A physics-based coordinate transformation for 3-D image matching.

Many image matching schemes are based on mapping coordinate locations, such as the locations of landmarks, in one image to corresponding locations in a second image. A new approach to this mapping (coordinate transformation), called the elastic body spline (EBS), is described. The spline is based on a physical model of a homogeneous, isotropic three-dimensional (3-D) elastic body.

Detection with MR imaging of residual tumor in the breast soon after surgery.

Objective: Difficulties in the preoperative assessment of tumor size and extent result in a positive pathologic margin in up to 70% of patients undergoing breast conservation surgery. Although positive margins usually require reexcision, the location and extent of surgery required are often difficult to establish by current imaging techniques. We investigated the accuracy of three-dimensional rotating delivery of excitation off resonance (3D RODEO) MR imaging of the breast in revealing the presence and extent of residual tumor within the breast soon after surgery.

MR imaging in the management before surgery of lobular carcinoma of the breast: correlation with pathology.

Objective: Our objective was to investigate the use of MR imaging in preoperative staging and characterization of lobular carcinoma.

Materials And Methods: MR imaging studies and mammographic studies in 20 patients with infiltrating lobular carcinoma were evaluated and correlated with pathology findings on serially sectioned tissue. The MR images and mammograms were reviewed retrospectively by three independent examiners unaware of the clinical, imaging, and pathology findings.

Three-dimensional RODEO breast MR imaging of lesions containing ductal carcinoma in situ.

Purpose: To assess whether rotating delivery of excitation off resonance (RODEO) breast magnetic resonance (MR) imaging can help detect ductal carcinoma in situ (DCIS) lesions, determine tumor extent, and differentiate pure DCIS from DCIS with an invasive component.

Materials And Methods: Twenty-two patients with DCIS lesions were evaluated with three-dimensional RODEO MR imaging. Nineteen patients had available mammograms for review.

Silicone-suppressed 3D MRI of the breast using rotating delivery of off-resonance excitation.

Objective: A new silicone-suppressed MR technique was developed, and its efficacy in identifying free silicone and differentiating it from other breast tissues was investigated.

Materials And Methods: Silicone-suppressed MRI was performed using the RODEO (rotating delivery of excitation off-resonance) pulse sequence, which selectively eliminated signal from the narrow range of (CH3)4Si resonance. Ninety breasts in 61 patients were evaluated with both a fat-suppressed 3D MR sequence and a silicone-suppressed 3D MR sequence.

MR imaging of the breast: current status and future potential.

Current and potential roles for MR imaging in the management of breast disorders are reviewed along with the specific technical requirements for each application. Major topics include (1) evaluating breasts before biopsy to reduce the number of surgical biopsies for benign lesions, (2) staging of breast carcinoma in breast conservation candidates, (3) evaluating breasts with inconclusive conventional imaging, (4) coordination of minimally invasive surgery, and (5) evaluating silicone implant integrity.

Staging of breast cancer with MR imaging.

The vastly improved sensitivity of new MR methods can be used to define disease within the breast that cannot be seen with conventional breast imaging methods. Breast MR imaging is expected to have a significant role for the staging of breast cancer in breast conservation candidates. Ultimately, breast MR will be integrated with interstitial laser photocoagulation as a treatment method for breast cancer.

MR imaging of the breast with rotating delivery of excitation off resonance: clinical experience with pathologic correlation.

An investigative study was undertaken to determine the potential for a new magnetic resonance (MR) imaging technique, RODEO (rotating delivery of excitation off resonance), for use as a diagnostic imaging tool for the breast. The RODEO technique provides fat suppression with T1 weighting and is ideal for gadolinium-enhanced breast imaging. It is a short repetition time, steady-state sequence for high-resolution three-dimensional acquisitions and provides a clinically efficient imaging time of approximately 5 minutes for 128 sections.

Fat-suppressed three-dimensional MR imaging of the breast.

Rotating delivery of excitation off-resonance (RODEO) is a new magnetic resonance (MR) imaging pulse sequence that uses a jump return sine excitation on fat resonance to produce fat-suppressed, T1-weighted images. New three-dimensional MR imaging techniques were used to examine 57 women with abnormalities suspicious for breast cancer. MR imaging findings were compared with those of mammography in all cases and with those of other imaging techniques when appropriate.

MR imaging of the breast.

The current strategy for breast cancer treatment involves early detection of the neoplasm before it has metastasized outside the breast, and surgical treatment of the lesion that minimizes deformity. Conventional methods of diagnostic imaging of the breast, including mammography, sonography, and galactography, do not adequately address clinical needs with regard to lesion characterization and staging. Magnetic resonance (MR) imaging has been proposed as a modality that may address these needs.

Magnetic resonance angiography. Application to the peripheral circulation.

Magnetic resonance angiography (MRA) for application in the musculoskeletal system is progressing at a rapid pace. The clinical role of this new technique is still being developed, although a number of uses have already become well recognized, and MRA is diffusing into clinical practice. This article describes the basic fundamentals of MRA as it applies to the peripheral circulation and to the evaluation of potential clinical procedures.

Magnetic resonance imaging of the breast.

The diagnosis and treatment of breast cancer is dependent upon accurate depiction of the disease by diagnostic imaging. In a number of clinical situations, conventional breast imaging does not adequately address these diagnostic needs. New magnetic resonance imaging (MRI) methods developed specifically for breast diagnosis may provide the additional capability needed to fill the gap between clinical needs and the information obtained by conventional breast imaging methods.

Magnetization transfer contrast in fat-suppressed steady-state three-dimensional MR images.

We demonstrate that magnetization transfer contrast can be used to improve the diagnostic utility of fat-suppressed steady-state three-dimensional gradient-recalled images. Fat suppression is achieved using a "jump-return" pair of contiguous shaped pulses. No time interval exists between the pulses, and no RF echo is generated.

Three-dimensional gadolinium-enhanced MR imaging of the breast: pulse sequence with fat suppression and magnetization transfer contrast. Work in progress.

A pulse sequence with magnetization transfer contrast and fat suppression was used in three-dimensional magnetic resonance imaging of the breast. Two healthy volunteers, one person with silicone implants, and 12 patients with clinical and/or mammographic findings suspicious for malignancy were evaluated prior to and following infusion of gadopentetate dimeglumine. Imaging time was approximately 7 minutes for each set of data (128 sections).

In vivo proton magnetic resonance spectroscopy studies of human brain.

In vivo localized proton magnetic resonance spectroscopy (MRS) studies of brain were performed on eighteen normal subjects using the stimulated echo (STE) sequence. The absolute concentrations and proton relaxation times of N-acetyl aspartate (NAA), total creatine (Cr) and choline (Cho) were estimated. The MRS data was quantitatively analyzed for repeatability and intersubject variability.

One-dimensional spectroscopic imaging with stimulated echoes: phantom and human leg studies.

One-dimensional phase encoding was incorporated in the stimulated echo single voxel localization sequence for in vivo proton spectroscopic studies. Phantom studies were performed to assess the effect of the number of phase encoding steps on the spectral contamination from the adjacent volumes. Both water suppressed and unsuppressed spectra were obtained in reasonable acquisition times from various regions in the human leg with a spatial resolution of around 1.

New method for fast MR imaging of the knee.

Thirty-five patients with suspected internal derangements of the knee were examined with conventional two-dimensional (2D) spin-echo magnetic resonance (MR) imaging techniques and a new rapid three-dimensional (3D) method called 3D FASTER (field echo acquisition with a short repetition time and echo reduction). A 9-minute 3D FASTER data acquisition achieves nearly isotropic voxels for the calculation of any desired image plane without a significant loss in image quality. Image contrast is optimized for visualization of knee anatomy in a single sequence.

Integrated MR imaging and spectroscopy with chemical shift imaging of P-31 at 1.5 T: initial clinical experience.

A section-selective three-dimensional phosphorus-31 chemical shift imaging (CSI) experiment was evaluated as the spatial localization method for spectroscopy in an integrated clinical magnetic resonance (MR) imaging and spectroscopy examination. The results of a CSI experiment can be displayed as either spectra related to specific voxels or "metabolite maps," in which the relative concentration of a given metabolite is displayed as an overlay of the MR image. This method was applied to the study of a soft-tissue mass and to a meningioma.

In vivo localized proton spectroscopic studies of human gastrocnemius muscle.

In vivo proton magnetic resonance spectroscopy studies of gastrocnemius muscle were performed in six normal volunteers. Both spatially resolved spectroscopy (SPARS) and stimulated echo acquisition mode (STEAM) sequences were used for volume localization. A number of water suppression sequences have been combined with these localization schemes.

Human in vivo phosphate metabolite imaging with 31P NMR.

Phosphorus (31P) spectroscopic images showing the distribution of high-energy phosphate metabolites in the human brain have been obtained at 1.5 T in scan times of 8.5 to 34 min at 27 and 64 cm3 spatial resolution using pulsed phase-encoding gradient magnetic fields and three-dimensional Fourier transform (3DFT) techniques.