Interactive MR imaging and tracking of catheters with multiple tuned fiducial markers.

Purpose: The lack of magnetic resonance (MR) safe catheters and guide wires remains an important obstacle to widespread clinical use of MR-guided endovascular procedures. The authors looked at the feasibility of using multiple tuned fiducial markers (TFM) and novel imaging sequences to track catheters reliably under MR and to evaluate the safety of such markers in terms of heating.

Materials And Methods: The visualization and tracking of a catheter with six quadrature tuned fiducial coils was carried out in a special designed in-vitro setup within a 1.

Esophageal cancer staging with endoscopic MR imaging: pilot study.

The authors defined esophageal anatomy and evaluated esophageal cancer staging in a pilot group by comparing endoscopic magnetic resonance (MR) imaging results with pathologic and endoscopic ultrasonographic (US) results when available. A porcine esophagus, one volunteer, and 23 patients suspected of having esophageal cancer were imaged at 0.5 T.

An inductively-coupled, detachable receiver coil system for use with magnetic resonance compatible endoscopes.

Purpose: To construct an inductively-coupled receiver coil system for use with a magnetic resonance (MR) compatible endoscope, and to evaluate its use in a pilot group of patients with esophageal cancer.

Materials And Methods: An inductively-coupled coil system, comprising a saddle geometry cylindrical receiver coil fitted as a sleeve around the endoscope tip and a pick-up coil housed within a channel of an MR-compatible endoscope, was designed and developed for use at 0.5 T.

Female urinary genuine stress incontinence: anatomic considerations at MR imaging of the paravaginal fascia and urethra initial observations.

Purpose: To compare, on high-spatial-resolution magnetic resonance (MR) images, the presence and distribution of the paravaginal fascia in continent women and in those with genuine stress incontinence (GSI) to establish its role in the pathophysiology of GSI.

Materials And Methods: Eleven continent reference subjects and 10 GSI patients underwent MR imaging with a specifically designed endovaginal receiver coil. A urinary continence questionnaire and urogynecologic clinical examination had been completed.

Developing an information pack for the Asian carers of people with autism spectrum disorders.

An investigation is described which forms the basis for the development of an information package for the Asian carers of people with autism spectrum disorders (ASD) and learning disabilities. The results of semi-structured interviews and planning for questionnaires with three different linguistic Asian groups (Urdu, Gujarati and Bengali) are presented. The views, attitudes and awareness of autism, knowledge of support services and perceived priority of needs are analysed for the three different communities.

Microstructured magnetic materials for RF flux guides in magnetic resonance imaging.

Magnetic resonance imaging and spectroscopy systems use coils, either singly or as arrays, to intercept radio-frequency (RF) magnetic flux from regions of interest, often deep within the body. Here, we show that a new magnetic material offers novel possibilities for guiding RF flux to the receiver coil, permitting a clear image to be obtained where none might otherwise be detectable. The new material contains microstructure designed according to concepts taken from the field of photonic band gap materials.

Magnetic resonance imaging of the primary site in stage I cervical carcinoma: A comparison of endovaginal coil with external phased array coil techniques at 0.5T.

Objective: To compare endovaginal with pelvic phased array coil magnetic resonance imaging (MRI) in detection of Stage I cervical carcinoma by correlating the findings with histopathology.

Patients And Methods: Forty consecutive patients with Stage I cervical carcinoma confirmed histologically were studied using an endovaginal coil alone immediately followed by a pelvic phased array coil. T1-W transverse and T2-W FSE sagittal images made with each coil were analyzed independently by two radiologists noting the presence and size of a mass within the cervix and any parametrial extension or involvement of adjacent organs.

Design and use of internal receiver coils for magnetic resonance imaging.

This review describes coils for MRI that are inserted into the body through natural orifices. It covers the design and implementation of small internal receiver coils for use in the pelvis and gastrointestinal tract. Normal anatomy delineated by the high resolution obtained by using these coils and the appearances in a number of disease states for each clinical application are described.

High-resolution magnetic resonance imaging of the anal sphincter using a dedicated endoanal receiver coil.

The use of a surface coil in MR imaging improves signal-to-noise ratio of adjacent tissues of interest. We therefore devised an endoanal receiver coil for imaging the anal sphincter. The probe is solid and re-usable: it comprises a saddle geometry receiver with integral tuning, matching and decoupling.

Integrated and interactive position tracking and imaging of interventional tools and internal devices using small fiducial receiver coils.

A method is described of tracking the position of a rigid device within an MR scanner and imaging with the image slice position determined by the current position of the device, such that the manipulation of the device can be achieved in a robust, interactive manner. The device can be either external or internal to the patient. The position tracking is performed by means of two or three small MR receiver coils attached to individual receiver channels.

Fecal incontinence in scleroderma: assessment of the anal sphincter with thin-section endoanal MR imaging.

Purpose: To compare the magnetic resonance (MR) imaging appearance of the anal sphincter in patients with fecal incontinence and scleroderma with that in patients with fecal incontinence alone, scleroderma alone, or neither.

Materials And Methods: The study population comprised 14 patients with fecal incontinence and scleroderma, four with scleroderma alone, 13 with incontinence alone, and six with neither. T1- and T2-weighted spin-echo, magnetization transfer contrast-weighted, and dynamic gadolinium-enhanced images were obtained and analyzed for the integrity, thickness, and length of sphincter components.

MRI of fistula-in-ano: a comparison of endoanal coil with external phased array coil techniques.

Purpose: The objective of our study was to compare MRI of fistulas-in-ano using an endoanal coil with that using a pelvic phased array coil and to assess the value of a combined approach by correlating the findings with those at surgery.

Method: Twenty consecutive patients with clinical suspicion of perianal sepsis were studied using an endoanal coil immediately followed by a phased array coil. T1 weighted and STIR images in transverse and coronal planes were made with each coil and analysed by noting the presence and site of a collection and primary track, the position of any internal opening, and subcutaneous or supralevator extension.

High-resolution MR imaging of the anal sphincter in children: a pilot study using endoanal receiver coils.

Objective: The purpose of this study was to obtain high-resolution MR images of the various components of the anal sphincter complex in children who have anorectal disorders. We therefore used dedicated endoanal receiver coils for MR imaging.

Conclusion: Our pilot study suggested that MR imaging that uses a dedicated endoanal coil may have considerable diagnostic potential in children who have anorectal disorders.

MR imaging of the anal sphincter in multiparous women using an endoanal coil: correlation with in vitro anatomy and appearances in fecal incontinence.

Objective: The aim of this study was to correlate the components of the normal female anal sphincter seen on high-resolution MR images with the in vitro anatomy and to describe the change in appearances of these components in multiparous women with fecal incontinence.

Subjects And Methods: Ten asymptomatic female volunteers (32-72 years old; mean, 54 years old) and 22 women with fecal incontinence were studied. In six patients (26-68 years old; mean, 49 years old) fecal incontinence began immediately after childbirth; in the remaining 16 patients (45-77 years old; mean, 58 years old) fecal incontinence developed 15- 30 years after childbirth.

A solid reusable endorectal receiver coil for magnetic resonance imaging of the prostate: design, use, and comparison with an inflatable endorectal coil.

We have designed a solid endorectal receiver coil for MRI of the prostate. The coil provided an improved signal-to-noise ratio up to 5 cm from its surface when compared with a standard pelvic phased array. This preliminary report describes 16 patients who were imaged using this coil, seven of whom had been examined previously with a balloon-design endorectal coil.

High resolution magnetic resonance imaging of the anal sphincter using a dedicated endoanal coil. Comparison of magnetic resonance imaging with surgical findings.

Purpose: To obtain high resolution images of the anal sphincter and adjacent anorectum using an endoanal coil in patients with sepsis, trauma, and low rectal tumors and to compare imaging appearances with findings at time of surgery.

Patients And Methods: A cylindrical saddle geometry coil (diameter, 9 mm; length, 75 mm) was used to examine 30 patients (mean age, 53.6 years).

High-resolution MR imaging of stage I cervical neoplasia with a dedicated transvaginal coil: MR features and correlation of imaging and pathologic findings.

Objective: The purposes of this study were to assess the appearance of stage 1 neoplasia of the cervix by high-resolution MR imaging with an enveloping transvaginal receiver coil and to correlate the imaging findings with the pathologic findings.

Subjects And Methods: Fifteen patients (25-73 years old; mean, 40 years old) with clinical stage I disease were examined with a 37-mm-diameter ring-design solenoid receiver coil placed around the cervix. Axial 2.

Endoscopic laser ablation of the prostate: MR appearances during and after treatment and their relation to clinical outcome.

Objective: Endoscopic laser ablation is a new treatment for benign prostatic hypertrophy. The objectives of this study were to determine the appearances of the prostate on MR images obtained during, 1 week after, and 3 months after this procedure and to determine if a correlation exists between the MR findings and the clinical outcome. Such appearances could then be used to guide the application of laser energy during the procedure in order to optimize the clinical result.

Magnetic resonance imaging of the anal sphincter using an internal coil.

A surface coil placed within the anal canal was used to image the anal sphincter and determine normal anatomy and contrast enhancement patterns as well as appearances in disease. Sixteen normal volunteers and 24 patients were examined. Imaging was performed on a 0.

The uterine cervix on in vitro and in vivo MR images: a study of zonal anatomy and vascularity using an enveloping cervical coil.

Objective: The purpose of this study was to characterize the normal zonal anatomy and vascularity of the cervix on in vivo and in vitro MR images obtained with a receiver coil surrounding the cervix. These appearances provide a normal data base from which to interpret subtle changes in early neoplasia.

Subjects And Methods: Thirteen women of reproductive age with clinically and cytologically normal cervices were imaged with a ring-design solenoid receiver coil that was placed intravaginally and enveloped the cervix.

Magnetic resonance imaging of the uterine cervix using an intravaginal coil.

Cylindrical receiver coils designed for intravaginal use were utilized to image the uterine cervix. Good quality images of the cervix, vaginal wall, and parametrium were obtained and patient tolerance of the procedure was good.

Use of high temperature superconductor in a receiver coil for magnetic resonance imaging.

A planar YBa2Cu3Ox (YBCO) coil has been used as a pick-up coil in a nuclear magnetic resonance imager. It was found that the quality factor (Q) of the YBCO coil was greater than its copper counterpart by approaching 50% even in a field of 0.15 T.

Investigation of a whole-body receiver coil operating at liquid nitrogen temperatures.

This communication describes the design and application of a receiver coil operating at liquid nitrogen temperature and intended as a surface coil in a whole-body imager. Its particular application is seen as the external receiver for parasitic internal or implanted detectors.