Impact of perioperative blood transfusions on oncologic outcomes after radical cystectomy: A systematic review and meta-analysis of comparative studies.

This study aimed at systematically analyzing and evaluating the impact of perioperative blood transfusions (PBT) on oncologic outcomes of patients undergoing radical cystectomy for bladder cancer. This systematic review follows the recommendations of the Cochrane Handbook for Systematic Reviews and Interventions and was conducted in line with the PRISMA statement and the AMSTAR II criteria. A comprehensive database search was performed based on the PICO criteria. Two independent reviewers performed all screening steps and quality assessment. Risk of bias and certainty in evidence were assessed with the Newcastle Ottawa Scale for non-randomized trials and the GRADE approach. Of 1123 identified studies 20 were eligible for qualitative analysis and 15 for quantitative analysis reporting on 21,915 patients. Receiving a PBT was associated with an increased risk of all-cause mortality (hazard ratio (HR) [95% confidence interval (CI)]: 1.29 [1.18, 1.40]; p < 0.001), cancer-specific mortality (HR [CI]: 1.27 [1.15; 1.41]; p < 0.001) and disease recurrence (HR [CI]: 1.22 [1.12; 1.34]; p < 0.001). Subgroup analysis of transfusion timing revealed a significantly increased risk of mortality with intraoperative or combined intra- and postoperative transfusions compared to postoperative transfusion only for all three outcomes (p < 0.001). Leukocyte-depletion was associated with increased all-cause mortality, but not cancer-specific mortality. The administration of PBT negatively impacts oncological outcomes after radical cystectomy. Therefore, careful treatment indication and strict adherence to transfusion guidelines is encouraged in order to avoid adverse effects during the perioperative course.

Early recovery after surgery for radical cystectomy: comprehensive assessment and meta-analysis of existing protocols.

PURPOSE: Different enhanced recovery after surgery (ERAS) protocols (EP) for radical cystectomy (RC) have been published. Protocols highly differ in number of included items and specific measures. MATERIALS AND METHODS: A systematic review and meta-analysis on EPs in RC were performed using the databases MedLine, Cochrane Library, Web of science, and Google Scholar. The specific ERAS measures of the protocols were extracted, analyzed, and compared. Pooling of available outcome data was performed for length of stay, complications, readmission rate, and time to defecation. RESULTS: The search yielded a total of 860 studies of which 25 studies were included in qualitative and 22 in quantitative analysis. Oral bowel preparation (BP) was omitted in 24/25 (96%) EPs, optimized fluid management was administered in 22/25 (88%) EPs and early mobilization (postoperative day 1) in 21/25 (84%). Gum chewing (n = 12, 46%), metoclopramide (n = 11, 44%), and alvimopan (n = 6, 24%) were the most common measures to prevent postoperative ileus. Our meta-analysis revealed a significant benefit in favor of EPs for the outcome parameters length of stay [mean difference (MD) - 3.46 d, 95% confidence interval (CI) - 4.94 to - 1.98, p < 0.01], complications [Odds ratio (OR) = 0.76, 95% CI 0.61-0.94, p = 0.01] and time to defecation (MD - 1.37 d, 95% CI - 2.06 to - 0.69, p < 0.01). Readmission rate did not show a significant difference (OR = 0.73, 95% CI 0.52-1.03, p = 0.07). CONCLUSION: Current EPs focus on omitting oral BP, early mobilization, and optimized fluid management while they differ in methods preventing postoperative ileus. Our meta-analysis revealed a benefit in introducing these protocols into clinical practice.

Asymmetry between Left and Right Eyes in Keratoconus Patients Increases with the Severity of the Worse Eye.

PURPOSE: To evaluate whether the inter-eye asymmetry of keratoconus (KC) patients is different from a healthy control group and to investigate how asymmetry changes with increasing severity of the disease. METHODS: In this retrospective study, we included both eyes of 350 patients with KC (age 35 ± 13 years) and 68 candidates planned for refractive surgery (control group, age 37 ± 11 years). Inclusion criteria for the KC group were keratoconus in at least one eye with Pentacam Topographical Keratoconus Classification (TKC) of at least 0.5. Patients eligible for refractive surgery in both eyes were included in the control group. Corneal tomography as well as Ocular Response Analyzer measurements were compared between both groups. Subgroup analysis was performed with respect to the TKC staging. Asymmetry was provided as worse eye (defined by higher TKC) minus fellow eye. RESULTS: In the KC group, both eyes showed the same TKC staging in 30.6%, a difference of one stage in 34.0% and of two stages in 24.6% of the patients. The inter-eye asymmetry in the keratoconus group was significantly larger than that in the control group. Corneal power showed an asymmetry of 3.8 ± 4.0 D in keratoconus eyes versus 0.22 ± 0.17 D in the control group. Central corneal thickness (CCT) asymmetry was 34 ± 30 µm versus 6 ± 5 µm, respectively. The Keratoconus Match Index showed an asymmetry of 0.40 ± 0.35 versus 0.15 ± 0.14. The difference between both eyes increased with increasing TKC of the worse eye. CONCLUSIONS: Inter-eye asymmetry is larger in keratoconus than in normal eyes, and it increases with keratoconus severity in the worse eye.

Lethal outcome after pelvic salvage radiotherapy in a patient with prostate cancer due to increased radiosensitivity : Case report and literature review.

BACKGROUND: In general, late side effects after salvage radiotherapy (RT) for prostate cancer are below 10%. Patients with impaired DNA repair ability and genetic instability can have significantly increased reactions after RT. CASE, CLINICAL FOLLOW-UP, AND EXAMINATION: We present a patient who experienced severe side effects after additive RT for prostate cancer and died from the complications 25 months after RT. Imaging (MR) is shown as well as three-color fluorescence in situ hybridization. The blood sample testing revealed that radiosensitivity was increased by 35-55%. We undertook a review of the literature to give an overview over the tests established that are currently considered useful. CONCLUSION: This case highlights that the identification of patients with increased radiosensitivity is an important task in radiation protection. Groups of patients who should be screened have to be found and corresponding research facilities have to be set up.

[Cystic tumor on the porta hepatis]. / Zystischer Tumor an der Leberpforte.

A cystic entity from the porta hepatis of a 64-year-old female patient was sent in for rapid section diagnostics with a clinical suspicion of pancreatic cancer. The rapid section diagnostics revealed aspects of glandular proliferation with mucous-like material in the lumina which led to the suspicion of infiltration of a highly differentiated mucinous adenocarcinoma. However, conventional paraffin-section histology and the immunohistochemical marker profile could not confirm this suspicion but an adenomatoid tumor was diagnosed. In typical locations in the genital area of both genders, this entity is a current differential diagnosis to infiltrations of an adenocarcinoma.

[PACS: acceptance by orthopedic surgeons]. / PACS: Akzeptanz bei Orthopäden und Unfallchirurgen.

PURPOSE: The goal of the study was to evaluate the acceptance of a web-based picture archiving and communication system (PACS) by orthopedic surgeons 1 year after implementation. MATERIALS AND METHODS: One year after the implementation of a web-based PACS all physicians were surveyed with a standardized questionnaire. Questions included: speed of PACS, quality of clinicoradiological meetings, quality of monitors, PACS training, and performance. Data were evaluated separately for the Department of Orthopedic Surgery and the reference group of all other physicians. RESULTS: Among the respondents, 92% of the orthopedic surgeons stated there was a reduction of time required to receive images, and 64% concluded that patient care was faster. Archived images were received in less than 5 min in 82% after PACS and in 8% before PACS. The clinicoradiological meetings improved with PACS in 100% due to beamer presentation. All would recommend a PACS. The equipment to view images in the operating theater was assessed as being good or very good by 83%; monitor quality was judged better for the outpatient clinics (100% good or very good). Conventional radiograms were missed at the ward rounds by 56%. Training for PACS was considered sufficient by 67%, and 15% asked for refresher courses. In the reference group 60% asked for refresher courses. In the comparison of orthopedic surgeons with the reference group PACS was judged better especially concerning the viewing software and quality of monitors. CONCLUSION: There is an over all acceptance of PACS by physicians outside the radiology department. The availability of images was not only facilitated it was faster as well. However, the quality of monitors in the operating theater should be improved. To achieve sustained success of PACS consistent training on PACS and its features is necessary. Conventional radiograms were often missed at the ward rounds.

[Radiological placement of peripheral central venous access ports at the forearm. Technical results and long term outcome in 391 patients]. / Radiologische Implantation zentralvenöser Portsysteme am Unterarm. Implantationsergebnisse und Langzeit-Follow-up bei 391 Patienten.

PURPOSE: To retrospectively analyze the technical result and long term outcome of central venous arm ports placed by radiologists. MATERIALS AND METHOD: Over a 5-year period, 399 arm ports were implanted by radiologists in 391 patients. The system consists of a low profile titanium chamber and a silicone catheter. Ports were placed at the forearm after puncture of a vein proximally to the elbow under fluoroscopic guidance. In a retrospective analysis the technical results and the long term outcome were evaluated. Complications were documented according to the standards of the society of interventional radiology. RESULTS: In 391 patients a total of 98 633 catheter days were documented (1 - 1325 days, mean 252 days). Primary technical success was 99.25 % (396 / 399) with a 100 % secondary technical success rate. No severe procedural complications, e. g. pneumothorax or severe hemorrhage, were found. A total of 45 complications occurred (11.28 %, 0.45 / 1000 catheter days), including 8 portal pocket infections (27 - 205 days, mean 115 days). Fifteen ports were explanted because of complications. The complication rate corresponds to the data from subclavian ports and is less than the complication rates published in large surgical trials. CONCLUSION: Implantation of central-venous arm ports by radiologists is safe and minimally invasive. No severe immediate procedural complications occur due to the peripheral implantation site. Long term complication rates are comparable to other studies of radiological or surgical port implantation at different sites.

[Evaluation of a liquid embolization agent (Onyx) for transcatheter embolization for renal vascular lesions]. / Endovaskuläre Behandlung akuter Nierenblutungen mit einem neuen Flüssigembolisat (Onyx): erste klinische Ergebnisse.

PURPOSE: To evaluate the therapeutic outcome after endovascular treatment of renal vascular lesions using the liquid embolization agent, Onyx. MATERIALS AND METHODS: Between 2004 and 2008 nine patients with renal vascular lesions were treated with transcatheter arterial embolization using Onyx. The renal vascular lesions consisted of 4 AV-fistulas, a pseudoaneurysm, bleeding from a single subsegmental artery, diffuse parenchymal bleeding after trauma, septic embolizations and multiple aneurysms in endocarditis. All patients underwent selective angiography of the renal artery. A dimethyl sulfoxide (DMSO)-compatible microcatheter was used and Onyx was injected. The technical and clinical success rate, examination time and procedure-related complications were documented. RESULTS: The overall technical and clinical success rate was 100 %. One patient had to be treated twice due to recurrent bleeding after an accidental puncture with a drainage catheter. No loss of viable renal tissue occurred in 4 cases. In 4 patients mild to moderate parenchyma loss was noted. In one patient having diffuse renal bleeding, occlusion of the main renal artery was performed. No procedure-related complications were noted. The mean examination time was 16.17 min when treating with Onyx alone and 60 min when using a combination of Onyx and coils. Within an average follow-up period of 21 months, no recurrent renal bleeding or recurrent AV-fistulas occurred. CONCLUSION: Onyx is an effective embolization agent for the treatment of renal vascular lesions. It allows controlled and quick application with low complication rates and a short examination time as a standalone agent or in combination with coils.

[Onyx (ethylene-vinyl-alcohol-copolymer)--a novel approach to the endovascular treatment of acute bleeding]. / Onyx (Ethylen-Vinyl-Alkohol-Kopolymer)--Ein neuer Anwendungsbereich in der endovaskulären Behandlung akuter peripherer Blutungen.

PURPOSE: The purpose of our retrospective study was to determine the feasibility and efficacy of the endovascular embolization of peripheral acute arterial hemorrhage using Onyx. MATERIALS AND METHODS: Between October 2003 and February 2007, 14 patients with acute arterial bleeding underwent percutaneous arterial embolization using Onyx. Bleeding was caused by iatrogenic vessel injury (6 patients), malignancy/inflammation (5 patients) and trauma (3 patients). Hematomas were located in the pelvis (5 patients), followed by liver (3 patients), retroperitoneal space (2 patients), thorax (2 patients), pancreas (1 patient), and thigh (1 patient). The number of embolized arteries, the volume and viscosity of embolic agent (Onyx), the number of additionally used coils, the embolization time, and the technical and clinical outcome were documented. Procedure-related complications, recurrent bleeding during hospital stay and outcome were recorded. RESULTS: In 14 patients selective endovascular embolization of 15 arteries was performed. The average volume of injected Onyx was 1.3 +/- 0.8 ml. In 6 cases (42.9%) Onyx was used in conjunction with coils. The average time between the correct placement of microcatheter and complete embolization was 24.9 +/- 12.6 minutes. In 13 of 14 patients (92.8%), embolization was technically successful. In one case, procedure-related complications occurred and embolization was performed in a second session a day later. After technically successful embolization, no recurrent bleeding occurred during hospitalization. Out of 14 patients, six (42.9%) died 1 - 38 days after technically successful embolization due to multiple organ failure (2 patients), hypoxic brain injury (2 patients), septic shock (1 patient) or malignancy-associated death (1 patient). CONCLUSION: We conclude that transcatheter embolization with the new liquid embolic agent Onyx is technically feasible and effective in patients with acute arterial hemorrhage.

[Carotid artery dissection with cerebral infarction after soft tissue trauma in the pharyngeal region]. / Karotisdissektion mit Mediainfarkt nach Weichteiltrauma im Bereich des Pharynx.

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.

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.

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.

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.

[Role of computed tomography and magnetic resonance imaging in the diagnosis of hepatitis and liver cirrhosis]. / Stellenwert der Computertomographie und der Magnetresonanztomographie in der Diagnostik von chronischer Hepatitis und Leberzirrhose.

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.

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.

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.

[Influence of sequence type on the extent of the susceptibility artifact in MRI--a shoulder specimen study after suture anchor repair]. / Abhängigkeit der Artefaktgrösse vom Sequenztyp in der MRT--Präparatstudie zur Beurteilung der postoperativen Schulter nach Labrumfixation.

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.

[In vitro examination of the visibility of 11 stent catheters with real-time MR imaging]. / In-vitro-Untersuchung der Sichtbarkeit von 11 Stentkathetern unter Echtzeit-MR-Kontrolle.

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.