Cylindrical Inversion Pulse for the Reduction of Cardiac Motion Artifacts in Contrast-enhanced Breast MRI.

We proposed a simple technique for reduction of cardiac-related motion artifacts on contrast-enhanced images in the breast by using cylindrical regional-suppression technique (CREST) that can directly suppress the heart signals. The purpose of this study was to select the optimal scan parameters and to evaluate the feasibility in the breast. We demonstrated that the optimized CREST could dramatically reduce the cardiac-related flow artifacts without any penalty to the acquisition time, signal-to-noise ratio and contrast-enhanced lesion-to-parenchyma contrast.

Hyperecho PROPELLER-MRI: Application to rapid high-resolution motion-insensitive T -weighted black-blood imaging of the carotid arterial vessel wall and plaque.

Purpose: To demonstrate the usefulness of hyperecho and PROPELLER (HEP) for carotid arterial vessel wall imaging by using a quantitative comparison with conventional methods. PROPELLER is a motion-insensitive turbo spin-echo (TSE) sequence and has recently been utilized in magnetic resonance (MR) plaque imaging instead of double inversion recovery TSE (DIR-TSE). Wider blade-width, higher k-space density, and an improved blood suppression effect result in better image quality.

Computed tomography osteoabsorptiometry for assessing the density distribution of subchondral bone as a measure of long-term mechanical stress in the "rugby shoulder".

Background: Rugby is a collision sport with a high risk of shoulder injury. Although traumatic anterior shoulder instability is common, the long-term effects of rugby and joint instability on the shoulder have not been described; thus, this study assessed the effects of rugby itself, and joint instability, on the glenoid cavity.

Materials And Methods: Both sides of the shoulders from 25 rugby players and 17 control patients with unilateral shoulder instability were prospectively evaluated by means of computed tomography osteoabsorptiometry, which represents the distribution of mineralization in subchondral bone plate (DMSB) as a marker of the long-term loading history of a joint.

Mechanical environment of the supraspinatus tendon: three-dimensional finite element model analysis.

Background: We analyzed the mechanical environment of the supraspinatus tendon using a three-dimensional finite element model with the software programs MENTAT and MARC.

Methods: The supraspinatus tendon that attaches to the superior facet was extracted and modeled. The geometric shape of the humeral head was determined from computed tomography images, and the shape of the supraspinatus tendon was determined from magnetic resonance images of the shoulder at 0 degrees of abduction in a healthy 27-year-old man.

Comparison of the MR findings on indirect MR arthrography in patients with rotator cuff tears with and without symptoms.

Purpose: To compare indirect magnetic resonance (MR) arthrography findings in patients with rotator cuff tears with and without symptoms.

Materials And Methods: Indirect MR arthrography results of 15 asymptomatic and 23 symptomatic rotator cuff tears were retrospectively reviewed, comparing the type and size of tears and amount of subacrominal-subdeltoid bursal fluid.

Results: There were 14 partial-thickness tears and one full-thickness tear in the asymptomatic group, with 4 small and 11 medium tears.

Visualization of lymphatic basin from the tumor using magnetic resonance lymphography with superparamagnetic iron oxide in patients with thoracic esophageal cancer.

Objective: To evaluate magnetic resonance (MR) lymphography with submucosal injection of superparamagnetic iron oxide (SPIO) for imaging lymphatic pathways from thoracic esophageal cancer.

Methods: In 24 patients with esophageal cancer, SPIO was injected into the submucosal layer of the peritumoral region endoscopically and MR lymphography was conducted. In study 1, fast spoiled gradient-recalled acquisition using a steady-state (FSPGR) sequence was performed from the neck to the upper abdomen before and at 20, 40, and 60 minutes after injection in 10 patients.

Evaluating benign and malignant musculoskeletal lesions with radionuclide angiography and SPECT using Tc-99m MIBI.

Purpose: The purpose of this study was to evaluate the use of radionuclide angiography and single photon emission computed tomography (SPECT) using Tc-99m hexakis-2-methoxyisobutylisonitrile (Tc-99m MIBI) for analyzing musculoskeletal lesions.

Materials And Methods: Radionuclide angiography and SPECT using Tc-99m MIBI were performed in 36 patients with various soft tissue and bone pathologies (18 benign and 18 malignant lesions). The ratio of the counts of the lesion to that of the contralateral normal area was calculated from the region of interest drawn on the MIBI scan.

Superior mediastinal and neck lymphatic mapping in mid- and lower-thoracic esophageal cancer as defined by ferumoxides-enhanced magnetic resonance imaging.

Objective: The purpose of this study was to detect lymphatic drainage into the superior mediastinum and neck in thoracic esophageal cancer patients using ferumoxides-enhanced magnetic resonance imaging (MRI), and to have this information assist in determining the appropriate extent of lymphadenectomy.

Methods: Nine male patients with T2-T3 mid- and lower-thoracic esophageal cancer with lymph node metastasis were examined. The day before surgery, ferumoxides was endoscopically injected into the submucosal layer of the peritumoral lesion.

Mechanical environment of the supraspinatus tendon: a two-dimensional finite element model analysis.

We performed 2-dimensional finite element model analysis to estimate the mechanical environment of the supraspinatus tendon. The geometric shape of the finite element model was determined by magnetic resonance imaging of a normal human shoulder obtained at 0 degrees, 30 degrees, and 60 degrees of abduction, whereas the histologic location of noncalcified and calcified fibrocartilage was determined from a cadaveric specimen. The supraspinatus tendon was pulled proximally with the force of 10 N at 0 degrees, 53 N at 30 degrees, and 115 N at 60 degrees of abduction.

Capsular elongation in shoulders with recurrent anterior dislocation. Quantitative assessment with magnetic resonance arthrography.

Background: Elongation of the shoulder capsule is often noticed on arthrograms or during surgery in shoulders of patients who have experienced recurrent anterior dislocations.

Hypothesis: We can quantify the elongation of the capsule in shoulders with recurrent anterior dislocations by using magnetic resonance arthrography.

Study Design: Retrospective review of prospectively collected data.

[Sentinel lymph node after intramammary injection of superparamagnetic iron oxide].

The purpose of this study was to evaluate enhancement (signal loss) of the axillary lymph nodes on MR lymphography after intramammary injection of superparamagnetic iron oxide (Ferumoxides) for detection of the sentinel lymph node. MR lymphography was performed in a total of 11 patients with breast cancer without palpable axillary lymph node swelling before operation. Coronal and axial images were obtained before and after intramammary injection of 1.

[Findings of the subcoracoid bursa on MR arthrography and their clinical significance].

We studied visualization of the subcoracoid bursa by conducting a retrospective analysis of the MR arthrograms of 101 shoulders with surgical confirmation. MR arthrography showed the subcoracoid bursa in 28 shoulders, among which the bursa was revealed by inadvertent direct injection of contrast material into the bursa in 10 shoulders. Of the remaining 18 shoulders, 16 shoulders had rotator cuff tears, one had shoulder instability, and one had dislocation of the long head of the biceps tendon.

Comparison of multishot echo-planar fluid-attenuated inversion-recovery imaging with fast spin-echo fluid-attenuated inversion-recovery and T2-weighted imaging in depiction of white matter lesions.

Purpose: To compare a multishot echo-planar fluid-attenuated inversion-recovery (EPI-FLAIR) sequence with fast spin-echo FLAIR (F-FLAIR) and fast spin-echo T2-weighted (FSE-T2W) sequences in depiction of white matter lesions.

Methods: Thirty-five patients with various white matter lesions were included in this prospective study. Two independent readers for lesion detection (lesion size, >2 mm) compared sequences quantitatively.

Decreased interposition after closed reduction in the hip joint: a case of developmental dislocation of the hip observed by MRI.

A 4-month-old Japanese girl with a developmental dislocation of the right hip was treated with manual reduction under general anesthesia followed by cast immobilization. Serial magnetic resonance imaging (MRI) revealed that a large interposition of fat tissue in the acetabulum, observed immediately after cast immobilization, became remarkably small in size as the congruity improved after 3 weeks. These MRI findings demonstrate the mechanism of a "squeezing phenomenon" after reduction of the hip.

Multi-shot echo-planar Flair imaging of brain tumors: comparison of spin-echo T1-weighted, fast spin-echo T2-weighted, and fast spin-echo Flair imaging.

Multi-shot echo-planar fluid-attenuated inversion-recovery (EPI-Flair) was compared with spin-echo T1-weighted (SE-T1W), fast SE T2-weighted (FSE-T2W), and fast Flair (F-Flair) in imaging brain tumors. In 32 patients with various different brain tumors, three reviewers independently evaluated image quality. Two reviewers evaluated the image quality of precontrast EPI-Flair to be significantly better than that of precontrast SE-T1W.

Position of immobilization after dislocation of the glenohumeral joint. A study with use of magnetic resonance imaging.

Background: Glenohumeral dislocations often recur, probably because a Bankart lesion does not heal sufficiently during the period of immobilization. Using magnetic resonance imaging, we assessed the position of the Bankart lesion, with the arm in internal and external rotation, in shoulders that had had a dislocation.

Methods: Coaptation of a Bankart lesion was examined with use of magnetic resonance imaging, with the arm held at the side of the trunk and positioned first in internal rotation (mean, 29 degrees) and then in external rotation (mean, 35 degrees), in nineteen shoulders.

Germ cell tumors of the central nervous system originating from non-pineal regions: CT and MR features.

CT and MR findings were retrospectively reviewed in 12 patients with germ cell tumors originating from the non-pineal regions. Cystic or necrotic components were seen in 6 patients. Of 4 germinomas, 2 showed mixed density on the CT.

Large bursa formation associated with osteochondroma of the scapula: a case report and review of the literature.

Bursitis or large bursa formation associated with osteochondroma has rarely been reported. A 33-year-old male presented with upper back pain, a rapidly developing mass beside the lateral border of his right scapula and snapping elicited by movement of the scapula. Plain radiograms and CT revealed osteochondroma on the ventral surface of the scapula without any unmineralized component and a huge cystic lesion around the osteochondroma.

Comparison of MR imaging with CT in depiction of tumour extension into the pterygopalatine fossa.

The computed tomography (CT) and magnetic resonance imaging (MRI) results of 30 consecutive patients with tumours in the skull base, and who had abnormalities of the pterygopalatine fossa (PPF) on CT or MRI, were retrospectively compared with respect to visualization of tumour infiltration into the PPF. CT did not depict the abnormalities in the PPF in five patients (17%), while unenhanced T1-weighted MR images depicted tumour infiltration in all patients. Obliteration of PPF fat was better visualized on CT than T2-weighted and proton density weighted MR images, as were bony abnormalities.

Comparison of MR imaging and CT in discriminating tumor infiltration of bone and bone marrow in the skull base.

We compared MR imaging with CT in revealing tumor infiltration of bone and bone marrow in the skull base of 54 patients. MR imaging had no advantages over when tumor involved the anterior compartment. However, precontrast T1-weighted MR images were more efficient than CT in 37.

[Central nervous system involvement of leukemia and systemic lymphoma in children: CT and MR findings].

The purpose of this paper is to retrospectively evaluate CT and MR findings of central nervous system (CNS) involvement of leukemia and systemic lymphoma in children. Over a 12-year period, sixty-five patients with leukemia and fifteen patients with systemic lymphoma underwent cerebral CT and/or MR imaging. Nine patients (11.