共查询到20条相似文献,搜索用时 281 毫秒
1.
Sung Ki Cho Dong Gyu Na Jae Wook Ryoo Hong Gee Roh Chan Hong Moon Hong Sik Byun Jong Hyun Kim 《Korean journal of radiology》2002,3(3):171-179
Objective
To determine the utility of perfusion MR imaging in the differential diagnosis of brain tumors.Materials and Methods
Fifty-seven patients with pathologically proven brain tumors (21 high-grade gliomas, 8 low-grade gliomas, 8 lymphomas, 6 hemangioblastomas, 7 metastases, and 7 various other tumors) were included in this study. Relative cerebral blood volume (rCBV) and time-to-peak (TTP) ratios were quantitatively analyzed and the rCBV grade of each tumor was also visually assessed on an rCBV map.Results
The highest rCBV ratios were seen in hemangioblastomas, followed by high-grade gliomas, metastases, low-grade gliomas, and lymphomas. There was no significant difference in TTP ratios between each tumor group (p>0.05). At visual assessment, rCBV was high in 17 (81%) of 21 high-grade gliomas and in 4 (50%) of 8 low-grade gliomas. Hemangioblastomas showed the highest rCBV and lymphomas the lowest.Conclusion
Perfusion MR imaging may be helpful in the differentiation of thevarious solid tumors found in the brain, and in assessing the grade of the various glial tumors occurring there. 相似文献2.
Bo Kiung Kang Dong Gyu Na Jae Wook Ryoo Hong Sik Byun Hong Gee Roh Yong Seon Pyeun 《Korean journal of radiology》2001,2(4):183-191
Objective
To document the signal characteristics of intracerebral hemorrhage (ICH) at evolving stages on diffusion-weighted images (DWI) by comparison with conventional MR images.Materials and Methods
In our retrospective study, 38 patients with ICH underwent a set of imaging sequences that included DWI, T1-and T2-weighted imaging, and fluid-attenuated inversion recovery (FLAIR). In 33 and 10 patients, respectively, conventional and echo-planar T2* gradient-echo images were also obtained. According to the time interval between symptom onset and initial MRI, five stages were categorized: hyperacute (n=6); acute (n=7); early subacute (n=7); late subacute (n=10); and chronic (n=8). We investigated the signal intensity and apparent diffusion coefficient (ADC) of ICH and compared the signal intensities of hematomas at DWI and on conventional MR images.Results
DWI showed that hematomas were hyperintense at the hyperacute and late subacute stages, and hypointense at the acute, early subacute and chronic stages. Invariably, focal hypointensity was observed within a hyperacute hematoma. At the hyperacute, acute and early subacute stages, hyperintense rims that corresponded with edema surrounding the hematoma were present. The mean ADC ratio was 0.73 at the hyperacute stage, 0.72 at the acute stage, 0.70 at the early subacute stage, 0.72 at the late subacute stage, and 2.56 at the chronic stage.Conclusion
DWI showed that the signal intensity of an ICH may be related to both its ADC value and the magnetic susceptibility effect. In patients with acute stroke, an understanding of the characteristic features of ICH seen at DWI can be helpful in both the characterization of intracranial hemorrhagic lesions and the differentiation of hemorrhage from ischemia. 相似文献3.
Sun Joo Lee Jae Hyoung Kim Young Mee Kim Gyung Kyu Lee Eun Ja Lee In Sung Park Jin-Myung Jung Kyeong Hun Kang Taemin Shin 《Korean journal of radiology》2001,2(1):1-7
Objective
To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas.Materials and Methods
In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas.Results
Mean rCBV ratios were 4.90°±1.01 for glioblastomas, 3.97°±0.56 for anaplastic gliomas and 1.75°±1.51 for low-grade gliomas, and were thus significantly different; p < .05 between glioblastomas and anaplastic gliomas, p < .05 between anaplastic gliomas and low-grade gliomas, p < .01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively.Conclusion
Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas. 相似文献4.
Objective
This study was designed to determine whether diffusion-weighted imaging (DWI) with sensitivity encoding (SENSE) could detect bone marrow involvement in patients with cranial bone marrow (CBM) metastases. DWI results obtained were compared with T1-weighted imaging (T1WI) findings.Materials and Methods
DWI with sensitivity encoding (SENSE; b value = 1,000) was performed consecutively in 13 patients with CBM metastases diagnosed pathologically and radiologically. CBM lesions were dichotomized according to the involved site, i.e., skull base or calvarium. Two radiologists qualitatively evaluated the relative conspicuousness of CBM lesions and image qualities in B0 and in isotropic DWI and in T1WI. According to region of interest analysis of normal and pathologic marrow for these three sequences, absolute signal difference percentages (SD%) were calculated to quantitatively analyze lesion contrast.Results
All 20 lesions in 13 patients with CBM metastases revealed abnormal DWI signals in areas corresponding to T1WI abnormalities. Both skull base and calvarial lesions provided better lesion conspicuousness than T1WI and B0 images. Although the image quality of DWI was less satisfactory than that of T1WI, relatively good image qualities were obtained. Quantitatively, B0 images (SD%, 82.1 ±7.9%) showed better lesion contrast than isotropic DWI (SD%, 71.4 ±13.7%) and T1WI (SD%, 65.7 ±9.3%) images.Conclusion
For scan times of less than 30 seconds, DWI with SENSE was able to detect bone marrow involvement, and was superior to T1WI in terms of lesion conspicuity. DWI with SENSE may be helpful for the detection of cranial bone/bone marrow metastases when used in conjunction with conventional MR sequences. 相似文献5.
Hyo-Cheol Kim Kee-Hyun Chang In Chan Song Sang Hyun Lee Bae Ju Kwon Moon Hee Han Sang-Yun Kim 《Korean journal of radiology》2001,2(4):192-196
Objective
To compare conventional and diffusion-weighted MR imaging in terms of their depiction of the abnormalities occurring in Creutzfeldt-Jakob disease.Materials and Methods
We retrospectively analyzed the findings of conventional (T2-weighted and fluid-attenuated inversion recovery) and diffusion-weighted MR imaging in four patients with biopsy-proven Creutzfeldt-Jakob disease. The signal intensity of the lesion was classified by visual assessment as markedly high, slightly high, or isointense, relative to normal brain parenchyma.Results
Both conventional and diffusion-weighted MR images demonstrated bilateral high signal intensity in the basal ganglia in all four patients. Cortical lesions were observed on diffusion-weighted MR images in all four, and on fluid-attenuated inversion recovery MR images in one, but in no patient on T2-weighted images. Conventional MR images showed slightly high signal intensity in all lesions, while diffusion-weighted images showed markedly high signal intensity in most.Conclusion
Diffusion-weighted MR imaging is more sensitive than its conventional counterpart in the depiction of Creutzfeldt-Jakob disease, and permits better detection of the lesion in both the cerebral cortices and basal ganglia. 相似文献6.
Seong Whi Cho Soon Gu Cho Jung Hee Lee Hyung-Jin Kim Myung Kwan Lim Jong Hwa Kim Chang Hae Suh 《Korean journal of radiology》2002,3(2):105-112
Objective
To explore the in-vivo 1H- MR spectral features of adnexal lesions and to characterize the spectral patterns of various pathologic entities.Materials and Methods
Thirty-one patients with surgically and histopathologically confirmed adnexal lesions underwent short echo-time STEAM (stimulated echo acquisition method) 1H- MR spectroscopy, and the results obtained were analysed.Results
The methylene present in fatty acid chains gave rise to a lipid peak of 1.3 ppm in the 1H- MR spectra of most malignant tumors and benign teratomas. This same peak was not observed, however, in the spectra of benign ovarian epithelial tumors: in a number of these, a peak of 5.2 ppm, due to the presence of the olefine group (-CH=CH-) was noted. The ratios of lipid peak at 1.3 ppm to water peak (lipid/water ratios) varied between disease groups, and in some benign teratomas was characteristically high.Conclusion
An intense lipid peak at 1.3 ppm is observed in malignant ovarian tumors but not in benign epithelial tumors. 1H- MRS may therefore be helpful in the differential diagnosis of adnexal lesions. 相似文献7.
Soo Mee Lim Hye-Young Choi Jung Soo Suh Jung Hee Lee Keun Ho Lim Dae Chul Suh Ho Kyu Lee Tae-Hwan Lim Young Shin Ra 《Korean journal of radiology》2003,4(2):71-78
Objective
To evaluate, using localized proton magnetic resonance spectroscopy (1H-MRS), the cerebral metabolic change apparent after revascularization surgery in patients with moyamoya disease.Materials and Methods
Sixteen children with moyamoya disease and eight age-matched normal controls underwent MR imaging, MR angiography, conventional angiography, and 99mTc-ECD SPECT. Frontal white matter and the basal ganglia of both hemispheres were subjected to localized 1H-MRS, and after revascularization surgery, four patients underwent follow-up 1H-MRS.Results
Decreased NAA/Cr ratios (1.35±0.14 in patients vs. 1.55±0.24 in controls) and Cho/Cr ratios (0.96±0.13 in patients vs. 1.10±0.11 in controls) were observed in frontal white matter. After revascularization surgery, NAA/Cr and Cho/Cr ratios in this region increased. In the basal ganglia, there is no abnormal metabolic ratios.Conclusion
Localized 1H-MRS revealed abnormal metabolic change in both hemispheres of children with moyamoya disease. Because of its non-invasive nature, 1H-MRS is potentially useful for the preoperative evaluation of metabolic abnormalities and their postoperative monitoring. 相似文献8.
Objective
To determine whether the time-intensity curves acquired by test and main dose contrast injections for MR angiography are similar.Materials and Methods
In 11 patients, repeated contrast-enhanced 2D-turbo-FLASH scans with 1-sec interval were obtained. Both test and main dose time-intensity curves were acquired from the abdominal aorta, and the parameters of time-intensity curves for the test and main boluses were compared. The parameters used were arterial and venous enhancement times, arterial peak enhancement time, arteriovenous circulation time, enhancement duration and enhancement expansion ratio.Results
Between the main and test boluses, arterial and venous enhancement times and arteriovenous circulation time showed statistically significant correlation (p < 0.01), with correlation coefficients of 0.95, 0.92 and 0.98 respectively. Although the enhancement duration was definitely greater than infusion time, reasonable measurement of the end enhancement point in the main bolus was impossible.Conclusion
Only arterial and venous enhancement times and arteriovenous circulation time of the main bolus could be predicted from the test-bolus results. The use of these reliable parameters would lead to improvements in the scan timing method for MR angiography. 相似文献9.
Ki Yeol Lee Taik-Kun Kim Minkyu Park Sungyu Ko In Chan Song Ik-Hwan Cho 《Korean journal of radiology》2004,5(2):96-101
Objective
This study was designed to compare three different measures of the elderly human brain; the magnetization transfer ratio (MTR) histogram, the percentage of brain parenchymal volume, and the volume of T2 hyperintense areas in terms of correlations with the study subjects'' neurocognitive performance.Materials and Methods
Thirty-five healthy community-dwelling elderly volunteers aged 60-82 years underwent dual fast spin-echo (FSE) imaging and magnetization transfer imaging. A semi-automated technique was used to generate the MTR histogram, the brain parenchymal volume, and the T2 lesion volume. The subjects'' neurocognitive performance was assessed by using the Korean-Mini Mental State Examination (K-MMSE) and additional tests. The peak height of the MTR (PHMTR), the percentage of brain parenchymal volume (PBV), and the normalized T2 lesion volume (T2LV) were compared between the normal group (Z score on the K-MMSE ≥ -2, n=23) and the mild cognitive impairment group (Z score on the K-MMSE < -2, n=12), and these parameters were correlated with age and various neurocognitive performance scores.Results
The PHMTR was significantly lower in the cognitively impaired subjects than the PHMTR in the normal subjects (p = 0.005). The PBV scores were lower in the cognitively impaired subjects than in the normal subjects (p = 0.02). The T2LV scores were significantly higher in the cognitively impaired subjects (p = 0.01). An inverse correlation was found between the PHMTR and T2LV (r = -0.747, p < 0.001), and also between the PBV and T2LV (r = -0.823, p < 0.001). A positive correlation was observed between the PHMTR and the PBV (r = 0.846, p < 0.001). Scores on the various neurocognitive tests were positively correlated with the PHMTR (6 of 7 items) and the PBV (5 of 7 items), and they were negatively correlated with the T2LV (5 of 7 items).Conclusion
Our findings of a correlation among the PBV, the T2LV, and the PHMTR suggest that MTR histograms and the PBV and T2LV can be used as a reliable method and valid statistical tool, respectively, for quantifying the total lesion burden in an aging brain. 相似文献10.
Myung Kwan Lim Chang Hae Suh Hyung Jin Kim Sung Tae Kim Jeong Seop Lee Min Hee Kang Ji Hye Kim Jung Hee Lee 《Korean journal of radiology》2003,4(2):79-84
Objective
To investigate the MR imaging and 1H-MR spectroscopic findings of acute fire-related post-traumatic stress disorder (PTSD).Materials and Methods
Sixteen patients (M:F=10:6; mean age, 16 years) with fire-related PTSD underwent MR imaging and 1H-MR spectroscopy, and for control purposes, the procedures were repeated in eight age-matched normal volunteers. In all patients and controls, the regions of interest where data were acquired at MRS were the basal ganglia (BG), frontal periventricular white matter (FWM), and parietal periventricular white matter (PWM).Results
In all patients with PTSD, MR images appeared normal. In contrast, MRS showed that in the BG, NAA/Cr ratios were significantly lower in patients than in volunteers. This decrease did not, however, show close correlation with the severity of the neuropsychiatric symptoms. In patients, neither NAA/Cr ratios in FWM nor PWM, nor Cho/Cr ratios in all three regions, were significantly different from those in the control group.Conclusion
Decreased NAA/Cr ratios in the BG, as seen at 1H-MRS, might be an early sign of acute fire-related PTSD. 相似文献11.
Alfonso Di Costanzo Tommaso Scarabino Francesca Trojsi Teresa Popolizio Simona Bonavita Mario de Cristofaro Renata Conforti Adriana Cristofano Claudio Colonnese Ugo Salvolini Gioacchino Tedeschi 《La Radiologia medica》2014,119(8):616-624
Objective
The discrimination between recurrent glioma and radiation injury is often a challenge on conventional magnetic resonance imaging (MRI). We verified whether adding and combining proton MR spectroscopic imaging (1H-MRSI), diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) information at 3 Tesla facilitate such discrimination.Materials and methods
Twenty-nine patients with histologically verified high-grade gliomas, who had undergone surgical resection and radiotherapy, and had developed new contrast-enhancing lesions close to the treated tumour, underwent MRI, 1H-MRSI, DWI and PWI at regular time intervals. The metabolite ratios choline (Cho)/normal( n )Cho n , N-acetylaspartate (NAA)/NAA n , creatine (Cr)/Cr n , lactate/lipids (LL)/LL n , Cho/Cr n , NAA/Cr n , Cho/NAA, NAA/Cr and Cho/Cr were derived from 1H-MRSI; the apparent diffusion coefficient (ADC) from DWI; and the relative cerebral blood volume (rCBV) from PWI.Results
In serial MRI, recurrent gliomas showed a progressive enlargement, and radiation injuries showed regression or no modification. Discriminant analysis showed that discrimination accuracy was 79.3 % when considering only the metabolite ratios (predictor, Cho/Cr n ), 86.2 % when considering ratios and ADC (predictors, Cho/Cr n and ADC), 89.7 % when considering ratios and rCBV (predictors, Cho/Cr n , Cho/Cr and rCBV), and 96.6 % when considering ratios, ADC and rCBV (predictors, Cho/Cho n , ADC and rCBV).Conclusions
The multiparametric 3-T MR assessment based on 1H-MRSI, DWI and PWI in addition to MRI is a useful tool to discriminate tumour recurrence/progression from radiation effects. 相似文献12.
Jongmin J. Lee Phillip J. Tirman Yongmin Chang Hun-Kyu Ryeom Sang-Kwon Lee Yong-Sun Kim Duk-Sik Kang 《Korean journal of radiology》2000,1(3):142-151
Objective
To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time.Materials and Methods
Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods.Results
Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method.Conclusion
The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method. 相似文献13.
Chang Hyun Lee Jin Mo Goo Young Tae Kim Hyun Ju Lee Chang Min Park Eun-Ah Park Ho Yun Lee Mi-Jin Kang In Chan Song 《Korean journal of radiology》2010,11(1):37-45
Objective
We wanted to determine the clinical feasibility of using non-breath-hold real-time MR-echo imaging for the evaluation of mediastinal and chest wall tumor invasion.Materials and Methods
MR-echo imaging was prospectively applied to 45 structures in 22 patients who had non-small cell lung cancer when the tumor invasion was indeterminate on CT. The static MR imaging alone, and the static MR imaging combined with MR-echo examinations were analyzed. The surgical and pathological findings were compared with using the Wilcoxon-signed rank test and McNemar''s test.Results
The accuracy, sensitivity and specificity of the combined MR-echo examination and static MR imaging for determining the presence of invasion were 84%, 83% and 85%, respectively, for the first reading session and they were 87%, 83% and 87%, respectively, for the second reading session (there was substantial interobserver agreement, k = 0.74). For the static MR imaging alone, these values were 62%, 83% and 59%, respectively, for the first reader and they were 69%, 67% and 74%, respectively, for the second reader (there was moderate interobserver agreement, k = 0.49). The diagnostic confidence for tumor invasion was also higher for the combined MR-echo examination and static MR imaging than that for the static MR imaging alone (p < 0.05).Conclusion
The combined reading of a non-breath-hold real-time MR-echo examination and static MR imaging provides higher specificity and diagnostic confidence than those for the static MR imaging reading alone to determine the presence of mediastinal or chest wall tumor invasion when this was indeterminate on CT scanning. 相似文献14.
Sunseob Choi Haiying Liu Tae Beom Shin Jin Hwa Lee Seong Kuk Yoon Jong Young Oh Young-Il Lee 《Korean journal of radiology》2004,5(3):143-148
Objective
The aim of this study was to examine the feasibility of perfusion imaging of the brain using the Z-score and subtraction dynamic images obtained from susceptibility contrast MR images.Materials and Methods
Five patients, each with a normal MRI, Moya-moya, a middle cerebral artery occlusion, post-trauma syndrome, and a metastatic brain tumor, were selected for a presentation. A susceptibility-contrast echo-planar image after a routine MRI was taken as the source image with a rapid manual injection of 0.1 mmol/kg of Gd-DTPA. The inflow and washout patterns were observed from the time-signal intensity curve of the serial scans using the standard program of an MRI machine. The repeated Z-score images of the peak and late phases were made using the threshold Z-score values between 1.4 and 2.0 in four to five studies of the pre-contrast, peak, and late phases. Dynamic subtraction images were produced by subtracting sequential post-contrast images from a pre-contrast image and coloring these images using a pseudocolor mapping method.Results
In the diseases with perfusion abnormalities, the Z-score images revealed information about the degree of perfusion during the peak and late phases. However, the quality varied with the Z-score threshold and the studies selected in a group. The dynamic subtraction images were of sufficient quality with no background noise and more clearly illustrated the temporal changes in perfusion and delayed perfusion.Conclusion
The Z-scores and dynamic subtraction images illustrated the degree of perfusion and sequential changes in the pattern of perfusion, respectively. These images can be used as a new complimentary method for observing the perfusion patterns in brain diseases. 相似文献15.
Kwang-Hun Lee Tae-Sub Chung Tae Joo Jeon Young Hwan Kim Daisy Chien Gerhard Laub 《Korean journal of radiology》2000,1(1):11-18
Objective
To evaluate the hydrodynamic changes occurring in cerebrospinal fluid (CSF) flow in cervical spinal stenosis using the spatial modulation of magnetization (SPAMM) technique.Materials and Methods
Using the SPAMM technique, 44 patients with cervical spinal stenosis and ten healthy volunteers were investigated. The degree of cervical spinal stenosis was rated as low-, intermediate-, or high-grade. Low-grade stenosis was defined as involving no effacement of the subarachnoid space, intermediate-grade as involving effacement of this space, and high-grade as involving effacement of this space, together with compressive myelopathy. The patterns of SPAMM stripes and CSF velocity were evaluated and compared between each type of spinal stenosis and normal spine.Results
Low-grade stenosis (n = 23) revealed displacement or discontinuity of stripes, while intermediate- (n = 10) and high-grade (n = 11) showed a continuous straight band at the stenotic segment. Among low-grade cases, 12 showed wave separation during the systolic phase. Peak systolic CSF velocity at C4-5 level in these cases was lower than in volunteers (p < .05), but jet-like CSF propulsion was maintained. Among intermediate-grade cases, peak systolic velocity at C1-2 level was lower than in the volunteer group, but the difference was not significant (p > .05). In high-grade stenosis, both diastolic and systolic velocities were significantly lower (p < .05).Conclusion
Various hydrodynamic changes occurring in CSF flow in cervical spinal stenosis were demonstrated by the SPAMM technique, and this may be a useful method for evaluating CSF hydrodynamic change in cervical spinal stenosis. 相似文献16.
H Yerli E Aydin N Haberal A Harman T Kaskati S Alibek 《Dento maxillo facial radiology》2010,39(6):349-355
Objectives
The purpose of this study was to evaluate the accuracy of MRI combined with diffusion-weighted imaging (DWI) vs fine-needle aspiration cytology (FNAC) in diagnosing common parotid masses.Methods
25 consecutive patients (mean age 61 years) with parotid masses were included in this study. Informed consent and ethical approval was obtained. 22 patients underwent both MRI combined with DWI and FNAC. From DWI data, apparent diffusion coefficient maps were generated. The MRI study protocol consisted of T1 weighted spin echo; T2 weighted and T2 weighted fat-suppressed turbo spin echo; DWI; and T1 weighted fat-suppressed post-contrast images. MRI and FNAC diagnoses were compared with histopathology. Youden''s index was used to compare the two methods.Results
Masses comprised eight Warthin tumours, eight adenomas (six pleomorphic adenomas, two basal cell adenomas), five carcinomas, two lipomas, one haemagioma and one benign lymphadenopathy. Technically, MRI was successful in 24 of the 25 patients (96%), FNAC was successful in 20 of the 23 patients (87.0%). The accuracy, sensitivity and specificity of MRI without DWI were 96%, 80% and 100%, respectively. Diagnostic accuracy did not increase by adding DWI to conventional MRI; however, DWI was helpful for diagnosing benign tumour histology. MRI combined with DWI was successful for determining accurate tumour typing in all benign masses except one lymphadenopathy. When FNAC had adequate material the accuracy, sensitivity and specificity were 95%, 75% and 100%, respectively. Youden''s index was 0.80 for MRI and 0.75 for FNAC.Conclusions
MRI combined with DWI seems to have similar diagnostic potential as FNAC in differentiation of benign vs malignant parotid masses. 相似文献17.
Ki Chang Lee Woo Kyung Moon Jin Wook Chung Seung Hong Choi Nariya Cho Joo Hee Cha Eun Hye Lee Sun Mi Kim Hoe Suk Kim Moon Hee Han Kee-Hyun Chang 《Korean journal of radiology》2007,8(1):9-14
Objective
We wanted to investigate the accuracy of contrast-enhanced MR imaging for the detection of lymph node metastases in a head and neck cancer rabbit model.Materials and Methods
The metastatic lymph node model we used was created by inoculating VX2 tumors into the auricles of six New Zealand White rabbits. T1-weighted MR images were obtained before and after injecting gadopentetate dimeglumine at three weeks after tumor cell inoculation. The sizes, signal intensity ratios (i.e., the postcontrast signal intensities of the affected nodes relative to the adjacent muscle) and the enhancement patterns of 36 regional lymph nodes (parotid and caudal mandibular nodes) were evaluated on MR images and then compared with the histopathologic findings.Results
No statistical difference was found between the sizes of 12 metastatic (10.5±3.2 mm) and 24 hyperplastic (8.0±3.6 mm) lymph nodes (p > 0.05). On the contrast-enhanced T1-weighted MR images, nine metastatic and four hyperplastic lymph nodes had peripheral high and central low signal intensity, whereas three metastatic and 20 hyperplastic lymph nodes had homogeneous high signal intensity. Using a signal intensity ratio less than one as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity and positive and negative predictive values of the enhanced MR images were 75% (9/12), 83% (20/24), 69% (9/13) and 87% (20/23), respectively, with areas under receiver-operating-characteristic curve values of 0.81.Conclusion
This experimental study confirms that metastatic and hyperplastic lymph nodes can be differentiated using MR images on the basis of the contrast uptake patterns, but that they cannot be differentiated using any particular size criteria. 相似文献18.
Joon Seok Lim Myeong-Jin Kim Yong Yun Jung Ki Whang Kim 《Korean journal of radiology》2005,6(4):229-234
Objective
To compare the efficacy of Mangafodipir trisodium (Mn-DPDP)-enhanced MR cholangiogrphy (MRC) and Gadobenate dimeglumine (Gd-BOPTA)-enhanced MRC in visualizing a non-dilated biliary system.Materials and Methods
Eighty-eight healthy liver donor candidates underwent contrast-enhanced T1-weighted MRC. Mn-DPDP and Gd-BOPTA was used in 36 and 52 patients, respectively. Two radiologists reviewed the MR images and rated the visualization of the common duct, the right and left hepatic ducts, and the second-order branches using a 4-point scale. The contrast-to-noise ratio (CNR) of the common duct to the liver in the two groups was also compared.Results
Mn-DPDP MRC and Gd-BOPTA MRC both showed similar visualization grades in the common duct (p = .380, Mann-Whitney U test). In the case of the proximal bile ducts, the median visualization grade was significantly higher with Gd-BOPTA MRC than with Mn-DPDP MRC (right hepatic duct: p = 0.016, left hepatic duct: p = 0.014, right secondary order branches: p = 0.006, left secondary order branches, p = 0.003). The common duct-to-liver CNR of the Gd-BOPTA MRC group was significantly higher (38.90±24.50) than that of the Mn-DPDP MRC group (24.14±17.98) (p = .003, Student''s t test).Conclusion
Gd-BOPTA, as a biliary contrast agent, is a potential substitute for Mn-DPDP. 相似文献19.
Using a transorbital approach we induced the temporal occlusion and reperfusion model in 18 cats. A vascular clamp was placed on the main trunk of the left middle cerebral artery (MCA) for 1 h. Diffusion- and perfusion-weighted MR images were obtained at 1, 3, 6 and 24 h after the clip was released. The cats were killed 24 h after reperfusion, and triphenyl tetrazolium chloride (TTC) staining was performed. After the relative cerebral blood volume (rCBV), time to peak enhancement (TTP) and apparent diffusion coefficient (ADC) maps had been acquired, ROIs were drawn on (1) the area of the infarct produced, (2) the area of high signal intensity on initial diffusion-weighted magnetic resonance imaging (DWI) but normal on TTC staining, e.g., salvaged parenchyma. The ratios of these areas to the normal contralateral cortex were calculated and compared with those of the areas of the final infarct and the salvaged parenchyma. Areas of final infarct showed a temporal increase of rCBV on 3 and 6-h imaging and a final depletion on 24-h imaging. A persistent decrease of ADC value and delayed TTP were observed. Salvaged parenchyma also showed increased rCBV after reperfusion until the last imaging comparing it to the final area of infarct (P < 0.05, 24-h rCBV). The initial decrease in the ADC and delayed TTP normalized on 24-h imaging. In conclusion, rCBV of 24-h imaging was the reliable parameter to predict final infarct. A combination of serial changes on DWI and perfusion-weighted imaging (PWI) can predict ischemic penumbra and outcome. 相似文献
20.
Constantino S. Pe?a Sanjay Saini Richard L. Baron Bernd A. Hamm Giovanni Morana Roberto Caudana Andrea Giovagnoni Andrea Villa Alessandro Carriero Didier Mathieu Michael W. Bourne Miles A. Kirchin Gianpaolo Pirovano Alberto Spinazzi 《Korean journal of radiology》2001,2(4):210-215