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At least 397 records · Page 22Linked to original sources
PubMed2006

[Analysis of MR image quality of echo planar diffusion-weighted imaging: investigations at 1.5 Tesla with higher gradient field strength].

PURPOSE: Single-shot echo planar Diffusion-weighted-Imaging (EPI DWI) requires extended gradient facilities with strong, fast switching gradients. Up to now the image quality of EPI DWI is enormously influenced by some kinds of artifacts. Therefore we evaluated the image quality of EPI DWI in demonstrating anatomical structures using a 1.5 T MR scanner with a higher gradient field strength of 40 mt/m, a risetime of 200 micros and a slewrate of 200T/m/s. MATERIALS AND METHODS: Using an evaluation scale with four categories two independent readers evaluated 12 different infra- and supratentorial anatomic regions of the brain on 50 DWI images and compared them with the corresponding T2 turbospin echo image. RESULTS: No region was judged to be undistinguishable. On axial DWI images the assessment of the brain stem was poor. In the level of the putamen and thalamus the image quality of DWI was judged to be from adequate to excellent. The central sulcus and the boundary of the white and grey matter was assessed to be adequately visible. The interobserver variability showed a good agreement between the two readers. CONCLUSION: The image quality of EPI DWI improves from a higher gradient field strength. The shortening rise time of 200 micros and the slewrate of 200 T/m/s will lead to a faster gradient switching. Single shot EPI DWI is less influenced by image artefacts and the presentation of different anatomical structures profits when a MR scanner with higher gradient field strength is used.

Adolescent↗
PubMed2004

Analysis of 3-D myocardial motion in tagged MR images using nonrigid image registration.

Tagged magnetic resonance imaging (MRI) is unique in its ability to noninvasively image the motion and deformation of the heart in vivo, but one of the fundamental reasons limiting its use in the clinical environment is the absence of automated tools to derive clinically useful information from tagged MR images. In this paper, we present a novel and fully automated technique based on nonrigid image registration using multilevel free-form deformations (MFFDs) for the analysis of myocardial motion using tagged MRI. The novel aspect of our technique is its integrated nature for tag localization and deformation field reconstruction using image registration and voxel based similarity measures. To extract the motion field within the myocardium during systole we register a sequence of images taken during systole to a set of reference images taken at end-diastole, maximizing the normalized mutual information between the images. We use both short-axis and long-axis images of the heart to estimate the full four-dimensional motion field within the myocardium. We also present validation results from data acquired from twelve volunteers.

Algorithms↗
PubMedDate not supplied

Quantitative MR evaluation of intracranial epidermoid tumors by fast fluid-attenuated inversion recovery imaging and echo-planar diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Quantification of MR can provide objective, accurate criteria for evaluation of a given MR sequence. We quantitatively compared conventional MR sequences with fast fluid-attenuated inversion recovery (fast-FLAIR) and echo-planar diffusion-weighted (DW) MR imaging in the examination of intracranial epidermoid tumors. METHODS: Eight patients with surgically confirmed intracranial epidermoid tumors were examined with T1-weighted MR sequences, fast T2- and proton density-weighted dual-echo sequences, fast-FLAIR sequences, and DW echo-planar sequences. We measured the MR signal intensity and apparent diffusion coefficient (ADC) of epidermoid tumors, normal brain tissue, and CSF and calculated the tumor-to-brain and tumor-to-CSF contrast ratios and contrast-to-noise ratios (CNR). Results were compared among the five MR methods. RESULTS: On fast-FLAIR imaging, the mean signal intensity of epidermoid tumors was significantly higher than that of CSF but significantly lower than that of the brain; the contrast ratio and CNR of tumor-to-CSF were 4.71 and 9.17, respectively, significantly greater than the values with conventional MR imaging. On echo-planar DW imaging, epidermoid tumors showed a remarkably hyperintense signal relative to those of the brain and CSF; the mean contrast ratio and CNR of tumor-to-CSF were 13.25 and 19.34, respectively, significantly greater than those on fast-FLAIR or conventional MR imaging. The mean ADC of epidermoid tumors was 1.197 x 10(-3) mm(2)/s, significantly lower than that of CSF but higher than that of brain tissues. CONCLUSION: Fast-FLAIR imaging is superior to conventional MR imaging in depicting intracranial epidermoid tumors. Echo-planar DW imaging provides the best lesion conspicuity among the five MR methods. The hyperintensity of epidermoid tumors on echo-planar DW imaging is not caused by the diffusion restriction but by the T2 shine-through effect.

Aged↗
PubMed1995

Brain metastases--comparison of gadodiamide injection-enhanced MR imaging at standard and high dose, contrast-enhanced CT and non-contrast-enhanced MR imaging.

The aim was to compare the abilities of contrast-enhanced CT, non-contrast-enhanced MR imaging and contrast-enhanced MR imaging using standard (0.1 mmol/kg b.w.) and high (0.3 mmol/kg b.w.) doses of Gadodiamide injection to detect brain metastases (i.e. blood-brain barrier damage). Sixteen patients with at least 2 metastases found by CT were evaluated by MR imaging using non-contrast-enhanced spin-echo, T1-weighted, T2-weighted sequences, and contrast-enhanced spin-echo T1-weighted sequences at 2 dose levels. Gadodiamide injection was first given at the dose of 0.1 mmol/kg b.w. After imaging, another 0.2 mmol/kg b.w. was given, yielding a cumulative dose of 0.3 mmol/kg b.w. No contrast media-related adverse events were recorded. The images were evaluated openly by one and blindly by 2 investigators and the number of metastases, size, delineation (open study) and diagnostic certainty (blind study) of each individual metastasis noted. High-dose MR imaging showed significantly more and smaller metastases than any other examination, and gave a higher diagnostic certainty. All high-dose images were superior to those with the standard dose MR imaging when compared blindly in pairs. We conclude that spin-echo MR imaging with a high dose of Gadodiamide injection is an efficient way to improve the detection of brain metastases, in particular of small ones.

Adult↗
PubMed2000

Effect of body image and self-image on women's sexual behaviors.

OBJECTIVES: To evaluate the relationship between women's body image, self-image, and sexual behaviors; to determine the effect of body image on personal and sex variables; and to identify factors that contribute to more frequent and greater comfort with sex. METHOD: A magazine survey that included items about body image, self-image, and sexual behaviors was completed by 3,627 women. RESULTS: Women more satisfied with body image reported more sexual activity, orgasm, and initiating sex, greater comfort undressing in front of their partner, having sex with the lights on, trying new sexual behaviors, and pleasing their partner sexually than those dissatisfied. Positive body image was inversely related to self-consciousness and importance of physical attractiveness, and positively related to relationships with others and overall satisfaction. Body image was predictive only of one's comfort undressing in front of partner and having sex with lights on. Overall satisfaction was predictive of frequency of sex, orgasm, and initiating sex, trying new sexual behaviors, and confidence in giving partner sexual pleasure. DISCUSSION: Results indicate that overall self-image and body image are significant predictors of sexual activity. Directions for future research are discussed.

Adolescent↗
PubMed2003

Enhanced gray and white matter contrast of phase susceptibility-weighted images in ultra-high-field magnetic resonance imaging.

PURPOSE: To evaluate if magnetic susceptibility sensitive phase postprocessed images can be used to enhance the inherent brain/gray white matter contrast in gradient echo (GE) images at 8-Tesla (T) magnetic resonance (MR). MATERIALS AND METHODS: Phase and magnitude images of high-resolution GE MR 8-T images were created. Comparisons were made between the magnitude, the product of the magnitude and phase, and pure phase images. RESULTS: The pure phase images significantly improved the contrast between the gray and white matter structures. In general, the higher the iron content or subvoxel field inhomogeneities, the higher was the contrast, and the greater were the resultant phase shifts. The phase images best demonstrated anatomy that was not apparent on the standard magnitude images. CONCLUSION: Phase imaging can significantly improve the demonstration of the internal anatomical brain structures over standard magnitude GE imaging techniques at high field.

Brain↗
PubMed2002

Study on the usefulness of whole body SPECT coronal image, MIP image in 67Ga scintigraphy.

In this study, we examined the usefulness of whole body coronal images and whole body cine display MIP images (CMIP) upon which image processing was carried out after whole body SPECT in comparison to the usefulness of whole body images (WB/SC) compensated by scattered radiation in tumor/inflammation scintigraphy with 67Ga-citrate (67Ga). Image interpretation was performed for the 120 patients with confirmed diagnoses, and the accuracy of their diagnoses was studied by three nuclear medical physicians and two clinical radiological technologists by means of sensitivity, specificity and ROC analysis. The resultant data show that sensitivity, specificity, accuracy and the area under the ROC curve Az in the WB/SC were approximately 65%, 86%, 74% and 0.724, respectively, whereas sensitivity, specificity, accuracy and Az of the image reading system in which CMIP is combined with whole body coronal images reconstructed by the OS-EM method were approximately 93%, 95%, 94% and 0.860, respectively. Furthermore, coronal images reconstructed by the OS-EM method tended to be superior to those produced by the FBP method in both diagnostic accuracy and ROC analysis. In conclusion, the image reading system in which CMIP is combined with whole body coronal images reconstructed by the OS-EM method was shown to be superior in diagnostic accuracy and ROC analysis. Our data suggest that whole body SPECT is an excellent technique as an alternative to WB/SC.

Adolescent↗
PubMed1999

Application of temporal subtraction for detection of interval changes on chest radiographs: improvement of subtraction images using automated initial image matching.

The authors developed a temporal subtraction scheme based on a nonlinear geometric warping technique to assist radiologists in the detection of interval changes in chest radiographs obtained on different occasions. The performance of the current temporal subtraction scheme is reasonably good; however, severe misregistration can occur in some cases. The authors evaluated the quality of 100 chest temporal subtraction images selected from their clinical image database. Severe misregistration was mainly attributable to initial incorrect global matching. Therefore, they attempted to improve the quality of the subtraction images by applying a new initial image matching technique to determine the global shift value between the current and the previous chest images. A cross-correlation method was employed for the initial image matching by use of blurred low-resolution chest images. Nineteen cases (40.4%) among 47 poor registered subtraction images were improved. These results show that the new initial image matching technique is very effective for improving the quality of chest temporal subtraction images, which can greatly enhance subtle changes in chest radiographs.

Humans↗
PubMed1991

Image compression techniques for medical diagnostic imaging systems.

As a result of recent technological advances, a significant (and increasing) number of the images in a typical radiology department are represented in digital form. This includes images that have been captured using digital imaging modalities such as computed tomography and magnetic resonance imaging as well as images that have been digitally converted from film originals as in computed radiography. To provide economical storage of such images and to allow for their efficient transmission over various networks, it becomes necessary to consider digital image compression techniques. In this article, the fundamental concepts of several popular reversible and nonreversible image compression schemes are reviewed. In addition, the performance of the schemes in terms of compression ratio and reconstructed image quality as applied to medical diagnostic images is investigated.

Diagnostic Imaging↗
PubMed2001

An affordable, portable fluorescence imaging device for skin lesion detection using a dual wavelength approach for image contrast enhancement and aminolaevulinic acid-induced protoporphyrin IX. Part I. Design, spectral and spatial characteristics.

Steady-state fluorescence imaging can be used in conjunction with selective exogenous or endogenous fluorescent compounds for the diagnosis of skin lesions, for example cancerous lesions. Depending on the excitation and emission properties of the fluorescent compound used, various excitation and/or emission wavelengths can be chosen in order to allow fluorescence imaging. Unwanted background signals like autofluorescence and scattering can decrease the image quality and hence the diagnosis potential of this imaging method. A method involving two excitation and/or emission wavelengths was used in order to suppress the unwanted background signal and allow contrast enhanced fluorescence imaging. A fluorescence imaging device prototype was assembled using both the two wavelength excitation method and the two wavelength emission method. Additionally, a white light source was included to allow the collection of images as seen with the naked eye. The prototype was designed to be affordable and portable and was laid out towards the diagnosis of skin lesions using aminolaevulinic acid-induced protoporphyrin IX (PpIX). This paper describes the excitation and detection characteristics of a fluorescence imaging device prototype. This includes spectral and spatial characteristics of the various light sources included in the device as well as specifications of the image detector used. Furthermore, the image analysis procedure used for the dual wavelength excitation/emission is described.

Aminolevulinic Acid↗
PubMed2004

Magnetic resonance imaging of the elbow. Part I: normal anatomy, imaging technique, and osseous abnormalities.

Part I of this comprehensive review on magnetic resonance imaging of the elbow discusses normal elbow anatomy and the technical factors involved in obtaining high-quality magnetic resonance images of the elbow. Part I also discusses the role of magnetic resonance imaging in evaluating patients with osseous abnormalities of the elbow. With proper patient positioning and imaging technique, magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the osseous structures of the elbow. Magnetic resonance imaging can detect early osteochondritis dissecans of the capitellum and can be used to evaluate the size, location, stability, and viability of the osteochondritis dissecans fragment. Magnetic resonance imaging can detect early stress injury to the proximal ulna in athletes. Magnetic resonance imaging can detect radiographically occult fractures of the elbow in both children and adults. Magnetic resonance imaging is also useful in children to further evaluate elbow fractures which are detected on plain-film radiographs.

Adult↗
PubMed2000

Multifocal nodular fatty infiltration of the liver mimicking metastatic disease on CT: imaging findings and diagnosis using MR imaging.

The aim of this study was to describe the MR appearance of multifocal nodular fatty infiltration of the liver (MNFIL) using T1-weighted in-phase (IP) and opposed-phase (OP) gradient-echo as well as T2-weighted turbo-spin-echo sequences with fat suppression (FSTSE) and without (HASTE). Magnetic resonance imaging examinations at 1.5 T using T1-weighted IP and OP-GRE with fast low angle shot (FLASH) technique, and T2-weighted FSTSE, T2-weighted HASTE of 137 patients undergoing evaluation for focal liver lesions were reviewed. Five patients were identified in whom CT indicated metastatic disease; however, no liver malignancy was finally proven. Diagnosis was confirmed by biopsy (n = 3), additional wedge resection (n = 1) or follow-up MRI 6-12 months later (n = 5). Regarding the identified five patients, the number of focal liver lesions was 2 (n = 2) and more than 20 (n = 3). The MR imaging characteristics were as follows: OP-image: markedly hypointense (n = 5); IP image: isointense (n = 2) or slightly hyperintense (n = 3); T2-weighted FSTSE-image: isointense (n = 5); T2-weighted HASTE image isointense (n = 1); slightly hyperintense (n = 4). On OP images all lesions were sharply demarcated and of almost spherical configuration (n = 5). Further evaluation by histology or follow-up MR imaging did not give evidence of malignancy in any case. Histology revealed fatty infiltration of the liver parenchyma in three patients. Magnetic resonance follow-up showed complete resolution in two patients and no change in three patients. Multifocal nodular fatty infiltration can simulate metastatic disease on both CT and MR imaging. The combination of in-phase (IP) and opposed-phase (OP) gradient-echo imaging can reliably differentiate MNFIL from metastatic disease.

Aged↗
PubMed1993

Magnetic resonance imaging of the temporomandibular joint. Value of axial images.

The purpose of this study was to determine the value of axial images for diagnosis of disk displacement and osseous changes of the temporomandibular joint. Sagittal, coronal, and axial magnetic resonance images were obtained of 35 fresh temporomandibular joint autopsy specimens. The sagittal and coronal images were interpreted for position of the disk and osseous changes. The value of the axial images for diagnosis of the disk and osseous components was classified into one of four categories: 1) did not add diagnostic information, 2) confirmed findings of sagittal and coronal images, 3) added diagnostic information but did not change the diagnosis, 4) changed the diagnosis. The results showed that the axial images did not add diagnostic information concerning position of the disk in 5 joints, confirmed the diagnosis in 29 joints, and added information but did not change the diagnosis in 1 joint. Concerning osseous abnormalities, the axial images did not add any diagnostic information in 5 joints, confirmed findings of the sagittal and coronal images in 26 joints, added information but did not change the diagnosis in 3 joints and changed the diagnosis in 1 joint. On the basis of these results, it is concluded that the axial plane of imaging of the temporomandibular joint is of relatively little value for assessment of disk displacement and osseous changes. Axial imaging is therefore not recommended for diagnosis of disk position and osseous abnormalities.

Aged↗
PubMed1995

An image correlation procedure for digitally reconstructed radiographs and electronic portal images.

PURPOSE: To study a procedure that uses megavoltage digitally reconstructed radiographs (DRRs) calculated from patient's three-dimensional (3D) computed tomography (CT) data as a reference image for correlation with on-line electronic portal images (EPIs) to detect patient setup errors. METHODS AND MATERIALS: Megavoltage DRRs were generated by ray tracing through a modified volumetric CT data set in which CT numbers were converted into linear attenuation coefficients for the therapeutic beam energy. The DRR transmission image was transformed to the grayscale window of the EPI by a histogram-matching technique. An alternative approach was to calibrate the transmission DRR using a measured response curve of the electronic portal imaging device (EPID). This forces the calculated transmission fluence values to be distributed in the same range as that of the EPID image. A cross-correlation technique was used to determine the degree of alignment of the patient anatomy found in the EPID image relative to the reference DRR. RESULTS: Phantom studies demonstrated that the correlation procedure had a standard deviation of 0.5 mm and 0.5 degrees in aligning translational shifts and in-plane rotations. Systematic errors were found between a reference DRR and a reference EPID image. The automated grayscale image-correlation process was completed within 3 s on a workstation computer or 12 s on a PC. CONCLUSION: The alignment procedure allows the direct comparison of a patient's treatment portal designed with a 3D planning computer with a patient's on-line portal image acquired at the treatment unit. The image registration process is automated to the extent that it requires minimal user intervention, and it is fast and accurate enough for on-line clinical applications.

Dose-Response Relationship, Radiation↗
PubMed2005

Rethinking orbital imaging establishing guidelines for interpreting orbital imaging studies and evaluating their predictive value in patients with orbital tumors.

PURPOSE: To establish guidelines for interpretation of orbital imaging by magnetic resonance imaging (MRI) and/or computed tomography (CT), and to apply these guidelines and examine their predictive value in 131 patients with biopsy-proven orbital tumors. DESIGN: Prospective evaluation of imaging studies. PARTICIPANTS: Imaging studies (CT and/or MRI) from 131 cases with biopsy-proven orbital tumors. METHODS: Guidelines for reviewing orbital imaging studies (MRI and/or CT) were established based on 5 major characteristics: (1) anatomic location, (2) bone and paranasal sinuses involvement, (3) content, (4) shape, and (5) associated features. In total, 84 features were established by an experienced orbital surgeon and a neuroradiologist. Applying these 84 features, imaging studies of 131 biopsy-proven orbital tumors were evaluated by 3 physicians. MAIN OUTCOME MEASURES: Imaging features: characteristics, sensitivity, specificity, and positive and negative predictive values in various groups of orbital tumors and kappa values. RESULTS: One hundred thirty-one cases of biopsy-proven orbital tumors were evaluated. Benign lesions were more likely to be smaller in size, round or oval in shape (29% of all benign tumors, 0% in malignant and inflammatory, P<0.001), and associated with hyperostosis (22% of all benign lesions, P<0.001). They were also more likely to be hyperdense or hypodense on CT imaging (15% and 11%, respectively; P<0.05 in comparison with inflammatory and malignant tumors). Inflammatory processes showed panorbital involvement (23% vs. 3%, and 0% in benign and malignant tumors, respectively; P<0.001). Orbital fat involvement and fat stranding were noticed only in inflammatory lesions (19% and 16%, respectively; P<0.001). None of the features occurred only in malignant tumors, but they tend to involve the anterior orbit more commonly (54% vs. 20%, and 29% in benign and malignant; P = 0.002), and were more likely to show bone erosion (31% vs. 6%, and 16% in benign and inflammatory tumors, respectively; P = 0.004) and molding around orbital structures (29% vs. 3% in benign, and 0% in inflammatory tumors, respectively; P<0.001). Features such as panorbital involvement, orbital fat, frontal sinus opacity, molding around orbital structures, perineural involvement, and fat stranding had specificity of 97% to 100%, but low sensitivity. CONCLUSIONS: Guidelines for analysis of orbital imaging studies (CT or MRI) are suggested. Based on these guidelines several imaging features showed significantly different occurrences in benign, malignant, and inflammatory processes; although this can help in differential diagnosis, tissue diagnosis may still be required.

Adult↗
PubMed2005

Ultrasonic temperature imaging for guiding focused ultrasound surgery: effect of angle between imaging beam and therapy beam.

Ultrasonic temperature imaging is a promising technique for guiding focused ultrasound surgery (FUS). The FUS system is run at an initial, nonablative intensity and a diagnostic transducer images the heat-induced echo strain, which is proportional to the temperature rise. The echo strain image portrays an elliptical "hot spot" corresponding to the focal region of the therapy transducer. It is anticipated that such images will be used to predict the location of the thermal lesion that would be produced at an ablative intensity. We demonstrated in vitro that heat-induced echo strain images can visualize a spatial peak temperature rise of <2 degrees C (starting at room temperature). However, the imaging beam was perpendicular to the treatment beam in these experiments, whereas the most convenient approach in vivo would be to mount the imaging probe within the housing of the therapy transducer such that the two beams are coaxial. A previous simulation experiment predicted that echo strain images would be noisier for the coaxial configuration because sharp lateral gradients in axial displacement cause increased RF signal decorrelation within the beam width. The aim of the current study was to verify this prediction in vitro. We found, that for a temperature rise of approximately 4 degrees C, the mean contrast-to-noise ratio for coaxial and perpendicular echo strain images was 0.37 (+/-0.24) and 2.00 (+/-0.72) respectively. Furthermore, the decorrelation noise seen in the coaxial images obscured the posterior axial border of the hot spot. We conclude that the coaxial configuration will be useful for localizing the hot spot in the lateral direction. However, it may not be able to depict the axial extent of the hot spot or to portray a parameter that is directly related to temperature rise.

Animals↗
PubMed1997

Normalisation of metabolite images in 1H NMR spectroscopic imaging.

Single slice proton magnetic resonance spectroscopic images were taken from a volume of interest (VOI), which was localised using the point resolved spectroscopy (PRESS) sequence. Non-uniformities in the excitation profile of the VOI within the image plane were accounted for using a uniformity correction image. Metabolite images were divided on a voxel-by-voxel basis with a water image obtained from a VOI of the same spatial dimensions from a phantom acquisition. Normalisation procedures carried out on phantom metabolite images were needed to account for the spatial shift in the excitation profile of the VOI, which varies linearly with the chemical shift of the metabolite. Patient metabolite images were then normalised using a VOI water image from a phantom acquisition, which was spatially shifted according to the metabolite chemical shift. In a study of 14 stroke patients, metabolite maps of the distribution of choline, creatine and N-acetyl aspartate (NAA) were constructed. The spectral signal intensities from these metabolites in the infarcted and in the contralateral region were calculated using the raw maps and secondly with the same maps after the B1 normalisation process. In the initial analysis only the metabolite NAA showed a significant decrease, whilst all three metabolites showed a significant reduction in the normalised analysis. These results confirm that normalisation of PRESS localised images does have a significant bearing upon any quantitative measurements made using such images.

Algorithms↗
PubMed1998

Three-dimensional imaging in aortic disease by lighthouse transesophageal echocardiography using intravascular ultrasound catheters. Comparison to three-dimensional transesophageal echocardiography and three-dimensional intra-aortic ultrasound imaging.

Two-dimensional (2D) transesophageal echocardiography (TEE) and 2D intravascular ultrasound (IVUS) imaging face their greatest limitation in visualizing aortic disease in patients. With the aid of three-dimensional (3D) image reconstruction, TEE and IVUS can potentially overcome this limitation but still provide only limited spatial appreciation in aortic disease because 3D imaging of the thoracic aorta requires a broader spatial visualization of the mediastinum than provided by both techniques. Moreover, for timely decision making about aortic disease TEE is limited by a large probe, which requires sedation. Therefore, we developed an approach called 3D lighthouse transesophageal echocardiography (LTEE) using a thin intravascular ultrasound catheter, which provides a full circumferential (360 degree) image and requires no sedation. The purpose of this study was to compare the feasibility and accuracy of 3D TEE, 3D IVUS, and 3D LTEE for obtaining spatial visualization of the thoracic aorta to detect aortic diseases in patients. 3D image datasets were obtained for 3D LTEE by a manual pullback of a 3.3 mm thick, 10 MHz intravascular ultrasound catheter positioned in the esophagus; for 3D TEE using a conventional 15 mm thick probe; and for 3D IVUS using a 2.6 mm thick, 20 MHz intravascular ultrasound catheter. In 12 consecutive patients, three with aortic dissection (two with type III, one with type I) and 11 with suspected artherosclerosis, we analyzed and compared spatial visualization of the thoracic aorta, 3D image quality, patient discomfort, and study time. Providing a 3D dataset of 360-degree tomographic images of the mediastinum, 3D LTEE was the only approach that allowed broad spatial visualization of the aortic arch (9 of 12 patients) with the detection of aortic dissection or atherosclerotic plaques. Spatial visualization of the aortic arch by 3D TEE was incomplete because of the relatively narrow 90-degree image sector. However, in other segments 3D image quality by 3D TEE was superior to 3D LTEE and 3D IVUS. Because of the thin catheter, patient discomfort (p < 0.0001) and examination time (p = 0.015) were significantly less for 3D LTEE compared with 3D TEE. 3D LTEE is a promising new technique for 3D imaging of the thoracic aorta and detection of aortic disease with improved spatial visualization and reduced patient discomfort compared with 3D TEE and 3D IVUS.

Aortic Dissection↗