ABSTRACT
The 3 Tesla (3T) magnetic resonance imaging (MRI) combined ultrasound (TRUS) targeted biopsy plus 12-core systematic biopsy (TBxâ¯+â¯12-SBx) was considered a reliable method for prostate cancer (PCa) diagnosis. To find another optimal sampling scheme with fewer cores and the same efficiency as TBxâ¯+â¯12-SBx for prostate biopsy, 113 patients who underwent five different hypothetical sampling schemes were analyzed and compared with TBxâ¯+â¯12-SBx. The detection rates of targeted biopsy plus 6-core lateral systematic biopsy (TBxâ¯+â¯lateral 6-SBx) for PCa and clinically significant prostate cancer (csPCa) (99.1% and 96.4%, respectively) were higher than other schemes, and the area under the receiver operating characteristic curve of TBxâ¯+â¯lateral 6-SBx for PCa and csPCa (0.991 and 0.990, respectively) were also significantly higher than other sampling schemes except TBx plus 6-core ipsilateral systematic biopsy (TBxâ¯+â¯ipsilateral 6-SBx). Additionally, TBxâ¯+â¯lateral 6-SBx had the lowest missed diagnosis rate. Thus, the TBxâ¯+â¯lateral 6-SBx may be the optimal scheme for patients undergoing MRI/TRUS fusion prostate biopsy.
Subject(s)
Biopsy, Large-Core Needle/methods , Image-Guided Biopsy/methods , Prostate/diagnostic imaging , Prostate/pathology , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Aged , Aged, 80 and over , Clinical Protocols , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Ultrasonography/methodsABSTRACT
RATIONALE AND OBJECTIVES: To evaluate the functional alterations of chronic kidney disease (CKD) with magnetic resonance dynamic perfusion imaging. MATERIALS AND METHODS: Twenty-one healthy subjects (42 kidneys) and 20 CKD patients (40 kidneys) underwent routine scans with fat-saturated T1-weighted fast low angle shot (FLASH) and true-fast imaging with steady-state precession (FISP) sequences followed by dynamic perfusion scans using a turbo-FLASH T1-weighted sequence. Signal intensity (SI) of the cortex and medulla on images was measured and plotted as a function of time. Peak height (P) and time to peak (T) of the cortex and medulla SI were estimated, and P/T ratio and the area under the time-intensity curves were calculated. We also tested the correlation between these data and serum creatinine (sCr) levels in patients. RESULTS: P, P/T ratio, and the area under the curve of patients' cortex and medulla were significantly decreased compared to control subjects, and T was delayed. In patients, P and P/T ratio of the cortex and P of the medulla were negatively correlated with sCr levels (r = -0.469, r = -0.419, and r = -0.423, respectively; P < 0.01). CONCLUSION: Renal dysfunction in CKD can be evaluated by magnetic resonance dynamic perfusion imaging.
Subject(s)
Gadolinium DTPA , Kidney Failure, Chronic/diagnosis , Magnetic Resonance Imaging/methods , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Young AdultABSTRACT
RATIONALE AND OBJECTIVES: Abnormalities in brain structure have been implicated in psychosis. Herein, we investigated the differences in fractional anisotropy (FA) and average diffusion coefficient (ADC) in the bilateral anterior limb of internal capsules between neuroleptic-naive schizophrenic patients and appropriately matched healthy controls. MATERIALS AND METHODS: Magnetic resonance imaging was performed with a 1.5 T superconductive MR scanner, and diffusion tensor imaging was carried out in 21 neuroleptic-naive schizophrenic patients and 18 matched healthy controls. FA and ADC were measured by region of interest analysis. RESULTS: Compared with healthy controls, the neuroleptic-naive schizophrenic patients showed significantly reduced FA in the bilateral anterior limb of the internal capsule. However, the difference in the ADC values between the patients and the controls was not significant. CONCLUSIONS: FA of the bilateral anterior limb of the internal capsule was reduced in neuroleptic-naive schizophrenic patients, indicating that the integrity of the white matter of the bilateral thalamus-frontal connection or the bilateral thalamus-anterior cingulate gyrus connection was destroyed.
Subject(s)
Diffusion Magnetic Resonance Imaging/methods , Internal Capsule/pathology , Schizophrenia/pathology , Adolescent , Adult , Anisotropy , Antipsychotic Agents , Case-Control Studies , Female , Gyrus Cinguli/pathology , Humans , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Prefrontal Cortex/pathology , Thalamus/pathologyABSTRACT
OBJECTIVE: to investigate the clinical feature and dynamic changes of the cervical dural sac and spinal cord during neck flexion in Hirayama disease (juvenile muscular atrophy of distal upper extremity). METHODS: Clinical data were taken and MRI in neutral neck position and a fully flexed neck position were performed on 27 cases of Hirayama disease. RESULTS: (1) All patients were consistent with the diagnostic criteria of Hirayama disease who had asymmetric muscular atrophy and weakness of the hand and forearm. All patients were young males and right handed of whom 77.8% had initial symptoms before they were 19 years old. More patients(20 cases,74%é had muscular atrophy in the right hand than in the left at onset. The duration after disease onset was from 2-72 months[(26.48+/-15.57) months]. (2) In neutral neck position by MIR examination, 16 patients showed abnormal cervical curvature, 14 showed atrophy of the lower cervical cord and 2 patients had intramedullary abnormal high signal. (3) In a fully flexed position of the neck, all patients showed forward displacement and flattening of the lower cervical cord, and a crescent-shaped high signal area behind the cord. (4) The crescent shaped area was enhanced on T1-weighed imaging and disappeared after the patient returned to a neural position in one case. CONCLUSION: Hirayama disease occurs mainly in young males. There are obviously dynamic changes of the cervical cord during neck flexion in Hirayama disease by MRI examination, which can help the doctor make diagnosis in the early stage.
Subject(s)
Magnetic Resonance Imaging/methods , Spinal Cord/pathology , Spinal Muscular Atrophies of Childhood/diagnosis , Adolescent , Adult , Humans , Male , Spinal Muscular Atrophies of Childhood/pathology , Upper ExtremityABSTRACT
BACKGROUND: About 50% - 70% of patients with Chiari malformation I (CMI) presented with syringomyelia (SM), which is supposed to be related to abnormal cerebrospinal fluid (CSF) flow around the foramen magnum. The aim of this study was to investigate the cerebrospinal fluid dynamics at levels of the aqueduct and upper cervical spine in patients with CMI associated with SM, and to discuss the possible mechanism of formation of SM. METHODS: From January to April 2004, we examined 10 adult patients with symptomatic CMI associated with SM and 10 healthy volunteers by phase-contrast MRI. CSF flow patterns were evaluated at seven regions of interest (ROI): the aqueduct and ventral and dorsal subarachnoid spaces of the spine at levels of the cerebellar tonsil, C2 - 3, and C5 - 6. The CSF flow waveforms were analyzed by measuring CSF circulation time, durations and maximum velocities of cranial- and caudal-directed flows, and the ratio between the two maximum velocities. Data were analyzed by t test using SPSS 11.5. RESULTS: We found no definite communication between the fourth ventricle and syringomyelia by MRI in the 10 patients. In both the groups, we observed cranial-directed flow of CSF in the early cardiac systolic phase, which changed the direction from cranial to caudal from the middle systolic phase to the early diastolic phase, and then turned back in cranial direction in the late diastolic phase. The CSF flow disappeared at the dorsal ROI at the level of C2 - 3 in 3 patients and 1 volunteer, and at the level of C5 - 6 in 6 patients and 3 volunteers. The durations of CSF circulation at all the ROIs were significantly shorter in the patients than those in the healthy volunteers (P = 0.014 at the midbrain aqueduct, P = 0.019 at the inferior margin of the cerebellar tonsil, P = 0.014 at the level of C2 - 3, and P = 0.022 at the level of C5 - 6). No significant difference existed between the two groups in the initial point and duration of the caudal-directed CSF flow during a cardiac cycle at all the ROIs. The maximum velocities of both cranial- and caudal-directed CSF flows were significantly higher in the patients than those in the volunteers at the aqueduct (P = 0.018 and P = 0.007) and ventral ROI at the inferior margin of the cerebellar tonsil (P < 0.001 and P = 0.002), as so did the maximum velocities of the caudal-directed flow in the ventral and dorsal ROIs at the level of C2 - 3 (P = 0.004; P = 0.007). CONCLUSIONS: The direction of CSF flow changes in accordance with cardiac cycle. The syringomyelia in patients with CMI may be due to the decreased circulation time and abnormal dynamics of the CSF in the upper cervical segment. The decompression of the foramen magnum with dural plasty is an alternative for patients with CMI associated with SM.
Subject(s)
Arnold-Chiari Malformation/cerebrospinal fluid , Syringomyelia/etiology , Adolescent , Adult , Arnold-Chiari Malformation/complications , Arnold-Chiari Malformation/diagnosis , Electrocardiography , Female , Humans , Magnetic Resonance Imaging , Male , Middle AgedABSTRACT
OBJECTIVE: To investigate the sensitivity and specificity of neutral position cervical MRI in the diagnosis of Hirayama disease. METHODS: Neutral position cervical MRI of 18 patients and 31 young normal control subjects were evaluated for localized lower cervical cord atrophy, asymmetric cord flattening, abnormal cervical curvature, loss of attachment (LOA) and noncompressed intramedullary high signal intensity on T2-weighted MRI. The difference in frequency of these findings between the control and patient groups was examined by means of the x' test. The sensitivity and specificity of these MRI findings in the diagnosis of Hirayama disease were calculated. Multiple logistic regression was performed to explore the relationship with Hirayama disease. RESULTS: (1) There was significant difference in the frequency of localized lower cervical cord atrophy, asymmetric cord flattening and LOA between the patient and control groups (P < 0.05). (2) After adjusting localized lower cervical cord atrophy, asymmetric cord flattening, abnormal cervical curvature and LOA, the analysis showed that LOA was the only significantly important predictor of the disease, with odds ratio of 49.38 (95% CI: 3.97 - 614.73). Sensitivity and specificity of LOA were 88.0% and 90.6% respectively. (3) Sensitivity and specificity of localized lower cervical cord atrophy were 84.6% and 80.6%. Sensitivity and specificity of asymmetric cord flattening were 87.5% and 73.2%, but our case-control study did not fine any significant association between localized lower cervical cord atrophy and Hirayama disease and also between asymmetric cord flattening and Hirayama disease. CONCLUSIONS: LOA between posterior dural sac and subjacent lamina is the most valuable finding in the diagnosis of Hirayama disease at neutral position MR imaging.
Subject(s)
Magnetic Resonance Imaging , Spinal Muscular Atrophies of Childhood/diagnosis , Adolescent , Adult , Case-Control Studies , Cervical Vertebrae/pathology , Humans , Male , Posture , Sensitivity and Specificity , Spinal Cord/pathology , Spinal Muscular Atrophies of Childhood/epidemiology , Spinal Muscular Atrophies of Childhood/pathologyABSTRACT
The aggregation behavior of the newly synthesized gadofullerene magnetic resonance imaging (MRI) contrast agent, i.e., Gd@C(82)O(6)(OH)(16)(NHCH(2)CH(2)COOH)(8) (abbreviated as AAD-EMF), was studied in detail by dynamic light scattering, scanning electron microscopy, T(1)-weighted magnetic resonance, and atomic force microscopy. It was revealed that the AAD-EMF aggregation in aqueous solution is pH-dependent. At pH 2, the AAD-EMF first self-assemble to form ca. 30 nm small clusters, and then dozens of the small clusters further aggregate to form large grapelike particles. At pH 7, the aggregates are also ca. 30 nm small clusters, but they are hard to further aggregate except for forming some cluster dimers or trimers, so AAD-EMF aggregates have a narrow size distribution by this time. At pH 9, the AAD-EMF aggregations cover a large range of continuous hydrodynamic diameters from 30 to 2000 nm. On the basis of the above observations, the aggregating mechanism of AAD-EMF under different pH values was proposed by concurrently considering the hydrogen-bonding effect and the dipolar interactions between AAD-EMF.