Search

Malignant hyperthermia (MH) is a metabolic myopathy with an abnormal release of calcium by the sarcoplasmic reticulum (SR), triggered by volatile anesthetics and succinylcholine. Similarly, caffeine enhances Ca(2+)release by the SR in vitro. In a prospective, randomized study, high-energy phosphates were studied by intramuscular 31-phosphorus magnetic resonance spectroscopy ((31)P-MRS) in 10 MH-susceptible (MHS) and 7 MH-nonsusceptible (MHN) subjects before and after injection of 0.5 ml caffeine (20 mM). Intramuscular energy balance, measured by the ratios of P(i)/PCr and P(i)/gamma-ATP, did not differ between MHS and MHN patients before and after intramuscular caffeine injection. However, within each group, P(i)/PCr and P(i)/gamma-ATP increased significantly only in the MHS group. Intramuscular caffeine injection seemed to impair the metabolic balance in MHS individuals. This may reflect a local calcium overload leading to consumption of high-energy phosphates and increase of inorganic phosphate. Intramuscular stimulation by caffeine and (31)P-MRS may provide a valuable tool to investigate MH-related metabolic disturbances.

BACKGROUND: Magnetization transfer (MT) MRI can provide in vivo markers reflecting the severity of irreversible, MS-related brain damage occurring within and outside T2-visible lesions.OBJECTIVE: To assess the effect of interferon (IFN) beta-1b treatment on the accumulation of brain damage in patients with secondary progressive (SP) MS, measured using MT MRI.METHODS: Eighty-two patients with SPMS from five centers participating in a European, multicenter, double-blind, placebo-controlled trial of IFNbeta-1b in SPMS underwent brain T2-weighted and MT MRI at baseline. Evaluable follow-up data were available for 75 patients at 12 months, 54 at 24 months, and 47 at 36 months. MT MRI scans were postprocessed and analyzed to obtain histograms of MT ratio (MTR) values from the whole brain. A region of interest-based analysis of MTR values from the normal-appearing white matter (NAWM) was also performed.RESULTS: In both the treatment arms, there was a decrease of average brain MTR values from baseline to month 24 (mean change -4.9%) and month 36 (mean change -4.3%). These changes were significant for the placebo group at both timepoints and for the IFNbeta-1b group at month 24 only, with no significant treatment effect. A decrease of NAWM MTR was also observed, with no significant difference between the two treatment arms.CONCLUSION: In this cohort of patients with secondary progressive MS, interferon beta-1b did not show an overall effect on the worsening of magnetization transfer MRI measures, when compared with placebo. The data show that change in magnetization transfer ratio is a promising tool for monitoring disease evolution in secondary progressive MS and that the information obtained from magnetization transfer MRI complements that obtained from MRI measures of lesion load and inflammation.

The unique characteristics of the human lung arising from low proton density and multiple air-tissue interfaces of the alveoli cause difficulty in 1H lung magnetic resonance imaging. In addition, the dominating signal from sources such as the thoracic muscle and subcutaneous fat hampers the visualization of the lung parenchyma. In this contribution, an efficient tissue suppression technique is presented which allows one to significantly enhance lung parenchyma visibility. A short inversion time inversion recovery (STIR) experiment combined with a magnetization transfer (MT) experiment was used for magnetization preparation in order to suppress the signal from muscle. A half-Fourier single-shot turbo spin-echo sequence was used as acquisition module. This approach was used to perform lung anatomical imaging in eight healthy human subjects and five patients with cystic fibrosis. The results obtained demonstrate that with MT-STIR approach high quality human lung images can be obtained and that this approach has the potential for the evaluation of lung pathologies.

Glomus organs are small arteriovenous anastomoses that are chiefly responsible for thermoregulation of the distal portion of the extremities. Glomangiomas are benign tumors of these bodies. Glomangiomas occur preferentially in the fingers and toes, but some case reports have described primary glomangiomas in the respiratory or gastrointestinal tract and the genitals. To date, no glomangiomas of the liver have been observed. We report on a 61-year-old patient in whom routine ultrasound disclosed a subcapsular well-defined mass in the liver. On imaging studies, no correspondence to the usual liver tumors was found. Magnetic resonance–guided biopsy showed a primary glomangioma of the liver. Clinically, the patient had no appetite and lost weight over several months. Due to the patient's weight loss and potential malignant transformation, the tumor was excised. Histologic work-up confirmed the diagnosis of a glomangioma with no signs of malignancy.

OBJECTIVE: Aortic stenosis leads to the derangement of cardiac function and contraction mode because of chronic pressure overload that is relieved after surgical valve replacement. The purpose of this study was to determine the changes in left ventricular systolic rotation and contraction using MR tagging in patients with aortic stenosis before and after surgical valve replacement compared with age-matched healthy volunteers. MATERIALS AND METHODS: Twelve patients with aortic stenosis were examined with an electrocardiographically triggered two-dimensional tagging sequence at 1.5 T before and 12 months after surgical valve replacement for the evaluation of wall function of the apical, mid ventricular, and basal levels. Eight healthy volunteers in the same age group served as the control group. RESULTS: Before surgery, all patients showed a significant increase of apical rotation (22.2 degrees +/- 5.9 degrees vs 10.3 degrees +/- 2.5 degrees, p < 0.0001) and overall left ventricular torsion (25.1 degrees +/- 6.6 degrees vs 14.5 degrees +/- 3.7 degrees, p < 0.001); basal rotation was not significantly different (-2.9 degrees +/- 2.1 degrees vs -4.2 degrees +/- 1.9 degrees, p = not significant) compared with the volunteer group. Apical rotation and torsion were negatively correlated with left ventricular mass (r = -0.73, p < 0.01, and r = -0.61, p < 0.05, respectively) and end-diastolic volume (r = -0.73, p < 0.01 and r = -0.64, p < 0.03, respectively). One year after surgery, basal rotation was reduced in the patients with aortic stenosis compared with the patients in the control group (-1.9 degrees +/- 1.8 degrees, p < 0.01). In comparison with preoperative values, apical rotation (14.2 degrees +/- 3.6 degrees, p < 0.01) also decreased but was still elevated, and this resulted in a normalization of left ventricular torsion (16.1 degrees +/- 3.7 degrees, p < 0.01). CONCLUSION: Surgical valve replacement for aortic stenosis leads to normalization of the left ventricular torsion 1 year after surgery. Pressure overload before surgery is associated with an increase of systolic left ventricular wringing motion, possibly serving as a compensatory mechanism. This mechanism declines with increasing left ventricular hypertrophy and dilatation.

Purpose To determine sodium transverse relaxation (T2*) characteristics for myocardium, blood and cartilage in humans. Methods T2* measurements were performed using a 3D ECG-gated spoiled gradient echo sequence. A 1.5 Tesla clinical scanner and a 23Na heart surface coil were used to examine eight healthy volunteers. In biological tissue, the sodium 23 nucleus exhibits a two-component T2 relaxation due to the spin 3/2 and its quadrupolar nature. The long T2* components of normal myocardium, blood, and cartilage were quantified. For myocardium, the T2* was determined separately for the septum, anterior wall, lateral wall, and posterior wall. Results The long T2* relaxation time components of 13.3 ± 4.3 msec (septum 13.9 ± 3.2 msec, anterior wall 13.8 ± 5.4 msec, lateral wall 11.4 ± 4.1 msec, posterior wall 14.1 ± 3.7 msec), 19.3 ± 3.3 msec, and 10.2 ± 1.6 msec, were significantly different for myocardium, blood, and cartilage, respectively (P < 0.00001, Friedman's ANOVA). Conclusion Measurement of 23Na T2* relaxation times is feasible for different regions of the human heart muscle, which might be useful for the evaluation of cardiac pathologies. J. Magn. Reson. Imaging 2002;15:215–218. © 2002 Wiley-Liss, Inc.

To calculate and evaluate absolute quantitative myocardial perfusion maps from rest first-pass perfusion MRI.10 patients after revascularization of myocardial infarction underwent cardiac rest first-pass perfusion MRI. Additionally, perfusion examinations were performed in 12 healthy volunteers. Quantitative myocardial perfusion maps were calculated by using a deconvolution technique, and results were compared were the findings of a sector-based quantification.Maps were typically calculated within 3 min per slice. For the volunteers, myocardial blood flow values of the maps were 0.51 ± 0.16 ml g(-1) per minute, whereas sector-based evaluation delivered 0.52 ± 0.15 ml g(-1) per minute. A t-test revealed no statistical difference between the two sets of values. For the patients, all perfusion defects visually detected in the dynamic perfusion series could be correctly reproduced in the maps.Calculation of quantitative perfusion maps from myocardial perfusion MRI examinations is feasible. The absolute quantitative maps provide additional information on the transmurality of perfusion defects compared with the visual evaluation of the perfusion series and offer a convenient way to present perfusion MRI findings.Voxelwise analysis of myocardial perfusion helps clinicians to assess the degree of tissue damage, and the resulting maps are a good tool to present findings to patients.

In this contribution, a rapid and robust technique for quantitative T(1) mapping of the human lung is presented. Based on a series of Snapshot FLASH tomograms acquired after a single inversion pulse, high quality and quantitative T(1) parameter maps acquired in under five seconds were obtained from six healthy volunteers. The measured T(1) values are in good agreement with previously reported literature values. T(1) maps were also acquired with the volunteers breathing room air or 100% O(2). The T(1) difference between breathing room air and 100% O(2) is statistically significant at P < 0.0001.

Our objective was to analyze contrast enhancement patterns (CEP) and their time course after myocardial infarction (MI) following injection of Gd-BOPTA in correlation with recovery of regional function. Seven patients with subacute MI (18 +/- nine days) were examined before, as well as three and six (n = six) months after, revascularization of the infarct-related artery. Regional wall motion abnormalities were assessed by cine-MRI, and repetitive images of one representative slice were acquired up to 45 minutes after 0.05 mmol/kg Gd-BOPTA using a T1-w TSE-sequence. Two patients showed mid-wall/subendocardial, one patient subendocardial enhancement of MI associated with mechanical improvement after revascularization. Three patients without improvement revealed a mid-wall hypoenhanced zone within the first five minutes after injection, which was unchanged at follow-up. One patient with partial functional improvement showed transmural enhancement and a mid-wall hypoenhanced zone in adjacent areas. With this feasibility study, we concluded that mid-wall and/or subendocardial enhancement after Gd-BOPTA was associated with viable myocardium, whereas detection of microvascular obstruction correlating with scar formation is suggested by mid-wall hypoenhancement within the first five minutes after injection.

Objective. To compare axial reconstructed ultrasonographic images from three-dimensional data volumes and conventional computed tomographic scans in documentation and detection of liver lesions. Methods. The livers of 23 patients were examined by a multifrequency curved array transducer to acquire three-dimensional data volumes and by conventional computed tomography. The ultrasonographic device was equipped with three-dimensional ultrasonographic technology allowing for real-time parallel movement in every plane within an acquired data volume. Axial ultrasonographic images reconstructed from three-dimensional data volumes were compared with conventional computed tomographic scans. Results. When both methods were taken together, a total of 51 different liver lesions could be detected. Reconstructed ultrasonographic images depicted 44 (86%) of 51 lesions, and computed tomographic scans showed 46 (90%) of 51 lesions. Compared with computed tomography, ultrasonography depicted 5 additional lesions in 3 of the patients (4 hemagiomas and 1 unspecified lesion), whereas 7 lesions were missed in another 4 patients (4 metastases, 2 calcifications, and 1 cyst). The Pearson correlation coefficient between ultrasonography and computed tomography was r = 0.84 (P

The aim of this study was to optimize bolus tracking for timing of the arterial phase of biphasic helical liver CT and to compare optimized bolus tracking to a standard delay. One hundred fifty patients were examined with six protocols: 5- or 10-s delay after triggering at a threshold of 50 or 75 or 100 HU enhancement in the aorta at the origin of the celiac arteries after injection of 120 ml contrast material at 3 ml/s. Optimal arterial enhancement was defined as 20-30% of hepatic enhancement in portal venous phase. Another 50 patients were examined with the optimized protocol and compared to 50 gender- and age-matched patients who underwent a 25-s standard delay. A 10-s delay after the 75-HU threshold resulted in the most patients with an optimal arterial phase (p0.01). Thirty-one of 75 patients examined with this protocol showed optimal early liver enhancement. Bolus tracking compared with standard delay revealed only a trend for a difference (p = 0.07). The outcome of automatic bolus tracking differs depending on the protocol used; however, optimal arterial phase imaging was seen in only 41% of patients, indicating only a trend for superior timing compared with a standard delay.

In adjunct to direct laryngoscopy, CT and/or MRI are needed for an accurate staging of laryngeal and hypopharyngeal carcinomas because both cross-sectional imaging modalities are known to reliably evaluate deep tumor infiltration. Except for the clinical background, this article reviews technical aspects of CT and MRI, the pathologic appearance of laryngeal and hypopharyngeal carcinomas, and therapeutically relevant diagnostic aspects.

OBJECTIVE: Experimental studies have demonstrated that acute myocardial infarction (MI) alters energy metabolism even in non-infarcted adjacent tissue. In patients with subacute MI, the influence of the regional ischemic insult on energy metabolism of intact septal myocardium was analyzed using 31P-Magnetic resonance spectroscopy (MRS). PATIENTS AND METHODS: In eight patients with wall motion abnormalities in the anterior wall 31P-spectra were obtained from non-infarcted adjacent septal myocardium, as well as infarcted anterior myocardium (voxel size 25 ccm each) 29+/-8 days after MI using a 3D-CSI technique. Additionally, cardiac function was analyzed using breath-hold cine MRI. MRI was repeated 6 months after revascularization to assess viability of infarcted segments. Eight age-matched healthy volunteers served as control group. RESULTS: According to follow-up MRI 4/8 patients showed regional wall motion recovery. Here, PCr/ATP-ratios were not significantly reduced in intact septal myocardium as well as infarcted anterior myocardium compared to healthy volunteers (1.28+/-0.10 and 1.14+/-0.09 vs. 1.45+/-0.29). No recovery of regional function was detected in 4/8 patients with-therefore-non-viable anterior myocardium. PCr/ATP-ratios were significantly reduced in intact and infarcted myocardium compared with healthy volunteers as well as to patients with wall motion recovery (0.77+/-0.17 and 0.49+/-0.23; P

The goal of this work was to verify in a phantom study the necessity of a calibration method for comparison in dynamic contrast-enhanced magnetic resonance imaging (MRI) examinations. A perspex phantom with a dilution series of Gd-DTPA was used to measure the dynamic signal enhancement of a sequence. With nine MRI scanners from Bruker (0.23, 0.5, and 2 Tesla), Philips [0.5 and 1.5 Tesla (ACS-NT and S15)], and Siemens (0.2, 1.0, and 1.5 Tesla) one 2D FLASH and two 3D FLASH experiments were performed under identical measurement conditions. Under different measurement conditions (2D and 3D FLASH, TR, TE, FA) different characteristics in signal enhancement exist on a scanner. The same measurement conditions at different scanners (same magnetic field strength) also result in different signal enhancement. Dynamic contrast enhanced MRI examinations from different measurement conditions or scanners cannot be compared. To solve this problem a calibration is needed.

Objective: Involvement of the autonomic system in multiple sclerosis (MS) may concur with dysfunction of the cardiovascular system. The introduction of potentially cardiotoxic immunosuppressive drugs like Mitoxantrone into the treatment of MS warrants proper assessment of preexisting heart disease. However, systematic analyses of functional and metabolic derangements in MS are missing. Using quantitative 31 P-MR-spectroscopy (MRS) and MR-imaging (MRI) metabolic and functional parameters were analyzed in patients with MS in comparison to healthy volunteers. Subjects/Methods: 14/15 patients with MS could be included in the study, as the MRS examination of one patient had to be excluded from analysis due to movement during the examination. Using chemical shift imaging (CSI) and AMARES, phosphocreatine (PCr) to adenosine triphosphate (ATP) ratios, characterizing myocardial high-energy phosphate metabolism, were determined. Additionally, absolute concentrations of PCr and ATP were calculated by SLOOP (Spatial Localization with Optimal Pointspread Function). Analysis of functional changes was performed by CineMRI. 14 healthy volunteers matched for age and gender served as control. Results: A significant decrease of absolute PCr concentration was observed in patients with MS compared to matched volunteers (p

Demonstration of the initial results of breath-hold 3D MR coronary angiography with patients using a new intravascular contrast agent (feruglose). Contrast-enhanced 3D MR-coronary angiography was performed in 5 patients with coronary artery disease after administration of feruglose in three different doses (0.5 (n = 3), 2, 5 mg Fe/kg body weight for each patient). MR coronary angiography was performed with an ECG-triggered 3D-FLASH-sequence during breath-hold at 1.5 T (TR 6.8 ms, TE 2.5 ms, flip-angle 30 degrees ). To reduce data acquisition time, only the two anterior elements of the phased-array body coil were activated. The data acquisition window within the cardiac cycle ranged between 217-326 ms depending on the matrix. Signal-to-noise (SNR) and contrast-to-noise ratios (CNR) of the coronary arteries were analyzed, and the results for the detection of coronary artery stenoses were compared with those obtained by conventional coronary angiography. SNR and CNR revealed an improved image quality at a dose of 2 mg Fe/kg compared with the lower dose, but no further improvement was obtained by rising the dose to 5 mg Fe/kg. Except for the left circumflex artery of one patient, at minimum the proximal parts of all four main coronary arteries could be imaged for all patients. Within the visible parts of the coronary arteries, six of eight significant coronary stenoses were identified correctly. Imaging of the proximal parts of the coronary arteries including detection of stenoses is possible during breath-hold using an intravascular contrast agent.

Angiomyoma is a benign tumor that arises from soft muscular tissue within the blood vessel wall. This lesion has been found in different organs. The preferential location of these tumors is the lower extremity. We describe the rare case of a hepatic angiomyoma and present the radiologic findings of computed tomography and magnetic resonance imaging.

The aim of this study was to determine the time of best contrast of neck malignancies in contrast-enhanced CT. The CT was done in 20 patients with squamous cell carcinoma using a standard protocol (100 ml contrast agent at 2 ml/s). Dynamic series of the tumors were performed (scan interval 6 s). In all relevant structures of the neck, densities were measured to obtain time-density curves. The best tumor contrast was measured > or =50 s after the start of the injection, and the best contrast of lymph nodes < or =75 s. For staging and volume measurements of neck primaries the best achievable contrast is necessary. Using the examined single-bolus technique, spiral CT allows a combination of perfect tumor contrast with a good contrast between lymph nodes and neck vessels between 50 and 75 s after starting the injection.

Noonan's syndrome is a rare congenital disorder that may be associated with abnormalities in the lymphatic drainage. In this case of a 21-year-old man CT after bipedal lymphangiography confirmed the diagnosis of intestinal lymphangiectasy causing protein-losing enteropathy in Noonan's syndrome by showing contrast-enhanced abnormal lymphatic vessels in the mesentery and the intestinal wall. Because of the benefit of diet in case of intestinal involvement, we recommend a thorough documentation of the lymphatic drainage with lymphangiography followed by CT, if clinical signs of lymphatic dysplasia, such as pleural effusions, lymphedema, or hypoproteinemia are present.

We sought to assess the value of aqueous and barium-containing contrast agents in the detection of pharyngeal perforation.Visual and objective in vitro comparisons of an iodinated aqueous contrast agent, a 50% weight/volume barium suspension, and a 100% weight/volume barium suspension were performed. Moreover, to exclude pharyngeal perforation after surgery, we prospectively examined 109 patients by pharyngography, using the aqueous contrast agent and the 100% weight/volume barium suspension. All patients with a pharyngeal perforation were followed up clinically to exclude complications due to barium application.As opposed to the 100% weight/volume barium suspension, in vitro comparison between the aqueous contrast agent and the 50% weight/volume barium suspension yielded no substantial differences. Seventeen perforations could be detected with the aqueous contrast agent. Although 10 of 17 perforations could be slightly better visualized with the 100% weight/volume barium suspension, two perforations were missed with this agent. Five perforations were equally well detected with both.Because of a higher radiopacity, 100% weight/volume barium suspensions may more sharply delineate perforations. However, in contrast to aqueous contrast media, narrow pharyngeal perforations can be missed. Thus, the use of a 100% weight/volume barium suspension does not improve the detection of pharyngeal perforation.

The aim of this study was to compare the latest ultrasound-array technology to a conventional “high-resolution” transducer, modified MRI technique, and nerve conduction studies (NCS), in the diagnosis of carpal tunnel syndrome (CTS). In 19 normal wrists and 15 wrists with CTS, US with two different transducers was performed: a conventional linear-array transducer (LA) and a newly developed Multi-D linear-array transducer (MDA) were used. The US images were evaluated determining the swelling and the flattening ratios of the median nerve and correlated to respective findings in MRI (1.5 T) and to NCS. The NCS confirmed CTS in all 15 wrists. Measures of median nerve compression (swelling and flattening ratios) were significantly different in patients with CTS and controls (p < 0.01) with both types of US transducers and MRI. The MDA yielded higher correlation to MRI than the LA. Using critical values of 1.3 for the swelling and 3.4 for the flattening ratio, MRI, and US with the MDA yielded a sensitivity of 100 % each. Modern imaging modalities allow for an exact diagnosis of CTS even in cases with only slight median nerve pathology.

The purpose of this study was to determine the changes in function of both the left and the right ventricles (LV, RV) before and after aortic valve replacement (AVR), compared with age-matched healthy volunteers using magnetic resonance (MR) imaging. Fourteen patients with aortic stenosis underwent MR imaging (1.5 T) before and 3 (n = 14) and 12 (n = 9) months after surgical valve replacement. An electrocardiographically triggered two-dimensional cine fast low-angle shot sequence was used for the evaluation of absolute values and indices related to 1 m(2) body surface area for function, mass, and LV wall thickening. Fourteen age-matched healthy volunteers served as controls. Before surgery, all patients showed significant abnormalities of LV mass and function, whereas RV mass and function were not different from those of volunteers and remained mostly unchanged. After surgery, normalization of LV ejection fraction, absolute mass, and end-systolic wall thickness was observed, whereas the LV mass index failed to normalize, and LV volumes remained elevated. Aortic stenosis combined with a significant, but not severe reduction in LV function only affects the LV, whereas the RV remains unaffected at this stage of disease. AVR leads to improved LV function and reduced hypertrophy, but without normalization of LV volumes or the LV mass index within 1 year.

Erdheim-Chester (EC) disease is a rare pathological entity with a highly specific and characteristic pattern of radiographic bone changes. Histologically it resembles Langerhans cell histiocytosis (LCH), and it is still a matter of discussion whether EC disease is a distinct entity or a type of LCH. In this study, 3 cases of Erdheim-Chester disease were followed up over years and examined in detail both radiologically and immunohistochemically. All 3 cases showed the pathognomonic skeletal features for EC disease as well as an identical immunohistochemical phenotype quite different from LCH. Macrophages and Touton cells reacted strongly positive with the histiocytic marker CD 68, whereas staining with S100 and CD1a, markers for Langerhans cells, were negative. Both the immunohistochemical phenotype and the bone changes were clearly distinct from LCH.

OBJECTIVE: The purpose of the study was to analyze first-pass and delayed contrast-enhancement patterns of dysfunctional myocardial regions on MR imaging after injection of gadopentetate dimeglumine to predict myocardial viability in patients with coronary artery disease. SUBJECTS AND METHODS: Twelve patients with wall motion abnormalities and related coronary artery disease revealed by conventional coronary angiography underwent MR imaging at 1.5-T before and 3 months after revascularization therapy. Short-axis images were acquired using a cine gradient-echo sequence. Each slice was divided into eight segments. Overall, 73 segments with impaired contractility were imaged during the first-pass and 14 +/- 2 min after injection of 0.05-mmol/kg gadopentetate dimeglumine at a flow of 3 ml/sec using a T1-weighted turbo fast low-angle shot sequence. Improved systolic wall thickening 3 months after revascularization served as the criterion of viability. RESULTS: At study entry, 26 dysfunctional segments showed delayed hyperenhancement compared with the adjacent functional segments within the same slice, and 47 did not reveal hyperenhancement. After revascularization, 25 (96%) of the 26 hyperenhanced segments did not recover function, whereas 39 (83%) of the 47 segments without hyperenhancement showed mechanical improvement. Segment-related sensitivity and specificity for the correlation of lack of delayed hyperenhancement with myocardial viability were 39 (98%) of 40 and 25 (76%) of 33, respectively. Hypoenhancement during first-pass did not serve as a reliable criterion of viability. CONCLUSION: Evidence of delayed hyperenhancement of dysfunctional myocardium may be used to predict lack of mechanical improvement or nonviability, whereas the lack of hyperenhancement can be correlated with improvement of regional contractility or viability after revascularization.

We examined possible age- and gender-specific differences in the function and mass of left (LV) and right (RV) ventricles in 36 healthy volunteers using cine gradient-recalled echo magnetic resonance imaging. Subjects were divided into four groups (nine men and nine women in each): men aged under 45 years (32 +/- 7), women aged under 45 (27 +/- 6), men aged over 45 (59 +/- 8), and women aged over 45 (57 +/- 9). Functional analysis of cardiac volume and mass and of LV wall motion was performed by manual segmentation of the endocardial and epicardial borders of the end-diastolic and end-systolic frame; both absolute and normalized (per square meter body surface area) values were evaluated. With age there was a significant decrease in both absolute and normalized LV and RV chamber volumes (EDV, ESV), while LV and RV masses remained unchanged. Gender-specific differences were found in cardiac mass and volume (for men and women, respectively: LV mass, 155 +/- 18 and 110 +/- 16 g; LV EDV, 118 +/- 27 and 96 +/- 21 ml; LV ESV, 40 +/- 13 and 29 +/- 9 ml; RV mass, 52 +/- 10 and 39 +/- 5 g; RV EDV, 131 +/- 28 and 100 +/- 23 ml; RV ESV, 53 +/- 17 and 33 +/- 15 ml). Normalization to body surface area eliminated differences in LV volumes but not those in LV mass, RV mass, or RV function. Functional parameters such as cardiac output and LV ejection fraction showed nonsignificant or only slight differences and were thus largely independent of age and gender. Intra- and interobserver variability ranged between 1.4% and 5.9% for all parameters. Cine magnetic resonance imaging thus shows age- and gender-specific differences in cardiac function, and therefore the evaluation of cardiac function in patients should consider age- and gender-matched normative values.

A standardized extended field-of-view sonographic examination technique of the neck is evaluated. In a prospective study we screened 50 patients suspected of having carcinoma or lymphoma for enlarged cervical lymph nodes. After conventional CT of the neck, extended field-of-view sonography was performed using defined axial parallel scanning sequences. The results were interpreted separately by two radiologists. Of 245 lymph nodes (diameter 1 cm or greater) diagnosed with conventional CT, 218 were correctly identified by extended field-of-view ultrasonography. With respect to the entire neck, the sensitivity of extended field-of-view sonography was 92%, and the correlation coefficient between the methods was r = 0.98 (P < 0.001). Fifteen of 17 false-negative lymph nodes were located in the mandibular angle region. False-positive results (N = 10) were caused by misinterpretation of primary tumors, blood vessels, lobulated salivary glands, and double imaged lymph nodes. Our results indicate that extended field-of-view sonography in parallel scanning sequences represents a reliable method for the detection of cervical lymphadenopathy.

The purpose of this work was to test the diagnostic value of dobutamine stress magnetic resonance imaging (MRI) for predicting recovery of regional myocardial contractility after revascularization. Cardiac wall motion abnormalities are due to either non-viable and/or scarred, or viable, but hibernating, myocardial tissue. Dobutamine stress leads to increased systolic wall thickening only in viable myocardium. Twenty-five patients with akinetic or dyskinetic myocardial regions were examined with a Cine FLASH-2D sequence at rest and during dobutamine stress (10 microg/kg/min). Patients were re-examined at rest 3, and in case of persisting wall motion defects, 6 months after revascularization. Criterion of viability was increasing end-systolic wall thickening during stress and/or at follow-up. Akinetic regions related either to the LAD (n = 19) or to the RCA (n = 6) were judged viable if > or = 50% of the affected segments improved. MR studies were completed in all subjects without arrhythmia or need for early terminations due to symptoms. Sensitivity, specificity, and positive predictive value for the prediction of myocardial viability were 61%, 90%, and 87% for the segment-related analysis, and 76%, 100%, and 100% for the patient-related analysis based on coronary artery distribution, respectively. Dobutamine stress MRI allows to predict global functional recovery of akinetic myocardial regions after revascularization with a high positive predictive value and high specificity.

Intranodal angioarchitecture was used as criterion for the differential diagnosis of lymph node alterations by colour duplex sonography. The influence of the adjustment of the duplex unit on the diagnostic accuracy and on the rate of lymph nodes with detectable intranodal flow signals was tested. A total of 243 superficial lymph nodes in 127 patients were included in a retrospective study. Diagnoses were approved by histopathology (n = 173) or clinical follow-ups (n = 70 reactive lymph nodes). The intranodal angioarchitecture and sonomorphology were assessed. We used nonparametric discriminant analysis in order to define appropriate settings for transducer frequency, flow mode, power and threshold which result in the best diagnostic quality. Of the lymph nodes, 87 % displayed flow signals using a threshold of ≥ 13 and the flow modes low or medium. Vascularisation was detected only in 47 % of the nodes assessed with different adjustments. Diagnostic accuracy dropped from 94 to 68–84 % if threshold was < 13 or power was less than –11 dB. An insufficient adjustment of the colour duplex unit decreases the chance of detecting intranodal flow signals and impairs the diagnostic quality of colour duplex sonography. Flow mode, power and threshold are the most important parameters which have to be adjusted properly.

A method for the fast acquisition of quantitative T1 maps is presented. It is based on the acquisition of a series of snapshot fast low-angle shot (FLASH) images after inversion of the magnetization. A drawback of this method is the necessity for a sufficiently long relaxation delay before each inversion pulse, leading to long experimental times if averaging or segmentation is required. Thus implementation of this method on a whole-body scanner is problematic, as the longer gradient rise times provide prolonged repetition times, which makes segmentation indispensable to provide a sufficient temporal resolution. We present a modification of the method that allows for reduction in the intermediate relaxation delays and thus for considerably reduced experimental durations.

Theoretical considerations on the signal-to-noise ratio (SNR) in FLASH-EPI-Hybrid imaging were published previously. The purpose of this work was to investigate in vivo the signal intensities in Hybrid images as a function of sequence specific parameters. In detail, the SNR as a function of the number of echoes m per RF excitation, the excitation flip angle α, and the dependence on the tissue relaxation times T1 and T2* were studied. In eight healthy subjects brain and abdominal Hybrid images were acquired where m and α were changed independently. Signal intensities in human brain, liver, and kidney were evaluated for each Hybrid experiment. Additionally, T1 and T2* values of these tissue types were quantified to allow for a comparison with the theory. An excellent agreement between calculated and measured signal behavior was found. The theory was therefore validated in vivo and can thus be used to optimize the signal-to-noise in Hybrid experiments.

Purpose: The treatment of inoperable tracheobronchial stenoses with Palmaz stents is analyzed in terms of the clinical effect, typical complications, and long-term follow-up. Methods: Twenty-seven Palmaz stents were placed in 22 patients with the help of a rigid bronchoscope. Results: Stents were implanted in the distal trachea, the main bronchi, and the lower lobe bronchi. Twenty-one of 22 patients reported an immediate subjective improvement in their respiratory situation. The mean survival time was 12 months; in two patients the stents were well tolerated for up to 40 months. A redilation of three stents was successful up to 33 months. In three cases a dislocation of the stent was observed; after bronchoscopic retraction a new stent was successfully implanted in each case. Conclusion: Treatment of inoperable tracheobronchial stenoses with the Palmaz stent is a safe procedure that provides an immediate improvement of the patient’s pulmonary situation. The Palmaz stent shows a minimal complication rate in the long-term follow-up.

A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100–150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause.

OBJECTIVE: We evaluated the diagnostic accuracy of three-dimensional (3D) MR coronary angiography with the navigator technique for the detection of coronary artery stenoses in comparison with that of conventional radiographic angiography. SUBJECTS AND METHODS: Thirty patients with coronary artery disease were examined with an ECG-triggered 3D fast low-angle shot sequence using retrospective respiratory gating and the navigator technique on a 1.5-T MR scanner. The data set was evaluated as a 3D view with a surface rendering technique. RESULTS: Imaging of the proximal coronary arteries was possible in all patients. The average visualized lengths of the left main, left anterior descending, left circumflex, and right coronary arteries were 1.9+/-0.5 cm (mean +/- SD), 5.2+/-2.3 cm, 4.2+/-1.9 cm, and 5.2+/-2.5 cm, respectively. Irregular breathing reduced image quality in seven of the 30 patients, making diagnosis of stenoses impossible. In the 77% of patients whose examinations resulted in high-quality images, the sensitivity and specificity for detection of significant stenoses and occlusions in all four main coronary arteries were 81% and 89%, respectively. CONCLUSION: The navigator technique allows reproducible imaging of the proximal course of coronary arteries. This technique obviates breath-hold studies, thus allowing more patients to be examined. In patients whose examinations resulted in high-quality images, significant coronary artery lesions could be seen. However, for widespread clinical use, further technical improvement is necessary to increase sensitivity and specificity.

We report a case of a 72-year-old man whose multi-slice cardiac computed tomography revealed an anomalous origin of the right coronary artery between the great arteries.

Background In patients with heart failure due to dilated cardiomyopathy, cardiac energy metabolism is impaired, as indicated by a reduction of the myocardial phosphocreatine-to-ATP ratio, measured noninvasively by 31 P-MR spectroscopy. The purpose of this study was to test whether the phosphocreatine-to-ATP ratio also offers prognostic information in terms of mortality prediction as well as how this index compares with well-known mortality predictors such as left ventricular ejection fraction (LVEF) or New York Heart Association (NYHA) class. Methods and Results Thirty-nine patients with dilated cardiomyopathy were followed up for 928±85 days (2.5 years). At study entry, LVEF and NYHA class were determined, and the cardiac phosphocreatine-to-ATP ratio was measured by localized 31 P-MR spectroscopy of the anterior myocardium. During the study period, total mortality was 26%. Patients were divided into two groups, one with a normal phosphocreatine-to-ATP ratio (>1.60; mean±SE, 1.98±0.07; n=19; healthy volunteers: 1.94±0.11, n=30) and one with a reduced phosphocreatine-to-ATP ratio (P =.036) and cardiovascular ( P =.016) mortality for patients with normal versus patients with low phosphocreatine-to-ATP ratios. A Cox model for multivariate analysis showed that the phosphocreatine-to-ATP ratio and NYHA class offered significant independent prognostic information on cardiovascular mortality. Conclusions The myocardial phosphocreatine-to-ATP ratio, measured noninvasively with 31 P-MR spectroscopy, is a predictor of both total and cardiovascular mortality in patients with dilated cardiomyopathy.

A total of 130 superficial lymph nodes were evaluated using color Doppler flow imaging (CDFI) in order to differentiate benign from malignant lymphadenopathy. The patterns of intranodal flow signals detected at standardized conditions by CDFI were classified using eight self-defined criteria and were correlated with the histopathological or clinical diagnosis. Nonparametric discriminant analysis showed that four vascular were suspicious of malignancy: (a) avascular areas, (b) displacement of intranodal vessels, (c) accessory peripheral vessels and (d) aberrant course of central vessels. Of the neoplastic lymph nodes (n = 73), 96% showed at least one pathological vascular pattern. Malignancy could be excluded in 95% of 57 reactive lymph nodes using these four criteria. Most reactive lymph nodes in contrast demonstrated a vascular hilus and/or vessels running at the long axis of the lymph node with branches to the cortex. There was a diagnostic accuracy of 41-82% in the additionally evaluated sonomorphological (size, shape, echogenicity) and Doppler (increased Pourcelot's or pulsatility indices) criteria. The definitive interpretation of the promising results of this retrospective study requires confirmation of examiner independency as well as a prospective evaluation.

Sixty femoral pseudoaneurysms were identified by colour Doppler flow imaging over a period of 27 months. One group (n = 42) was treated immediately by ultrasound-guided compression repair (UGCR). In the remaining 18 pseduaneurysms a conservative theraphy attempt, which was successful in 9 patients within 1 week, preceded UGCR. Unsuccessful conservative theraphy did not prejudice the feasibility and outcome of UGCR. the success rate (50 of 51 UGCR) was higher than that reported in the literature, but was at the expense of a longer compression time.Multiple parameters were correlated with the compression time. A significant correlation was found with the size of the perfused lumen in the pseudoaneurysm and with the diameter, lenght and shape of the aneurysm neck. Follow-up at 24 h and 1 week after UGCR revealed 1 thrombotic complication and 4 partial recurrences. Within 1 week there was a significant decrease in the size of the (then thrombosed) pseudoaneurysms.

Using 31P-MR spectroscopy, abnormalities of cardiac energy metabolism have been demonstrated in patients with dilated cardiomyopathy (DCM). However. a detailed analysis of the correlations among energy metabolism, cardiac hemodynamics and myocardial hypertrophy obtained from 31P-MR, right and left heart catheterization and echocardiography has not been presented, 23 patients with DCM (left ventricular (LV) EF 34 ± 3%; NYHA class 2.7 ± 0.1; SE) underwent right and left heart catheterization and echocardiography ± 3 days before/after MR spectroscopy. Coronary artery disease was ruled out by coronary angiography. ECG-triggered. localized 31 P-MR spectra from the anteroseptal myocardium were acquired at rest (prone position) during 30 min on a 1.5 T Philips Gyroscan MR system using ISIS localization, adiabatic pulses. and a 15 sec repetition time. Peak areas were corrected for T1 effects and for blood contamination. and were determined with Lorentzian line fits in the time domain. Linear correlations between creatine phosphate (CP)/ATP ratios and hemodynamic parameters were calculated. Download : Download high-res image (69KB) Download : Download full-size image LV pressures and diameters. cardiac output, stroke volume, pulmonary arterial pressures, right atrial pressure and pulmonary arterial oxygen saturation did not correlate with CP/ATP. Thus, our data demonstrate that in DCM, the extent of high-energy phosphate depletion is related to the extent of mechanical dysfunction as well as to LV wall thickness.

AIM: To evaluate contrast-enhanced ultrasonography (CEUS) using SonoVue (R) in the detection of liver metastases in patients with known extrahepatic primary tumors versus the combined gold standard comprising CT, MRI and clinical/histological data.METHODS: It is an international multicenter study, and there were 12 centres and 125 patients (64 males, 61 females, aged 59 11 years) involved, with 102 patients per protocol. Primary tumors were colorectal in 35%, breast in 27%, pancreatic in 17% and others in 21%. CEUS using SonoVue (R) was employed with a low-mechanical-index technique and contrast-specific software using Siemens Elegra, Philips HDI 5000 and Acuson Sequoia; continuous scanning for at least five minutes.RESULTS: CEUS with SonoVue (R) increased significantly the number of focal liver lesions detected versus unenhanced sonography. In 31.4% of the patients, more lesions were found after contrast enhancement. The total numbers of lesions detected were comparable with CEUS (55), triple-phase spiral CT (61) and MRI with a liver-specific contrast agent (53). Accuracy of detection of metastatic disease (i.e. at least one metastatic lesion) was significantly higher for CEUS (91.2%) than for unenhanced sonography (81.4%) and was similar to that of triple-phase spiral CT (89.2%). In 53 patients whose CEUS examination was negative, a follow-up examination 3-6 months later confirmed the absence of metastatic lesions in 50 patients (94.4%).CONCLUSION: CEUS is proved to be reliable in the detection of liver metastases in patients with known extrahepatic primary tumors and suspected liver lesions. (c) 2006 The WIG Press. All rights reserved.

A 23-year-old medical student presented with slowly progressive swelling of the terminal digits that had a duration of 3 years (Figure 1). Figure 1. Photograph of the patient’s left hand showing clubbing. There was no family history of clubbing or cyanosis. The patient had no signs of cyanosis or a history of cardiac, pulmonary, or …