minimally invasive approach is desirable. Herein, eight percutaneously treated patients are described. In four patients, the thoracic duct was embolized with use of coils and glue. In the other four patients, lymphatic ducts were disrupted by multiple needle punctures. The median chest tube drainage substantially decreased in both patient groups from more than 1,300 mL the day before the procedure to less than 300 mL 2 days after the procedure. The median times to chest tube removal were 7 days in the embolization group and 3.5 days in the needle disruption group.

Adhesives↗
PubMed2004

Fallopian tube occlusion with use of a small intestine submucosa device: evaluation in a rabbit model.

PURPOSE: The present study evaluates the short- and midterm efficacy of a small intestinal submucosa (SIS) device for fallopian tube occlusion in rabbits. MATERIALS AND METHODS: In a pilot study, several SIS device designs were tested for positional stability (absence of migration). The design selected for further testing consisted of a center of spongy SIS surrounded by an SIS sheet and held together by a 0.006-inch wire helix with two barbs. It was delivered on the tip of a short coaxial 3-F/5-F catheter set. Using this design, bilateral transuterine fallopian tube occlusion was performed in eight New Zealand White rabbits. Follow-up consisted of plain radiography at 2 weeks and hysterosalpingography at 6 weeks (n = 4 animals; eight tubes), 12 weeks (n = 2 animals; four tubes), or 24 weeks (n = 2 animals; four tubes). Thereafter, the animals were killed and the fallopian tubes were harvested for histologic evaluation. RESULTS: A single device was placed successfully in each fallopian tube. Fifteen of 16 devices (94%) remained in place throughout follow-up. One device migrated into the vagina at 2-week follow-up. Hysterosalpingography of the 15 tubes with occluders in place showed occlusion in seven of seven (100%) at 6 weeks, three of four (75%) at 12 weeks, and two of four (50%) at 24 weeks. Histologic evaluation revealed luminal occlusion by reorganized SIS containing macrophages, fibrocytes, and scant foreign-body giant cells. Only a mild inflammatory reaction was observed around the tube. In the animals with recanalization at 12 and 24 weeks, new channels were found alongside the original still-occluded fallopian tube lumen. CONCLUSIONS: The original lumen of the fallopian tube was effectively occluded by the SIS occluder, which was remodeled within the fallopian tubes of rabbits. Partial peripheral recanalization was observed over time.

Animals↗
PubMed2004

Peripheral vascular disease: blinded study of dedicated calf MR angiography versus standard bolus-chase MR angiography and film hard-copy angiography.

PURPOSE: To compare the accuracy of contrast material-enhanced three-dimensional (3D) dedicated calf magnetic resonance (MR) angiography with that of bolus-chase MR angiography, with conventional angiography as the reference standard, in patients with symptomatic peripheral vascular disease (PVD). MATERIALS AND METHODS: Thirty men with symptomatic PVD were examined. MR angiography was performed at 1.5 T before conventional angiography. MR angiographic examination included 3D contrast-enhanced dedicated calf MR angiography and three-station bolus-chase MR angiography. Two radiologists blinded to conventional angiographic results evaluated the MR angiograms independently. Two angiographers evaluated the conventional angiograms in consensus. Calf artery segments were graded as having 50% or less stenosis, greater than 50% stenosis, or occlusion or as being nondiagnostic. Statistical analyses were performed with paired permutation testing. RESULTS: Analyses of 472 calf segments and 420 pelvic and thigh segments were performed. Of the 472 calf segments, three and 75 segments (reader 1) and seven and 91 segments (reader 2) were graded as nondiagnostic at dedicated calf MR angiography and bolus-chase MR angiography, respectively. Differences in diagnostic grade between the two examinations were significant (P <.001), accounting for within-subject correlations, with a mean estimated difference of -17.1% (95% confidence interval [CI]: -25.8%, -8.4%). In the calf arteries, the dedicated and bolus-chase MR angiographic sequences had diagnostic accuracies, respectively, of 81.5% (reader 1) and 79.1% (reader 2) and of 67.8% (reader 1) and 63.4% (reader 2). The dedicated calf sequence was significantly more accurate than the bolus-chase sequence (P =.001). The point estimate of the difference was 14.7%, with estimated correct diagnosis rates of 80.3% and 65.6% for the dedicated calf and bolus-chase examinations, respectively (95% CI for difference: 4.0%, 25.4%). The diagnostic accuracy of bolus-chase MR angiography at the pelvis-thigh level was slightly higher when it was performed first: 81.9% (reader 1) and 83.8% (reader 2) versus 74.3% (reader 1) and 80.0% (reader 2) when it was performed last. The difference was not significant (P =.21). CONCLUSION: Use of dedicated calf MR angiography led to significantly increased diagnostic accuracy in the calf arteries compared with standard bolus-chase MR angiography. Use of the dual-bolus technique did not jeopardize the diagnostic accuracy in the pelvic and thigh arteries.

Aged↗
PubMed2003

CT arthrography of the glenohumeral joint: CT fluoroscopy versus conventional CT and fluoroscopy--comparison of image-guidance techniques.

PURPOSE: To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography. MATERIALS AND METHODS: Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software. RESULTS: Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv. CONCLUSION: CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.

Adolescent↗
PubMed2003

Relative rates of blood flow reduction during transcatheter arterial embolization with tris-acryl gelatin microspheres or polyvinyl alcohol: quantitative comparison in a swine model.

PURPOSE: To determine whether two commonly used embolic agents have differing rates of blood flow reduction during transcatheter embolization of the renal arteries in an animal model. MATERIALS AND METHODS: The renal arteries of 10 pigs were embolized with either polyvinyl alcohol (300-500 or 500-700- micro m) or tris-acryl gelatin microspheres (300-500 or 700-900- micro m). Equivalent unit doses of each agent were suspended in 40 mL of fluid and injected in 1-mL aliquots for 20 mL and then in 5-mL aliquots for 20 mL. Blood flow was measured after each aliquot with an intraarterial Doppler flow wire placed through the embolization catheter. RESULTS: Renal arterial blood flow was most rapidly and reliably decreased by 300-500- and 700-900- micro m microspheres, both of which had achieved >90% reduction from baseline flow after the injection of 6 mL of suspension. An equivalent reduction in flow required 25 mL of 300-500- micro m PVA suspension and 30 mL of 500-700- micro m PVA suspension. The reduction in blood flow with microspheres was significantly greater (P <.05) than that with PVA between 5 and 19 mL of suspension delivered. Differences between larger and smaller particle sizes of the same agent were not statistically significant. CONCLUSIONS: Tris-acryl gelatin microspheres reduced renal blood flow more quickly and reliably than did PVA. The type of agent used in embolization had a greater impact on the rate of flow reduction than did particle size in the range of sizes tested.

Angiography, Digital Subtraction↗
PubMed2003

Articular cartilage lesions of the glenohumeral joint: diagnostic effectiveness of MR arthrography and prevalence in patients with subacromial impingement syndrome.

PURPOSE: To determine the prevalence of articular cartilage lesions in patients with subacromial impingement syndrome and to assess the diagnostic effectiveness of magnetic resonance (MR) arthrography in detecting such cartilage abnormalities. MATERIALS AND METHODS: MR arthrographic images obtained in 52 consecutive patients (mean age, 45.8 years; age range, 17-73 years; 26 male and 26 female patients) were retrospectively evaluated for glenohumeral cartilage lesions. Two experienced musculoskeletal radiologists who were blinded to the arthroscopy report independently analyzed the articular cartilage. Humeral and glenoidal cartilage were assessed separately. The lesions were graded as either subtle or marked. Arthroscopic findings were the standard of reference. Sensitivity, specificity, accuracy, and interobserver agreement were calculated. RESULTS: At arthroscopy, humeral cartilage lesions were found in 15 patients (frequency, 29%). Four lesions were subtle, and 11 were marked. Cartilage lesions of the glenoid were less frequent (eight patients; frequency, 15%): Three were subtle, and five were marked. For reader 1 and reader 2, respectively, sensitivity of MR arthrography for humeral cartilage lesions was 53% and 100%, specificity was 87% and 51%, and accuracy was 77% and 65%; sensitivity for glenoidal cartilage lesions was 75% and 75%, specificity was 66% and 63%, and accuracy was 67% and 65%. Interobserver agreement for the grading of cartilage lesions with MR arthrography was fair (humeral lesions, kappa = 0.20; glenoidal lesions, kappa = 0.27). CONCLUSION: Glenohumeral cartilage lesions are found in up to one third of patients referred for MR arthrography for subacromial impingement syndrome. The performance of MR arthrography in the detection of glenohumeral cartilage lesions is moderate.

Adolescent↗
PubMed2002

Two fatal complications after parallel tracheal-esophageal stenting.

Two patients with malignant obstructions of both the trachea and esophagus underwent parallel stent placement with Gianturco-Rösch Z (GRZ) stents for palliation of symptoms. Fatal hemorrhage occurred in both patients 2 and 3 weeks after stent placement respectively. An autopsy performed on one of these patients demonstrated esophageal tissue necrosis and erosion with perforation of both the tracheal and esophageal walls at sites where the stent struts were in direct opposition, leading to bleeding from the esophageal venous plexus. GRZ stents have been successful in the treatment of both solitary tracheal and esophageal stenoses. However, parallel tracheal-esophageal stenting with GRZ stents places patients at high risk for complications due to the high radial force exerted by this particular stent and the minimal amount of intervening tissue between the two structures.

Aged↗
PubMed2002

Lack of suitability of the rabbit model for particulate uterine artery embolization.

PURPOSE: The goal of this study was to evaluate the rabbit model for studies of particulate uterine artery embolization (UAE). Rabbits were chosen because it was believed that their year-round breeding time and short duration of pregnancy would be useful in studies of fertility and pregnancy after UAE. MATERIALS AND METHODS: Bilateral UAE was performed in 12 adult female New Zealand White rabbits weighing 4-5.2 kg. All animals were proven to be breeders before treatment. Each uterine artery was embolized to stasis with use of 180-300- microm polyvinyl alcohol (PVA) particles (n = 9 animals), 500-710- microm PVA particles (n = 1), or tris-acryl 500-700- microm gelatin microspheres (n = 2). RESULTS: Two rabbits died 7 days after embolization and the other 10 rabbits had to be killed because of malaise and weight loss 4-8 d after embolization. In all animals, necropsy demonstrated extensive uterine necrosis sparing only the tip of the uterine horn. CONCLUSION: Rabbits are an unsuitable model for studies of UAE with the embolic agents in clinical use.

Angiography↗
PubMed2002

Laser-induced thermotherapy of the vertebral body: preliminary assessment of safety and real-time magnetic resonance monitoring in an animal model.

RATIONALE AND OBJECTIVES: To evaluate the safety of percutaneous laser-induced thermotherapy (LITT) of vertebral bodies and the feasibility of monitoring the thermal effects with real-time magnetic resonance (MR) imaging. MATERIALS AND METHODS: Laser fibers were placed in nine vertebral bodies of two minipigs under CT-guidance. LITT was performed in an open 0.5 T MR scanner using an Nd: YAG laser source. A T1-weighted MR sequence was used for continuous color-coded temperature monitoring. Histology of the vertebral body and spinal cord were subsequently obtained. RESULTS: Thermal lesions of the vertebral bodies measured 8 to 11 mm (mean 9.3 mm) in diameter. Thermal injuries of the spinal cord were observed in all four levels in which cortical bone surrounding the spinal canal was damaged during needle placement and in none with intact cortical bone. MR monitoring of the thermal effect was possible only if acquired in breath-hold technique. CONCLUSIONS: An intact cortical bone seems to be a prerequisite for safe LITT of the vertebral body. Real-time MR-monitoring of the thermal effect in vertebral bodies and the spinal canal was feasible with breath-hold acquisition. Larger studies are necessary to further evaluate accuracy of real-time MR imaging.

Animals↗
PubMed2002

Bone marrow abnormalities of foot and ankle: STIR versus T1-weighted contrast-enhanced fat-suppressed spin-echo MR imaging.

PURPOSE: To compare short inversion time inversion-recovery (STIR) and T1-weighted contrast material-enhanced fat-suppressed spin-echo magnetic resonance (MR) sequences for depiction of bone marrow abnormalities of the foot and ankle. MATERIALS AND METHODS: Fifty-one consecutive patients with bone marrow abnormalities depicted on turbo STIR images were examined with additional T1-weighted contrast-enhanced (0.1 mmol/kg gadopentetate dimeglumine) MR imaging with fat suppression. Volume and signal difference-to-noise ratio (SDNR) were measured. An additional qualitative analysis was performed by two experienced musculoskeletal radiologists to correlate the presence or absence of ill-defined edema-like zones, well-defined zones, and cystlike zones. Diagnoses determined with MR findings with each sequence were compared with the results of a review panel. Correlation coefficients (r(2)) and paired t tests were calculated for all measurements. Agreement percentages and kappa values were calculated for inter- and intraobserver reproducibility. RESULTS: Regarding volume of bone marrow abnormalities, a high correlation (r(2) = 0.98) of both sequences was found. SDNR was substantially higher on T1-weighted contrast-enhanced images than on STIR images (mean, 125.9 vs 95.4; P <.001). The qualitative analysis demonstrated identical imaging patterns with both sequences in 96% (79 of 82, kappa = 0.38) of ill-defined zones, in 88% (72 of 82, kappa = 0.76) of well-defined zones, and in 98% (80 of 82, kappa = 0.84) of cystlike zones. Interobserver reproducibility of the three imaging patterns was similar for both sequences. The kappa values for these three zones with STIR sequence were 0.55, 0.68, and 0.69, and those for the T1-weighted contrast-enhanced MR sequence were 0.49, 0.73, and 0.58, respectively. Diagnoses determined with MR findings were equal with both sequences in 94% (80 of 85) of involved bones. CONCLUSION: STIR images and T1-weighted contrast-enhanced fat-suppressed MR images demonstrate almost identical imaging patterns, and diagnoses determined with these findings show little difference.

Adult↗