Biomedical subjects

M Lenhart

Publications and source records attributed to M Lenhart.

At least 19 recordsLinked to original sources

PubMed2006

[Carotid artery dissection with cerebral infarction after soft tissue trauma in the pharyngeal region].

We report the case of an 8-year-old boy who suffered an internal carotid artery dissection as a result of an enoral soft tissue trauma. After an initial interval with minor symptoms he developed a cerebral infarction in the vascular region of the left middle cerebral artery. The patient was treated with decompression hemicraniectomy while therapy was monitored with intracranial pressure (ICP) measurements.

Carotid Artery, Internal, Dissection↗

PubMed2006

Intra-arterial MR angiography in the iliac system: initial clinical experience with 25 patients.

The aim of this study was to evaluate intra-arterial magnetic resonance angiography (MRA) of the iliac arteries. Therefore, 25 consecutive patients (17 male, 8 female) suffering from symptomatic occlusive disease of the lower limbs were investigated prospectively. Catheter angiography was performed before MRA and served as the standard of reference. Contrast-enhanced intra-arterial MRA was performed using a 1.5 Tesla MRI system. Contrast agent (gadodiamide) was injected by a conventional pigtail-shaped angiography catheter placed in the abdominal aorta. Vascular lesions were assessed by four investigators. The degree of stenosis was compared with the findings of conventional catheter angiography. Additionally, the diagnostic quality of the MR angiograms was assessed by the investigators using a semi quantitative five-point scale. All lesions shown by catheter angiography were detected and correctly localized by intra-arterial MRA. MR angiograms exhibit a specificity of 95% and a sensitivity of 96% for stenoses of 50% or more. The diagnostic quality of the images was judged from good to excellent, on average. Intra-arterial MRA exhibits a specificity and sensitivity comparable with intravenous angiography. The image quality appears to be adequate for supporting MR-guided vascular intervention.

Adult↗

PubMed2006

Vascularization of liver tumors - preliminary results with Coded Harmonic Angio (CHA), phase inversion imaging, 3D power Doppler and contrast medium-enhanced B-flow with second generation contrast agent (Optison).

PURPOSE: To investigate the dynamic value of contrast medium-enhanced ultrasonography with Optison for appraisal of the vascularization of hepatic tumors using harmonic imaging, 3D-/power Doppler and B-flow. MATERIALS/METHODS: 60 patients with a mean age of 56 years (range 35-76 years) with 93 liver tumors, including histopathologically proven hepatocellular carcinoma (HCC) [15 cases with 20 lesions], liver metastases of colorectal tumors [17 cases with 33 lesions], metastases of breast cancer [10 cases with 21 lesions] and hemangiomas [10 cases with 19 lesions] were prospectively investigated by means of multislice CT as well as native and contrast medium-enhanced ultrasound using a multifrequency transducer (2.5-4 MHz, Logig 9, GE). B scan was performed with additional color and power Doppler, followed by a bolus injection of 0.5 ml Optison. Tumor vascularization was evaluated with coded harmonic angio (CHA), pulse inversion imaging with power Doppler, 3D power Doppler and in the late phase (>5 min) with B-flow. In 15 cases with HCC, i.a. DSA was performed in addition. The results were also correlated with MRT and histological findings. RESULTS: Compared to spiral-CT/MRT, only 72/93 (77%) of the lesions could be detected in the B scan, 75/93 (81%) with CHA and 93/93 (100%) in the pulse inversion mode. Tumor vascularization was detectable in 43/93 (46%) of lesions with native power Doppler, in 75/93 (81%) of lesions after administering contrast medium in the CHA mode, in 81/93 (87%) of lesions in the pulse inversion mode with power Doppler and in 77/93 (83%) of lesions with contrast-enhanced B-flow. Early arterial and capillary perfusion was best detected with CHA, particularly in 20/20 (100%) of the HCC lesions, allowing a 3D reconstruction. 3D power Doppler was especially useful in investigating the tumor margins. Up to 20 min after contrast medium injection, B-flow was capable of detecting increased metastatic tumor vascularization in 42/54 (78%) of cases and intratumoral perfusion in 17/20 (85%) of HCC cases. All 19 hemangiomas were correctly classified by phase inversion imaging. CONCLUSIONS: Contrast medium-enhanced ultrasound investigation of liver tumors with Optison allowed reliable detection of tumor foci and, in most cases, appraisal of tumor vascularization. The time available for evaluation of tumor margin vascularization was substantially longer in B-flow.

Adult↗

PubMed2005

[Role of computed tomography and magnetic resonance imaging in the diagnosis of hepatitis and liver cirrhosis].

Computed tomography (CT) and Magnetic Resonance Imaging (MRI) have no significant impact in the evaluation of diffuse liver disease. Cirrhosis and hepatitis are not of specific imaging findings, the image of cirrhosis is depending on degree of disease. Nodular lesions are frequent findings in cirrhotic livers. For differentiation of regenerative nodules, dysplastic nodules and hepatocellular carcinoma CT and MRI are playing their role in localization and characterization of these lesions. Sensitivity and specificity are varying, depending on the technical applications of CT and MRI, and the application of contrast materials. MRI is superior in characterizing the lesions due to the different appearance of the lesions in different sequences. CT is superior as the staging modality. Complications of cirrhosis like ascites, varices of the oesophageal veins are diagnosed. CT and MRI are necessary when interventional or surgical procedures are planned or for therapy surveillance.

Ascites↗

PubMed2005

Intra-arterial magnetic resonance angiography of the iliac arteries: clinical experience using two different protocols.

PURPOSE: To assess the feasibility of intra-arterial magnetic resonance angiography (iaMRA) with two different protocols. MATERIAL AND METHODS: Twenty patients were prospectively examined after digital subtraction angiography. Contrast-enhanced iaMRA was performed using a 1.5T magnetic resonance imaging (MRI) system. Contrast agent (gadodiamide) was injected through a conventional angiography catheter placed in the abdominal aorta. The patients were randomized into two groups each comprising 10 patients. Group 1 was examined with a FLASH-3D (fast low-angle shot) sequence, allowing the center of the k-space to be acquired 0.5 s after initiation of the measurement. Group 2 was examined with the identical sequence, but the center of the k-space was acquired after 8.7 s. The increase in the intravascular signal intensity was determined and the diagnostic value of the angiograms was independently scored by 4 investigators using a 5-point scale. RESULTS: Nineteen of 20 MRAs were scored as diagnostic; only 1 was scored as non-diagnostic by 2 observers. The diagnostic value of the angiograms of group 2 was judged superior to that of group 1 owing to a more homogeneous intravascular contrast distribution. CONCLUSION: Intra-arterial MRA is feasible. The diagnostic value of angiograms using a flash sequence with center of the k-space acquisition after 8.7 s ranged from good to excellent. This sequence is appropriate for iaMRA of iliac arteries to support MR guided intervention.

Adult↗

PubMed2004

Feasibility of MR-guided angioplasty of femoral artery stenoses using real-time imaging and intraarterial contrast-enhanced MR angiography.

PURPOSE: To show the feasibility of magnetic resonance (MR) for guided interventional therapy of femoral and popliteal artery stenoses with commercially available materials supported by MR real-time imaging and intraarterial MR angiography. MATERIALS AND METHODS: Three patients (1 female, 2male), suffering from symptomatic arterial occlusive disease with stenoses of the femoral (n = 2) or popliteal (n = 1) arteries were included. Intraarterial digital subtraction angiography was performed in each patient pre- and post-interventionally as standard of reference to quantify stenoses. The degree of the stenoses reached from 71 - 88 %. The MR images were acquired on a 1.5 T MR scanner (Magnetom Sonata; Siemens, Erlangen, Germany). For MR-angiography, a Flash 3D sequence was utilized following injection of 5 mL diluted gadodiamide (Omniscan; Amersham Buchler, Braunschweig, Germany) via the arterial access. Two maximum intensity projections (MIP) were used as road maps and localizer for the interactive positioning of a continuously running 2D-FLASH sequence with a temporal solution of 2 images per second. During the intervention, an MR compatible monitor provided the image display inside the scanner room. Safety guidelines were followed during imaging in the presence of a conductive guidewire. The lesion was crossed by a commercially available balloon catheter (Wanda, Boston Scientific; Ratingen, Germany), which was mounted on a 0.035" guidewire (Terumo; Leuven, Belgium). The visibility was provided by radiopaque markers embedded in the balloon and was improved by injection of 1 mL gadodiamide into the balloon. After dilation, the result was checked by intraarterial MR angiography and catheter angiography. RESULTS: The stenoses could be correctly localized by intraarterial MR angiography. There was complete correlation between intraarterial MR angiography and digital subtraction angiography. The combination of guidewire and balloon was visible and the balloon was placed correctly to cover the entire stenoses. Balloon dilation reduced the degree of stenosis about 45 % on average. A prolonged dilation was necessary in one patient due to a relevant residual stenosis, which was recognized by intraarterial MR angiography. CONCLUSION: MR-guided balloon dilatation of femoral and popliteal artery stenoses supported by real time imaging and intraarterial MR angiography is feasible with commercially available materials in the above mentioned way.

Aged↗

PubMed2004

[In vitro examination of the visibility of 11 stent catheters with real-time MR imaging].

PURPOSE: To evaluate artifacts of unexpended stents and to determine their exact position for MR-guided percutaneous transluminal angioplasty using real-time sequences. MATERIALS AND METHODS: By using an in vitro model, 11 unexpended stents - 9 nitinol, 1 stainless steel, and 1 cobalt alloy - were investigated by MR. Each stent was studied in a vessel-phantom filled with saline solution. Imaging was performed using five different real-time sequences: fast low angle shot (Flash 2D), fast imaging with steady precession (true FISP, FISP, interactive true FISP) and segmented echo planar imaging (seg. EPI). Artifacts of the introducer system and the stent were calculated by four blinded radiologists (scale: 1 - artifacts, making an excellent contribution to visualization; 2 - artifacts, making mainly a contribution to visualization; 3 - artifacts, making no contribution to visualization). Furthermore, an evaluation of the visibility of the tip of the stent-catheter and the proximal and distal end of the stent was performed using a four-point scale (very good visibility to invisible). RESULTS: The artifacts of the introducer system and stent were rated best for Omnilink (1.3 +/- 0.47), Wallstent (1.6 +/- 0.5), Jostent (1.65 +/- 0.5) and Luminexx (1.65 +/- 0.5). The differences between Omnilink and Jostent as well as Omnilink and Luminexx were significant. A very good to good visibility of the catheter tip was observed with a mean of 1.7 +/- 0.66 for Omnilink followed by the Jostent (1.95 +/- 0.69), by the Wallstent(R) (2.1 +/- 0.72) and by Luminexx (2.5 +/- 1.14). Differences between Omnilink and Luminexx were significant. The visibility of the proximal and distal end of the stent was evaluated as very good to good in 4 stent catheters (Omnilink, Wallstent, Jostent, Luminexx). However, the differences between Omnilink and Jostent as well as between Omnilink and Luminexx, and between Wallstent and Luminexx were significant. For all evaluation criteria, the segmented EPI and the interactive true FISP were rated to be most suitable for visualization. There were no significant differences in the evaluation of these two sequences. CONCLUSION: Omnilink stent, Jostent, Wallstent, and Luminexx stent are suitable for MR-angioplasty due to their good visibility in MR. Segmented EPI- and a newly developed interactive true FISP-sequence enable an effective visualization of these stent-catheters.

Alloys↗

PubMed2004

[Influence of sequence type on the extent of the susceptibility artifact in MRI--a shoulder specimen study after suture anchor repair].

PURPOSE: To compare the extent of susceptibility artifacts after metallic suture anchor implantation by analyzing 14 different MRI sequences. MATERIALS AND METHODS: A metallic suture anchor was implanted in the central area of three glenoid porcine specimens. The specimens were imaged with a 1.5 T scanner using a protocol of 14 standard sequences including gradient echo, spin echo and turbo spin echo sequences with and without fat-saturation. Artifact size was measured for each specimen and sequence. The resulting mean artifact areas were determined for each type of sequence and the mean values of the three specimens compared. RESULTS: Gradient echo-sequences produced significantly larger artifact areas than the spin echo and turbo spin echo sequences, whereby the artifacts of the 3D-gradient echo sequences were smaller than the artifacts of the 2D-gradient echo sequences. A turbo spin echo sequence with a high readout band width and a short effective echo time showed the best results. For the conventional spin echo sequence, a reduction in the echo time did not significantly decrease the artifact size. Spectral fat-saturation did not affect the area of the susceptibility artifact compared to the non-saturated sequence. CONCLUSION: Gradient echo sequences should not be used after metallic suture anchor repair. Turbo spin echo sequences showed a decrease in the artifact size compared to conventional spin echo sequences and should be performed with a short effective echo time and a high band width. Spectral fat- saturation did not increase the artifact size significantly.

Animals↗

PubMed2004

[Tissue harmonic imaging (THI) and contrast harmonic imaging (CHI) for sonographically guided vacuum-assisted biopsy of mammographically occult breast tumors].

PURPOSE: To assess the guidance of tissue harmonic imaging (THI) and contrast harmonic imaging (CHI) for vacuum assisted biopsies of suspicious breast lesions compared to fundamental B-mode ultrasound-guided biopsies. MATERIAL AND METHODS: In 550 patients, ultrasound examinations of the breast were performed prospectively using fundamental B-scan, THI, and CHI. Focal lesions were documented in comparable projections for all three ultrasound modes. As contrast agent, a dose of 0.5 milliliters of Perflutren Protein-Type A microspheres ( Optison) was injected. An ultrasound-guided biopsy was performed in 38 focal lesions. Three radiologists experienced in breast imaging retrospectively assessed the lesions on the ultrasound images. RESULTS: Thirty-eight suspicious focal lesions [size 4 - 15 mm; median 8 mm] were detected by ultrasound. Of these, 29 were detected by fundamental B-scan images, 34 by THI, and 38 by CHI. Ultrasound-guided biopsy was performed on all of these lesions. No complications related to the biopsy were observed. In 25/38 cases, invasive carcinomas were found; in 6/38 ductal carcinomas in situ; in 3 cases metastases of already known invasive ductal carcinomas; and in 4 cases fibroadenomas. The size of the lesion was best identified using THI, smaller lesions (< 10 mm) using CHI. CONCLUSION: THI and CHI can help to detect focal lesions in dense breasts. Both modes can make it easier to perform ultrasound-guided biopsies of focal breast lesions.

Biopsy, Needle↗

PubMed2004

Clinical and angiographic outcome after interventional treatment of the iliac arteries with a new carbofilm coated stent: preliminary results.

PURPOSE: To evaluate the handling, the procedural success rate and the six-month outcome of a new Carbofilm coated balloon-expandable stent in iliac artery lesions. MATERIALS AND METHODS: In a prospective study, 46 stenoses and 2 occlusions of the iliac arteries were primarily stented in 30 patients with the Isthmus CarboStent (Sorin Biomedica Cardio S.p. A., Saluggia, Italy). The ankle-brachial index (ABI) at rest was determined before intervention and at the six-month follow-up visit. Iliac angiography, including intraarterial pressure measurement, was performed before intervention, post-procedurally and at the follow-up visit. RESULTS: All lesions were treated with procedural success. The mean degree of all stenoses was 73.9 % +/- 14.6 before and 2.4 % +/- 8.2 after intervention. The mean pressure gradient was 15.6 mm Hg +/- 10.1 before and 2.5 mm Hg +/- 2.7 after treatment. No or only a mild restenosis developed in 27 patients. The mean ABI increased from 0.64 +/- 0.21 to 0.86 +/- 0.33 and the mean pressure gradient was 2.7 mm Hg +/- 5.4 at the six-month visit. The six-month patency rate was 97.9 %. Three patients showed acute stent thrombosis due to an insufficient postprocedural antiplatelet regimen. DISCUSSION: The Isthmus CarboStent is a safe and easy to handle balloon-expandable stent for interventional therapy of iliac artery lesions. The six-month patency rate is good. Despite its Carbofilm coating, postprocedural antiplatelet therapy is necessary.

Administration, Oral↗

PubMed2004

High-resolution contrast-enhanced magnetic resonance angiography of the carotid arteries using fluoroscopic monitoring of contrast arrival: diagnostic accuracy and interobserver variability.

PURPOSE: To evaluate the diagnostic accuracy of high-resolution contrast-enhanced magnetic resonance angiography (CE-MRA) of the supra-aortic arteries using the CareBolus technique. Digital subtraction angiography was the standard of reference. MATERIAL AND METHODS: Fifty consecutive patients with suspected internal carotid artery stenosis underwent CE-MRA and digital subtraction angiography. CE-MRA was performed on a 1.5-T superconducting scanner with the CareBolus technique. CareBolus combines a nearly real-time 2D-FLASH (fast low angle shot) sequence for fluoroscopic triggering and a high-resolution 3D-FLASH with elliptical centric view order for the angiographic pulse sequence (6.0/2.16 ms [TR/TE], 30 degrees flip angle, 30.98 s acquisition time, 0.88 mm effective (interpolated) partition thickness and a 160 x 512 matrix). Intra-arterial digital subtraction angiography and CE-MRA studies were evaluated independently by four blinded readers. Internal carotid artery stenoses were graded according to the NASCET criteria. RESULTS: CE-MRA had an accuracy of 92.53%, a sensitivity of 95.64%, and a specificity of 90.39% for the identification of carotid artery stenoses > or = 70% (grade 3). Image quality for suppression of stationary tissue and venous contrast was good, but was reduced in five cases due to patient motion. CONCLUSION: The CareBolus technique is a useful non-invasive method for high-resolution imaging of the supra-aortic vessels because of its easy application and high sensitivity and specificity. Limitations can occur in non-compliant patients due to motion artifacts during the measurement time.

Adult↗

PubMed2003

[Evaluation of a hemostatic device with percutaneous collagen application (VasoSeal) compared to a mechanical compression system (Compressar) after transfemoral catheterization of patients suffering from arterial occlusive disease].

PURPOSE: Comparison of the efficacy of VasoSeal and a mechanical compression system (Compressar) for percutaneous hemostasis after femoral arterial catheterization of patients with arterial occlusive disease. MATERIALS AND METHODS: 60 patients underwent either diagnostic angiography or interventional procedures. The level of anticoagulation, blood pressure, and activation clotting time were recorded, and the time to hemostasis after sheath removal was measured. VasoSeal application was considered "successful" if the compression time was less than two minutes. On the subsequent day as well as 4 months later, color coded Doppler ultrasound was performed to register treatment success and potential (late) complications. RESULTS: 57 patients qualified for inclusion in this study. In 21 of the 26 patients who underwent the procedure with the VasoSeal, immediate hemostasis was achieved within 1.75 minutes. In all 31 patients who had the Compressar applied, hemostasis was successful with a mean compression time of 17.4 minutes. Thus, VasoSeal significantly reduced hemostasis time irrespective of anticoagulation status, but it had a much higher incidence of minor local complications (bleeding, hematoma) compared to the control group (34.6 % vs. 5.8 %). The technical success was lower with VasoSeal than with Compressar (81 % vs. 100 %). Both groups had no severe or late complications. CONCLUSION: According to our results, VasoSeal does not provide a suitable alternative compared to the effective, safe and cheap application of Compressar as a hemostatic device.

Adult↗

PubMed2003

[Indirect MR-arthrography of the shoulder-value in the detection of SLAP-lesions].

PURPOSE: A prospective study to assess the value of indirect magnetic resonance-arthrography (MR-Arthro) in the detection of lesions of the superior labrum (SLAP-lesions). MATERIALS AND METHODS: Unenhanced magnetic resonance imaging (MRI) and indirect MR-Arthro of the shoulder were performed in 35 patients (9 females and 26 males) with a history of acute or chronic shoulder disorder. The images of unenhanced MRI and indirect MR-Arthro were analyzed independently from each other for the occurrence of SLAP-lesions and the findings correlated with the arthroscopic results. For arthroscopy, MRI and MR-Arthro, the SLAP-lesions were categorized based on the classification system of Snyder. RESULTS: SLAP-lesions were diagnosed by arthroscopy in 22 of 35 patients (63 %). 9 of the 22 lesions (41 %) were classified as type 1, 9 (41 %) as type 2, three (13.5 %) as type 3 and one (4.5 %) as type 4. Using unenhanced MRI sensitivity, specificity and accuracy in the detection of SLAP-lesions were calculated to be 73 %, 85 % and 77 %. Indirect MR-Arthro showed a sensitivity of 91 %, a specificity of 85 % and an accuracy of 89 %. Unenhanced MRI revealed correlation to the arthroscopic classification in 9 of 22 cases (41 %) and indirect MR-Arthro in 18 of 22 cases (82 %). CONCLUSION: Indirect MR-Arthro is a non-invasive method which offers excellent sensitivity in the diagnosis of SLAP-lesions. It provides important preoperative informations with regard to the exact location and extent of a tear.

Adult↗

PubMed2003

Selective intraarterial fibrinolysis of acute central retinal artery occlusion.

PURPOSE: To evaluate the outcome of our patients with central retinal artery occlusion after local fibrinolysis and to compare these data with results reported in the literature. MATERIAL AND METHODS: Over a period of 7 years, 22 patients (11 male, 11 female, mean age 64.6 +/- 12.1 years) were treated with super-selective local fibrinolysis. In 1 case, treatment was carried out via the maxillary-ophthalmic anastomoses due to preexisting occlusion of the ipsilateral internal carotid artery. The latency period from the onset of symptoms to the beginning of therapy was 7.6 +/- 1.8 h. Urokinase was used in 7 cases (300,000-1.1 million units) and recombinant tissue plasminogen activator (20-40 mg) was applied in 15 patients. Visual acuity and fundus were examined before and after treatment. RESULTS: One patient (1/22 = 4.6%) recovered completely and regained a visual acuity of 20/20. Six patients (6/22 = 27.3%) showed a marked improvement with a range of visual outcome from 20/800 to 20/320. In 2 cases (2/22 = 9.1%) only a slight improvement was observed, with a visual outcome allowing detection of hand movements. In 13 cases (13/22 = 59.1%) no change in visual acuity as a result of treatment was observed. In 2/22 cases (9.2%) reversible neurological side-effects occurred, in 1 case suffered a stroke, and in another case intracerebral bleeding was observed. CONCLUSION: In our study, the recovery of visual acuity and the complication rate were not as positive as reported in the literature.

Acute Disease↗

PubMed2002

[Cost analysis of radiological interventional procedures and reimbursement within a clinic].

PURPOSE: Analysis of costs for vascular radiological interventions on a per patient basis and comparison with reimbursement based on GOA (Gebührenordnung für Arzte) and DKG-NT (Deutsche Krankenhausgesellschaft-Nebenkostentarif). MATERIAL AND METHODS: The ten procedures most frequently performed within 12 months were evaluated. Personnel costs were derived from precice costs per hour and estimated procedure time for each intervention. Costs for medical devices were included. Reimbursement based on GOA was calculated using the official conversion factor of 0.114 DM for each specific relative value unit and a multiplication factor of 1.0. The corresponding conversion factor for DKG-NT, determined by the DKG, was 0.168 DM. RESULTS: A total of 832 interventional procedures were included. Marked differences between calculated costs and reimbursement rates were found. Regarding the ten most frequently performed procedures, there was a deficit of 1.06 million DM according GOA data (factor 1.0) and 0.787 million DM according DKG-NT. The percentage of reimbursement was only 34.2 (GOA; factor 1.0) and 51.3 (DKG-NT), respectively. CONCLUSION: Reimbursement of radiological interventional procedures based on GOA and DKG-NT data is of limited value for economic controlling purposes within a hospital.

Angioplasty, Balloon↗

PubMed2002

[Contrast-enhanced MR angiography in the routine work-up of the lower extremity arteries].

PURPOSE: Prospective evaluation of the effectiveness of contrast-enhanced moving-table magnetic resonance angiography (CE-MRA) as the sole routine tool for the diagnosis of peripheral arterial occlusive disease and determination whether it can replace catheter arteriography. SUBJECTS AND METHODS: In a time period of 23 weeks, 100 consecutive patients were evaluated. A total of 112 contrast-enhanced moving-table MR angiograms were performed at 1.5 Tesla. A dedicated vascular coil system was used. It was evaluated in which cases MR angiography was sufficient to determine the treatment plan and in which cases limited quality required additional examinations. RESULTS: In 93.75 % (105/112) of all examinations, the treatment plan was determined by MRA as the sole diagnostic tool. Twenty-two patients underwent surgery or percutaneous angioplasty based on MRA findings. Additional examinations due to impaired quality were performed in seven (6.25 %) cases: two MR angiographies of the pelvic arteries, one MR angiography of the calf, and four selective arteriographies because of venous overlay at the calf. CONCLUSION: Contrast-enhanced MR angiography can take the place of catheter angiography in the routine work-up of patients with peripheral arterial occlusive disease. Further assessment might be necessary in five to ten percent of the cases when the diagnostic quality is inadequate, mostly due to venous overlay in the lower leg.

Adult↗

PubMed2002

[Percutaneous therapy of inoperable biliary stenoses and occlusions with a new self-expanding nitinol stent (SMART)].

OBJECTIVE: To evaluate the treatment of malignant biliary stenoses and occlusions using a new stent. METHODS: In a prospective study, 25 patients with malignant obstructive jaundice were treated with SMART(R) stents. The handling and the quality of stent expansion were documented. Stent function was assessed 2 - 4 days after intervention by cholangiography and laboratory tests. A follow-up was performed three months, after stent placement. RESULTS: All lesions were treated successfully, with a total of 35 stents implanted. In 14 patients a further balloon dilatation was performed after stent placement (8 - 10 mm diameter/ 40 - 80 mm length). The mean serum bilirubin level decreased significantly from 11.6 mg/dl to 4.6 mg/dl after intervention (p < 0.05). The follow-up showed a mean serum bilirubin level at 4.0 mg/dl. In 4 cases (16 %) a further intervention (PTCD or stent) was performed. Six patients died due to tumor progression. The stents proved to be patent in 79 % (n = 15) of patients alive at the time of follow-up. CONCLUSIONS: Placement of the SMART stent for the therapy of malignant biliary lesions yields good technical and clinical results.

Aged↗

PubMed2002

Evaluation of arterial bypass grafts of the pelvic and lower extremities with gadolinium-enhanced magnetic resonance angiography: comparison with digital subtraction angiography.

RATIONALE AND OBJECTIVES: The aim of this study was to compare contrast-enhanced magnetic resonance angiography (CE MRA) with digital subtraction angiography (DSA) in the assessment of patency and stenoses in bypass grafts. METHODS: Fifteen patients were examined with both CE MRA and DSA. Fifteen bypass grafts were evaluated by four readers for potential stenosis in five locations. The stenoses were classified in five types: 1 (0% to 24% stenosis), 2 (25% to 49%), 3 (50% to 74%), 4 (75% to 99%), and 5 (occlusion). RESULTS: Using both techniques, 70 of 75 evaluated locations (93.3%) were classified identically. This included six stenoses < 50% and six stenoses > 50%, respectively. Four of five overestimations of stenoses were scaled in DSA as stenoses type 1. One stenosis was categorized as type 3 in DSA. Sensitivity for CE MRA for detecting stenoses >or= 25% was 100% and the specificity 90%. Interobserver agreement for all evaluations was 0.77 (Spearman rank correlation test). CONCLUSION: In the assessment of low-grade stenosis in bypass grafts, CE MRA overestimates stenoses slightly but yields good results in comparison with DSA.

Angiography, Digital Subtraction↗