Novel application of T1-weighted BLADE sequences with fat suppression compared to TSE in contrast-enhanced T1-weighted imaging of the neck: cutting-edge images?

PURPOSE: To evaluate if the use of BLADE sequences might overcome some limitations of magnetic resonance imaging (MRI) in the extracranial head and neck, which is a diagnostically challenging area with a variety of artifacts and a broad spectrum of potential lesions. MATERIALS AND METHODS: After informed consent and Institutional Review Board approval, two different BLADE sequences with (BLADE IR) and without inversion pulse (BLADE) were compared to turbo-spin echo (TSE) with fat saturation for coronal T1-weighted postcontrast imaging of the extracranial head and neck region in 40 individuals of a routine patient collective. Visual evaluation of image sharpness, motion artifacts, vessel pulsation, contrast of anatomic structures, contrast of pathologies to surrounding tissue as well as BLADE-specific artifacts was performed by two experienced, independent readers. Statistical evaluation was done by using the Wilcoxon test. RESULTS: Both BLADE and BLADE IR were significantly superior to TSE regarding pulsation artifacts and delineation of thoracic structures. TSE provided better results concerning contrast muscle/fat tissue and contrast lymph nodes/fat. More important, it showed significantly better contrast of several lesions, facilitating the detection of patient pathology. CONCLUSION: T1-weighted coronal imaging of the extracranial head and neck region is demanding. T1-weighted BLADE sequences still have drawbacks in anatomical contrast and lesion detection but offer possibilities to achieve reasonable image quality in difficult cases with a variety of artifacts.

MISAGO 2: one-year outcomes after implantation of the Misago self-expanding nitinol stent in the superficial femoral and popliteal arteries of 744 patients.

PURPOSE: To evaluate the safety and efficacy of the Misago self-expanding rapid-exchange nitinol stent system for the treatment of femoropopliteal occlusive disease in a prospective multicenter observational trial (ClinicalTrials.gov; identifier NCT01118117). METHODS: Between April and October 2008, the registry enrolled 744 patients (496 men; 69 ± 10 years) who had symptomatic ≥ 70% stenosis or occlusion of the superficial femoral or popliteal arteries treated with the Misago stent. Mean length of the 750 lesions was 63.9 mm; 282 (37.6%) vessels were completely occluded. Primary study endpoints were the need for target lesion revascularization (TLR) and event-free survival rates for the assessment of efficacy and safety, respectively. At 6 and 12 months post intervention, clinical symptoms of recurrent ischemia and/or claudication, Rutherford category, and ankle-brachial index (ABI) at rest were assessed. RESULTS: In the study period, 945 stents were successfully deployed in the 750 lesions. The overall TLR rate was 10.1% among 671 (90.3%) patients evaluated at 1 year [3.1% among 709 (95.3%) patients at 6 months]. Event-free survival at 12 months was 84.9%. Mean ABIs improved by ≥ 0.1 in three quarters of the patients (76.0%) over 12 months. The Rutherford grade improved or remained stable in the majority of patients (95.5%) after 1 year. Stent fractures (13 grade 1, 2 grade 2) in 3.1% of stents examined radiographically (n=484) at 1 year were not related to any clinical events. Primary patency was recorded in 574 (87.6%) patients evaluated at 1 year post procedure. CONCLUSION: The Misago rapid-exchange nitinol stent showed promising efficacy and safety results, with a low stent fracture rate, in patients with femoropopliteal disease, making it a safe and reliable treatment option.

Health Care Workers' Sick Leave due to COVID-19 Vaccination in Context With SARS-CoV-2 Infection and Quarantine-A Multicenter Cross-Sectional Survey.

Background: Reactogenicity of coronavirus disease 2019 (COVID-19) vaccines can result in inability to work. The object of this study was to evaluate health care workers' sick leave after COVID-19 vaccination and to compare it with sick leave due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and quarantine leave. Methods: A multicenter cross-sectional survey was conducted at Regensburg University Medical Center and 10 teaching hospitals in South-East Germany from July 28 to October 15, 2021. Results: Of 2662 participants, 2309 (91.8%) were fully vaccinated without a history of SARS-CoV-2 infection. Sick leave after first/second vaccination occurred in 239 (10.4%) and 539 (23.3%) participants. In multivariable logistic regression, the adjusted odds ratio for sick leave after first/second vaccination compared with BNT162b2 was 2.26/3.72 for mRNA-1237 (95% CI, 1.28-4.01/1.99-6.96) and 27.82/0.48 for ChAdOx1-S (95% CI, 19.12-40.48/0.24-0.96). The actual median sick leave (interquartile range [IQR]) was 1 (0-2) day after any vaccination. Two hundred fifty-one participants (9.4%) reported a history of SARS-CoV-2 infection (median sick leave [IQR] 14 [10-21] days), 353 (13.3%) were quarantined at least once (median quarantine leave [IQR], 14 [10-14] days). Sick leave due to SARS-CoV-2 infection (4642 days) and quarantine leave (4710 days) accounted for 7.7 times more loss of workforce than actual sick leave after first and second vaccination (1216 days) in all fully vaccinated participants. Conclusions: Sick leave after COVID-19 vaccination is frequent and is associated with the vaccine applied. COVID-19 vaccination should reduce the much higher proportion of loss of workforce due to SARS-CoV-2 infection and quarantine.

Risk to Radiology Staff for Occupational COVID-19 Infection in a High-Risk and a Low-Risk Region in Germany: Lessons from the "First Wave". / Risiko radiologischer Mitarbeiter für eine COVID-19-Infektion in einer Hoch- und Niedrigrisikoregion in Deutschland: Lehren aus der "ersten Welle".

PURPOSE: The recent COVID-19 pandemic has resulted in an increasing overload of the medical system. Healthcare workers (HCW) in radiology departments are exposed to a high infection risk similar to HCWs in the ICU or dedicated COVID wards. The goal of our paper is to evaluate the prevalence of IgG antibody against SARS-CoV-2 among radiology HCWs in two different hospitals and regions in Germany with a low and high COVID-19 prevalence and to compare it to the prevalence in other clinical personnel. Additionally, we assessed the number of radiological procedures performed in patients with a positive PCR test (C+) followed by a short review of the risk for nosocomial infections of radiology HCWs. MATERIALS AND METHODS: During the first COVID-19 wave between March and July 2020, we evaluated a region with one of the highest COVID-19 rates (776-1570/100 000) in Germany (Hospital A). Additionally, we assessed Hospital B in a region with a low prevalence (65/100 000). We tested the serum prevalence of SARS-CoV-2 IgG antibodies among the whole staff with a subgroup analysis for radiology in both hospitals. We calculated the total number of different radiological procedures performed in C+ patients. RESULTS: In Hospital A 594 PCR-proven C+ patients were treated resulting in 2723 radiological procedures. 24 % (n = 6) of the radiology technicians and 13.35 (n = 2) of radiologists had a positive IgG test. The rates were similar to positive rates in HCWs in COVID-19 wards and ICUs within the hospital. The most frequently performed procedures in C+ patients were chest X-rays (3.17/patient) and CT examinations (1.15/patient). In Hospital B 50 C+ patients were treated, resulting in 64 radiological procedures. None of the HCWs tested IgG positive. The most frequently performed examinations were also chest X-rays (1.04/patient) and CT (0.2/patient). CONCLUSION: HCWs in radiology have a high occupational infection risk similar to that of HCWs in ICUs and dedicated COVID wards. KEY POINTS: · The risk of acquiring COVID-19 increases with the amount of contact with infected individuals.. · The occupational risk of a SARS-CoV-2 infection for radiology staff is similar to that of nurses and physicians in COVID wards.. · Hygiene concepts and medical resources have to be adapted for further COVID outbreaks.. · Reporting of an occupational disease can be considered in the case of seropositive staff.. CITATION FORMAT: · Finkenzeller T, Lenhart S, Reinwald M et al. Risk to Radiology Staff for Occupational COVID-19 Infection in a High-Risk and a Low-Risk Region in Germany: Lessons from the "First Wave". Fortschr Röntgenstr 2021; 193: 537 - 543.

Superselective arterial embolisation with a liquid polyvinyl alcohol copolymer in patients with acute gastrointestinal haemorrhage.

OBJECTIVES: To evaluate the results of emergency embolisation in acute arterial bleeding of the gastrointestinal tract with a liquid polyvinyl alcohol copolymer from two centres. METHODS: We retrospectively analysed 16 cases (15 patients) of acute arterial bleeding of the gastrointestinal tract where emergency embolotherapy was performed by using the copolymer when acute haemorrhage was not treatable with endoscopic techniques alone. Cause of haemorrhage and technical and clinical success were documented. RESULTS: Arterial embolotherapy was successful in all 16 cases. The technical success rate was 100%. The cause of bleeding was pancreatitis in four, graft-versus-host disease (GVHD) of the colon in three, malignancy in three, angiodysplasia in two, ulcer in two and panarteritis nodosa and trauma in one each. There were no procedure-related complications. No bowel necrosis occurred because of embolisation. In 13 cases, the patients were discharged in good condition (81%); the three patients with GVHD died because of the underlying disease. CONCLUSIONS: The copolymer seems to have great potential in embolotherapy of acute arterial gastrointestinal bleeding. In our series none of the patients had rebleeding at the site of embolisation and no clinically obvious bowel necrosis occurred.

The 24-Month Results of the Lutonix Global SFA Registry: Worldwide Experience With Lutonix Drug-Coated Balloon.

OBJECTIVES: The Global SFA Registry sought to assess safety, clinical benefit, and outcomes of the Lutonix 035 drug-coated balloon (DCB) in a heterogeneous, real-world patient population at 12 and 24 months. BACKGROUND: Numerous clinical studies have evaluated the use of angioplasty for revascularization of femoropopliteal arteries in peripheral arterial disease with restenosis rates of 40% to 60% at 6 to 12 months. Data from recent studies document decreased restenosis rates and improvement in patency in patients receiving angioplasty of femoropopliteal arteries with DCBs. METHODS: The multicenter, prospective study enrolled 691 patients in 38 centers from 10 countries treated with the Lutonix 035 DCB in femoropopliteal lesions. The primary safety endpoint was freedom from a composite of target vessel restenosis, major index limb amputation, and device- or procedure-related death at 30 days. The primary effectiveness endpoint was freedom from target lesion restenosis at 12 months. Secondary endpoints were acute device and procedural success and clinically assessed primary patency. RESULTS: Freedom at 30 days from the composite safety endpoint was 99.4%. Freedom from target lesion restenosis was 93.4%/89.3% for the overall population, 93.2%/88.2% for long lesions up to 500 mm, and 90.7%/84.6% for in-stent restenosis at 12/24 months. Clinically assessed primary patency by Kaplan-Meier estimates was 85.4%/75.6% at 12/24 months. More than 76% of patients showed improvement of at least 1 Rutherford category. CONCLUSIONS: The Global SFA Registry 24-month outcomes confirm the Lutonix 035 DCB is a safe and effective long-term treatment option in real-world patients with peripheral arterial disease with superficial femoral artery lesions, also in long lesions and in-stent restenosis. (Lutonix Global SFA Registry; NCT01864278).

Planimetry of mitral valve stenosis by magnetic resonance imaging.

OBJECTIVES: We sought to determine whether noninvasive planimetry of the mitral valve area (MVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with mitral stenosis (MS). BACKGROUND: Accurate assessment of MVA is particularly important for the management of patients with valvular stenosis. Current standard techniques for assessing the severity of MS include echocardiography (ECHO) and cardiac catheterization (CATH). METHODS: In 22 patients with suspected or known MS, planimetry of MVA was performed with a 1.5-T magnetic resonance scanner using a breath-hold balanced gradient echo sequence (true FISP). Data were compared with echocardiographically determined MVA (ECHO-MVA, n = 22), as well as with invasively calculated MVA by the Gorlin-formula at (CATH-MVA, n = 17). RESULTS: The correlation between MRI- and CATH-MVA was 0.89 (p < 0.0001), and the correlation between MRI- and ECHO-MVA was 0.81 (p < 0.0001). The MRI-MVA slightly overestimated CATH-MVA by 5.0% (1.60 +/- 0.45 cm(2) vs. 1.52 +/- 0.49 cm(2), p = NS) and ECHO-MVA by 8.1% (1.61 +/- 0.42 cm(2) vs. 1.48 +/- 0.42 cm(2), p < 0.05). On receiver-operating characteristic curve analysis, a value of MRI-MVA below 1.65 cm(2) indicated mitral stenosis (CATH-MVA < or =1.5 cm(2)), with a good sensitivity and specificity (89% and 75%, respectively). CONCLUSIONS: Magnetic resonance planimetry of the mitral valve orifice in mitral stenosis offers a reliable and safe method for noninvasive quantification of mitral stenosis. In the clinical management of patients with mitral stenosis, it has to be considered that planimetry by MRI slightly overestimates MVA, as compared with MVA calculated echocardiographically and at catheterization.

Position of the acetabular cup -- accuracy of radiographic calculation compared to CT-based measurement.

OBJECTIVE: A variety of mathematical and trigonometric methods has been described for determining the position of the acetabular cups from conventional radiographs. However, these formulae are subject to unduly large inaccuracies. The aim of the study was to compare the reliability and the accuracy of radiological and CT-based determination of acetabular cup position. MATERIALS AND METHODS: The positions of acetabular cups of 31 patients were calculated in conventional plain radiographs of the hip using the method described by Widmer. Further, in all patients computed tomograms of the pelvis were performed and the cup position was measured with the aid of a CT-based computer-assisted navigation software. As reference values inclination and anteversion of the cups were calculated in 3D reconstructions of the pelvis with the aid of an image processing software. RESULTS: The radiological measurement as well as the CT-based method showed good intra- and inter-observer reliability and no significant difference in the calculation of the inclination (p=0.409). However, CT-based determination of anteversion was significantly more exact than radiological measurement (p<0.001). The calculation of the cup anteversion from the X-rays showed serious deviations from the reference method and a substantial error range (X-ray: mean deviation +1.74 degrees, range -16.6 degrees to +29.8 degrees , S.D. +/-9.32 degrees; CT-based: mean deviation -0.74 degrees, range -6.6 degrees to +5.3 degrees, S.D. +/-2.87). CONCLUSION: For any clinical problem or for clinical studies in which acetabular positions of acetabular cups have to be exactly determined, CT-based measuring methods are obviously the method of choice. Evaluations based only on conventional plain X-rays and calculation of the acetabular cup position using the formula described by Widmer must be regarded as unreliable, particularly, because of problems in measuring the anteversion.

Magnetic resonance-guided percutaneous angioplasty of femoral and popliteal artery stenoses using real-time imaging and intra-arterial contrast-enhanced magnetic resonance angiography.

OBJECTIVE: The aim of this study was to demonstrate the possibility of performing magnetic resonance (MR)-guided interventional therapy for femoral and popliteal artery stenoses with commercially available materials supported by MR real-time imaging and intra-arterial MR angiography. MATERIALS AND METHODS: A total of 15 patients suffering from symptomatic arterial occlusive disease of the lower limbs with 19 stenoses were included. Interventional intra-arterial digital subtraction angiography was performed before and after angioplasty on each patient as standard of reference. MR images were acquired on a 1.5-T MR scanner. A fast-low-angle shot (FLASH) 3D sequence was applied for a contrast enhanced MR-angiography (ceMRA). A total of 5 mL of diluted gadodiamide was injected via the arterial access. Maximum intensity projections (MIPs) were used as roadmaps and localizers for the interactive positioning of a continuously running 2D-FLASH sequence with a temporal solution of 2 images/second. The lesion was crossed by a balloon-catheter, which was mounted on a guidewire. The visibility was provided by the radiopaque markers on the balloon and was improved by injection of 1 mL of gadolinium into the balloon. Postinterventional control was performed by intra-arterial MR angiography and catheter angiography. RESULTS: Stenoses were localized by intra-arterial MR angiography. The guidewire/balloon combination was visible, and the balloon was placed correctly to cover the entire stenoses. Balloon dilation reduced the degree of stenosis by approximately 57% on average. No complications were observed. CONCLUSION: MR-guided balloon dilation of femoral and popliteal artery stenoses supported by real-time MR imaging and intra-arterial MR angiography is feasible with commercially available materials.

Contrast-enhanced magnetic resonance angiography of the carotid arteries: influence of injection rates and volumes on arterial-venous transit time.

RATIONALE AND OBJECTIVES: To assess the influence of injection rates and volumes on the arrival time of contrast material (CM) in the common carotid artery, the jugular vein and the resulting arterial-venous transit time. Additionally the relationship between injection parameters and the extent of a CM plateau was evaluated. MATERIALS AND METHODS: In 60 patients a CM injection was necessary to investigate suspected cranial disease. All patients were prospectively assigned to 6 protocol groups with varying volumes of gadolinium dimeglumine (2, 10, 20 mL) and injection rates (0.5, 1, 2, 4 mL/s). Simultaneously to the CM injection, 50 repetitive transverse measurements (1/s) were acquired at the level of the common carotid artery. Based on the resulting signal-time curves, the arrival time of the contrast material in the common carotid artery and the jugular vein, the resulting arterial-venous transit time, the peak enhancement and the extent of a CM-plateau were calculated as a function of the injection parameters. RESULTS: Smaller flow rates (0.5 mL/s) resulted in a longer arrival time in the common carotid artery (mean value 22,6 seconds +/- 2.3) and the jugular vein (mean value 32.6 seconds +/- 2.6) and resulted in longer arterial-venous transit time (mean value 10.1 second +/- 1.9). The volume showed no effect on these parameters. The peak arterial and venous signal intensity and a consistent CM-plateau after 50 seconds were dependent on the volume, but not on the injection rate. CONCLUSION: The injection rate showed an influence to the arrival time in the common carotid artery and the jugular vein and also to the arterial-venous transit time. The injected volume only affected the extent of the contrast plateau. A flow rate of 1 to 2 mL/s and a minimum of 20 mL gadolinium dimeglumine are recommended to achieve optimal image quality without venous overlay.

Amorphous silicon, flat-panel, x-ray detector: reliability of digital image fusion regarding angle and distance measurements in long-leg radiography.

RATIONALE AND OBJECTIVES: To evaluate composed long-leg images acquired with a large-area, flat-panel x-ray detector with regard to angle and distance measurements. METHODS: Radiographs of a long-leg phantom were acquired at 13 different angle settings with a 43-cm x 43-cm digital x-ray detector based on cesium iodide (CsI) and amorphous silicon (a-Si) technology. Three overlapping single images of the phantom were reconstructed at a workstation using a generalized correlation method. Four blinded observers were instructed to determine the angle of the axis of the long-legs as well as the length of "femur" and "tibia" on soft-copy displays. For that, the angle and distance measurement software integrated in the workstation was used. The images were analyzed with and without prior manual fine tuning of the primary composition result according to a mapped scale. Standard of reference was angle and distance determination at the phantom. RESULTS: On average, the difference between the observers' angle measurements and the standard of reference was 0.4 degrees for both images with and without prior manual correction. Regarding distance measurements, the average discrepancies to the standard were 0.2 cm (femur) and 0.1 cm (tibia) when analyzing images that had undergone manual fine tuning and 0.5 cm and 0.7 cm, respectively, for images without manual correction. CONCLUSIONS: The evaluated image fusion algorithm in conjunction with a 43-cm x 43-cm flat-panel detector is feasible regarding angle and distance measurements on long-leg images. In the case of inaccurate primary composition, results can be corrected easily by manual fine tuning.

Routine skeleton radiography using a flat-panel detector: image quality and clinical acceptance at 50% dose reduction.

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate image quality and clinical acceptance of a large-area, flat-panel X-ray detector for routine skeleton examinations at 50% dose reduction. METHODS: A total of 153 examinations (307 images) of 100 consecutive patients were evaluated. The cesium iodide-amorphous silicon active-matrix imager had a panel size of 43 x 43 cm, a matrix of 3000 x 3000, and a pixel pitch of 143 microm. All images were obtained with a kilovoltage setting identical to conventional radiographies of speed class 400. The amperage values were reduced by 50% compared with standard dose. Images were presented to 3 radiologists, who subjectively rated image quality on a 4-point scale according to 5 criteria (bone cortex, bone trabecula, soft tissue, overall contrast, and overall impression). Three trauma surgeons rated the clinical acceptance on a 4-point scale. Clinical acceptance was defined as directly derived consequences or therapy based on the presented image quality. For both evaluations, 1 represented excellent, 2 represented good, 3 represented moderate, and 4 represented nondiagnostic image quality/clinical acceptance. Intermediate scores at 0.5 intervals were allowed. RESULTS: The mean values for all 5 image quality criteria were rated good or excellent (< or = 2). A total of 4.2% (13 of 307) of the images were rated 2.5 to 3.5 concerning the overall impression. None of the imaging features was ranked more than 3.5 by any radiologist. The mean value of the clinical acceptance was between good and excellent (1.47). A total of 98.7% (151 of 153) of the examinations were rated < or = 2.5; 1.3% (2 of 153) of examinations were of moderate clinical acceptance (< or = 3.5). None of the examinations was of nondiagnostic image quality or clinical acceptance (>3.5); therefore, no study had to be repeated. CONCLUSION: Routine skeleton images with 50% dose reduction yield good image quality and good clinical acceptance. In cases with abundant soft tissue, less dose reduction or standard dose is required.

Sonographic evaluation of the elbow in rheumatoid arthritis: a classification of joint destruction.

The purpose of this study was to evaluate and classify sonographically the joint damage of the elbow in patients with rheumatoid arthritis. Standardized sonography of the elbow joint was performed in patients with rheumatoid arthritis between 1998 and 2002; from 2000 onwards in a controlled and prospective study. A grading of the joint damage was developed, evaluated and compared with the radiographic standard reference films of the Larsen classification. A total of 320 consecutive patients were included in this study; 250 elbows of 125 patients (93 women/32 men) were examined in a prospective way. Mean age was 62.5 years and mean disease duration was 11.9 years. The sonographically visible changes could be divided into six stages. In 24% of the patients graded Larsen 0, sonography detected definite abnormalities classified as stages 1 to 3. Sonography is a valuable tool to assess and classify elbow joint alteration in rheumatoid arthritis. Particularly in early stages of joint affection, ultrasound (US) is superior to X-ray in detecting soft tissue changes and minor erosions.

Mesenteric histiocytosis or only an inflammatory infiltration of histiocytes? A case report from a surgical point of view.

The mesenteric sclerosing processes are very rare tumors. There are only a few cases of mesenteric fibromatosis described in literature. A case of mesenteric histiocytosis or a mesenteric infiltration by histocytes as a reactive inflammatory process is not described in the surgical literature. Because of its clinical and macroscopic similarity to a fibromatosis or a reactive inflammatory process and a lack of articles in the literature on mesenteric histiocytosis we concentrated our research in literature on the mesenteric fibromatosis and its differential diagnosis.

Dynamic magnetic resonance defecography in 10 asymptomatic volunteers.

AIM: Evaluation of the wide range of normal findings in asymptomatic women undergoing dynamic magnetic resonance (MR) defecography. METHODS: MR defecography of 10 healthy female volunteers (median age: 31 years) without previous pregnancies or history of surgery were evaluated. The rectum was filled with 180 mL gadolinium ultrasound gel mixture. MR defecography was performed in the supine position. The pelvic floor was visualized with a dynamic T2-weighted sagittal plane where all relevant pelvic floor organs were acquired during defecation. The volunteers were instructed to relax and then to perform straining maneuvers to empty the rectum. The pubococcygeal line (PCGL) was used as the line of reference. The movement of pelvic floor organs was measured as the vertical distance to this reference line. Data were recorded in the resting position as well as during the defecation process with maximal straining. Examinations were performed and evaluated by two experienced abdominal radiologists without knowledge of patient history. RESULTS: Average position of the anorectal junction was located at -5.3 mm at rest and -29.9 mm during straining. The anorectal angle widened significantly from 93° at rest to 109° during defecation. A rectocele was diagnosed in eight out of 10 volunteers showing an average diameter of 25.9 mm. The bladder base was located at a position of +23 mm at rest and descended to -8.1 mm during defecation in relation to the PCGL. The bladder base moved below the PCGL in six out of 10 volunteers, which was formally defined as a cystocele. The uterocervical junction was located at an average level of +43.1 mm at rest and at +7.9 mm during straining. The uterocervical junction of three volunteers fell below the PCGL; described formally as uterocervical prolapse. CONCLUSION: Based on the range of standard values in asymptomatic volunteers, MR defecography values for pathological changes have to be re-evaluated.

Endovascular repair of proximal endograft collapse after treatment for thoracic aortic disease.

We report two cases of proximal endograft collapse with an almost complete aortic occlusion after endovascular tube-graft treatment of thoracic aortic disease (thoracic aneurysm after a type B dissection, traumatic blunt aortic rupture) using the TAG Gore system. Oversizing of endografts is known to cause this complication. In our two cases, however, the oversizing was between 12% and 21.7%, which is less than the allowed oversizing of 25% that is recommended by the manufacturer. This endograft-related complication might be due to a poor alignment of the currently available endografts in highly angulated and tight aortic arches. In the first case, a combined endovascular and open emergent repair procedure achieved a reopening of the proximal endograft by proximal extension (TAG Gore). In the second case, proximal extension was not considered owing to a precise positioning of the endograft distal to the left carotid artery. A balloon-expanding Palmaz stent was therefore placed interventionally in the proximal part of the TAG graft to expand the endograft and to avoid another collapse of the device. This proximal endograft collapse has to be acknowledged as a potentially hazardous complication. We therefore recommend that the proximal part of thoracic endografts in the aortic arch should be closely monitored and we offer two possible endovascular solutions for resolving the problem of proximal endograft collapse.

Indirect MR arthrography of the shoulder: use of abduction and external rotation to detect full- and partial-thickness tears of the supraspinatus tendon.

PURPOSE: To evaluate prospectively the accuracy of indirect magnetic resonance (MR) arthrography for supraspinatus tendon tears during neutral positioning or abduction and external rotation (ABER) and neutral positioning. MATERIALS AND METHODS: Informed consent was obtained in all patients, and the study was approved by the institutional review board. Indirect MR arthrography of the shoulder was performed in 51 symptomatic patients (14 female, 37 male; mean age, 47 years) in the neutral position (set 1) and in the neutral and ABER positions (set 2). Two readers independently interpreted both sets, and diagnoses were compared with arthroscopic findings. Diagnostic accuracy was calculated, and 95% confidence intervals were used to detect significant differences between sets. Diagnostic confidence was recorded by using a three-level confidence score. Differences between sets were evaluated by using the Wilcoxon signed rank test. Interobserver agreement was determined separately for each set and for all diagnoses, full-thickness tears, and partial-thickness tears. RESULTS: For full-thickness tears, there was no benefit to reading set 2. For reader 1, sensitivity and specificity were 95% and 100%, respectively, for set 1 and 100% and 100%, respectively, for set 2. For reader 2, sensitivity and specificity were 80% and 100%, respectively, for set 1 and 100% and 100%, respectively, for set 2. For partial-thickness tears, sensitivity was significantly higher after reading set 2. For reader 1, sensitivity and specificity were 71% and 88%, respectively, for set 1 and 93% and 100%, respectively, for set 2. For reader 2, sensitivity and specificity were 50% and 88%, respectively, for set 1 and 86% and 94%, respectively, for set 2. For both readers, diagnostic confidence for partial-thickness tears was significantly higher after reading set 2. After the interpretation of set 2, kappa values increased from 0.35 to 1.00 for full-thickness tears and from 0.12 to 0.63 for partial-thickness tears. CONCLUSION: Indirect MR arthrography with supplementary images obtained with patients in the ABER position significantly improved sensitivity and increased diagnostic confidence for partial-thickness tears of the supraspinatus tendon. Interobserver agreement was improved for both full- and partial-thickness tears.

Proposal for a sonographic classification of target joints in rheumatoid arthritis.

OBJECTIVE: The purpose of this study was to classify sonographically the joint damage of target joints in patients with rheumatoid arthritis (RA). METHODS: During a 3-year cross-sectional study, standardized arthrosonography of symptomatic target joints was performed in patients with RA. According to those findings, a classification with progressive deterioration of joint alteration in RA was created that grades visible morphological changes of the joint components. Using elbow joints as a subgroup, inter- and intraobserver reliability was calculated. RESULTS: Examined and included in this study were 1211 joints of 425 patients with RA. The mean disease activity score was 5.2 (range 0.75-7.79). Sonographically visible changes could be classified and divided into six stages. A standardized sonographic evaluation system was developed. In reference to the elbow joint, overall percentages for intra- and interobserver reliability of sonography were 90.8% and 88.8%, respectively. CONCLUSION: Sonography is a valuable tool for assessing and classifying joint alteration in RA. Particularly in early stages of joint affection, ultrasound is superior to X-ray in detecting soft tissue changes and minor erosions.

In vivo evaluation of patency and in-stent stenoses after implantation of nitinol stents in iliac arteries using MR angiography.

OBJECTIVE: Our study was a prospective in vivo study to evaluate whether MR angiography is suitable for assessing stent patency and grading in-stent stenoses and to examine whether the accuracy of MR angiography changes with time after stent implantation. SUBJECTS AND METHODS: In a prospective study, 34 iliac stenoses in 27 patients were treated by implantation of 35 nitinol stents. MR angiography was performed immediately after stent placement for 32 stents, and both digital subtraction angiography (DSA) and MR angiography were repeated at the 6-month follow-up for 23 stents. Three blinded observers assessed stent patency and the degree of in-stent stenoses on MR angiography and DSA (the standard of reference) images. The difference between the observers' grading of stenoses on DSA and on MR angiography was determined. Statistical analysis was performed using the Student's t test for paired samples. RESULTS: Stent patency was assessed correctly for all stents and both sets of MR angiography images. Evaluation of DSA 1 images (obtained at end of implantation procedure) revealed that 96.9% of in-stent stenoses were less than 50%. On DSA 2 images (obtained at follow-up), 95.7% of in-stent stenoses were graded as less than 50%. The difference between grading of stenoses on DSA and MR angiography images was 15.0% +/- 16.0% (minimum, 0.0%; maximum, 63.3%) for DSA 1 versus MR angiography 1 (statistically significant, p = 0.037) and 9.8% +/- 13.5% (minimum, 0.0%; maximum, 63.3%) for MR angiography 2 versus DSA 2 (not statistically significant, p = 0.355). CONCLUSION: Patency was correctly assessed for all stents on MR angiography. The quality of MR angiography regarding characterization of in-stent stenoses improved with time after stent placement. However, discrepancies of more than 60% between grading of lumen narrowing on DSA and MR angiography images occurred even at the 6-month follow-up. Thus, MR angiography is not yet a reliable technique for characterization of in-stent stenoses.

Intraarterial gadolinium-enhanced MR angiography in humans for the detection of infrainguinal arterial stenoses before and after percutaneous angioplasty.

OBJECTIVE: The objectives of this study were to show the feasibility of intraarterial MR angiography of the infrainguinal arteries and to compare the accuracy of intraarterial MR angiography with selective intraarterial digital subtraction angiography for the detection of stenoses before and after percutaneous balloon angioplasty. SUBJECTS AND METHODS: Fifteen patients underwent digital subtraction angiography and intraarterial MR angiography before and after balloon angioplasty. For intraarterial MR angiography, 30 mL of diluted contrast agent (5 mL of gadodiamide diluted in 55 mL of 0.9% saline solution) was injected through a sheath in the superficial femoral artery using a flow rate of 2.5 mL/sec. A 3D gradient-echo sequence was performed. Four independent blinded observers assessed differences in the quantitative measurement of stenoses and localization of lesions between digital subtraction angiography and intraarterial MR angiography. The overall impression of the intraarterial MR angiography images was documented on a 4-point scale (1 = excellent, 4 = poor). Interobserver variability was calculated. RESULTS: Intraarterial MR angiography from the upper leg to the trifurcation was feasible in all 30 examinations with a mean overall impression of all segments of 1.3 (SD, 0.68). For the detection of significant stenoses (> or = 50% stenosis), the overall sensitivity and specificity for the femoropopliteal and crural vessels were 92.4% and 91.7% and 91.9% and 87.8%, respectively. For the complete leg, sensitivity and specificity were 92.2% and 88.6%, respectively. Interobserver variability for intraarterial MR angiography of the crural vessels exceeded that of the femoropopliteal arteries. CONCLUSION: Intraarterial MR angiography of the infrainguinal arteries is feasible in humans using injections of diluted contrast agent at concentrations as low as 8%. It has a high sensitivity for detecting stenoses and an acceptable interobserver variability.