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1.
Sixty-nine patients with traumatic knee hemarthrosis were evaluated an average of 3 days after trauma by high field (1.5T) magnetic resonance imaging (MRI) using sagittal T1, T2-weighted and coronal 3D-gradient echo images. All knees were arthroscopically examined shortly afterwards. The diagnostic validity of MRI for intraarticular pathology was determined using arthroscopy as golden standard. All patients had pathological findings on arthroscopy. The injuries were sports-related in 77% of the cases. MRI was highly sensitive (86%) and specific (92%) for diagnosis of anterior cruciate ligament tears. Diagnosis of medial meniscal tears showed a 74% sensitivity and 66% specificity. MRI detected lateral meniscal tears in 50% with an 84% specificity. As such, MRI missed 10 significant meniscus ruptures requiring surgical treatment. The sensitivity for partial or total medial collateral ligament tears was 56%, the specificity 93%. Rupture of the medial retinaculum in cases with patellar dislocation or significant damage of articular cartilage were only detected by MRI in a few cases (27% and 20% sensitivity, respectively). MRIs low diagnostic validity for intraarticular pathology with hemarthrosis may be attributed to the shifting paramagnetic properties of the blood remains and catabolic processes in meniscal and chondral tissues during the hemoglobin degradation process. Accordingly, MRI, with the technique used, could neither replace arthroscopy in the diagnosis and screening of acute knee injuries, nor select patients with need for immediate arthroscopic meniscal surgery.  相似文献   

2.
The accuracy of magnetic resonance imaging (MRI) in diagnosing knee pathology in the pediatric and adolescent population is not well established. The purpose of this study was to correlate the findings of MRI and knee arthroscopy in children and adolescents. One hundred and eight consecutive knee arthroscopies performed in patients ages 4-17 years between 1992 and 1996 were retrospectively reviewed. Fifty-three of these patients underwent preoperative MRI. Age-related comparisons were then made between MRIs and observed intraoperative meniscal and anterior cruciate ligament pathology. The pediatric group (ages 4-14 years) was demonstrated to have an appreciable decrease in sensitivity, specificity, positive predictive value, and accuracy for essentially all categories of pathologic changes. Conversely, negative predictive values for the pediatric group exceeded those of the adolescent group (ages 15-17 years) in each category. The ability of MRI to predict intraarticular knee pathology among adolescents is comparable to that in adults, whereas it is much less accurate in the pediatric population.  相似文献   

3.
AIMS: Although fine needle biopsy (FNB) is a well established diagnostic technique there continues to be controversy concerning its use in the pre-operative assessment of intraparotid masses. The purpose of this study was to evaluate the diagnostic accuracy, specificity and sensitivity of FNB in parotid tumours and consequently to asses its clinical value. METHODS: Over a 6-year period, 129 consecutive patients with parotid masses underwent pre-operative FNB evaluation and in 121 of these cases the cytological diagnosis was confirmed. RESULTS: Out of the 86 cases cytologically diagnosed as benign, two false negative results were obtained by FNB, whereas out of the 38 cytological diagnoses of malignant tumours one case was found histologically to be Warthin's tumour. In the FNB results of the two cases suspicious for malignancy, one was confirmed histologically as malignant. Three cases of FNB with inadequate material were found to be benign lesions. In this trail, the diagnostic accuracy of FNB was 96.7%, the specificity, 97.6% and the sensitivity, 95%. CONCLUSIONS: Our results show that FNB is a valuable examination technique in the pre-operative evaluation of parotid masses.  相似文献   

4.
In addition to the patient's history and a thorough clinical investigation, magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) has been introduced to complete the findings for the diagnosis of internal derangement of the TMJ. However, 'dynamic information' is desirable to help us to understand the mechanism of internal derangement. This information is given for example by electronic axiography recording systems. The lack of any ability to assess joint function dynamically in MRI is a point of criticism. Using a computer-driven pseudodynamic MRI system (CINE mode) 'dynamic information' should be now available. In this investigation 21 patients with TMJ disorders were examined using both conventional static MRI and CINE mode. For the diagnosis of an anterior displaced disc with or without reduction in 18 cases (86%) it was only necessary to consider two static MRIs: a closed mouth position and a maximal open mouth position. Comparison showed there was no advantage in using CINE mode. Contrast and resolution of the static MRIs were shown to be better and so additional findings such as joint effusion and disc deformation could be diagnosed on static MRIs with greater certainty. Only in three (14%) cases was the dynamic information from CINE mode useful for the diagnosis of the displacement of the disc.  相似文献   

5.
BACKGROUND: The use of surface coils for magnetic resonance imaging (MRI) allows enhanced image definition and so potentially more accurate staging of colorectal cancer. Endorectal coil imaging is invasive, operator dependent and impossible in a high proportion of patients due to rectal stricture. The phased-array pelvic coil, however, is non-invasive and applicable to all rectal tumours. METHODS: A pelvic phased-array coil was used for preoperative MRI staging of 38 primary rectal carcinomas. Results were expressed according to the Dukes and tumour nodes metastasis (TNM) classifications. After resection of the tumour, the stage predicted on MRI was compared with the pathological classification. RESULTS: The overall accuracy of preoperative staging with the pelvic phased-array coil was 55 per cent for both Dukes class and T stage. Assessment of nodal involvement gave an overall accuracy for MRI of 76 per cent with a sensitivity of 57 per cent and specificity of 88 per cent. CONCLUSION: Use of a pelvic phased-array coil did not improve the staging accuracy of MRI to a clinically useful level.  相似文献   

6.
OBJECTIVE: The purpose of this prospective, observational study was to examine the relationship of clinical examination, plain radiograph (XR), triple-phase bone scan (TPBS), and magnetic resonance imaging (MRI) in the investigation of patients presenting with acute shin splints. METHODS: 23 subjects with exercise induced lower leg pain and diffuse tibial tenderness of less than 3 months' duration were recruited. Subjects were excluded if there was clinical evidence of compartment syndrome, muscle hernia, or stress fracture. Each subject underwent XR, TPBS, and MRI within 2 wk of physical examination. Four asymptomatic controls underwent TPBS and MRI. Clinical findings, XR, TPBS, and MRI findings were independently recorded using a consistent template and subsequently analyzed. A single consensus lesion was chosen that provided the greatest overlap and highest grade to allow comparison of clinical and imaging findings. Sensitivity and specificity were calculated from data relating to clinical findings and diagnostic imaging. RESULTS: Eighteen subjects had bilateral symptoms and five unilateral with a mean duration of symptom of 5.4 wk (+/- 3.5). Of 41 symptomatic lower legs, there were TPBS abnormalities in 36 and MRI findings in 34. Analysis of clinical findings to TPBS and MRI demonstrated a sensitivity and specificity of 84%, 33% and 79%, 33%, respectively. Assuming TPBS as the "gold-standard," MRI findings demonstrated a sensitivity of 95% and specificity of 67%. There was poor agreement between the grading of TPBS and MRI (k = 0.3). In the 5/46 asymptomatic limbs, 3/5 demonstrated uptake on bone scan and 4/5 signal change with MRI. Imaging abnormalities were similarly seen in the four control patients. CONCLUSIONS: MRI may be used rather than TPBS and radiographs for evaluating acute tibial pain in athletes where avoidance of radiation exposure is desirable. Similar sensitivity and specificity may be expected from both investigations; however, in the light of abnormal TPBS and MRI findings in control and asymptomatic limbs, we recommend further studies be performed to define the extent of nonpathological TPBS and MRI changes.  相似文献   

7.
Scintimammography is a recently verified technique that will expand the use of nuclear medicine to a new group of patients in whom scintigraphic imaging has not been widely used. If performed correctly, and in certain groups of patients, it delivers a sensitivity as high as X-ray mammography or magnetic resonance imaging (MRI) in palpable tumours but with greater specificity. It is best used in patients in whom X-ray mammography, ultrasound and MRI prove non-diagnostic or unhelpful, particularly those women with dense breasts or who have had previous breast surgery. The mechanism of uptake of 99Tcm-MIBI in breast tissue is only partly understood and in itself may help in determining important aspects of tumour function, such as the response to cytotoxic chemotherapy. Other scintigraphic methods for imaging breast cancer may be able to look at other aspects of cancer function, for example blood supply, metabolic rate or the in vivo assessment of oestrogen or somatostatin receptor status. This in turn may be useful in planning treatment. Metastatic disease may best be monitored with 18F-FDG PET, which has a sensitivity greater than MRI but a similar specificity. Much furtner work will need to be done on the use of nuclear medicine in breast cancer, but the addition of unique functional information to the anatomical data from X-ray and MRI should benefit future patients' management.  相似文献   

8.
Magnetic resonance imaging (MRI) is used increasingly for evaluating the rotator cuff. This study of 39 shoulders (38 patients) compared the accuracy of MRI interpretation of rotator cuff integrity by a group of community hospital radiologists (clinical community scenario, CCS) with that of a musculoskeletal radiologist (experienced specialist scenario, ESS), relative to arthroscopy. For the CCS subgroup, the sensitivity, specificity, positive predictive value (PV), negative PV, and accuracy for partial tears were: 0%, 68%, 0%, 82%, and 59%, respectively; for complete tears: 56%, 73%, 36%, 86%, and 69%, respectively; and for all tears combined: 85%, 52%, 50%, 87%, and 64%, respectively. For the ESS subgroup, the respective values for partial tears were: 20%, 88%, 20%, 88%, and 79%, respectively; for complete tears: 78%, 83%, 58%, 92%, and 82%, respectively; and for all tears: 71%, 71%, 59%, 81%, and 71%, respectively. We concluded that MRI assessment of the rotator cuff was not accurate relative to arthroscopy. MRI was most helpful if the result was negative, and MRI diagnosis of partial tear was of little value. Considering the high cost of shoulder MRI, this study has significant implications for the evaluation of patients with possible rotator cuff pathology.  相似文献   

9.
Contrast-enhanced MRI of the breast is probably the most sensitive method to detect breast pathology. It is best used to improve the sensitivity of mammography and sonography in selected patient groups with high breast cancer prevalence, where conventional methods are known to be less sensitive. Despite the high sensitivity of MRI, 5-12 % of invasive carcinomas are not recognized during MRI, because of lack of the typical criteria of carcinoma. MRI is probably inferior to mammography in detecting ductal in-situ carcinoma or very small carcinomas (< 3 mm), because the neo-angiogenesis induced by these small carcinomas is too faint to be detected by contrast-enhanced MRI. These tumours cannot be excluded by a normal MRI examination. MRI is non-specific as the distinction of benign and malignant breast lesions is unreliable. Only in selected cases (fat- or blood-containing lesions) may it improve the specificity of mammography and sonography. Mostly image-guided core biopsy is by far the most specific and least expensive method to establish a definitive diagnosis. For lesions exclusively detected by contrast-enhanced MRI, simple and reliable localisation devices are urgently needed. Presently accepted indications for MRI of the breast are: patients with silicone implants after mastectomy or augmentation mammoplasty (detection of recurrence/prosthesis rupture/silicon leakage); patients whose breasts are difficult to evaluate by combined mammography and sonography, who have had breast conservation therapy (local recurrence), or who have proven carcinoma in one breast (multifocality/-centricity or contralateral breast carcinoma) or proven axillary lymph node metastases from an unknown primary tumor, especially when these are hormone receptor positive; patients with extensive postoperative scarring. In the future, genetically defined high breast cancer risk may become an indication.  相似文献   

10.
OBJECTIVE: To determine the accuracy of MRI in the assessment of the radiographically occult scaphoid fracture. DESIGN: This prospective study compared the sensitivity and specificity of MRI for detection of radiographically occult scaphoid fractures with bone scintigraphy (BS), the currently accepted imaging modality of choice. Consecutive patients with clinical signs of a scaphoid injury but no evidence of fracture on plain radiographs at presentation and after 7-10 days were evaluated by MRI and BS. All images were reported in masked fashion and the sensitivities and specificities of the imaging modalities determined. All patients with a scaphoid fracture demonstrated by MRI or BS were followed for at least a year after injury. PATIENTS: Forty-three subjects (aged 12-74 years) had both MRI and BS carried out on average 19 days from the injury date. RESULTS AND CONCLUSIONS: Six patients (14%) had scaphoid waist fractures. There were other bony injuries in a further six. In 40 patients there was agreement between the BS and MRI findings. In three cases there was discrepancy between the imaging modalities; in all three MRI was found to be the more sensitive and specific. MRI could become the investigation of choice for this injury.  相似文献   

11.
RATIONALE AND OBJECTIVES: The authors evaluate the role of low-field strength magnetic resonance imaging (MRI) compared with sonography in the evaluation of degenerative changes of tendons, with histologic correlation, based on investigations of horse cadavers. METHODS: Low-field MRI and sonography was performed in 42 hours specimens for the evaluation of tendons and ligaments. Magnetic resonance imaging included sagittal and axial T1-weighted, T2-weighted, and gradient echo images. Sonography and MR images were evaluated for degenerative changes or tears and the findings were correlated with the histologic results. RESULTS: Using histologic findings as a gold standard, the accuracy for the sonographic evaluation was 65.9%, sensitivity was 16.7%, and specificity was 100%. The corresponding data for low-field MR imaging were 70.5% accuracy, 44.4% sensitivity, and 88.5% specificity. CONCLUSIONS: Low-field MRI investigation allows more accurate staging of tendinous changes than sonography. It is more reproducible and potentially includes the advantages of the combined evaluation of bones, ligaments, and soft tissue.  相似文献   

12.
Diagnostic imaging, consisting of roentgenograms and magnetic resonance images (MRIs), was performed as part of an evaluation of the effects of a functional electrical stimulation (FES) program on the knee joints of 29 adolescents with spinal cord injuries following implantation of fine-wire intramuscular electrodes in their lower extremity muscles. The subjects underwent a regimen consisting of stimulated exercise, standing and/or walking. The effects of FES on knee joints were prospectively studied by reviewing diagnostic imaging data. Evaluation of MRIs and plain radiographs showed no evidence of knee joint pathology secondary to FES exercise or weight bearing. In fact, based on follow-up of MRI scan, many of the joints improved following participation in the program. The MRI data supported the clinical examination of the knee joints of these children. Clinical examination appears adequate for screening for potential knee joint problems.  相似文献   

13.
OBJECTIVE: To evaluate if pelvic magnetic resonance imaging (MRI) is reliable for differentiating leiomyoma subtypes. DESIGN: Prospective study. SETTING: Academic center. PATIENT(S): Forty-five patients underwent MRI before surgery for leiomyomata. INTERVENTION(S): One radiologist blinded to patient history and histologic diagnosis recorded the MRI characteristics and classification of the largest leiomyoma. MAIN OUTCOME MEASURE(S): Comparison of MRI and histologic diagnoses. RESULT(S): Leiomyoma subtypes were diagnosed accurately by MRI in 69% of cases. Magnetic resonance imaging had a 95% sensitivity and 72% specificity for diagnosing an uncomplicated leiomyoma and a 10% sensitivity and 100% specificity for a cellular leiomyoma. For cystic leiomyomata, the sensitivity was 80% and specificity was 98%, and for hemorrhagic leiomyomata, 100% and 86%, respectively. Magnetic resonance imaging correctly diagnosed all malignant tumors and did not incorrectly diagnose a leiomyoma as a leiomyosarcoma in any case. Ill-defined MRI margins were significantly more likely to be leiomyosarcoma, whereas well-defined margins were characteristic of benign lesions. Hemorrhagic leiomyomata were significantly more likely to be hyperintense on T1-weighted images than other subtypes. CONCLUSION(S): Although MRI is only fairly accurate in differentiating the subtypes of benign uterine smooth muscle tumors, signal intensities and margin characteristics are useful to distinguish accurately benign from malignant tumors.  相似文献   

14.
To identify brain lesions most often associated with cerebral visual i mpairment (CVI) after neonatal encephalopathy and to evaluate the prognostic value of MRI for visual outcome, the authors reviewed visual assessments and brain MRI of 80 infants and young children with documented perinatal hypoxic-ischaemic and/or haemorrhagic insults. MRIs were classified according to the severity of lesions at the optic radiations and at the visual cortex; visual acuity was tested with the acuity card procedure. Among the 48 children found to have a CVI, 42 had moderate to severe lesions of the optic radiations and 19 had lesions of the visual cortex. In both cases visual acuity was statically correlated with MRI grading, but the damage at the optic radiations was the better predictor. Early detection of abnormal MR findings in the visual cortex and especially, at the optic radiations may indicate which infants with neonatal encephalopthy should receive longitudinal visual assessment and specific rehabilitation and educational management.  相似文献   

15.
Forty-two patients with acoustic neuroma (AN) were studied to determine whether different types of neuroma could be correlated with specific signs and symptoms of the disease. Based on gadolinium-enhanced TI-weighted MRI sequences, the 42 cases of AN could be divided into three groups, either by size (small: 11.9%, medium: 50%, and large: 38.1%) or by site of origin of the tumour (lateral: 16.7%, intermediate: 69%, and medial: 14.3%). Relations were found between the size and the site of origin of the neuromas and certain clinical, audiological and vestibular findings. The clinical presentation seemed to vary with the site of origin and the size of the tumour: patients with lateral neuromas generally had small tumours, sometimes only located in the internal auditory canal (IAC), and presented early subjective hearing loss while patients with medial neuromas had larger tumours which grew without causing significant audiological symptoms. Normal hearing function was seen only in the patients with medial ANs; however, a significant relation between the size or the site of origin of the AN and the average hearing threshold was not demonstrated. The sensitivity of the stapedial reflex test (SR) was higher for lateral ANs. Anomalies in the brainstem auditory evoked potentials (BAEPs) did not seem to be related to either the size or the site of origin of the AN. The vestibular tests demonstrated a higher frequency of central vestibular involvement in the large tumours, while normal function was more frequent in the lateral tumours. In the group studied the combination of BAEPs and vestibular tests allowed us to identify all the ANs with an optimal level of sensitivity.  相似文献   

16.
OBJECTIVE: To assess dynamic Gd-DTPA-enhanced magnetic resonance (MR) imaging in the diagnosis of primary breast pathology, and to test the hypothesis that analysis of contrast agent kinetics increases specificity. METHODS: Forty-seven women underwent breast MR imaging using three-dimensional and dynamic spoiled gradient-recalled sequences. Image interpretation was based on the evaluation of lesion conspicuity, signal intensity, contour and enhancement pattern from the static acquisitions. Assessment of contrast kinetics was based on pixel-by-pixel analysis of the dynamic data. A two-compartment model described by three parameters (amplitude of uptake, exchange rate and washout rate), and a three-compartment model described by two parameters (permeability and exchange rate) were used. Regions of interest were drawn for all lesions found in the dynamic sections. Mean regional pixel values were calculated for each parameter and tested for diagnostic efficacy. RESULTS: Twenty-two malignant and 36 benign lesions were examined. Fibroadenomas accounted for 86% of the benign tumours. Image interpretation had a sensitivity of 0.95 and specificity of 0.86. The fat-suppressed post-contrast images permitted good visualization of the contour and matrix characteristics of fibroadenomas, but all non-fibroadenomatous benign lesions were classified as indeterminate or suspicious. Significant differences were found between benign and malignant lesions in the amplitude of uptake (P = 0.0008) and exchange rate (P < 0.00005) of the two-compartment model, and permeability (P=0.0001) and exchange rate (P < 0.00005) of the three-compartment model. However, image interpretation was superior to the isolated use of quantitative indices (P=0.02). The most discriminating parameters were the exchange rates of both models, with no significant difference between them. CONCLUSION: Assessment of lesion morphology is essential and probably sufficient for the differentiation of fibroadenomas from malignant tumours. However, specificity of conventional MR imaging may be much lower for other types of primary benign breast pathology. Analysis of Gd-DTPA kinetics improves the specificity obtained using simple enhancement measurements and can be used to produce parametric images that provide information about lesion heterogeneity, permeability and vascularity.  相似文献   

17.
The aim of the study was to compare the diagnostic accuracy of scintimammography with technetium-99m methoxyisobutylisonitrile (MIBI; SMM) in the detection of primary breast cancer with that of mammography (MM) and magnetic resonance imaging (MRI). Fifty-six patients with suspected lesions detected by palpation or MM were included in the study. Within the 4 weeks preceding excisional biopsy, MM and MRI were performed in all patients. Between 5 and 10 min after the injection of 740 MBq 99mTc-MIBI, SMM in the prone position was performed. In the total group of 56 patients, 43 lesions were palpable, while 13 were non-palpable but were detected by MM. Breast cancer was confirmed by histopathology in 27 of the patients (22 palpable and 5 non-palpable carcinomas). The tumour size ranged from 6 to 80 mm in diameter. For non-palpable lesions, the sensitivity of SMM, MM and MRI was 60%, 60% and 100%, respectively, while the specificity was 75%, 25% and 50%, respectively. For palpable breast lesions, all methods showed high sensitivity (SMM 91%, MM 95%, MRI 91%) but SMM demonstrated significantly higher specificity (SMM 62%, MM 10%, MRI 15%). In two mammographically negative tumours (dense tissue), SMM showed a positive result. In comparison to MRI, one additional carcinoma could be diagnosed by SMM. It may be concluded that for palpable breast lesions, the diagnostic accuracy of SMM is superior to that of MM and MRI. Through the complementary use of SMM it is possible to increase the sensitivity for the detection of breast cancer and multicentric disease. In patients in whom the status of a palpable breast mass remains unclear, SMM may help to reduce the amount of unnecessary biopsies.  相似文献   

18.
The uptake of L-1-[11C]-tyrosine (TYR) in cervical lymph nodes of eleven patients with squamous-cell carcinoma (SCC) of the oral cavity was studied with PET to detect lymphogenic metastases. METHODS: The TYR-PET results were compared with clinical, MRI, CT, histopathologic findings and historical data of patients studied with FDG. Sensitivity, specificity, accuracy and the positive and negative predictive values were calculated. RESULTS: TYR-PET had sensitivity of 83% and a specificity of 95%. In contrast, the sensitivity and specificity for MRI were 33% and 96%, respectively. The sensitivity and specificity for CT were 55% and 91%, respectively. TYR-PET results compared favorably with FDG. CONCLUSION: With TYR-PET, SCC metastases of the oral cavity can be visualized with high sensitivity and specificity. TYR-PET can be an additional tool for further evaluation of neck malignancies.  相似文献   

19.
OBJECTIVE: Imaging studies of patients with bipolar disorder demonstrate changes in deep white matter and subcortical gray nuclei that are seen as focal hyperintensities on T2-weighted magnetic resonance imaging (MRI). The objective of this study was to examine MRIs in a family with a strong history of bipolar disorder to look for possible MRI abnormalities in members with and without affective illness. METHOD: The authors obtained MRIs of 21 members of a family with a strong history of bipolar disorder. Eight of the family members studied had bipolar illness, one had symptoms of bipolar disorder but did not meet full DSM-III-R criteria, two had unipolar disorder, and 10 did not have bipolar disorder. RESULTS: Fifteen of the 21 family members had MRI findings, including six of 10 family members who had no affective disorder and all of those with bipolar disorder. Lesions of both white matter and subcortical gray nuclei were found. CONCLUSIONS: Although the clinical significance of these MRI findings is unknown, the high prevalence of MRI findings in both affected and unaffected family members suggests that MRI findings may potentially serve as a biological marker for bipolar disorder. Recent genetic studies have established a link between familial leukoencephalopathy and chromosome 19. If leukoencephalopathy appears to be related to bipolar disorder, it may allow clearer characterization of the genetics of the disorder.  相似文献   

20.
OBJECTIVE: To compare 201thallium (T1) uptake and SPECT with MRI in children with brainstem gliomas. MATERIALS AND METHODS: Ten children with brainstem gliomas were prospectively evaluated by 201Tl-SPECT and MRI. Histological verification was obtained in eight children - two died prior to surgery. Quantitative thallium uptake index (UI) was obtainable in five cases and was compared to tumour grade. In addition, two patients with known benign brainstem lesions (neurofibromatosis and tuberculoma) were similarly prospectively evaluated. RESULTS: All children with brainstem glioma accumulated thallium. (Mean U1 3.23, 100% sensitivity). The single patient with brainstem tuberculoma also accumulated thallium (UI 2.80, 91.7% specificity). There was no correlation between thallium uptake and tumour grade. Uptake could not be conclusively correlated with the following MR features: gadolinium enhancement, exophytic or intrinsic gliomas, necrosis and location of glioma within the brainstem. CONCLUSIONS: 201T1-SPECT is a promising imaging adjunct in the assessment of childhood brainstem gliomas.  相似文献   

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