Computed tomography in primary lymphoma of the brain

Summary C. T. scans of 19 patients with histologically proved primary lymphoma of the brain were reviewed and divided into three groups: solitary tumors (58%), multifocal tumors (31,5%), diffuse involvement of the brain (10,5%). The C. T. differential diagnosis are manifold, including meningioma, glioma, metastases, progressive multifocal leukoencephalopathy. Arteriography is not specific, but, correlation with C. T. results may suggest the correct diagnosis and encourage biopsy. The radiosensitivity of primary lymphoma of the brain emphasizes, the importance of an early diagnosis.     

Correlation of computed tomography with the histopathology of primary malignant lymphoma of the brain

Summary The authors present seven autopsy cases of non-AIDS primary malignant lymphoma of the central nervous system to correlate the pathology with the findings of the most recent pre-mortem computed tomogram (CT). Of 10 primary contrast-enhancing (CE) lesions treated by chemotherapy alone, radiotherapy alone, radiochemotherapy, or surgery combined with radiochemotherapy, all but one completely disappeared after the initial course of therapy. However, in six of the seven patients, the final pre-mortem CT demonstrated CE lesions. In three cases CE lesions were at the same site as the primary lesion, in one case in a remote location, and in two cases in diffuse and multiple locations. In all but one case these CE lesions corresponded histologically to tumor nodules or to white matter densely infiltrated by tumor cells. The sole exception was diagnosed pathologically as delayed radiation necrosis. The final CT also showed five low-density areas (LDAs) which had evolved from CE lesions after the completion of therapy. These LDAs corresponded to rarefied or necrotic parenchyma in which tumor cells remained, mainly in the perivascular spaces. One case exhibited diffuse tumor infiltration of periventricular structures which appeared to have normal density and no CE on the final pre-mortem CT.     

Computed tomography brain changes in Parkinsonian dementia

Summary In order to evaluate the relationship between brain atrophy and the motor and cognitive function in Parkinson's disease, we have evaluated CT changes in 132 consecutive patients and compared them to measures of physical and mental decline, using intercorrelations and variance analysis. The result demonstrated age as a most important factor relating to brain atrophy. After correction for this determinant, it became clear that the motor and cognitive parameters were interdependent but they affected similar CT parameters. The effect of motor decline was the stronger of the two and it was the only one which correlated with cortical atrophy. The results support the notion of subcortical changes underlying the dementia of Parkinson's disease.     

Cranial computed tomography of patients with malignant melanoma

Summary Sixty-eight patients with malignant melanoma were examined by CCT and the findings analyzed. Cerebral metastases were detected in 19 patients. Meningiomas were found in three patients, one with neurological symptoms and two without. Typical metastases less than 10 mm in diameter were located superficially in the grey matter, regular, homogenous, hyperdense, with no edema. Extensive peripheral edema was often associated with metastases measuring more than 10 mm. CCT revealed cerebral metastases in 6 (13%) of 46 asymptomatic patients. The metastases measured less than 10 mm in four and less than 20 mm in two of these patients. Scintigraphy was falsly negative in six patients with metastases smaller than 10 mm. Therefore, CCT is the method of choice for screening asymptomatic patients. Angiography may be of value in the differentiation between meningioma and melanoma metastases.     

Computed tomography of the ossicles

Summary Otologists and otolaryngologists have described in detail the disorders which are unique to the ossicles. However the anatomy and spectrum of pathology of the ossicles are not familiar to most radiologists. Recent advances in computed tomography (CT) and a systematic approach to evaluation now allow accurate identification of even subtle abnormalities of the ossicles. We present the normal anatomy, ossicular abnormalities, and indications for computed tomographic study. Because of the greater diagnostic capability of CT, the radiologist's role has increased in evaluation and treatment planning of patients with suspected ossicular abnormalities.     

Computed tomography of benign supratentorial astrocytomas of infancy and childhood

Summary The CT findings of 15 benign supratentorial astrocytomas in children less than 15 years of age are compared with the CT findings of 19 supratentorial tumors of other histological types in the same age group. Astrocytomas were more often hypodense, lacked calcification and showed greater contrast enhancement than other tumors. Seven of the 15 astrocytomas were hypodense, without calcification and showed contrast enhancement of more than 10 Hounsfield units, whereas this coexistence was not present in any of the 19 tumors of the other histological types.     

Computed tomography during Creutzfeldt-Jakob disease

Summary A case of extremely advanced Creutzfeldt-Jakob disease of the cortico-striato-cerebellar type is described. The different stages of the disease are documented by computer-tomography.     

Computed tomography of malignant lymphoma involving the skull

The CT findings in two patients with the unusual presentation of malignant lymphoma in the skull are described. The dominant CT findings were contrast enhanced large soft tissue masses without calcifications on both sides of the bone with very little or no changes in the bone itself. This characteristic CT appearance may be helpful to differentiate primary lymphoma of the skull from other bone tumors and osteomyelitis.     

Computed tomography and angiography do not reliably discriminate malignant meningiomas from benign ones

Summary Histological anaplasia, found in up to 10% of meningiomas, is an important prognostic sign as it is associated with increased recurrence rate and volume growth rate. We studied in retrospect a series of 230 primary intracranial meningiomas to discover whether histological anaplasia can be reliably foreseen in CT scans and angiograms. 205 meningiomas were histologically benign, and 25 meningiomas were classified as malignant (atypical or anaplastic), with either incipient (20) or overt (5) signs of anaplasia. Often CT parameters tested, three were associated significantly more often with malignant meningiomas: nodular contour (58.3% vs 26.7%), cysts (20.0% vs 4.4%) and absence of calcifications (92% vs 65.3%); none of these parameters was an absolute sign of anaplasia. Mushrooming, previously regarded as a definite sign of malignancy, was seen in 9% of benign meningiomas and in 21% of malignant ones. In angiography, no apparent differences between benign and malignant meningiomas were seen. The conclusion is that it is not possible to distinguish malignant meningiomas from benign ones with CT or angiography.     

CT-guided biopsy with cutting-edge needle for the diagnosis of malignant lymphoma: experience of 267 biopsies

AIM: We performed a retrospective study of 267 core needle aspiration biopsies in order to estimate the accuracy of CT-guided aspiration core needle biopsies for the diagnosis and subsequent treatment of malignant lymphoma. MATERIALS AND METHODS: Between 1989 and 1999, 267 CT-guided core needle biopsies were performed in 241 patients with either primary or recurrent malignant lymphoma. Patients age ranged from 4--88 years. One hundred and sixty-six (62.2%) nodal and 101 (37.8%) extranodal aspiration biopsies were performed using either 18G or 20G Turner needles. Statistical method used was Chi-square analysis. RESULTS: An accurate histological diagnosis was made in 199 (82.5%) patients, the remaining 42 (17.4%) patients had non-diagnostic CT biopsies. Thirty-seven of them were diagnosed by a surgical biopsy, four by bone marrow biopsy and in one patient by paracentesis. One hundred and seventy-nine patients had non-Hodgkin's lymphoma (NHL) and 62 had Hodgkin's disease (HD); 23 (9.54%) patients underwent repeated CT biopsy which was diagnostic in 17 (73.9%) and non-diagnostic in six (26%). CONCLUSION: CT-guided aspiration core biopsies were sufficient to establish a diagnosis in lymphoproliferative disorders in 82.5% of cases. In the light of this experience we suggest that imaging-guided core needle biopsy be used as the first step in the work up of many patients with lymphoma.     

Computed tomography of the sternum and its articulations

The chest wall presents diagnostic difficulties for both the clinician and the radiologist. Because of normal variations in anatomy and ossification, analysis of the sternal region can be particularly confusing. We reviewed the normal computed tomographic (CT) appearance of the sternum in 354 patients. Important normal sternal variants included cortical unsharpness along the posterior aspect of the manubrium, lateral surfaces of the body, and at the sternal fibrocartilaginous articulations; soft tissue prominence at the junction of the sternum and costochondral cartilage; and bony sclerosis at the transitions from manubrium to body and from body to xiphoid. In seven patients with clinically significant sternal abnormality, key CT features were abnormal soft tissue mass (7/7), destruction or irregularity of the cortical contour (7/7), and abnormal increased attenuation of bone (1/7). CT should be the radiologic study of choice in patients with suspected abnormality of the sternum and its articulations.     

原发性回盲部淋巴瘤的CT表现

目的 探讨原发性回盲部淋巴瘤(PIL)的CT征象,以提高该疾病的CT诊断水平.方法 回顾性分析12例经手术病理证实的PIL的CT资料,所有患者均行CT平扫,其中8例加扫CT增强.结果 12例PIL中,肿块型2例,弥漫增厚型10例,病变肠管长约7.8~18.5 cm,平均约10.2 cm.9例病变肠腔不规则或瘤样扩张,3例明显狭窄;10例病变肠壁柔和,2例肠壁僵硬.CT平扫增厚肠管呈软组织密度影,8例增强扫描中,6例增厚肠管呈延迟均匀轻中度强化,2例见小片状坏死区;最大密度投影(MIP)示8例病变肠管均可见增粗肠系膜上动脉分支供血.9例病变肠管周围、肠系膜根部或腹膜后伴肿大淋巴结.1例并发肠梗阻,1例并发肠穿孔.结论 CT检查发现回盲部肠管呈均匀环形软组织肿块,且病变肠管范围较长,相应管腔扩张,管壁柔和,增强呈均匀轻中度延迟强化时,应考虑淋巴瘤可能.     

Computed tomography of lambdoid calvarial defect in neurofibromatosis

Summary A patient with neurofibromatosis is reported in whom cranial computed tomography (CT) revealed a calvarial defect with an associated soft-tissue mass in the region of the left lambdoid suture. This defect has been the subject of several previous reports, having been demonstrated by means of conventional skull radiography. It should be included in the differential diagnosis when a lytic calvarial lesion is found on CT.     

Computed tomography in migratory disorders of human brain development

Summary Computed tomographic findings in developmental brain anomalies are more easily classified when the system used is based on embryogenesis related to morphology. Analysis of computed tomographic findings in a series of 154 patients with brain anomalies (Chiari malformation not included) revealed that specific examples of abnormalities occurring in major stages of brain development may be recognized by computed tomography. This paper deals with a group of patients with abnormalities that reflect a disturbance in neuronal migration.     

原发性颅脑恶性淋巴瘤的CT和MRI表现

目的探讨颅脑原发性恶性淋巴瘤的CT和MRI表现特征。方法收集经病理证实颅脑原发性恶性淋巴瘤9例,MRI平扫和增强,CT平扫和增强,分析病灶的影像表现。结果 9例中单发6例,多发3例,共检出14个病灶,11个病灶位于中线两旁的深部脑组织内,3个病灶位于脑实质表面,7个病灶呈结节状或团块状,病灶周围水肿中到重度,占位效应较明显。CT平扫病灶全均表现为稍高密度,6例增强扫描病灶呈明显强化。MRI平扫病灶T1WI呈等、低信号,T2WI以高信号多见,增强时实质部分明显均匀强化。结论颅脑原发性恶性淋巴瘤CT、MRI表现具有一定特征性,为临床治疗方案的选择提供重要依据。     

Computed tomography in spastic cerebral palsy

Summary Eighty-three children with spastic cerebral palsy (CP) were examined with cranial CT. In 56 cases the CT findings were abnormal. The most frequent abnormality was atrophy, present in 44 patients. The frequency of pathologic CT increased with severity of the CP. Patients with CP of postnatal aetiology more often had abnormal CT than patients with other known causes. Pathologic CT findings were seen more often in patients with seizures than in patients without. Infarctions and hemiatrophy were much more frequent in patients with hemiplegia than in patients with other types of spastic CP. A special kind of central atrophy, called isolated atrophy around the cella media, is described. This condition was seen in 20% of cases, most often in hemi- and paraplegic patients. Early infarctions in the border areas between the vascular territories of the internal carotid and the posterior cerebral artery may be the reason for this kind of atrophy.     

A case of primary malignant lymphoma of the brain with high uptake of 123I-IMP

Summary In general the ¹²³I-IMP SPECT image of a brain tumor is visualized as a defect. Tumor case with high IMP uptake have been rarely reported. We encountered a case of primary malignant lymphoma of the brain with high IMP uptake on both early and late scans corresponding to the CT lesions. Previously reported positive cases seemed to be confined to the early scan. For the present the exact behaviour of IMP is incompletely understood, but the mechanism of high uptake has been accounted for by increased extraction and increased amine receptors at the tumor sites. We need further information to establish whether these SPECT findings were specific for primary malignant lymphoma of the brain.     

A brain phantom for studying contrast recovery in emission computerized tomography

A brain phantom is described that is characterized by a high anatomical definition and by the possibility of varying the internal contrast with the use of a single radioactive solution. The experimental work was done with a single-photon emission computerized tomographic (SPET) rotating camera. The phantom was used to study the contrast recovery of both the filtered back-projection and an iterative reconstruction algorithm. Moreover, it was also used to find a cross-calibration factor between activity concentrations in the SPET slices and an external reference.     

囊性肾恶性肿瘤的CT诊断

目的 :探讨囊性肾恶性肿瘤的CT表现与临床病理基础 ,提高对囊性肾恶性肿瘤的认识。方法 :对经手术病理证实的 2 2 7例肾恶性肿瘤中 2 5例囊性肾恶性肿瘤的CT图像进行回顾分析。结果 :2 5例囊性肾恶性肿瘤中肾盂移行细胞癌 8例 ,肾细胞癌 16例 ,肾胚胎癌 1例。本组 2 5例囊性肾恶性肿瘤的壁均显示较厚 (厚于 3 .0mm) ,且厚薄不均 ,占 10 0 %。囊变区有不规则的分隔或囊内有实性成分 2 0例 ,占 80 %。增强后囊壁、囊内分隔及实性成分均有强化。囊变区内CT值较单纯性肾囊肿高 ,P <0 .0 1。结论 :囊性肾恶性肿瘤的CT表现有一定特征性 ,了解这些特征有利于正确诊断     

Early response monitoring in malignant lymphoma using fluorine-18 fluorodeoxyglucose single-photon emission tomography

Metabolic response monitoring early during chemotherapy may have a major impact on clinical management of patients with malignant lymphoma. In two patients with non-Hodgkin's lymphoma fluorine-18 fluorodeoxyglucose (IgFDG) single-photon emission tomography (SPET) studies were performed during the first two chemotherapeutic cycles. Persisting uptake predicted treatment failure whereas a sharp reduction of ¹⁸FDG uptake was demonstrated in the case of a responsive tumour. Qualitative analysis of conventional ¹⁸FDG imaging may thus serve to identify patients with a non-responding tumour. The potential of this technique in the determination of the initial response remains to be established. Imaging with ¹⁸FDG and SPET appears promising as a more easily available methodology than ¹⁸FDG positron emission tomography.