Bone tumors: magnetic resonance imaging versus computed tomography

The magnetic resonance (MR) imaging characteristics of bone tumors are described and the clinical utility of MR imaging in patient evaluation is reported. Fifty-two patients with skeletal lesions were examined with a Picker MR imager (0.15-T resistive magnet). Twenty-five patients had primary malignancies, seven had benign bone neoplasms, 15 had skeletal metastases, and five had neoplasm simulators. Forty-five patients had CT scans available for comparison. For demonstrating the extent of tumor in marrow, MR was superior to CT in 33% of cases, about equal to CT in 64%, and inferior to CT in 2%. For delineating the extent of tumor in soft tissue, MR was superior to CT in 38% of cases and about equal to CT in 62%. CT was superior in all cases for demonstrating calcific deposits and pathologic fractures. In four patients with metal prostheses or surgical clips, MR was superior to CT in documenting recurrent tumor because of artifactual degradation of the CT image. Direct sagittal and coronal images from MR permit accurate assessment of the relationship of tumor to adjacent normal structures, including the physis, joints, and neurovascular structures. MR is useful in the evaluation of bone tumors: it is of greatest value in evaluations of the peripheral skeleton, the medullary canal, soft tissues, and postoperative tumor recurrence. With a 0.15-T magnet, MR is less useful in the evaluation of the axial skeleton and cortical bone.     

Magnetic resonance imaging of primary tumours and tumour-like lesions of bone

The experience with magnetic resonance imaging (MRI) of 81 patients with primary bone tumours and tumour-like lesions is reported. MRI proved to be a sensitive method of detecting primary bone tumours. Intramedullary and extraosseous parts of bone tumours were, delineated better than by plain films and computed tomography (CT). Surgical clips and Harrington rods did not appreciably limit the estimation of tumour recurrence. MRI provided definite advantages compared to CT in the surgical staging of bone tumours and tumour-like lesions. MRI was found to be an imaging method with low specificity. Differentiation of tissue components, such as haematoma, fat, necrosis, and cystic areas, led to a specific diagnosis only in rare cases. Plain films and CT were found to be superior to MRI in assessing the biological activity and the differential diagnosis of bone tumours and tumour-like lesions.     

Nasopharyngeal carcinoma: MRI and CT assessment

Precise assessment of the extent of nasopharyngeal carcinoma (NPC) represents the basic step towards optimal treatment. We compared the capacity of CT and MRI in assessing the extent of NPC in 67 patients. MRI was superior to CT in demonstrating lesions in the retropharyngeal node, skull base, intracranial area, carotid space, longus colli muscle and levator palatini muscle. Of 25 cases in which retropharyngeal adenopathy was recognised only on MRI, seven had been reported as showing oropharyngeal involvement and 18 as primary extension to the carotid space on CT. MRI showed skull-base involvement in 40 patients compared with 27 on CT and intracranial involvement in 38 patients versus 24 on CT. There was not a single case in which skull base invasion was seen on CT but not on MRI. MRI enabled improved recognition of tumour infiltration of longus colli muscles (34 cases compared with 15 on CT). It allowed us to clarify 12 questionable sinonasal opacities on CT. Overall, T-staging was changed in 18 of 67 patients (26.9 %), including upstaging in 15 cases and downstaging in 3 cases, after comparing CT with MRI. The nodel status was changed from negative on CT to positive on MRI in 4 of 67 patients (6 %). We believe that MRI allows more accurate evaluation of the extent of NPC than CT and should be the primary mode of investigation. Received: 18 November 1996 Accepted: 22 January 1997     

A comparative study of magnetic resonance imaging and computed tomography-assisted myelography in spinal dysraphism

Thirty-seven patients with a wide spectrum of spinal dysraphic lesions were studied by both magnetic resonance imaging (MRI) and myelography complemented by computed tomography (CT). Magnetic resonance imaging proved to be superior for tissue characterization, overall anatomical definition, topographical relationships of the cranio-cervical junction and demonstration of the presence and extent of hydrosyringomyelia. Demonstration by CT myelography of fine neural structures such as the filum terminale and nerve roots remains the superior technique; however, with constantly improving spatial resolution and thinner-slice imaging, MRI will become increasingly competitive in this respect. The osseous component of these lesions was best demonstrated by CT myelography. A high incidence of associated syrinx (8/15 cases) was found in the diastematomyelia group, with an overall incidence of 15 cases in all the dysraphic patients studied. The use of both T1- and T2-weighted sequences is required for tissue characterization. Whilst both imaging modalities proved complementary in the investigation of spinal dysraphism, we suggest that, with its superior tissue characterization and anatomical display of these lesions. MRI should be the primary imaging technique. Avoidance of an invasive procedure and use of ionizing radiation confers additional benefits upon MRI. The relative ease and shorter examination time of MRI makes this technique ideal for pre- and post-operative monitoring and assessment.     

纵隔型肺癌的CT及MR表现分析

目的 探讨纵隔型肺癌CT及MRI诊断能力.方法 回顾分析15例经纤支镜、穿刺活检及手术病理证实为纵隔型肺癌的CT及MRI影像资料,15例全部行CT平扫,其中11例增强扫描,3例行MR平扫与增强扫描.分析CT及MRI图像上肿块的位置、大小、形态、边缘及其与纵隔和肺的关系.结果 15例纵隔型肺癌为单发肿块,5例小细胞型肺癌,8例鳞癌、腺癌及腺鳞癌各1例.肿块均位于纵隔胸膜下,与纵隔呈宽基底相贴,大多呈类圆形或椭圆形.边缘分叶12例,毛刺9例.肿块位于上纵隔8例,中纵隔5例,下纵隔2例.其中前中纵隔区12例,后纵隔3例.肿块与肿大淋巴结融合7例.癌肿邻近相应支气管变窄或闭塞9例.4例有胸廓骨转移性骨质破坏.结论 纵隔型肺癌易误诊,仔细分析CT及MRI表现,结合临床可作出较准确的诊断.     

脊柱骨巨细胞瘤的影像学诊断

目的 评价脊柱骨巨细胞瘤的影像学表现。资料与方法 回顾性分析16例脊柱骨巨细胞瘤的CT和MRI表现，全部病例均经穿刺或手术病理证实。结果 发生于颈椎8例。胸椎1例，腰骶椎7例。除7例侵犯相邻2个椎体，余均累及1个椎体，除单纯溶骨性破坏和椎体压缩性改变各1例外，CT主要表现为椎体偏心性，膨胀性破坏，10例MRI检查中除2例巨大软组织肿块的病灶中可见无强化的囊性信号外，8例为T1WI稍低信号，T2WI稍高信号，增强扫描均匀强化。结论 影像学对骨巨细胞瘤有很高的诊断价值。     

Comparing computerized tomography and magnetic resonance in the study of articular pathology of the knee

The authors present a comparison between the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the articular pathologies of the knee. CT and MRI were performed in 30 patients who subsequently underwent surgery. CT and MRI results were compared on three bases: technique, definition of normal anatomy, and diagnostic accuracy. CT allowed a standardization of the technique, while MRI was superior in defining normal anatomy--especially in the study of capsulo-ligamentous structures. In all cases the use of both CT and MRI allowed a correct diagnosis, showing the site, extent and gravity of the lesion. CT proved to be superior to MRI in 4 cases, while MRI corrected CT diagnosis in 11 cases; in 15 patients both techniques had the same diagnostic accuracy. Meniscal tears were better identified by CT, while MRI was superior in the detection of ligamentous lesions and in the characterization of PVNS and tendinitis of the patellar tendon. In conclusion, MRI should be performed in selected cases only, or when CT cannot be trusted; on the other hand, it might also be used as a first-choice diagnostic procedure for synovial pathologies and acute lesions of the anterior cruciate ligament.     

Differential diagnosis of truly suprasellar space-occupying masses: synopsis of clinical findings,CT, and MRI

This review demonstrates the features of truly suprasellar masses in modern imaging based on the clinical, CT, and MRI findings of 42 patients with suprasellar masses in correlation to the histologic findings. The radiologic examinations were evaluated retrospectively to determine if diagnosis can be made based on specific imaging patterns. The most frequent clinical findings of space-occupying suprasellar masses were visual disturbances, diabetes insipidus, and symptoms and signs of occlusive hydrocephalus. There were no clinical features specific for any of the observed masses. Craniopharyngiomas were the most frequent tumors. They appeared in two different forms, as cystic and as solid enhancing masses. The cystic tumors could not be differentiated from cystic hamartomas or cystic gliomas by CT or MRI. The solid craniopharyngiomas were similar to meningiomas and hamartomas. In craniopharyngiomas of adults calcifications were not common. In CT and especially in MRI gliomas were characterized by the diffuse infiltration of the adjacent brain tissue or optic nerve. Except for meningiomas, all lesions were highly variable in appearance, making a reliable characterization by CT and MRI difficult in many cases. However, administration of contrast media in some cases resulted in a better tumor delineation. Compared with unenhanced MRI the enhanced scans did not increase diagnostic efficacy for neoplasms, but were helpful in the differentiation from inflammatory diseases. The MRI technique was superior to CT in demonstrating the anatomic relationships, thus facilitating evaluation of origin and extent of the lesions. The CT technique, of course, was more reliable in the detection of calcifications. Both CT and MRI are not tissue-specific, however,and suprasellar tumors as well as many other neoplasms cannot be classified using only one of these imaging techniques.To optimize the diagnostic strategy both imaging modalities should be used with close regard to patient history, physical examination, and clinical parameters. Correspondence to: J. Reul     

脊索瘤的C T、MR I表现及其误诊分析

目的：探讨脊索瘤的CT、MRI表现及分析其误诊原因。方法回顾性分析18例脊索瘤 CT、MRI 图像,对术前诊断错误者进行影像分析及总结。结果术前12例诊断正确,6例误诊。颅底部9例,骶尾部8例,颈椎1例。CT与 MRI显示病灶呈圆形或类圆形12例,不规则形6例;14例边界清楚,4例边界不清。CT见膨胀性溶骨性骨质破坏,肿块呈不均匀等密度或稍低密度;9例病灶内或周边见点片状钙化或残存骨质。MRI示病灶呈等稍低T1 WI、高T2 WI信号;CT及 MRI增强后肿块呈不均匀轻中度强化。结论脊索瘤具有一定的CT、MRI特征,CT与 MRI结合对脊索瘤的定位、定量、定性诊断具有重要的价值。     

Comparison of computed tomography and other imaging modalities in the evaluation of musculoskeletal tumors.

An algorithmic approach for the evaluation of musculoskeletal tumors is proposed on the basis of a prospective comparison of different imaging techniques in 50 unselected patients. Conventional radiography was superior to other techniques in predicting the nature of primary bone tumors. Computed tomography proved the most effective method for assessing the extent of musculoskeletal tumors and therefore had a significant influence on management in 66% of patients studied. CT was more informative than angiography and also provided more anatomical detail than ultrasound. Radionuclide scanning was mainly of value in detecting unsuspected skeletal metastases in patients with apparently solitary skeletal lesions.     

Primary malignant fibrous histiocytoma of the chest wall: CT and MR appearance

PURPOSE: The purpose of this work is to describe the CT and MR appearance of primary malignant fibrous histiocytoma (MFH) of the chest wall. METHOD: Eleven men and eight women (45-76 years old) with primary MFH of the chest wall who underwent both CT and MRI were enrolled, and the imaging interpretation was retrospectively compared to the pathologic specimen. RESULTS: All tumors were inhomogeneous in appearance on CT scans. All tumors showed high signal intensity on T2-weighted images. On T1-weighted MR images, tumors displayed inhomogeneous isosignal intensity in 15 cases (79%) and low signal intensity in 5 (21%) compared with the surrounding muscle. Tumors exhibited inhomogeneous enhancement in all except three localized tumors on enhanced CT and MRI. Invasion of intercostal muscle was noted on MR images in 18 patients (95%) and on CT in 11 patients (58%). CONCLUSION: There might be various radiologic appearances of MFH. However, CT and MRI are able to demonstrate the exact localization and disease extent of MFH arising in the chest wall.     

99mTc-MIBI scintigraphy in untreated stage III multiple myeloma: comparison with X-ray skeletal survey and bone scintigraphy

Technetium-99m 2-methoxyisobutylisonitrile (99mTc-MIBI) is a lipophilic agent that has been proposed as a useful tracer for the detection of disease sites in patients with multiple myeloma (MM). We performed a prospective study to determine the potential of 99mTc-MIBI imaging for the evaluation of the extent of primary disease in patients with advanced stage MM, compared with skeletal survey and bone scintigraphy. Twenty patients with advanced stage MM at initial diagnosis underwent whole-body 99mTc-MIBI imaging, together with contemporaneous skeletal survey and bone scintigraphy. The findings of 99mTc-MIBI imaging were correlated with the results of skeletal survey and bone scan. All 99mTc-MIBI scans were positive for the presence of active MM, whereas skeletal surveys were positive in 18 patients (90%) with osteolytic lesions. Bone scintigraphy demonstrated MM in only 15 patients (75%). In two patients with no detectable lesions on skeletal survey, 99mTc-MIBI imaging revealed uptake in the spine, corresponding to the abnormalities seen on magnetic resonance imaging (MRI). With respect to the localization of bone lesions, 99mTc-MIBI imaging was superior to bone scintigraphy in 15 patients (75%) and had concordant results with bone scintigraphy in four (20%). 99mTc-MIBI imaging is a very sensitive imaging modality for the identification of the extent of disease in patients with advanced MM. It is clearly superior to bone scintigraphy and complements the results of skeletal survey by finding additional disease sites. Hence, in active MM patients, 99mTc-MIBI imaging has the potential to detect bone marrow disease that cannot be detected by skeletal survey and bone scintigraphy.     

原发性骨恶性纤维组织细胞瘤的CT和MRI诊断

目的:探讨原发性骨恶性纤维组织细胞瘤(BMFH)的CT和MRI表现,以提高影像诊断水平。方法:收集经手术病理证实的原发性BMFH 13例,9例行CT检查,其中行增强扫描3例;6例行MRI检查,其中行增强扫描2例;2例同时行CT和MRI检查。分析原发性BMFH的CT和MRI表现,并与组织病理学表现相对照。结果:13例中,长骨骨端11例,长骨骨干1例,髂骨1例。骨质表现为溶骨性破坏,其中6例病灶边缘有轻度骨硬化,7例骨质破坏区间夹杂粗细不等的骨嵴,骨膜反应1例;MRI表现为T1WI等低信号,T2WI混杂高信号。13例均见超过骨破坏范围的软组织肿块,钙化1例;T1WI表现为等或等低信号,T2WI为等高或混杂高信号。CT、MRI增强扫描病变不均匀强化。结论:原发性BMFH的CT、MRI表现有一定的特征,能较好地反映病变的病理特点,对术前明确诊断具有重要意义。     

脑部剪裂伤的CT与MRI诊断(附19例报告)

目的 评价CT和MRI对脑部剪裂伤的诊断功效。方法 回顾性分析了19例脑深部剪裂伤的CT和MRI影像表现和特点。结果 CT显示3个病灶，MRI显示了30个损伤灶，19例全部经MRI确诊，CT的敏感性只有MRI的10%。结论 MRI检查尤其是高场强MRI在颅脑剪裂伤的诊断中具有重要意义。比CT检查有显的优越性，随着MRI设备的普及，对颅脑损伤的病人行MRI检查应作为常规。     

脊柱原发性骨肿瘤CT和MRI观察

目的：了解脊柱肿瘤的CT和MRI表现特征。资料与方法：分析49例脊柱肿瘤的CT和MRI表现，包括成骨细胞瘤、骨髓瘤和骨肉瘤各2例，动脉瘤样骨囊肿（ABC）3例，血管瘤和淋巴瘤各5例，骨巨细胞瘤多位于椎体，呈溶骨性破坏；成骨细胞瘤和骨肉瘤CT呈骨性密度，MRI信号较低，后者伴软组织肿块；22例脊索瘤伴骶前包块，11／16例CT上出现钙化，9例在T2WI有条状低信号纤维结构和高信号粘液基质。骨髓瘤（1例）、淋巴瘤在T1WI和T2WI分别呈略低信号和较高信号，1例骨髓瘤在T2WI呈高信号。结论；CT和MRI可清楚地显示肿瘤的部位和范围，两者结合，多数肿瘤可以定性。     

骨肉瘤病的影像学诊断

目的分析骨肉瘤病的影像学表现，评价影像学的诊断价值。方法总结分析15例骨肉瘤病的影像学特点。15例均行平片检查，其中13例行CT检查，11例行发射型计算机体层摄影(ECT)检查，5例行MR检查。4例行DSA造影检查。结果15例中骨肉瘤病主病灶位于股骨远端者8例，胫骨近端5例，肱骨近端1例，锁骨1例。主病灶之外的多发病灶发生在股骨远端者6例，其中双侧病变2例。位于胫骨近端者8例，骨盆2例，脊柱椎体6例，颅骨1例，髂骨及骶髂关节4例，双侧股骨近端3例，胫骨远端2例。15例主要病变X线表现为典型骨肉瘤样，而发生在其他部位的病灶表现不同，多呈圆形成骨样改变。13例CT观察到病变范围分布及软组织肿块的情况；其中发生在骨髓病变区内的病变多为边缘清楚的高密度瘤骨，5例病变在MRI呈圆形信号改变。特别是髓腔内低信号的骨化区域显示得很清楚。11例ECT检查者可见呈全身分布的广泛浓聚区域。4例于DSA可观察到肿瘤血管边界及肿瘤血管的走行。结论骨肉瘤病为全身的多发病灶，影像学检查可观察全身发病的部位、表现，对疾病的诊断和治疗将提供可靠的依据。     

FDG positron emission tomography in the surveillance of hepatic tumors treated with radiofrequency ablation

PURPOSE: Radiofrequency thermal ablation (RFA) is an emerging technique in the treatment of focal hepatic tumors. Magnetic resonance imaging (MRI) and computed tomography (CT) are currently used to monitor hepatic tumors after RFA for residual disease and recurrence. Fluorodeoxyglucose (FDG) positron emission tomography (PET) is an excellent imaging method for the detection of liver metastases, but it has not been thoroughly evaluated as an alternative to anatomic imaging in the surveillance of liver tumors treated with RFA. The purpose of this investigation was to determine the role of FDG-PET imaging in the surveillance of liver tumors treated with RFA. METHODS: Thirteen patients with histories of malignant tumors of the liver treated with RFA and who had received post-treatment FDG-PET scans were assessed retrospectively. One patient had two post-RFA FDG-PET scans, eight patients had concurrent MRI scans, and six patients had concurrent CT scans. Imaging findings were compared with the results of clinical follow-up. RESULTS: There were either recurrent tumors at the ablation site (8 patients) or new metastases (3 patients) in 11 patients. FDG-PET identified all 11 cases and did not misidentify any cases. Of the seven patients with positive PET findings who received an MRI scan, three were also positive on MRI (42.9%); the other four cases were either negative or equivocal. Of the four patients with positive PET findings who received a CT scan, only two had positive CT scan findings (50%). All recurrences diagnosed by PET were confirmed on clinical follow-up. CONCLUSION: In this preliminary study, FDG-PET was superior to anatomic imaging in the surveillance of patients treated with RFA for malignant hepatic tumors.     

髂骨原发囊样骨肿瘤及瘤样病变的影像学诊断

目的:分析髂骨囊样骨肿瘤及肿瘤样病变的影像学表现。方法:回顾性分析经穿刺或/和手术病理证实的46例髂骨囊样骨肿瘤及肿瘤样病变影像学表现。46例全部行X线片检查,38例行CT检查,20例行MRI检查(增强16例)。结果:46例中骨肿瘤29例,其中良性肿瘤12例(骨巨细胞瘤4例,内生软骨瘤、软骨母细胞瘤各2例,血管瘤、骨母细胞瘤、骨样骨瘤、软骨黏液样纤维瘤各1例),恶性肿瘤17例(恶性巨细胞瘤、骨恶性纤维组织细胞瘤各1例,软骨肉瘤、淋巴瘤各4例,骨肉瘤7例),肿瘤样病变17例(单纯性骨囊肿1例,邻关节骨囊肿、动脉瘤样骨囊肿、嗜酸性肉芽肿各2例,骨纤维异常增生症10例)。发病部位为髂翼39例,髋臼7例。病变主要表现为髂骨囊样骨质破坏,呈膨胀性改变30例,硬化环形成24例,病变内见钙化灶14例,软组织肿块20例。结论:常见的髂骨囊样骨肿瘤和肿瘤样病变一般都具有某些特征性的CT表现,必要时综合X线、MRI表现,可提高定性诊断符合率。     

Computed tomography of cardiac and pericardial tumors

Computed tomography (CT) scans in 30 patients with neoplastic involvement of the heart and pericardium were retrospectively reviewed. Computed tomography was compared with echocardiography in three of four patients with large primary cardiac tumors and in three patients with metastatic pericardial disease. Computed tomography was superior to echocardiography in determining tumor extent and site of origin of a right atrial sarcoma, as well as in assessing tumor extent and presence of pulmonary arterial hypertension in a left atrial malignant fibrous histiocytoma and a left atrial myxoma. Pericardial effusions were detected by echocardiography in two out of three patients with metastatic pericardial disease, but the malignant nature of the effusion was not recognized; in all three cases CT showed nodular pericardial thickening. Of the 23 patients with evidence on CT of direct extension of anterior mediastinal masses, bronchogenic carcinoma or mesothelioma to the pericardium 21 had nodular pericardial thickening and 2 diffuse thickening; only 6 had pericardial effusion. We conclude that CT is useful in the characterization of large primary cardiac tumors that are incompletely visualized with echocardiography. Computed tomography is superior to echocardiography in assessing tumor involvement of the pericardium because pericardial effusions are often absent; CT is also superior in identifying nodular pericardial thickening.     

基底动脉尖综合征CT与MRI表现

目的评价CT与MRI对诊断基底动脉尖综合征（BATS）的能力并计算这两种影像技术的检出率。方法8例BATS患者最初于临床症状出现后24h内均经CT与MRI头颅扫描,2～5d后,全部病例又经CT复查。观察记录了每一例的CT与MRI表现,并计算和比较了这两种影像技术的检出率。结果最初的CT扫描准确诊断了8例中的3例,显示病灶数12个,最初的MRI扫描准确诊断了所有8例,显示病灶数45个,CT复查确诊了所有8例,显示病灶数56个。与CT复查检出数比较,最初CT扫描的检出率为21%（12/56）,MRI的检出率为80.4%（45/56）。主要CT与MRI表现为双侧丘脑、中脑梗死,不同程度合并颞枕叶、小脑半球、内囊后肢以及脑桥梗死。结论CT和MRI两者都能准确诊断BATS,但在早期诊断中,MRI明显优于CT,然而,CT复查可为BATS的确诊提供可靠依据。