Fast Imaging Employing Steady-state Acquisition Research Articles

Trigeminal neuralgia: Assessment of neurovascular decompression by 3D fast imaging employing steady-state acquisition and 3D time of flight multiple overlapping thin slab acquisition magnetic resonance imaging

Background:Trigeminal neuralgia is most commonly caused by vascular compression at the trigeminal nerve (TN) root entry zone. Microvascular decompression (MVD) has been established as a useful treatment. Outcome depends on the correct identification of the compression site and its adequate decompression at surgery. Preoperative identification of neurovascular compression might predict which patients will benefit from MVD. Management of persistent or recurrent trigeminal neuralgia after an MVD is a baffling problem for neurosurgeons. An accurate neuroradiological evaluation of the TN padding following a failed MVD might help identify the underlying cause and plan further treatment.Case description:A 68-year-old female presented with a right-sided trigeminal neuralgia (V3) refractory to medical therapy. A high-resolution three-dimensional magnetic resonance imaging (3D MRI) study included fast imaging employing steady-state acquisition (FIESTA) and time of flight multiple overlapping thin slab acquisition (TOF MOTSA) sequences to evaluate the neurovascular anatomy in the cerebellopontine angle. An unambiguous compression of the right TN at the rostral-medial site by the superior cerebellar artery (SCA) was identified. The SCA loop compressing the TN was identical in location and configuration to that predicted in the preoperative study. After the MVD, the patient was relieved from her pain and a postoperative high-resolution 3D MRI study confirmed the appropriate placement of the Teflon implant between the TN and SCA.Conclusion:To our knowledge, this is the first report that characterizes the proper TN padding by high-resolution 3D MRI after trigeminal MVD. The present case also emphasizes the importance of performing a 3D MRI in patients with trigeminal neuralgia to anticipate the surgeon's view and predict the outcome after MVD.

聴神経腫瘍手術の術前検討に必要な顔面神経の検出

Objective: To preoperatively predict the facial nerve location more accurately in patients undergoing surgery for large vestibular schwannoma. Method: First, three-dimensional (3D) models of arteries and veins around the tumor are combined with contrast-enhanced (CE) fast imaging employing steady-state acquisition (FIESTA) to detect the nerve more accurately. Second, a 3D model of the nerve is constructed to investigate its three-dimensional location. Then, the nerve, which keeps continuity to internal auditory canal or brain stem and runs in the direction of brain stem to internal auditory canal, is recognized as the facial nerve. Result: Using this method, the facial nerve was detected in seven of 10 patients. Conclusion: In large vestibular schwannoma, this method can detect the facial nerve more accurately than existing reports.

A Case of Posterior Cerebral Artery Dissection Presenting with Migraine-Like Headache and Visual Field Defect: Usefulness of Fast Imaging Employing Steady-State Acquisition (FIESTA) for Diagnosis

We report a 34-year-old woman with sudden onset of unilateral migraine-like headache and right homonymous hemianopsia. Fast imaging employing steady-state acquisition (FIESTA) of the posterior cerebral artery captured an intimal flap and a pseudolumen, leading to a diagnosis of posterior cerebral artery dissection. This case was considered a spontaneous posterior cerebral artery dissection causing migraine-like headache. The treatment of migraine-like headache hinges on correct diagnosis. In this case, FIESTA was very useful in diagnosing an intracranial artery dissection.

SU‐E‐T‐281: Quantitative Evaluation of the MRI Image Distortion in Gamma Knife Radiosurgery

Purpose: To quantify the spatial distortion of the MRI images in the Elekta Leksell GammaPlan version 9 planning system using different registration methods. Methods: The RPC SRS phantom was imaged using a GE Signa HDxt 1.5Tesla MR scanner and a GE LightSpeed VCT CT scanner. Both the T1 weighted MRI images and the fast imaging employing steady state acquisition (FIESTA) MRI images were acquired, along with the axial and helical CT images. The skull shell and the target in the phantom were contoured in all the four series of images acquired. The MRI images were registered in the planning system in three different ways: 1) using the fiduciary marks in the imaging box; 2) using a global co‐registration with FOV just covering skull shell; 3) using a local co‐registration to max 8.5cm FOV at image center. The target positions in all the four series of images were compared using the software tool in the planning system. Results: The target positions as obtained from the helical and the axial CT images agree within 0.1mm. For the registration method the fiduciary marks, the T1 weighted MRI images are shifted from the CT images 0.9mm in the anterior‐posterior direction, and 0.5mm in both the superior‐inferior and the left‐right directions. The corresponding displacements for the FIESTA images are 0.6mm, 0.5mm and 0.5mm respectively. The shifts of the target positions are significantly reduced in the global co‐registration approach, and all less than 0.2mm in the local co‐registration approach. Conclusions: MRI image distortion in GammaPlan version 9 is in the sub‐millimeter range for the central region of the MRI image. The spatial distortion in the FIESTA images is smaller than that in the T1 weighted images. Co‐registration to the central region of images can reduce MRI imaging distortion effect significantly.

Bilateral cerebellopontine angle lipomas

Cerebellopontine angle (CPA) lipomas are extremely rare lesions and usually unilateral. We describe a case of a 36-year-old man with bilateral aural fullness that was discovered to have bilateral CPA lipomas associated with an abnormal hindbrain segmentation appearance. The patient was evaluated with 3.0T magnetic resonance imaging (MRI) system. MRI demonstrated the presence of bilateral CPA masses partially extending into the internal auditory canals. These lesions were hyperintense on both T1- and T2 weighted images. Facial and vestibulo-cochlear nerves together with tortuous vascular structures and fibro-connective septa were identified on T2-weighted 3D Fast Imaging Employing Steady-state Acquisition (FIESTA) sequences as areas of lower intensity coursing through the masses. Gadolinium administration yielded no enhancement. Conservative management was adopted.

Initial experience with combined endoscopic third ventriculostomy and choroid plexus cauterization for post-hemorrhagic hydrocephalus of prematurity: the importance of prepontine cistern status and the predictive value of FIESTA MRI imaging

Post-hemorrhagic hydrocephalus of prematurity (PHHP) is among the most common causes of infant hydrocephalus in developed nations. This population has a high incidence of shunt failure, infection, and slit ventricle syndrome. Although effective for other etiologies of infant hydrocephalus, the efficacy of combined endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC) in PHHP has not been investigated. This pilot study reports the initial experience. Ten patients (four grade III and six grade IV intraventricular hemorrhage) requiring definitive treatment for PHHP underwent ETV/CPC within 6 months of birth. Seven had a prior ventriculo-subgaleal shunt. Mean age at birth was -12.8 weeks, or 25.2 weeks gestation (24-28 weeks), and at surgery was -1.6 weeks (-11 to +11 weeks). Mean weight at surgery was 3.3 (1.0-5.5 kg). Each patient had preoperative magnetic resonance imaging (MRI) with fast imaging employing steady-state acquisition (FIESTA). Four of ten (40%) required no further operations related to hydrocephalus (mean follow-up, 29.7 months). Six required another procedure (five ultimately shunted). Prepontine cistern status correlated with outcome (p = 0.033). Procedures in all infants with unobstructed cisterns were successful but failed in six of seven with cisternal obstruction, with the one success having an alternative lamina terminalis endoscopic third ventriculostomy. Preoperative MRI FIESTA images correlated well with intraoperative assessment of the cistern. Results from this small homogenous cohort suggest cistern status is an important determinant of outcome. FIESTA imaging correlated with endoscopic observation. Preliminary analysis suggests ETV/CPC as an effective treatment for PHHP, but only when the cistern is unscarred. This information should guide patient selection for future study protocols.

MR enterography in the investigation of abdominal pain

IntroductionMagnetic Resonance Enterography (MRE) has an established role in the management of patients with small bowel Crohn's disease1 and has the advantages of diagnosing extra-enteric lesions which may be clinically...

CT and MRI findings of temporal bone anomaly in patients with tinnitus

Objective To study high resolution CT (HRCT) and MRI findings of temporal bone anomaly in patients with tinnitus and identify the optimal examination method in the detection of the anomaly. Methods The HRCT and MRI data were analyzed retrospectively in 1015 patients including 145 patients with pulsatile tinnitus (PT) and 870 patients with nonpulsatile tinnitus (NPT). The positive rates of HRCT and MRI in the identification of temporal bone anomaly were analyzed and the efficiency of various examination methods was compared in revealing the anomaly. Data were tested by Chi-square test analysis. Results Among 1015 patients, anomaly was seen in 767 cases (75.57%). High jugular bulb was found in 414 patients, accounting for 40. 79%. Sigmoid sinus anomaly was detected in 387 patients (38. 13%), while otitis media was found in 148 cases (14. 58%), and low middle cranial fossa in 70 cases (6. 90%). The positive rate of HRCT in the detection of high jugular bulb was 54. 89% (365/665), which was significantly higher than those of other methods (P ＜ 0. 05). The positive rate of enhanced HRCT in showing sigmoid sinus anomaly was 73.68% (56/76), which was significantly higher than those of other methods(P ＜0. 05). Sigmoid sinus anomaly was the most frequent finding in patients with PT, accounting for 66. 21% (96/145). The incidence of sigmoid sinus anomaly was higher in PT than in NPT (291/870,33.45% ;χ2 =56. 537 ,P ＜0. 01). The fast imaging employing steady-state acquisition (FIESTA) sequence was the best examination method in displaying the vessel within the internal auditory canal (42/42,100%).Conclusions High jugular bulb and sigmoid sinus anomaly were the most frequent abnormal findings of temporal bone in patients with tinnitus. Enhanced HRCT was the choice of modality in patients with PT.Plain HRCT was recommended for NPT. FIESTA sequence was the best in the evaluation of the vessel within the internal auditory canal. Key words: Tinnitus; Temporal bone; Tomography, X-ray computed; Magnetic resonance imaging

Role of FIESTA combined with conventional MRI in the evaluation of traumatic brachial plexus roots injury

PurposePurpose was to evaluate the role of Fast imaging employing steady-state acquisition (FIESTA) together with conventional MR sequences in the evaluation of traumatic brachial plexus roots injury compared to post contrast MR and Spin Echo MR myelographic studies. Patients and methodsIn this prospective study, 16 patients with a mean age of 17.9y who presented with traumatic brachial plexus roots injury in motor cycle and car accidents were studied with FIESTA, conventional MR, post contrast MR and MR myelography sequences. Imaging findings included: pseudo-meningocele/hemorrhage near the nerve root exit, failure of visualization of the nerve root (dorsal, ventral or both), retracted avulsed nerve root ends, spinal cord edema, and para spinal muscles edema and hemorrhage. Diagnostic accuracy was calculated for each MR sequence. Imaging findings were compared with the gold standard operative findings. ResultsFIESTA combined with conventional MR depicted pseudomeningoceles, non visualized nerve roots, cord displacement, and para spinal muscles abnormalities in 15 patients (93.8%), cord edema in four patients (25%). Pre and post contrast MR detected pseudomeningoceles and non visualized nerve roots in 13 patients (81.3%) while Spin Echo myelography detected pseudomeningoceles and non visualized nerve roots in 14 patients (87.5%). FIESTA combined with conventional MR showed the highest diagnostic accuracy (93.8%) compared to pre and post MR (81.3%) and Spin Echo myelography (87.5%). ConclusionIt is crucial to differentiate between preganglionic and postganglionic injuries for optimal treatment planning in patients with BPI. Conventional MR imaging yielded suboptimal information regarding the fine details of nerve roots’ injury. MR myelography showed some artifacts that decreased overall diagnostic accuracy, FIESTA combined with conventional MR depicted nerve segments in greater detail and provided important information about the relationship of the nerves to nearby structures, it provided high contrast resolution between cerebrospinal fluid and solid structures, allowing the reconstruction of elegant multi-planar images that highlight the injured nerves. Contrast study is recommended in mild trauma cases with normal morphological study.

Preoperative Evaluation of Unruptured Cerebral Aneurysms by Fast Imaging Employing Steady-State Acquisition Image

In aneurysm surgery, understanding the microanatomy around the aneurysm such as perforating arteries and cranial nerves is mandatory. To assess the usefulness in determining the microanatomy around the cerebral aneurysms by the use of fast imaging employing steady-state acquisition (FIESTA) images of magnetic resonance imaging preoperatively, in addition to computed tomography and digital subtraction angiography. Between October 2006 and June 2009, 123 patients with 140 unruptured cerebral aneurysms were treated in our institution. Eighty-two patients were assessed with FIESTA by the operators on the workstation of the magnetic resonance image before surgical clipping of the aneurysms. The small vessels and cranial nerves were confirmed intraoperatively before or after obliteration of the aneurysms. Sensitivities and specificities of FIESTA imaging were 100% in detecting hypothalamic artery around anterior communicating artery aneurysms, oculomotor nerve attachment to the posterior communicating artery aneurysm domes, and anterior choroidal artery adhesion to the posterior communicating artery aneurysms. This technique was also useful for predicting adhesion between the aneurysm and adjacent main trunks or perforators. Although the specificity was 100%, sensitivity was 56% in detecting vessel adhesion around the middle cerebral aneurysms. This technique can provide limited information in large aneurysms or aneurysms located in minimal cerebrospinal fluid space. The overall outcomes of the patients included 120 excellent recoveries, 1 moderate deficit, 1 severe deficit, and 1 persistent vegetative state according to the Glasgow Outcome Scale. By giving information on the minute anatomical structure around the aneurysm, FIESTA can contribute to thorough preoperative evaluations of cerebral aneurysms.

The role of 3D volumetric MR sequences in diagnosing intraventricular neurocysticercosis: preliminar results

The purpose of this paper was to investigate the role of two three-dimensional magnetic resonance (MRI) sequences: enhanced spoiled gradient recalled echo (SPGR), and fast imaging employing steady-state acquisition (FIESTA) in the evaluation of intraventricular neurocysticercosis cysts and scolices. Seven neurocysticercosis patients suspected of presenting intraventricular lesions were evaluated by magnetic resonance imaging using enhanced SPGR, and FIESTA. Enhanced SPGR detected eight cystic lesions, with scolices in four. Contrast enhancement was observed in three cysts. FIESTA also detected eight cystic lesions with the presence of scolices in seven of those cystic lesions. Four patients presented parenchymal involvement, while the remaining three presented the racemose form. FIESTA and SPGR are sequences that can detect intraventricular cysts of neurocysticercosis, and FIESTA also is good for the detection of the scolex. Considering this information we suggest that FIESTA and SPGR should be included in the MRI protocol for the investigation of intraventricular neurocysticercosis.

A case of late-onset aqueductal membranous occlusion and a successful treatment with neuro-endoscopic surgery

A 57 year-old man developed broad-based unsteady gait and memory loss over a period of one year. On admission, bradykinesia and impairment of postural reflex were evident. Mini-mental state examination scored 27/ 30. Urinary control was normal. MRI revealed symmetric dilatation of lateral and 3rd ventricles, but the 4th ventricle appeared normal. Partial obstruction of the aqueduct with a membranous structure was disclosed by fast imaging employing steady state acquisition (FIESTA), and the diagnosis of late-onset aqueductal membranous occlusion (LAMO) was made. The symptoms were ameliorated shortly after endoscopic aqueductoplasty (EAP) and endoscopic third ventriculostomy (ETV). Membranous occlusion of the aqueduct can be detected by FIESTA and it can be cured by neuro-endoscopic measures.

MRI findings in Hirayama disease

The objective of the study was to study the magnetic resonance imaging (MRI) features of Hirayama disease on a 3 Tesla MRI scanner. Nine patients with clinically suspected Hirayama disease were evaluated with neutral position, flexion, contrast-enhanced MRI and fast imaging employing steady-state acquisition (FIESTA) sequences. The spectrum of MRI features was evaluated and correlated with the clinical and electromyography findings. MRI findings of localized lower cervical cord atrophy (C5-C7), abnormal curvature, asymmetric cord flattening, loss of attachment of the dorsal dural sac and subjacent laminae in the neutral position, anterior displacement of the dorsal dura on flexion and a prominent epidural space were revealed in all patients on conventional MRI as well as with the dynamic 3D-FIESTA sequence. Intramedullary hyperintensity was seen in four patients on conventional MRI and on the 3D-FIESTA sequence. Flow voids were seen in four patients on conventional MRI sequences and in all patients with the 3D-FIESTA sequence. Contrast enhancement of the epidural component was noted in all the five patients with thoracic extensions. The time taken for conventional and contrast-enhanced MRI was about 30–40 min, while that for the 3D-FIESTA sequence was 6 min. Neutral and flexion position MRI and the 3D-FIESTA sequence compliment each other in displaying the spectrum of findings in Hirayama disease. A flexion study should form an essential part of the screening protocol in patients with suspected Hirayama disease. Newer sequences such as the 3D-FIESTA may help in reducing imaging time and obviating the need for contrast.

Dual source computed tomography in assessment of left atrial appendage volume and function:a comparison with MRI

Objective To use dual source computed tomography (DSCT) for assessment of left atrial appendage volume and function,and to compare the results with those of cardiac cine MR (CMR).Methods Sixty-two patients who received computed tomography angiography (CTA) during March 2008 to Feb.2009 were included in the present study.The DSCT data sets (Somatom Definition,Siemens Medical Solutions,Forchheim,Germany) and FIESTA (fast imaging employing steady-state acquisition) cines (Signa Excite HD 3T,GE) of the vertical long axis covering the left atrium were obtained on the same day.The images were analyzed to obtain LAAVmax,LAAVmin and LAAEF using Vitrea Heart Function software and Report Card 2.0 software,for DSCT and CMR.Intermodality agreement between DSCT and CMR was tested using linear regression and t test.Interobserver variability was tested by Bland-Altman analyses.Results The DSCT and CMR measurements of the left atrial appendage volume and function were not significantly different,and the measurements of the two methods were well correlated with each other,with the coefficient of LAAVmax,LAAVmin,and LAAEF(%) being 0.85,0.86,and 0.76,respectively.However,compared with CMR,DSCT showed a tendency of overestimating LAAVmax,LAAVmin and underestimating LAAEF.The interobserver variability of DSCT measurements was lower than that of CMR measurements.Conclusion DSCT is accurate in assessing the left atrial appendage volume and function of patients referred for coronary CT imaging,and the results are reproducible.

The history of neurosurgery at the House Clinic in Los Angeles.

Although most widely known as the birthplace of neuro-otology, the House Clinic in Los Angeles has been the site of several major contributions to the field of neurosurgery. From the beginning of the formation of the Otologic Medical Group in 1958 (later renamed the House Ear Clinic), these contributions have been largely due to the innovative and collaborative work of neurosurgeon William E. Hitselberger, MD, and neuro-otologist William F. House, MD, DDS. Together they were responsible for the development and widespread adoption of the team approach to skull-base surgery. Specific neurosurgical advances accomplished at the House Clinic have included the first application of the operative microscope to neurosurgery, the application of middle fossa and translabyrinthine approaches for vestibular schwannoma, and the development of combined petrosal, retrolabyrinthine, and other alternative petrosal approaches and of hearing preservation surgery for vestibular schwannoma. The auditory brainstem implant, invented at the House Clinic in 1979, was the first ever successful application of central nervous system neuromodulation for restoration of function. Technological innovations at the House Clinic have also advanced neurosurgery. These include the first video transmission of microsurgery, the first suction irrigator, the first debulking instrument for tumors, and the House-Urban retractor for middle fossa surgery.

Aqueductal web causing obstructive hydrocephalus demonstrated on sagittal FIESTA sequence

A 4-month-old boy presented with a rapidly increasing head circumference, a bulging anterior fontanelle and dilated scalp veins. Sagittal FIESTA sequence (Fig. 1) demonstrated a marked dilatation of the lateral and third ventricles with a normal fourth ventricle. A small web was noted within the aqueduct (arrow) that was obstructing the aqueduct and resulting in hydrocephalus. An aqueductal web is a congenital translucent membrane composed of fibrillary neuroglia with clumps of ependymal cells [1]. Recognition of this entity is crucial since it is curable by surgical resection, which avoids the morbidity and risks associated with shunting. The FIESTA (fast imaging employing steady state acquisition) is an ultrafast pulse sequence that provides high-resolution images with outstanding image contrast between the cerebrospinal fluid and brain parenchyma and high signal-to-noise ratio, thereby improving conspicuity of small intraventricular lesions like aqueductal webs. A 3D-CISS (constructive interference in steady state) sequence is a similar sequence on scanners from other manufacturers [2].

Evaluation of the Optic Nerve Complex in the Orbit Using Coronal Fast Magnetic Resonance Imaging

Recently available coronal fast magnetic resonance imaging (MRI) has very high spatial resolution with good contrast between the optic nerves and cerebrospinal fluid (CSF). The aim of this study was to evaluate the diagnostic value of coronal fast imaging in optic nerve diseases. Thirty-five patients with various Neuro-ophthalmic conditions including 9 with optic neuritis, 6 with optic atrophy, 5 with glaucoma, 4 with segmental optic nerve hypoplasia and 11 with other optic neuropathies including orbital apex syndrome were evaluated with the three-dimensional fast imaging employing steady-state acquisition (FIESTA) sequence in addition to standard MRI protocols. The optic nerve complexes were evaluated on coronal images of the orbits. Detailed demonstration of the optic nerve complex—the optic nerve, the perineural CSF space and dural sheath—could be readily obtained with FIESTA sequence. The acute phase of both optic neuritis and perineuritis showed enlargement of the perineural CSF space; the optic nerve was swollen in optic neuritis but not in perineuritis. Cases of optic atrophy and glaucoma showed perineural CSF space enlargement with normal optic sheath circumference and a thinner optic nerve, while optic nerve hypoplasia showed a smaller dural sheath circumference without perineural CSF space enlargement. In the cases of orbital apex syndrome optic nerve compression by the extraocular muscles was clearly shown. Coronal FIESTA imaging of the orbit is capable of delineating detailed structural changes in the optic nerve complex and is of diagnostic value for the differentiation of optic nerve diseases.

Quantitative evaluation of optimal imaging parameters for single-cell detection in MRI using simulation

Super-paramagnetic iron oxide (SPIO) nanoparticles are actively investigated to enhance disease detection through molecular imaging using magnetic resonance imaging (MRI). Detection of the cells labeled by SPIO depends on the MRI protocols and pulse sequence parameters that can be optimized. To evaluate the sensitivity and specificity of the image acquisition methods and to obtain optimal imaging parameters for single-cell detection, we further developed an MRI simulator. The simulator models an object (tissue) at a microscopic level to evaluate effects of spatial distribution and concentration of nanoparticles on the resulting image. In this study, the simulator was used to evaluate and compare imaging of the labeled cells by the gradient-echo (GE), true-FISP [fast imaging employing steady-state acquisition (FIESTA)] and echo-planar imaging (EPI) pulse sequences. Effects of the imaging and object parameters, such as field strength, imaging protocol and pulse sequence parameters, imaging resolution, cell iron load, position of SPIO within the voxel and cell division within the voxel, were investigated in the work. The results suggest that true-FISP has the highest sensitivity for single-cell detection by MRI.

Assessing the left atrial phasic volume and function with dual-source CT: comparison with 3T MRI

We wanted to assess the performance of dual-source CT (DSCT) for evaluating the left atrial volume and function and we compared this performance to that of the standard reference technique,cardiac cine MR (CMR). Fifty-one patients who were referred for CT coronary angiography were included in the study. Two were subsequently excluded for having un-analyzable MR images at the onset of left atrial contraction. For the remaining 49 patients, the DSCT data sets and FIESTA (fast imaging employing steady-state acquisition) cines of the vertical long axis covering the left atrium and the short axis covering the left ventricle were obtained on the same day. All the images were analyzed to obtain the maximal left atrial volume (LAVmax), the minimal left atrial volume (LAVmin), the left atrial volume just before left atrium contraction (LAVp), the left atrial reservoir volume (LARV), the left atrial ejection fraction (LAEF), the left atrial passive emptying volume (LAPV), the left atrial active emptying volume(LAAV), the left atrial conduit volume (LACV), the left ventricular end-diastolic volume (LVEDV), the left ventricular end-systolic volume (LVESV) and the left ventricular stroke volume (LVSV) by using 3D semi-segmentation software and Report Card 2.0 software, respectively, for the DSCT and CMR. All the parameters were normalized to the body surface area. Intermodality agreement was tested through linear regression and Bland-Altman analyses.Repeated measurements were performed to determine the interobserver variability. The DSCT measurements resulted in good correlation (r > 0.75) compared with those of CMR. However, DSCT slightly,but insignificantly overestimated the indexed LAVmax, LAVmin, LAVp, LARV, LAPV, LAAV and LACV, as reflected by biases of 1.2, 0.9, 1.1, 0.3, 0.1,0.2 and 0.4 ml/m(2), respectively. The LAEF was minimally, but insignificantly underestimated as reflected by a bias of -0.6% (P = ns). The variability of the DSCT measurements was lower than that of the CMR values. DSCT provides highly reliable and reproducible measurements of the left atrial phasic volume and function in patients who are referred for coronary CT imaging.

膝関節軟骨における脂肪抑制ｔｈｒｅｅ−ｄｉｍｅｎｓｉｏｎａｌ ｃｏｈｅｒｅｎｔ ｏｓｃｉｌｌａｔｏｒｙ ｓｔａｔｅ ａｃｑｕｉｓｉｔｉｏｎ ｆｏｒ ｔｈｅ ｍａｎｉｐｕｌａｔｉｏｎ ｏｆ ｉｍａｇｅ ｃｏｎｔｒａｓｔ（３Ｄ−ＣＯＳＭＩＣ）シーケンスの基礎的検討

Fat-suppressed three-dimensional coherent oscillatory state acquisition for the manipulation of image contrast (3D-COSMIC) is a sequence that is based on fast imaging employing steady state acquisition (FIESTA) of balanced steady-state free precession (balanced SSFP). Since the data acquisition of steady-state transition is filled up with the center of k-space, improvement in the contrast of the cartilage, which is a low T₂/T₁ value domain, is expected. This time we report on the usability in applying the above sequence to cartilage imaging of the knee joint and comparing and examining this sequence with the sequence in the past from the viewpoints of the contrast and scan time. As a result, compared with fat-suppressed three-dimensional spoiled gradient echo (3D-SPGR), the contrast of marrow and synovial fluid was equivalent to that of the cartilage, and imaging time was shorter than half of that with the cartilage. Compared with a fat-suppressed two-dimensional proton density weighted image (2D-PDWI), the contrast of the cartilage and synovial fluid was significantly improved, and spatial resolution was also excellent. As a short imaging time and a high resolution image pick-up are possible for fat-suppressed 3D-COSMIC, and it can describe minute damage of the cartilage since it depicts synovial fluid as high-level signals, I think this technique is useful.