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ABSTRACT: The purpose of this study was to establish an MRI protocol on a clinical scanner for assessment of left (LV) and right (RV) ventricular myocardial function of the murine heart, and to apply this protocol for the first in vivo assessment of myocardial function in a mouse model of cardiomyopathy (Desmin-/-). MRI was performed on a clinical 3 T whole body MRI system using a dedicated solenoid receive-only coil. Contiguous short axis slices were acquired covering the entire heart using a spoiled cine gradient echo sequence (TR 9-12 ms, TE 3-4 ms, α 25°, 1.0 × 0.23 × 0.23 mm³). Global LV- and RV-myocardial functional parameters such as end-diastolic ventricular volume, ejection fraction (EF), LV mass and cardiac output (CO) of Desmin-/- mice and age-matched controls were determined. Global myocardial functional data of healthy controls (n = 4) were in very good agreement with previously reported data. The transgenic mice (n = 8) revealed a significantly reduced LV- and RV-EF as well as CO. Body weight-normalized LV- and RV-end-diastolic volumes and LV mass were significantly increased. In addition desmin deficient mice exhibited segmental wall thinning and akinesia, suggesting myocardial necrosis. This study demonstrates that clinical 3 T MRI-systems may reliably be used for non-invasive assessment of LV- and RV-myocardial function in normal and in genetically engineered mice with cardiomyopathies. In addition, this proof of principle study presents first in vivo MRI data of the cardiac phenotype of desmin knock-out mice.
The international journal of cardiovascular imaging 12/2011; 28(7):1699-705. · 2.15 Impact Factor
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ABSTRACT: Evaluation of a handheld sonographic tool for the automatic estimation of bladder volume in comparison with conventional sonography in children under clinical conditions.
139 children (age: 30 days - 17 years) were examined with both conventional sonography and the handheld scanning device BVI 6200. For conventional sonography two different formulas were used to calculate the bladder volume.
The mean error of the three methods was 22.4 % for the handheld tool, 37.4 % for the most frequently used prolate ellipsoid formula in conventional sonography, and 23 % for an alternative formula recommended in the literature. In 19 cases the first automated sonography scan showed a false-negative result (empty bladder), while the automatically calculated volumes were between 17 and 60 ml in 5 cases of empty bladder. In one of these cases a megaureter and in another an ovarian cyst were detected by conventional ultrasound.
Since pathologies are not visualized and can be misinterpreted as a nonempty bladder, the automated method should only be used in follow-up studies. In every case automated volumetry should be performed repeatedly to avoid false-negative results.
RöFo - Fortschritte auf dem Gebiet der R 11/2009; 182(4):341-7. · 2.76 Impact Factor
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ABSTRACT: The purpose of this study was to assess shortterm effects of transjugular intrahepatic shunt (TIPS) on cardiac function with cardiac magnetic resonance imaging (MRI) in patients with liver cirrhosis. Eleven patients (six males and five females) with intractable esophageal varices or refractory ascites were imaged with MRI at 1.5 T prior to, within 24 h after, and 4-6 months after TIPS creation (n = 5). Invasive pressures were registered during TIPS creation. MRI consisted of a stack of contiguous slices as well as phase contrast images at all four valve planes and perpendicular to the portal vein. Imaging data were analyzed through time-volume curves and first derivatives. The portoatrial pressure gradient decreased from 19.8 + or = 2.3 to 6.6 + or = 2.3, accompanied by a nearly two fold increase in central pressures and pulmonary capillary wedge pressure immediately after TIPS creation. Left and right end diastolic volumes and stroke volumes increased by 11, 13, and 24%, respectively (p\0.001), but dropped back to baseline at follow-up. End systolic volumes remained unchanged. E/A ratios remained within normal range. During follow-up the left ventricular mass was larger than baseline values in all patients, with an average increase of 7.9 g (p\0.001). In conclusion, the increased volume load shunted to the heart after TIPS creation transiently exceeded the preload reserve of the right and left ventricle, leading to significantly increased pulmonary wedge pressures and persistent enlargement of the left and right atria. Normalization of cardiac dimensions was observed after months together with mild left ventricular hypertrophy.
CardioVascular and Interventional Radiology 09/2009; 33(2):290-6. · 2.09 Impact Factor
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ABSTRACT: To evaluate the detectability of the Adamkiewicz artery (AA) in patients with acute Stanford type A aortic dissections with multi-detector computed tomography (MDCT).
51 patients with Stanford type A dissection underwent contrast-enhanced 64-row MDCT of the entire aorta (collimation 64 x 0.625 mm; rotation time 0.4sec; 120 kV; 300 mAs). The visualization of the AA, its origin, and whether it originated from the true or false lumen were analyzed using source and multiplanar reformation images.
A single anterior radicular artery that formed a hairpin turn constituting the anterior spinal artery was visualized in 36 (70 %) patients. Thirty (83 %) of these arteries originated from the left side, and 35 (97 %) originated between the level T 7 and L 2. Twenty-three (64 %) arteries originated from the true and 13 (36 %) from the false lumen. Two AAs in the same patient were not observed.
MDCT depicts the AA in a high percentage of patients with acute Stanford type A aortic dissection.
RöFo - Fortschritte auf dem Gebiet der R 07/2009; 181(9):870-4. · 2.76 Impact Factor
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ABSTRACT: High field magnetic resonance imaging (MRI) provides higher lesion load measurements in patients presenting with clinically isolated syndromes (CIS) suggestive of demyelination and has impact upon the classification of these syndromes and potentially, the diagnosis of multiple sclerosis (MS).
To investigate whether high field MRI can provide an earlier diagnosis of definite MS within the International Panel (IP) and Swanton criteria.
Forty patients presenting with CIS suggestive of MS were included. All patients received multi-sequence MRI at 1.5 Tesla (T) and 3T as well as a neurological assessment at baseline. Follow-up visits including MRI at both field strengths and neurological examinations were scheduled 3-4 and 6-7 months after the first clinical event. Based on MRI and clinical findings, fulfilled IP criteria as well as Swanton criteria were analysed.
At baseline, the higher detection rate of inflammatory lesions using high field MRI leads to higher classifications according to the Swanton criteria in 15 % of the patients. One additional patient was diagnosed with dissemination in space according to Swanton and IP criteria. During follow-up, an earlier diagnosis of definite MS could not be accomplished, neither according to the IP nor to the Swanton criteria.
Although high field MRI shows a higher detection rate of inflammatory brain lesion in CIS and MS patients with an influence according to MRI criteria, this influence does not lead to an earlier diagnosis of lesion dissemination in time and therefore definite MS.
Journal of Neurology 06/2008; 255(8):1159-63. · 3.47 Impact Factor
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ABSTRACT: Iodinated contrast media (CM) can inhibit phagocytosis. To better understand the importance of this effect upon the elementary defence mechanism, the aim of the study was to compare the in vivo effect of non-ionic CM on the engulfing ability of peripheral blood phagocytic cells from patients undergoing CM-enhanced CT. Neutrophil granulocytes and monocytes from patients' peripheral blood obtained before and 30 min after CM injection were incubated with fluorescent-labelled Escherichia coli bacteria. Both the percentage of cells that engulfed bacteria and the phagocytic activity per cell has been determined by flow cytometry. We found that phagocytosis was greater in neutrophils than in monocytes. CM decreased the percentage of monocytes phagocyting bacteria, both at 4 degrees C (20.3%+/-3.3% versus 16.1%+/-2.0%; p<0.03) and at 37 degrees C (51.6%+/-4.1% versus 47.5%+/-2.6%; p>0.05), and increased the percentage of neutrophils at 4 degrees C (11.8%+/-2.1% versus 14.3%+/-2.2%; p<0.002) and at 37 degrees C (83.1%+/-3.6% versus 85.1%+/-3.2%; p>0.05). The phagocytic activity decreased significantly at 37 degrees C in monocytes (p<0.02), and was not affected in neutrophils. CM injection has different effects on both the percentage of phagocytosing cells and the phagocytic activity in monocytes and neutrophils. The inhibitory effect on monocyte phagocytosis seems to be compensated by neutrophils.
The British journal of radiology 03/2008; 81(963):199-203. · 2.11 Impact Factor
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ABSTRACT: In the field of oncologic surgery, an accurate local staging, i.e. the delineation of local disease extent, is considered of key importance to guide treatment decisions in patients with operable cancers, in particular patients who are operated on with curative intention. Imaging studies are used to provide a road map for the surgeon to help him or her obtain clear margins-which, in turn, is considered essential in order to avoid recurrent disease. It is well established that breast MRI is by far superior to mammography, with or without concomitant ultrasound, for the local staging of breast cancer. MRI allows the most accurate delineation of the size and the local extent of cancer, including the depiction of multifocal or multicentric or contralateral disease. MRI offers the highest sensitivity for demonstrating intraductal extensions around invasive cancers. Due to its very high negative predictive value, MRI can be used to confidently exclude the presence of breast cancer, and, thus, avoid unnecessary surgery. For all these reasons, MRI should be considered an integral part of the work up of patients who undergo breast-conserving treatment for breast cancer. And yet, the technique is only slowly adopted in clinical practice. Arguments against the use of breast MRI include costs, frequency of false positive diagnoses, lack of availability of minimally invasive biopsy capabilities, lack of evidence by randomized controlled clinical trials, and, last, fear of overtreatment. In this article, these concerns are explained, discussed and weighted against the advantages of pre-operative breast MRI for breast cancer staging. The point is made that breast MRI is essential for surgical planning, but that indeed unnecessary mastectomy may result if old guidelines are simply copied onto a new situation. Guidelines that require mastectomy for multicentric breast cancer have been established before the advent of MRI. Using the same guidelines to manage MR-detected multicentric cancer foci may be inappropriate because some small MRI detected additional multicentric breast cancer foci will be sufficiently treated by radiation therapy.
The Breast 01/2008; 16 Suppl 2:S34-44. · 2.49 Impact Factor
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ABSTRACT: This paper aims to demonstrate the capabilities of a speed optimized T(2) weighted single-shot turbo spin echo sequence, using parallel imaging, variable flip angle refocusing and half-Fourier acquisition (FAS-TSE), in comparison with a standard TSE (sTSE) sequence in patients with suspected multiple sclerosis (MS). 33 patients presenting with a clinically isolated syndrome (CIS) suggestive of MS were prospectively examined on a 3.0 T MR system using FAS-TSE and a sTSE sequence. The FAS-TSE (scan time 11 s) and the sTSE (scan time 122 s) were compared regarding lesion detectability, lesion contrast, grey/white matter contrast, overall image quality and artefacts. Scanning parameters affecting image contrast and spatial resolution were kept identical. 208 lesions were detected using the sTSE sequence compared with 183 lesions (88%) using the FAS-TSE. The FAS-TSE was rated inferior regarding lesion contrast. The mean value/range/standard deviation of the lesion/white matter contrast were 0.26/0.06-0.49/0.089, respectively, with the sTSE vs 0.21/0.04-0.40/0.081 with the FAS-TSE. The FAS-TSE was rated inferior regarding overall image quality, but superior regarding motion artefacts. The grey/white matter contrast was qualitatively judged as comparable for both sequences. FAS-TSE provides sufficient T2-SE contrast and diagnostic image quality for whole brain studies in 11 s. It is suited to reduce motion artefacts in restless patients and for fast acquisition of additional scanning planes.
The British journal of radiology 09/2007; 80(956):668-73. · 2.11 Impact Factor
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ABSTRACT: Molecular imaging of functional parameters such as apoptosis (programmed cell death) in vivo opens new possibilities in clinical diagnostic and scientific research. Especially in the case of cardiovascular diseases that are mainly responsible for both morbidity and mortality in Western industrial nations, innovative non-invasive examination strategies are necessary for early diagnosis of these diseases. Since apoptosis unlike necrosis is present even after minor alterations of the microenvironment of cells and has been shown to be involved in a large number of cardiovascular diseases, there are currently several experimental studies underway with the goal of imaging apoptosis in vivo. The review discusses the basics of apoptosis in myocardial infarction, myocarditis, atherosclerosis, restenosis after angioplasty and stent implantation, currently used imaging techniques, achieved results, and future possibilities for molecular imaging of apoptosis.
RöFo - Fortschritte auf dem Gebiet der R 09/2007; 179(8):780-9. · 2.76 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate high-resolution (HR) myocardial first-pass perfusion in healthy volunteers at 3 T compared to a typical clinical imaging protocol at 1.5 T, with respect to overall image quality and the presence of subendocardial dark rim artifacts. Myocardial first-pass rest perfusion studies were performed at both field strengths using a T1-weighted saturation-recovery segmented k-space gradient-echo sequence combined with parallel imaging (Gd-DTPA 0.05 mmol/kg). Twenty-six healthy volunteers underwent (1) a HR perfusion scan at 3 T(pixel size 3.78 mm(2)) and (2) a standard perfusion approach at 1.5 T(pixel size 9.86 mm(2)). The contrast enhancement ratio (CER) and overall image quality (4-point grading scale: 4: excellent; 1: non-diagnostic) were assessed, and a semiquantitative analysis of dark rim artifacts was performed for all studies. CER was slightly higher (1.31 +/- 0.32 vs. 1.14 +/- 0.34; p<0.01), overall image quality was significantly improved (3.03 +/- 0.43 vs. 2.37 +/- 0.39; p<0.01), and the number of dark rim artifacts (139 +/- 2.09 vs. 243 +/- 2.33; p<0.01) was significantly reduced for HR perfusion imaging at 3 T compared to the standard approach at 1.5 T. HR myocardial rest perfusion at 3 T is superior to the typical clinical perfusion protocol performed at 1.5 T with respect to the overall image quality and presence of subendocardial dark rim artifacts.
European Radiology 07/2007; 17(7):1829-35. · 3.22 Impact Factor
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ABSTRACT: The purpose of this study was to compare the in-built body coil of the 3.0-Tesla (T) scanner with a dedicated surface coil of a 1.5 T system regarding knee imaging. We performed an intraindividual prospective clinical trial on 17 patients with knee pain using magnetic resonance imaging (MRI) at 1.5 and 3.0 T systems equipped with identical gradient systems. Proton-density-weighted turbo spin echo sequences with the same spatial resolution and comparable contrast parameters were used. A quantitative measurement of signal to noise ratio (SNR), relative contrast (RC) and contrast to noise ratio (CNR) between muscle and bone marrow was performed, followed by a qualitative assessment of anatomic/pathologic structures and the extent of artefacts. At 3.0 T, 30 lesions (91%) compared to 33 lesions at 1.5 T were detected. The SNR/CNR/RC were moderately reduced at 3.0 T versus 1.5 T (muscle 42 vs 47 and bone 83 vs 112/46 vs 69/0.33 vs 0.43). Motion artefacts from the pulsating popliteal artery were significantly increased at 3.0 T. A visible and measurable signal loss occurred at 3.0 T using the built-in body coil compared with the dedicated 1.5 T knee coil, but nearly all clinically important information could be obtained.
European Radiology 03/2007; 17(2):503-8. · 3.22 Impact Factor
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ABSTRACT: Stress testing for detection of ischemia-induced wall-motion abnormalities has become a mainstay for noninvasive diagnosis and risk stratification of patients with suspected coronary artery disease (CAD). Recent technical developments in magnetic resonance imaging (MRI), including the adoption of balanced steady-state free precession (b-SSFP) sequences-preferentially in combination with parallel imaging techniques-have led to a significant reduction of imaging time and improved patient safety. The stress protocol includes application of high-dose dobutamine (up to 40 microg/kg/min) combined with fractionated atropine (up to a maximal dose of 1.0 mg). High-dose dobutamine stress MRI revealed good sensitivity (83-96%) and specificity (80-100%) for detection of significant CAD. Myocardial tagging methods have been shown to further increase sensitivity for CAD detection. Severe complications (sustained tachycardia, ventricular fibrillation, myocardial infarction, cardiogenic shock) are rare but may be expected in 0.1-0.3% of patients. Dobutamine stress MRI has emerged as a reliable and safe clinical alternative for noninvasive assessment of CAD. New pulse sequences, such as real-time imaging, might obviate the need for breath holding and electrocardiogram (ECG) triggering in patients with severe dyspnoea and cardiac arrhythmias, which may further improve the clinical impact and acceptance of stress MRI in the future.
European Radiology 01/2007; 16(12):2728-38. · 3.22 Impact Factor
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ABSTRACT: The diagnosis of prostate cancer is suggested on the basis of an elevated PSA level, abnormal digital exam, and abnormal transrectal ultrasound. US-guided biopsy is used to confirm the diagnosis, but up to 30% of prostate cancer may be missed with this approach. Meanwhile MR imaging and proton MR spectroscopy have emerged as the most sensitive additional tools for the noninvasive evaluation of prostate cancer.This article reviews the clinical indications for MRI of the prostate and summarizes new techniques such as high field strength (3 tesla) and dynamic contrast-enhanced MRI.
Der Urologe 06/2006; · 0.50 Impact Factor
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ABSTRACT: Myotonic Dystrophy
Type 1 (DM1) and 2 (DM2) present
with distinct though overlapping
clinical phenotypes. Comparative
imaging data on skeletal muscle involvement
are not at present available.
We used the novel technique
of whole body 3.0 Tesla (T) Magnetic
Resonance Imaging (MRI) to
further characterize musculoskeletal
features in DM2 and compared
the results with DM1.
MRI findings of 15 DM1 and 14
DM2 patients were evaluated with
respect to patterns of skeletal muscle
affection and clinical data using
the Muscular Impairment Rating
Scale (MIRS) and Medical Research
Council scale (MRC).
All DM1 patients had pathological
MRI compared with only 5
DM2 patients. In contrast to DM2,
DM1 patients showed a characteristic
distribution of muscle involvement
with frequent and early degeneration
of the medial heads of
gastrocnemius muscles, and a perifemoral
semilunar pattern of
quadriceps muscle affection sparing
the rectus femoris. The most
frequently affected muscles in DM1
were the medial heads of gastrocnemius,
soleus, and vastus medialis
muscles. In DM2, however, the
erector spinae and gluteus maximus
muscles were most vulnerable
to degeneration. MRI data were in
line with the clinical grading in 12
DM1 and 3 DM2 patients. In 3 DM1
and 5 DM2 patients, MRI detected
subclinical muscle involvement. 9
DM2 patients with mild to moderate
proximal muscle weakness
and/or myalgias had normal MRI.
Pathological MRI changes in DM2
emerged with increasing age and
were restricted to women.
Whole body 3.0T MRI is a sensitive
imaging technique that
demonstrated a characteristic
skeletal muscle affection in DM1.
In contrast, MRI was no reliable indicator
for skeletal muscle involvement
in mildly affected DM2 patients
since myalgia and mild
paresis were usually not reflected
by MRI signal alterations.
Journal of Neurology 05/2006; 253(6):753-761. · 3.47 Impact Factor
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ABSTRACT: Soon molecular imaging techniques will play a prominent role in basic scientific research and clinical approaches. In particular, important aspects of medicine such as apoptosis and gene- and stem-cell therapy will play a pivotal role in radiology too. This review presents the basic principles of apoptosis, recent results and future perspectives of apoptosis imaging. Apoptosis or programmed cell death is a precisely regulated, complex cascade of molecular events to eliminate individual cells. Disturbances may lead to diseases like malignancies and neurodegenerative diseases that are of clinical relevance. Several therapeutic strategies in oncology are based on apoptosis induction; conversely, resistance to therapy is indicative of decreased apoptosis induction. Whereas up to now the clinician had to depend exclusively on biopsy specimens to detect apoptosis, the feasibility of non-invasive imaging of this cell-biological phenomenon in vivo opens up new horizons in future. This review focuses on different modifications of this imaging technique, with and without the use of molecular probes (e. g. annexin V, synaptotagmin I), in vitro and in vivo using the various detector systems (like MRI, flow cytometry) currently available. Future perspectives are also addressed.
RöFo - Fortschritte auf dem Gebiet der R 04/2006; 178(3):263-71. · 2.76 Impact Factor
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ABSTRACT: To survey contrast media (CM)-induced alterations of complement factors.
In 31 adult patients, who received either an iotrolan (n = 19) or iopromide (n = 12) i. v. injection for CT examination, complement factors C1 q, C3, C4, C5 a, and C1-esterase inhibitor in serum/plasma samples were analyzed. The samples were obtained prior to and 5 min., 30 min., 1 hr., 6 hrs. and 24 hrs. after CM injection.
5 patients (16.1 %) developed a CM reaction. 4 of these were patients who received iotrolan. Other than minimal data, we neither found a significant influence of the CM on complement activation nor a difference between the analyzed CM. In detail, 5 min. after CM administration, we found the tendency to be for the values to decrease and then to return to the basic value. The changes induced by iotrolan were more pronounced than those induced by iopromide; nevertheless the differences were not statistically significant. A more pronounced decrease of C3 and C4 after iotrolan injection indicates the activation of the classic way, while this could not been observed after iopromide injection. One patient who experienced an unwanted reaction towards iotrolan showed shifts of C1 q, C1 INH, C3 and C4.
The presented data shows different influences of CM injection on the analyzed complement factors after 5 min. that were commonly no longer present 30 min. after CM injection. The dimeric iotrolan induced a significantly increased frequency of unwanted CM reactions than the monomeric iopromide. The question of whether iotrolan is possibly able to activate the classic way of the complement cascade should be analyzed in the future in a greater patient group.
RöFo - Fortschritte auf dem Gebiet der R 04/2006; 178(3):306-12. · 2.76 Impact Factor
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ABSTRACT: The management of women with an increased lifetime risk of breast cancer is a difficult task. This is especially true for women with a documented mutation in a breast cancer susceptibility gene (BRCA), and also for those who tested negative for a mutation, but have a family history that is suggestive of familial breast cancer. Primary prevention by prophylactic mastectomy has been shown to reduce breast cancer incidence in these women, but this intervention is still not considered a "first-line" option in the majority of guidelines. Instead, secondary prevention (intensified surveillance) is recommended. However, due to the early onset of familial breast cancer, screening must start at a substantially younger age than in women at average risk. This, together with the fact that familial breast cancers may differ from sporadic cancers in many aspects, will have a significant impact on the design and on the success rates of surveillance protocols. This article describes the different management options that exist for women at increased genetic risk and provides a survey of the current evidence regarding mammographic and non-mammographic imaging techniques. The conclusion is that mammographic screening, with or without concomitant ultrasound and clinical breast examination, is probably not sufficient to ensure an early diagnosis of familial breast cancer. If MRI is integrated in surveillance programs, early diagnosis seems to be possible. Still, the efficacy of screening even with MRI is unclear in terms of morbidity and mortality, and this lack of evidence must be communicated to women at high genetic risk.
The Breast 01/2006; 14(6):480-6. · 2.49 Impact Factor
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ABSTRACT: Reliable visualization of the coronary arteries with multislice spiral CT angiography (MSCTA) in patients with atrial fibrillation (AF) remains a challenge despite retrospective ECG gating. A recently developed new algorithm automatically compensates dynamic changes in the heart rate during the scan, thus reducing misregistration and motion artifacts. The HeartBeat-RT algorithm combines a fixed-percent delay determined from the first R wave and the fixed offset delay based on the second R wave in the ECG cycle. The purpose of this study was to find out the optimal reconstruction window in MSCTA in patients with AF for each of the three major coronary arteries during the cardiac cycle.
20 patients with permanent AF were imaged on a 16-slice scanner (slice collimation: 16 x 0.75 mm; rotation time 0.42 s; 140 kV; 380 mAs; 120 ml Ultravist 370 (R) i.v.). The patients had not received any previous drugs for heart frequency regulation. Acquisition was started after bolus tracking of a biphasic bolus of 120 ml Ultravist 370 injected intravenously. Each coronary segment was reconstructed at 0 % - 90 % of the cardiac cycle in increments of 10 %. For image analysis we used coronary segments as defined by the American Heart Association. Two blinded independent readers assessed the image quality in terms of visibility and artifacts (five-point rating scale 1 = very poor, 2 = poor, 3 = fair, 4 = good and 5 = excellent) and the degree of stenosis (five-point rating scale 1 = 0 %, 2 = 1 % - 49 %, 3 = 50 % - 74 %, 4 = 75 % - 99 %, 5 = 100 %) on axial slices, multiplanar reconstructions and three-dimensional volume-rendered images.
The heart rate during examination ranged between 42 and 156 beats per minute, the average heart rate was 78 +/- 23. Each of the two readers evaluated 300 segments in 20 patients. Visualization of all coronary artery segments was superior at 40 % (mean score of the image quality 2.79) as compared to the standard diastolic reconstruction window at 80 % (image quality 2.33). The second best image quality (2.57) was acquired at 0 % of the cardiac cycle.
The use of a frequency adapted delay algorithm with the choice of an end-systolic reconstruction window provided diagnostically valuable images in patients with AF.
RöFo - Fortschritte auf dem Gebiet der R 01/2006; 177(12):1655-62. · 2.76 Impact Factor
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ABSTRACT: Patients (pts.) with atrial fibrillation (AF) and atrial thrombi are known to have an increased risk for cerebral embolism. However, little is known about the clinical course of atrial thrombi and the incidence of cerebral embolism in those patients during anticoagulation therapy. The high sensitivity of MR imaging (MRI) including diffusion-weighted imaging (DWI) suggests that this technique could provide an improved estimate of cerebral embolism associated with the presence of left atrial thrombi. The aims of this prospective study were to evaluate 1) the prevalence of clinically silent and apparent cerebral embolism in pts. with newly diagnosed AF and atrial thrombi using MRI/DWI, 2) the long-term fate of atrial thrombi under continues anticoagulation therapy and 3) the incidence of cerebral embolism during a follow-up period of 12 months with continuous anticoagulation therapy.
The study group consisted of 32 pts. with 1) newly diagnosed AF and evidence of left atrial (LA) thrombi detected by TEE and 2) a new start of anticoagulation therapy [International Normalized Ratio (INR) 2.0 - 3.0]. 19 pts. with 1) newly diagnosed AF and no evidence of atrial thrombi and 2) an equivalent anticoagulation regimen served as the control group. In both groups a) MRI/DWI studies of the brain (weeks 0, 4, 8, 12, 20, 28, 36, 44, and 52), b) transesophageal echocardiographic studies (TEE) for assessment of LA-Thrombi (weeks 0 and 52) and c) clinical neurological assessments (weeks 0, 20 and 52) were performed.
In the study group (AF and LA-Thrombi) 11 out of 32 pts. (34 %) displayed signs of acute (n = 8) or chronic (n = 3) cerebral embolism in the initial MRI studies. In 4 out of 32 pts. (13 %), MRI/DWI depicted new or additional cerebral emboli (n = 12) during the follow-up period despite continuous anticoagulation therapy. 2 (n = 2/4; 50 %) of these patients had clinically apparent neurological deficits. In the control group 1 out of 19 pts. (5 %) showed evidence of chronic cerebral embolism as assessed by MRI/DWI at the beginning of the study (week 0). No embolic cerebral lesions were detected during the 12-month follow-up. Within 12 months only 63 % (n = 20/32) of LA thrombi in the study group resolved completely under anticoagulation.
1. The incidence of clinically inapparent cerebral emboli in pts. with newly diagnosed AF and atrial thrombi is much higher than the incidence of clinically apparent emboli and has been underestimated in the past. 2. New cerebral embolism may occur even with continued effective anticoagulation therapy in 13 % of pts. 3. Only 63 % of atrial thrombi resolve completely within 12 months under anticoagulation therapy.
RöFo - Fortschritte auf dem Gebiet der R 01/2006; 177(12):1706-12. · 2.76 Impact Factor
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ABSTRACT: Inflammatory pseudotumor is a rare benign tumor entity. Because inflammatory pseudotumors mimic malignant tumors both clinically and radiologically, the radiologist should be familiar with this entity. Inflammatory pseudotumor most commonly involves the lung and the orbit, but it has been reported to occur in nearly every site in the body. For making a definite diagnosis a biopsy is often essential. The treatment options are varied and consist of surgery, high-dose steroids, irradiation, and chemotherapeutics.
RöFo - Fortschritte auf dem Gebiet der R 12/2005; 177(11):1506-12. · 2.76 Impact Factor
