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Akira Fujikawa

Publications and source records attributed to Akira Fujikawa.

16 recordsLinked to original sources
PubMed2006

Value of diffusion-weighted MR imaging in acute cervical cord injury as a predictor of outcome.

INTRODUCTION: We analyzed the findings of diffusion-weighted (DW) imaging using the single-shot fast spin-echo sequence in acute cervical cord injury and evaluated the usefulness of this method for predicting the prognosis. METHODS: Our patient group comprised 14 patients examined 2 h to 3 days after injury. First, we visually evaluated the DW imaging findings in all patients. Apparent diffusion coefficient (ADC) maps were also assessed in 13 patients. Second, we assessed follow-up magnetic resonance (MR) examinations obtained in six patients whose DW images showed hyperintensity. Third, we reviewed the functional outcome at discharge. RESULTS: The lesions showed hyperintensity in ten patients, and no abnormal signal was noted in the remaining four patients. The ADC maps showed restricted diffusion in all patients with hyperintensity on DW imaging except in one patient for whom the ADC map was unavailable. Repeated MR examinations obtained in six of the ten patients showed either myelomalacia or exacerbation. Seven of the ten patients (70%) required assistance and the other three were independent. Among the four patients without hyperintensity on DW imaging, three (75%) were independent and only one required assistance. CONCLUSION: DW imaging in acute cervical cord injury often reveals restricted diffusion. This finding may predict an unfavorable functional prognosis.

Adolescent↗
PubMed2006

Evidence that bovine forebrain embryonic zinc finger-like gene influences immune response associated with mastitis resistance.

Mastitis, a mammary gland inflammation in response to bacterial infection, is a major problem in the dairy industry. We found that cows susceptible to mastitis have a three-base insertion in a glycine-coding stretch of the gene for forebrain embryonic zinc finger-like (FEZL), a transcription factor with a role in neuronal development. Mastitis induces FEZL expression in mammary glands, and induced FEZL promotes expression of the axon-attracting molecule semaphorin 5A (SEMA5A) through a GCAG sequence. FEZL also induces SEMA5A expression in susceptible cattle but at a lower level than in resistant cattle. Enhanced SEMA5A induces expression of at least nine genes related to the host's immune response, including TNF-alpha and IL-8. We propose that susceptibility to mastitis results from an impaired immune response due to the lower transcription activity of susceptible FEZL. Our results provide an avenue to select for genetic improvement of resistance to mastitis and suggest that the FEZL-SEMA5A pathway might control both neuronal development and innate immunity.

Adaptor Proteins, Vesicular Transport↗
PubMed2006

Comparison of MRI sequences to detect ventriculitis.

OBJECTIVE: The ability of different MRI sequences to depict characteristic findings suggestive of ventriculitis was compared. CONCLUSION: The study comprised 20 brain MRI studies in 13 patients who had a final diagnosis of ventriculitis. Both diffusion-weighted imaging and FLAIR imaging were equally and highly sensitive for detecting intraventricular debris and pus--the most common MRI finding suggestive of ventriculitis. FLAIR imaging was superior to contrast-enhanced T1-weighted imaging for depicting ventricular wall abnormalities--a less common finding that also is suggestive of ventriculitis.

Adolescent↗
PubMed2005

Diffusion tractography of the cervical spinal cord by using parallel imaging.

We applied a single-shot echo-planar axial diffusion tensor sequence with parallel imaging for tractography of the cervical cord. Placing a large region of interest on a reconstructed sagittal image, the cervical cord was depicted as a tract bundle showing color-encoded cephalocaudally. By setting one region of interest in the cerebral peduncle and another in the entire cord on source images, tracts on each side were visualized. This method is promising for tractography of the cervical cord.

Adult↗
PubMed2005

Postoperative assessment of extracranial-intracranial bypass by time-resolved 3D contrast-enhanced MR angiography using parallel imaging.

PURPOSE: Our goals were to assess image quality of time-resolved contrast-enhanced MR angiography (CE MRA), by using 3D data acquisition along with a parallel imaging technique that can improve temporal resolution and to compare this technique with 3D-time-of-flight (TOF) MRA in the postoperative assessment of extracranial (EC)-intracranial (IC) bypass surgery. METHODS: On a 1.5T imaging system, we performed CE MRA by using a 3D fast field-echo sequence in combination with a parallel imaging technique, to obtain images in the coronal plane centered at the postoperative site. Our patient group comprised 17 patients, including 13 after superficial temporal artery-middle cerebral artery (MCA) anastomosis, 3 after external carotid artery-MCA anastomosis, and one after extracranial vertebral artery-posterior cerebral artery anastomosis. Visualization of the anastomosis and the distal flow on the CE-MRA images was assessed comparatively with that on 3D-TOF MR angiograms obtained at the same time. In 6 patients, we also compared the efficiency of visualization on CE-MRA images with that on conventional angiograms. RESULTS: A temporal resolution of 0.8 s/frame could be achieved with the technique employed. The bypass was better demonstrated postoperatively on CE-MRA images than on 3D-TOF MR angiograms in 13 patients (76%), whereas the 2 methods were equivalent in 4 patients (24%). Good correspondence of results was observed in the 6 patients for whom CE MRA and conventional digital subtraction angiography (DSA) images were compared. CONCLUSION: CE MRA by using the parallel imaging technique can increase image acquisition speed with sufficient image quality. This technique is at least equivalent to 3D-TOF MRA to evaluate the postoperative status of EC-IC bypass.

Adult↗
PubMed2004

Three-dimensional MR digital subtraction angiography using parallel imaging and keyhole data sampling in cerebrovascular diseases: initial experience.

We assessed the feasibility of MR digital subtraction angiography (DSA) using parallel imaging and keyhole data sampling in the diagnosis of cerebrovascular diseases (CVDs) in 11 patients. Their diseases included arterial trunk stenosis/occlusion ( n=4), aneurysm ( n=3), arteriovenous malformation ( n=2), venous angioma ( n=1), and sinus thrombosis ( n=1). The technique depicted not only anatomical features, comparably to MR angiography ( n=10/11), but also hemodynamics such as collateral flow at a temporal resolution of 1.68 s/frame. When compared with conventional angiograms ( n=7), details were missed in four patients (incomplete demonstration of aneurysmal neck in two and poor separation of AVM components in two). Although inferior to conventional angiography, this technique can provide both anatomical and hemodynamic information of CVDs.

Adolescent↗
PubMed2004

Diffusion-weighted MR imaging in acute spinal cord ischemia.

We report diffusion-weighted (DW) MR findings for acute spinal cord ischemia in a 56-year-old patient. MR imaging obtained approximately 3 h after symptom onset demonstrated an area of hyperintensity on DW images, but no conspicuous signal abnormality on T2-weighted images in the conus medullaris. DW imaging of the spinal cord can contribute to the early detection of spinal cord vascular compromise.

Acute Disease↗
PubMed2003

Schwannoma of the trachea; a new resection technique.

Tumors of the trachea are rare, especially schwannoma. We diagnosed a 27-year-old man with schwannoma of the trachea after he was admitted to our hospital with complaints of progressive dyspnea and wheezing. He was treated as having bronchial asthma initially, but his signs and symptoms did not improve with conventional therapy. Flexible fiberscopy revealed the presence of a submucosal tumor in the subglottic area. Tracheal tomography, computed tomography (CT) and magnetic resonance imaging (MRI) revealed the presence of a mass in the trachea that extended from the cricoid cartilage level to the second tracheal ring. After tracheostomy, we removed the tumor from a tracheostoma upwards to the larynx without a laryngofissure, using forceps and scissors usually used for laryngomicrosurgery and endoscopes usually used for sinus surgery. No complications developed during or after the procedure. To our knowledge, this is the first report of the removal of a tracheal schwannoma by this technique.

Adult↗
PubMed2002

MR imaging of meniscal malformations of the knee mimicking displaced bucket-handle tear.

We report two cases of patients with lateral meniscal malformations of the knee that were found incidentally. Magnetic resonance imaging (MRI) of both cases showed a fragment-like meniscus structure located in the intercondylar notch, very similar to the "fragment in the intercondylar notch sign" observed in displaced bucket-handle tear. Arthroscopic examinations revealed a ring-shaped lateral meniscus in one case, and "flipped-over" lateral meniscus in the other. In the latter, a similar lateral meniscal malformation was observed contralaterally at MR arthrography.

Adult↗
PubMed2002

Immediate improvement of a persistent cough after tumor embolization for renal cell carcinoma--a rare manifestation of paraneoplastic syndrome.

We report an interesting case of a patient with renal cell carcinoma who developed a refractory cough, which immediately resolved after tumor embolization. Patient's symptoms including low-grade fever, weight loss, and abnormal laboratory results also improved shortly after subsequent nephrectomy. The clinical manifestations of the patient are most likely representing paraneoplastic syndrome secondary to renal cell carcinoma.

Adult↗
PubMedDate not supplied

Case report: spinal cord infarction demonstrated on diffusion-weighted MR imaging with a single-shot fast spin-echo sequence.

We describe the diffusion-weighted (DW) MR imaging findings in three cases of spinal cord infarction using a recently developed single-shot fast spin-echo (SSFSE) technique. The SSFSE-DW MR images, which were obtained 20 hours, 3 days, and 18 days, respectively, after the ischemic event, demonstrated conspicuous areas of hyperintensity in the affected portions. Follow-up DW MR images, obtained in two of the patients at 17 days and 3 months, respectively, showed persistent decreased apparent diffusion coefficient values. SSFSE-DW imaging of the spinal cord may provide additional information for assessment of ischemic changes.

Aged↗
PubMedDate not supplied

Retained surgical sponge in the thigh: report of the third known case in the limb.

We report a retained surgical sponge (gossypiboma) in the thigh, which mimicked a neoplasm. A 25-year-old man, who had a past history of external fixation for femoral shaft fracture, complained of swelling in the left thigh with pain. A radiograph of the thigh showed periosteal reaction. T1-weighted magnetic resonance (MR) images showed a well-defined mass with heterogenous signal intensity, and T2-weighted images showed tortuous lines of low signal intensity within the mass. Surgical excision revealed a retained gauze sponge within the mass. Histopathological examination revealed foreign body reaction related to the retained gauze sponge. Our case, the third to our knowledge of gossypiboma in a limb, demonstrated characteristic MR imaging findings.

Adult↗