Computed tomography versus magnetic resonance imaging of the brain. A collaborative interinstitutional study

A retrospective study (1983-1984) of magnetic resonance imaging (MRI) and computed tomography (CT) examinations in 471 patients with known pathology in the brain and craniocervical junction was conducted in order to determine the relative efficacy of MRI versus CT. All MRI examinations involved slice thickness greater than 10 mm, and only single-slice single-echo or multislice single-echo imaging techniques were available. These studies were evaluated independently by two neuroradiologists from a panel of six for anatomic abnormalities, lesion contrast, and radiologist's impression. Results, which excluded microadenomas of the pituitary and approximately 9% of studies in which consensus was not achieved by the readers, were as follows: (1) 14% of the studies were positive on MRI but normal on CT; (2) in 55% of the studies, MRI was better than CT; (3) MRI was equal or better than CT in 95% of the studies; and (4) CT was better than MRI in 5% (21/421) of the examinations. There were no patients in this series where CT was positive but MRI missed the abnormality.     

Ependymomas of the posterior cranial fossa: CT and MRI findings

We studied nine children with posterior cranial fossa ependymomas to identify specific neuroradiological features. Patients were studied preoperatively with CT and MRI; T1-, T2-and proton-density (PD)-weighted images were obtained. All children underwent surgery and a definite histopathological diagnosis was made. All the tumours grew into the fourth ventricle and caused dilatation of its upper part, which resembled a cap. All but one were separated from the vermis by a cleavage plane. In eight cases there was desmoplastic development through the foramina of the fourth ventricle, and five were heterogeneous due to necrosis and cystic change; one had a haemorrhagic area. In most cases the solid portion was isointense with grey matter on T1-weighted images, hyperintense on PD weighting, and isointense on T2-weighted images. On CT the tumour was isodense in six cases and calcification was detected in four. The presence of both desmoplastic development and a tumour/vermis cleavage plane in a posterior cranial fossa tumour isodense on CT is highly suggestive of ependymoma.     

Multiple glioblastomas: CT and MR features

The aim of this study was to analyze the CT and MR features of multiple glioblastomas, and to determine the best imaging modality for the initial diagnosis. The CT (four exams) and MR imaging (eight exams) of eight patients with proven multiple glioblastomas were reviewed by two neuroradiologists. The lesions were always hypo- or isodense on CT and hyperintense on T2-weighted images (100 %). They were usually hypo- or isointense on T1-weighted images (90 %). Edema and mass effect were very variable. After contrast media administration, the enhancement was mostly strong (71 % on CT and 70 % on MR), often either heterogeneous or ring-like. The different lesions of a patient often had a different pattern on MR (75 % of cases). Meningeal or ventricular enhancement, suggestive of a possible way of dissemination, was rare. In case of multiple cerebral masses, multiple glioblastomas should be considered as a possible diagnosis in addition to the better known diagnosis of brain metastases, abscesses, or multifocal lymphomas. Moderate edema and mass effect on MR associated with strong and heterogeneous enhancement are suggestive of feature of multiple glioblastomas. Magnetic resonance allows rarely the visualization of a dissemination route. Received: 10 March 2000 Revised: 18 May 2000 Accepted: 22 May 2000     

Medulloblastoma in children: CT and MRI findings

Our purpose was to determine whether medulloblastoma (MB) shows specific neuroradiological features which may be employed in differential diagnosis from other common posterior cranial fossa tumours in childhood. Preoperative MRI was performed on 20 children with MB, and preoperative CT in 17 of them. All underwent surgery and histopathological diagnosis. There was a constant relationship between high density on CT and low signal on T1-weighted images. Signal behaviour on T2-weighted images and the degree of contrast enhancement were more variable. Most tumours arose in the midline, from the cerebellar vermis, involving the fourth ventricle, but hemisphere and extra-axial neoplasms were also seen. The combination of high density on CT and low signal on T1-weighted images is highly suggestive of MB and may assist preoperative differential diagnosis from other posterior cranial fossa tumours.     

MRI versus CT in the diagnosis of Nelson's syndrome

The purpose of the study was to evaluate the utility of MRI and CT in the diagnosis of Nelson's syndrome, i. e. pituitary tumours in patients bilaterally adrenalectomized for Cushing's disease. Thirteen patients, followed up for 5–29 years after adrenalectomy, were studied. In 6 of them CT and MRI revealed no changes in the pituitary gland. In the remaining 7 patients only three CT scans were suggestive of a pituitary adenoma. MRI studies with administration of gadodiamide confirmed the CT diagnosis of Nelson’s tumour in 3 patients and disclosed microadenomas in a further 4 patients. Neurosurgical treatment in 4 patients confirmed the MRI findings. Additionally CT and MRI examinations were performed in 5 patients suspected of a recurrent Nelson's tumour 3–11 years after neurosurgery. MRI visualized recurrent adenomas in 3 patients that were not well seen by CT scans. In our experience MRI was more effective than CT in the diagnosis of Nelson's syndrome. Received 17 October 1995; Revision received 25 January 1996; Accepted 31 January 1996     

化脓性髋关节炎的CT与MRI表现

目的分析化脓性髋关节炎的CT与MRI表现,并评价其临床意义。方法回顾性分析30例经临床和手术病理证实的化脓性髋关节炎患者的CT与MRI表现,其中,行CT检查24例,MRI检查15例,同时行CT与MRI检查者9例。结果在CT与MR像上,软组织肿胀分别见于20例和14例,关节腔积液分别见于24例和15例,滑膜及肉芽组织增生分别见于13例和11例,关节间隙改变分别见于13例和9例,骨质改变分别见于24例和15例。CT显示骨内积气4例,MRI显示软组织脓肿1例。结论 MRI对化脓性髋关节炎的早期病理改变,诸如少量关节腔积液、邻近软组织轻度肿胀以及骨质早期改变的显示,明显优于CT,但是CT对骨内积气和骨质晚期改变的显示优于MRI。CT与MRI在化脓性髋关节炎诊断与指导治疗中起重要作用。     

肺外炎性肌纤维母细胞瘤的影像学表现与病理对照

目的探讨肺外炎性肌纤维细胞瘤（IMT）的影像学诊断价值并与病理对照。 方法回顾性分析8例经手术病理证实的肺外IMT的CT、MRI表现。将CT、MRI表现与病理进行对照分析,探讨其CT、MRI表现的病理基础。 结果8例肺外IMT患者中7例行CT检查,其中1例同时行MRI检查;1例行MRI检查。CT平扫病灶表现为实性软组织密度,平扫密度均匀2例;不均匀5例,其中3例增强扫描呈明显不均匀强化;伴有邻近骨质破坏3例。MRI增强扫描1例明显均匀强化;1例增强后不均匀强化。病理表现为为成纤维细胞增生,间质胶原化、毛细血管增生与黏液变性,伴多量炎性细胞浸润。 结论肺外IMT的CT、MRI征象与病理表现相符合,影像学检查有助于IMT的正确诊断和鉴别诊断,对明确病灶范围以及与邻近组织器官关系有重要价值,对术前诊断、指导临床选择合理的治疗方案有很大帮助。     

腹部巨大淋巴结增生CT及MRI表现

目的：巨大淋巴结增生的CT和MRI增强表现特点,旨在提高对本病的认识,方法：自1984年1月－2000年5月间,4例巨大淋巴结增生病例接受CT和MRI检查并经手术和病理证实,其中,男2例,女2例,年龄18＝56岁平均41岁,结果：4个病例中2例病灶位于肠系膜,2例位于腹膜后区,局限型3例弥漫型1例,采用动态增强和螺旋CT多期扫描, 灶在动脉期或在动态增强早期明显强化,所有的病灶在延期均表现为持续强化,MRI T1WI 1例表现为低信号,1例为中等信号,T2WI均呈高信号,动态增强扫描病灶的强化方式与CT一致,结论：系膜或腹膜后区富血供的病变,在动脉期明显强化,延迟期持续强化,CT值接近主动脉密谋者,提示巨大淋巴结增生的诊断。     

In vivo MRI of the fetal brain

We report MRI of the brain in 45 fetuses; the findings were confirmed by pathological examination or postnatal neuroradiological studies. MRI necessitates medication to eliminate fetal motion; curare was injected into the umbilical cord, and MRI is therefore limited to cases in which umbilical cord puncture is indicated. T1-weighted images were obtained in axial, sagittal and coronal planes; the last of these was generally as the most useful as regards morphology. We demonstrated cerebral malformations (n=13), brain haemorrhage (n=1), a facial angioma (n=1), a facial mass (n=1), hydrocephalus (n=5), unilateral ventricular enlargement (n=1), atrophy (n=4), a porencephalic cyst (n=1) and normal appearances of the brain in 18 cases. Twenty-two of the fetuses were born alive, and the clinical and/or neuroradiological examination confirmed the antenatal findings. The diagnosis was also confirmed in 8 cases in which a neuropathological examination was possible.     

Hepatic fascioliasis: report of two cases

Two cases of hepatic fascioliasis with characteristic features in US examinations and CT scans are presented. In both modalities they show tunnel-like branching and clustered areas of low echogenicity/density, which reach subcapsular regions. These cases are presented to recall the imaging features in hepatic fascioliasis especially outside endemic regions. Not only CT but also US is able to detect these characteristic lesions, which may help to make the diagnosis of hepatic fascioliasis in patients with clinical symptoms suggestive of parasitic disease. Received: 4 November 1999; Revised: 30 March 2000; Accepted: 4 April 2000     

Comparison of CT with diffusion-weighted MRI in patients with hyperacute stroke

Tissue changes in ischaemic stroke are detectable by diffusion-weighted MRI (DWI) within minutes of the onset of symptoms. However, in daily routine CT is still the preferred imaging modality for patients with acute stroke. Our purpose of this study was to determine how early and reliably ischaemic brain infarcts can be identified by CT and DWI. Three neuroradiologists, blinded to clinical signs but aware that they were dealing with stroke, analysed the CT and DWI of 31 patients with an acute ischaemic stroke. We calculated k-values to analyse inter-rater variability. The ratings were compared with follow-up studies showing the extent of the infarct. The combined assessment of all observers gave positive findings in 77.4 % of all CT examinations, with k = 0.58. Areas of high signal were seen on all DWI studies by all observers (k = 1). Estimation of the extent of the infarct based on DWI yielded k = 0.70 and that based on CT k = 0.39. DWI was much more reliable than CT in the detection of early ischaemic lesions and we believe that it should be used in acute ischaemic stroke before aggressive therapeutic intervention. Received: 11 August 2000 Accepted: 29 November 2000     

Pancreatic cancer: correlation of MR findings, clinical features, and tumor grade

PURPOSE: To assess the frequency of occurrence of poorly-marginated and focally-defined pancreatic ductal adenocarcinoma by MRI and to determine whether these appearances correlate with clinical features and histopathological grade. MATERIALS AND METHODS: Institutional review board with waiver of informed consent was obtained for this HIPAA compliant study. A total of 33 patients (16 female, 17 male, mean age = 63.5 +/- 12.8, ranging from 41 to 80 years) with histopathologically-proven pancreatic ductal adenocarcinoma who underwent MR examination between August 2000 and February 2005 were retrospectively evaluated. Clinical data and histopathological tumoral grade were obtained from clinical charts; nine of 33 patients were excluded of the histopathological evaluation since their diagnosis was performed by fine needle aspiration biopsy and it was not possible to obtain the histopathological grade. Two radiologists reviewed all cases independently to identify whether cancers were poorly-marginated or focally-defined. Agreement between radiologists was assessed using the kappa coefficient. The overall correlation between imaging findings, clinical features, and histopathological grade was assessed with contingency tables using the Fisher's exact test. RESULTS: Of the 33 patients, nine (27.2%) were classified as poorly-marginated and 24 (72.8%) as focally-defined. Agreement between the two reviewers was excellent (k = 0.92, 95% confidence interval (CI) = 0.78-1.0). Poorly-marginated cancers exhibited well- to moderately-differentiated histopathology in 71.4% of cases, while focally-defined cancers had well- to moderately-differentiated histopathology in 17.6% of cases, P = 0.02. CONCLUSION: A poorly-marginated appearance of pancreatic ductal carcinoma on MRI is not uncommon. These cancers exhibited statistically significant moderate- to well-differentiated histopathology compared to focally-defined cancers.     

MR增强扫描在骨样骨瘤诊断中的临床价值

目的分析骨样骨瘤的X线、CT、MRI的影像表现,总结其影像学特征,比较不种影像学检查方法的诊断价值,优化检查,提高对骨样骨瘤的诊断及鉴别诊断能力。方法对我院经手术或穿刺病理证实的32例骨样骨瘤的影像学表现进行回顾性分析。男23例,女9例,男女之比2.61;年龄1.6~42岁,平均年龄9岁。13例同时行X线、CT、MRI检查,26例行X检查,21例行CT检查,20例行MRI检查,8例增强。结果32例骨样骨瘤中,有24例出现大小不一的圆形或椭圆形瘤巢,直径为0.28^-2.22cm,瘤巢周围伴有不同程度的骨质硬化。X线对瘤巢显示率为35%(9/26),4例瘤巢中心出现钙化;CT对瘤巢显示率为90%(19/21),出现钙化者16例,8例显示“血管沟征”;MRI平扫对瘤巢显示率为55%(11/20),增强MRI对瘤巢的显示率为100%(8/8)。20例MRI检查均显示不同程度的骨髓水肿。结论瘤巢是确诊骨样骨瘤的关键,MRI增强扫描对瘤巢的显示率不亚于CT,增强MRI检查在一定程度上能够准确地诊断骨样骨瘤,不用暴露于放射线就可定位瘤巢。     

MRI在主动脉夹层诊断中的应用价值

目的：探讨磁共振技术在诊断主动脉夹层的应用价值。方法：通过对24例主动脉夹层的MRI影像分析,并与CR对照,结果：MRI在破口位置,内膜片及附壁血栓的显示皆优于CT,而在真假腔显示上两者相近。结论：MRI是诊断主动脉夹层的主要检查方法之一。     

Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations

Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.     

Comparison of magnetic resonance imaging sequences with computed tomography to detect low-grade subarachnoid hemorrhage: Role of fluid-attenuated inversion recovery sequence

OBJECTIVES: To compare computed tomography (CT) with magnetic resonance imaging (MRI) for the presumptive diagnosis and localization of acute and subacute low-grade subarachnoid hemorrhage (SAH). METHODS: We consecutively enrolled 45 patients clinically suspected of low-grade SAH, comparing them with a control group. We obtained axial nonenhanced CT scans as well as fluid-attenuated inversion recovery (FLAIR) and T2-weighted gradient echo (T2*) MRI sequences at 1.0 T. Two neuroradiologists scrutinized the presence of blood at 26 different regions in the intracranial subarachnoid space (SAS). RESULTS: Three of 45 patients had normal CT and MRI scans, and SAH was excluded by lumbar puncture. We demonstrated SAH on CT scans in 28 of 42 (66.6%) patients, T2* sequences in 15 of 42 (35.7%) patients, and FLAIR sequences in 42 of 42 (100%) patients. Fluid-attenuated inversion recovery sequences were superior to CT in 16 of the 26 evaluated regions. CONCLUSIONS: The FLAIR sequence was superior for presumptive diagnosis and localization of acute and subacute low-grade SAH, representing a potential tool in this setting.     

肾癌的影像学表现

目的:探讨提高肾癌的诊断准确率。方法:搜集82例经手术病理证实的肾癌病例,就其B超、X线(静脉或逆行肾盂造影)、CT、MRI及血管造影表现及误诊原因进行回顾性分析。结果:82例中,80例行B超检查,均发现异常,确诊18例,误诊8例;48例X线检查,42例发现异常,确诊6例,误诊12例;72例行CT检查,均发现异常,确诊49例,误诊8例;12例MRI检查,均发现异常,确诊8例,误诊3例;69例血管造影检查,68例发现异常,确诊56例,误诊8例。结论:B超在发现肾脏病变中具有较高的检出率;CT对确定诊断有较高价值,是目前最可靠的诊断肾癌的影像学方法。对CT不能确诊的可行MRI或血管造影,静脉或逆行肾盂造影检查助诊。     

Correlation between computed tomography and magnetic resonance imaging in diastematomyelia.

Preoperative neuroradiological evaluation of diastematomyelia cases is of vital importance in order to increase surgical success rate. This paper reports the neuroradiological data of diastematomyelia cases in the light of surgical findings, and discusses the efficacy of CT and MRI in the evaluation of patients with diastematomyelia.     

大脑胶质瘤病的MRI表现特征及其病理基础

目的探讨大脑胶质瘤病（GC）的MRI表现特点及其病理基础。资料与方法分析经活检、手术病理证实的12例GC的MRI表现特征,并与病理切片进行对照研究。对其中8例于同期行常规头颅CT扫描。结果MRI显示GC病变广泛,11例（91,7％）累及三叶以上大脑,以额、颞、顶叶受累多见。病变区脑组织肿胀,无囊变、钙化和肿块形成,占位效应不明显,周围正常脑组织结构仍可辨识。同时伴胼胝体侵犯10例（83.3％）,基底节和丘脑侵犯5例,脑干侵犯3例,小脑和脊髓侵犯各1例。病变在T1WI上均以低信号为主;T2WI、液态衰减反转恢复序列（FLAIR）上均为均匀高信号。增强扫描10例（83、3％）无强化。8例CT扫描仅显示大脑弥漫性等或低密度,显示的病变范围均小于MRI。在病理上表现为不同分化程度的胶质肿瘤细胞在神经束间、神经细胞及血管周围浸润性生长,其中纤维型星形细胞瘤8例,胖细胞型星形细胞瘤2例,混合型星形细胞瘤和少枝胶质瘤各1例。结论MRI不仅能反映GC的病理特性,而且能清楚显示肿瘤在颅内的侵犯范围,是诊断GC的首选影像学方法。