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To retrospectively compare the diagnostic accuracy of three cardiac magnetic resonance (MR) imaging approaches for the detection of histologic and immunohistologic criteria (reference standard) proved myocardial inflammation in patients clinically suspected of having chronic myocarditis (CMC).Cardiac MR imaging was performed in 83 consecutive patients (55 male, 28 female; mean age, 44.8 years +/- 17.7 [standard deviation]) clinically suspected of having CMC, after written informed consent was obtained according to guidelines of the local ethics committee, which approved the study. T2-weighted triple-inversion-recovery imaging to calculate the edema ratio (ER), T1-weighted imaging before and after contrast agent administration to calculate the myocardial global relative enhancement (gRE), and inversion-recovery gradient-echo imaging to evaluate areas of late gadolinium enhancement (LE) were performed. The MR results were correlated with the endomyocardial biopsy (EMB) findings to detect intramyocardial inflammation and cardiotropic viral genomes analyzed at polymerase chain reaction assay. For statistical analyses, receiver operating characteristic analysis and the Wilcoxon test for unpaired data were used because the Kolomogorov-Smirnov test revealed a distribution of data that was different from normality.Intramyocardial inflammation and cardiotropic viral persistence were confirmed at immunohistologic analysis in 48 and 49 of the 83 patients, respectively. The sensitivity, specificity, and diagnostic accuracy of the MR parameters, as compared with the immunohistologic detection of inflammation, were, respectively, 62%, 86%, and 72% for gRE; 67%, 69%, and 68% for ER; and 27%, 80%, and 49% for LE. Cardiac MR-derived gRE, ER, and LE were not associated with polymerase chain reaction proof of viral genomes.In patients clinically suspected of having CMC, increased gRE and ER indicating inflammation were common findings that could be confirmed at immunohistologic analysis, whereas LE had low sensitivity and accuracy. Cardiac MR imaging may be helpful in detecting intramyocardial inflammation noninvasively, but it fails to depict viral persistence.

To assess the potential use of spirometrically gated lung computed tomographic (CT) findings in the diagnosis of bronchiolitis obliterans syndrome after lung transplantation.Forty-nine lung transplant recipients were examined at least 8 months after surgery with spirometrically gated thin-section CT of the lung. In addition to visual signs of small-airway disease at CT, mean lung attenuation and the SD were numerically determined and compared with the results of lung function testing at the time of the CT examination and 1 year later by using factorial analysis of variance.Mean lung attenuation was significantly lower in patients who developed bronchiolitis obliterans syndrome within 1 year after the CT study (-837 HU +/- 3) than in patients with persistent normal lung function (-812 HU +/- 3, P.001). With an optimal threshold, sensitivity was 69%, specificity was 71%, and accuracy was 84%. Visual analysis did not significantly contribute to the prognostic power of CT.Spirometrically gated CT measurements of lung attenuation can be used to predict the onset of bronchiolitis obliterans syndrome after lung transplantation.

To investigate the radiation dose for conventional computed tomography (CT) and spiral CT during different CT examinations at various hospitals and practices.CT dose index with an active length of 15 cm was measured in 16 different types of CT scanners by using ionization chamber dosimetry. Twenty-six holders (one who has legal responsibility under national law for a radiologic installation) operating a total of seven conventional and 20 spiral CT scanners were asked for their standard parameters for various CT examinations. Weighted CT dose index and dose-length product were determined for each examination.For most examinations, the tube current time product was significantly higher for conventional CT than for spiral CT (.002/= P/=.05). The ratio of section distance to section thickness for conventional CT was significantly lower than the pitch for spiral CT (.001/= P/=.05). The weighted CT dose index and dose-length product for spiral CT were about half of those for conventional CT. The third quartiles for weighted CT dose index and dose-length product for spiral CT were much lower than those recommended as reference doses.CT examinations with conventional CT scanners are often performed with unnecessarily high radiation dose. For the establishment of reference doses, the radiation dose with spiral CT scanners should be taken into account.

To evaluate the effect of iodine concentration on the detection of focal liver lesions at biphasic spiral computed tomography (CT).One hundred two patients (64 men, 38 women) with neoplastic (n = 85) and nonneoplastic focal lesions (n = 17) were prospectively assigned to biphasic injection group A or B and received 180 mL of iopromide containing 370 or 300 mg of iodine per milliliter, respectively, during spiral CT. Comparison included assessment of quantitative and qualitative parameters.Hepatic time-attenuation curves and mean hepatic enhancement in the portal venous phase and aortic time-attenuation curves in both arterial and portal venous phases were statistically superior in group A compared with group B. There was no significant difference in the mean enhancement in all lesions in either group. In contrast, among patients with hepatocellular carcinoma, mean contrast enhancement in lesions in the arterial phase was significantly superior in group A compared with group B. Blinded readers classified hepatic attenuation and lesion visibility as very good and as improved significantly more often in group A than in group B.A decrease in iodine concentration significantly affects aortic and hepatic contrast enhancement and may impair the detectability of focal liver lesions during biphasic spiral CT.

To evaluate whether the different signal intensities at magnetic resonance (MR) imaging of melanoma are associated with a higher content of melanin.In a prospective study, MR imaging and ophthalmoscopic examination findings in 42 patients (19 women, 23 men; age range, 30-87 years) with uveal melanoma were compared with histopathologic examination findings obtained after enucleation. MR imaging was performed with 2-mm sections by using a 5-cm surface coil. T1- and T2-weighted images were obtained before and after contrast material administration.In 33 (79%) of the patients, there was homogeneous tumor pigmentation, whereas in nine (21%) patients, there was inhomogeneous bipartite tumor pigmentation. Compared with the histopathologic data, the results of qualitative evaluation were accurate in 29 (58%) of 50 and in 26 (53%) of 49 tumorous areas on T1- and T2-weighted images, respectively. Quantitative evaluation yielded better results, especially at T1-weighted imaging; an 86% correlation was found. Because of methodological reasons, only the superficial pigmentation of inhomogeneous tumors could be evaluated with ophthalmoscopy.Thin-section MR imaging of the eye enables an accurate prediction of melanomatous pigmentation with quantitative evaluation of plain T1-weighted images and is superior to ophthalmoscopy in cases of inhomogeneous pigmentation.

To evaluate experimentally and clinically an internally cooled power laser system for percutaneous treatment of liver metastases, with magnetic resonance (MR) imaging guidance, to increase the volume of coagulative necrosis with single laser beam applications.The power laser system consisted of standard cannulation paraphernalia and a specially designed 7-F protective catheter for cooling the laser tip during treatment to avoid carbonization. A microdome laser beam applicator with a laser tip diameter of 0.95 mm kept the entire device as small as possible. After the unit was tested in 40 porcine livers, 532 laser beam applications (mean power, 27.5 W [range, 22.1-30.0 W]; mean application time, 19.8 minutes [range, 14-30 minutes]) were performed with MR guidance in 127 patients with 318 liver metastases. The safety of the procedure and the volume of induced necrosis were evaluated.In vitro, cuboid areas of coagulative necrosis with a mean greatest diameter of 4.3 cm +/- 0.5 (SD) were demonstrated after single applications. In vivo, MR thermometry allowed accurate demarcation of changes induced by heat, with a mean diameter of necrosis of 3.3 cm +/- 1.4. No carbonization or vaporization of tissue or damage of equipment occurred during treatment.This power laser system can increase the volume of laser-induced necrosis in liver metastases with a single application, thereby simplifying and accelerating the treatment of larger lesions.

To assess the value of the peripheral washout sign on delayed contrast material-enhanced magnetic resonance (MR) images in differentiation of benign from malignant breast masses.In 49 women with 79 breast lesions (55 malignant and 24 benign), dynamic contrast-enhanced MR imaging was performed every 90 seconds during the first 7 minutes and repeated at 10, 20, 30, 40, 50, and 60 minutes after injection of contrast material. Qualitative analysis of the images was performed to evaluate the presence of the peripheral washout sign (a hypointense zone in the periphery of the lesion relative to the center). Quantitative analysis of the images was performed by measuring the signal intensity of the periphery and center of the lesions.The peripheral washout sign was seen in 28 (51%) of the 55 carcinomas on delayed contrast-enhanced MR images (10 minutes). Quantitative analysis demonstrated different enhancement profiles of the periphery and center of these lesions. The periphery showed early increase and decrease of enhancement, while the center showed gradual increase and persistent enhancement. The peripheral washout sign was not seen in any of the benign lesions. Specificity was 100% and sensitivity was 51% for diagnosis of breast carcinoma.Peripheral washout may be a reliable sign of malignancy on delayed contrast-enhanced MR images of the breast.

To evaluate criteria for differentiating malignant versus reactive lymph nodes in the head and neck on the basis of findings at helical computed tomography (CT).Helical CT scans were evaluated of 70 consecutive patients (46 men and 24 women, aged 20-78 years [mean, 51 years]) with known head and neck tumors and cervical lymph node enlargement. The ratio of the maximal longitudinal to the maximal axial diameter (L/T) was calculated for nodes larger than 8 mm in diameter based on measurements obtained from coronal, paraxial, and sagittal reconstructions.At histologic examination, 96 of 164 nodes were malignant. Of these, 94 of 96 nodes had an L/T of less than 2 (sensitivity, 97%; specificity, 97%; accuracy, 97% for malignancy). Minimal diameter was more than 8 mm in 83 of 96 nodes (sensitivity, 87%; specificity, 89%; accuracy, 88% for malignancy). Low-attenuation centers and rim enhancement were seen in 75 of 96 nodes (sensitivity, 78%; specificity, 100%; accuracy, 86% for malignancy).The L/T at helical CT provide an accurate assessment of reactive versus malignant nodes in the head and neck.

To identify morphologic differences between Kallman syndrome (KS) and idiopathic hypogonadotropic hypogonadism (IHH) and establish a role for magnetic resonance (MR) imaging in these disorders.Twenty-eight patients were compared with 10 eugonal male volunteers. Eighteen patients had KS (hypogonadotropic hypogonadism with anosmia) and 10 had IHH. All participants underwent hormone analysis, a sniff-bottle smell test, and gadolinium-enhanced MR imaging. Changes in the hypothalamic-hypophyseal region and the rhinencephalon were evaluated.MR imaging revealed intracranial morphologic changes in all patients on plain T1-weighted sections. Seventeen patients with KS demonstrated aplasia of an olfactory bulb; one olfactory sulcus was absent in six, rudimentary in four, and normal in eight. Olfactory bulbs were present in all 10 IHH patients and three showed one slightly hypoplastic bulb. Ten patients with KS and three with IHH showed an enlarged paranasal sinus system. Further MR findings were similar.MR imaging demonstrates abnormalities of the rhinencephalon present in KS patients and occasionally absent in IHH patients.

The purpose of this first patient study (phase II) was to evaluate the clinical usefulness of a new echo contrast agent at transcranial Doppler ultrasonography (US). Twenty patients were selected from a group of 242 patients undergoing conventional transcranial Doppler US who had low (n = 18) or absent (n = 2) Doppler signals from the middle cerebral artery (MCA). The extent and duration of Doppler signal increase was measured in 30 MCAs and in 14 basilar arteries following the intravenous injection of a transpulmonary galactose microparticle suspension (SH U 508 A) at three concentrations (200, 300, and 400 mg/mL). Doppler waveform analysis became possible in 93% (28 of 30) of the MCAs following injection. The maximal increase in average Doppler signal intensity (11 dB at 200 mg/mL, 15 dB at 300 mg/mL, and 17 dB at 400 mg/mL) and the increase in average duration of the signal enhancement (163 seconds at 200 mg/mL, 219 seconds at 300 mg/mL, and 240 seconds at 400 mg/mL) depended on contrast agent concentration. Doppler waveform analysis became possible in 79% (11 of 14) of the basilar arteries. The intravenous injection of this new echo contrast agent markedly increases Doppler signal intensity in patients with nondiagnostic results at conventional Doppler US.

Twenty-three patients with malignant hepatic tumors underwent magnetic resonance (MR) imaging before and after intravenous administration of gadolinium-diethylene-triaminepentaacetic acid (DTPA). Two different doses were used, 0.1 mmol/kg and 0.2 mmol/kg. The larger dose proved to be more effective than the smaller dose. The signal-enhancement-to-noise ratio was significantly larger in the tumor than in the liver (2 alpha less than or equal to .05). In a moderately T1-weighted spin echo (SE) sequence (SE 400/30) (repetition time [TR] msec/echo time [TE] msec), the tumor was better defined 6 minutes after administration of Gd-DTPA. More strongly T1-weighted sequences--that is, SE 200/20 and inversion recovery 1,500/35/400 (TR msec/TE msec/inversion time, msec)--showed significantly worse contrast between tumor and liver (signal-difference-to-noise ratio [SD/N]) 10 and 15 minutes after administration (2 alpha less than or equal to .05). On the other hand, the low SD/N in the rapid MR imaging sequence was significantly improved (2 alpha less than or equal to .05). The most important indications for administration of Gd-DTPA in diagnosing hepatic tumors are the presentation of perfusion conditions and contrast optimization in rapid MR images.

Magnetic resonance (MR) imaging was performed on 40 patients with intracranial tumors, before and after intravenous administration of gadolinium-DTPA (Gd-DTPA). Precontrast studies included a comprehensive protocol of spin-echo sequences. Tumors were visualized on precontrast images either directly or indirectly by anatomic distortion caused by the mass. However, differentiation of the tumor from adjacent tissues was possible in only 17 of 40 cases. Delineation of the tumor was best on precontrast, T2-weighted images. After administration of Gd-DTPA (0.1 mmol/kg), increased signal intensity from the tumor was observed in all patients. The localized increase in signal intensity in the tumor considerably improved the tumor delineation in 36 of 40 patients. Whereas most of the meningiomas, neuromas, and adenomas could be delineated prior to administration of contrast material if appropriate pulse sequences were applied, glioblastomas and intracranial metastases required Gd-DTPA administration for diagnostically sufficient tumor display.