Isodense subdural haematomas on CT: MRI findings

Summary MRI findings are described in two patients with subdural haematomas isodense on CT. In one patient, admitted 6 weeks after trauma, a chronic subdural haematoma showed extreme hypointensity on T2-weighted images, suggesting acute trauma, and therefore acute rebleeding. In the second patient with severe anaemia, an acute subdural haematoma was hyperintense on T2-weighted images, suggesting chronic trauma; this may be explained by the low haematocrit and a possible mixture of blood with cerebrospinal fluid. The MRI features of subdural haematomas and hygromas have to be kept in mind, in order not to misjudge the age of the haematoma.     

Acute spontaneous spinal subdural haematoma: MRI features

We present MRI findings in three patients with acute spontaneous subdural haematomas of the spine. Acute haematomas (1–3 days) were isointense or gave slightly high signal on T1- and heterogeneous signal on T2-weighted images. MRI precisely defined the level and extent of the haematoma preoperatively. The MRI was prospectively correctly interpreted as acute subdural haematomas in all patients. As a specific, noninvasive modality, MRI is the preferred imaging technique in this rare clinical entity. Received: 13 September 1999 Accepted: 17 January 2000     

Characteristics of symptomatic chronic subdural haematomas on high-field MRI

We studied the frequency of various features of the appearances on high-field MRI in symptomatic patients with chronic subdural haematomas (CSDH). The ability to predict recurrence after treatment with one burr-hole procedure using MRI was evaluated. A total of 40 patients with symptomatic CSDH underwent MRI at 1.5 T. All haematomas were evacuated within a few days of the MRI examination. Symptomatic CSDH were divided into five groups according to the MRI findings: group A (11 cases), isointense or low signal on T1- and low signal on T2-weighted images; group B (18 cases), high signal on T1- and low signal on T2-weighted images; group C (5 cases), high signal on both T1- and T2-weighting; group D (1 case), low signal on T1- and high signal on T2-weighted images; group E (5 cases), heterogeneous intensity on T1- and T2-weighting throughout the haematoma cavity. The mean interval between onset of symptoms and MRI for group A was 5.0 ± 4.1 days, which was significantly shorter than that for group B (9.4 ± 4.4 days, P < 0.02), group C (27.8 ± 20 days, P < 0.005) or group E (17.8 ± 12.2 days, P < 0.01). Recurrence was seen in three haematomas of group A and one of group B. Reoperation was most closely correlated with diffuse low signal on T2-weighted images but not with a multiloculated appearance. Low signal on T2 weighting was surprisingly high (72.5 %) and the age of the haematomas as estimated on the MRI correlated well with the interval between the onset of symptoms and MRI. Our findings support the causative role of recurrent bleeding in the enlargement of CSDH. Received: 24 March 1998 Accepted: 15 July 1998     

CT and MRI of haemorrhage into intracranial neuromas

Six patients with haemorrhage into intracranial neuromas were studied by computed tomography (CT) and magnetic resonance imaging (MRI) at 0.5 T with spinecho pulse sequences. The nature of the tumour and the presence of a haematoma were confirmed by surgery and microscopic examination in all cases. Four neuromas arose from the acoustic nerves and two from the trigeminal. Four of the six patients suffered from sudden onset or rapid worsening of symptoms including headache, vertigo and/or hemifacial motor and sensory disturbances. CT in the acute stage revealed a hyperdense area or a fluid-fluid level (FFL). The hyperdense area disappeared on CT repeated in the chronic stage. On MRI in subacute and chronic stages the haemorrhage showed hyperintensity on both T1 and T2 weighting in five cases examined between 16 and 46 days after the onset, and isointensity on T1 weighting and an FFL on T2 weighting in one case examined 12 days after the onset of symptoms. A well-defined low intensity rim indicating prior haemorrhage was observed on T2-weighted images in three cases. MRI was more effective than CT in detecting haemorrhage into the tumours and in staging it.     

Ruptured spinal dermoid cyst with chemical arachnoiditis and disseminated intracranial lipid droplets

A 33-year-old man presented with a 3-month history of gradually progressive leg weakness. Spinal MRI and myelography with CT demonstrated an extensive intradural abnormality suggesting a diffuse inflammatory or neoplastic process. Only after cranial CT and MRI demonstrated lipid droplets was the diagnosis of a ruptured spinal dermoid cyst suggested. Subsequent laminectomy revealed a ruptured intradural dermoid cyst in the lumbar spine, with chemical arachnoiditis.     

Musculoskeletal haemangiomas: comparison of MRI with CT

MRI and CT findings were reviewed from 11 patients with musculoskeletal haemangiomas. With MRI, morphological characteristics and extent of haemangiomas were optimally demonstrated on T₂-weighted spin echo scans. High-resolution contrast-enhanced CT provided equivalent information regarding lesional characteristics and extent for small, localized haemangiomas. In CT evaluation of the extent of large haemangiomas, the radiation dose, transaxial scan plane, amount of intravenous contrast medium required and the necessity for correct timing of post-contrast scans became limiting factors. For such lesions, particularly those extending into the trunk, MRI supplemented by a plain radiograph is the optimum method of evaluation.     

Intracranial tuberculoma: CT and MRI

The appearances of intracranial tuberculoma on CT and MRI are described. Eight patients (6 males and 2 females) with intracranial tuberculomas studied over the past 4 years are presented. Four patients had AIDS and among the four non-AIDS patients 1 had undergone hepatic transplantation. All the cases were studied with CT and 6 underwent MRI. Five lesions were infratentorial, and 2 patients had double lesions. In 2 patients obstructive triventricular hydrocephalus was present. No patient had meningeal involvement. The stage of evolution was cerebritis in 1 case, incipient tuberculoma in 3 cases, mature tuberculoma in 1 case and tuberculous abscess in 5 cases. Diagnosis of intracranial tuberculoma was determined histologically in 5 patients and by good response to specific therapy in the remaining patients. Although CT allows differentiation between incipient and mature tuberculoma, MRI allows a better determination of the evolutonary stage. In most cases combined CT and MRI examinations provide an accurate diagnosis of intracranial tuberculoma.Correspondence to: N. Bargallo     

Intracranial meningeal melanocytoma: CT and MRI

We report the MRI and CT findings of an intracranial meningeal melanocytoma (IMM) arising from Meckel's cave and review the imaging characteristics of IMM. On CT, IMM constantly appear as well-circumscribed, isodense to slightly dense, extra-axial tumours with homogeneous contrast enhancement. This appearance is nonspecific and similar to that of meningiomas or small neuromas. On MRI, the signal of IMM is strongly related to the amount of melanin pigment: the more melanin, the more shortening of T1 and T2 relaxation times. Only when it shows as a homogeneous mass, bright on T1 and dark on T2 weighting, can a specific diagnosis of a melanin-containing tumour be made. However, this still cannot provide a distinction between IMM and malignant meningeal melanoma. Received: 31 January 1997 Accepted: 17 February 1997     

Periodontoid pseudotumor: CT and MRI imaging

Periodontoid pseudotumor (PP) can be a severe and disabling disease. This disease process typically presents in elderly patients with a longstanding history of myelopathy. We reviewed four cases of PP in order to summarize the clinical and imaging features.     

Traumatic atlanto-occipital dislocation: MRI and CT

CT and MRI were employed to help characterize an atlanto-occipital dislocation injury, providing useful information for planning surgical stabilization and directing rehabilitation. Received: 18 June 1999/Accepted: 8 March 2000     

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     

An unusual cervical chordoma: CT and MRI

We report CT and MRI findings of an unusual cervical chordoma. CT showed only minimal bony destruction with a lobulated prevertebral mass. Sagittal MRI, however, clearly demonstrated a lesion involving the body of C2 extending prevertebrally and into the spinal canal.     

Pleomorphic xanthoastrocytoma with CT and MRI appearance of meningioma

We describe a pleomorphic xanthoastrocytoma (PXA) in a young girl whose frontal lobe location, solid structure, dural tail and MRI signal characteristics led to a preoperative diagnosis of meningioma. PXA should be considered in differential diagnosis of tumours affecting young patients with neuroradiological characteristics suggestive of meningioma. Received: 4 July 1997 Accepted: 12 May 1998     

Laryngeal amyloidosis with laryngocele: MRI and CT

A case of laryngeal amyloidosis associated with a laryngocele is reported. Preoperative CT showed diffuse thickening of the epiglottis, aryepiglottic folds and false vocal cords with well-defined calcific foci. MRI revealed contrast enhancement and increased signal intensity on T2-weighted images. Received: 7 February 1997 Accepted: 14 October 1997     

CT and MRI of microcephalia vera

CT and MRI findings in three patients, two of them siblings, with microcephalia vera are presented. In this rare entity, a very small brain with an extremely thin, smooth cortex and increased surrounding cerebrospinal fluid are observed. Received: 22 March 1997 Accepted: 14 October 1997     

Ecchordosis physaliphora arising from the cervical vertebra,the CT and MRI appearance

Summary The authors report a rare case of ecchordosis physaliphora arising from C2, manifested with clinical symptoms, with the findings of CT scans and MRI.     

脑室星形胶质细胞瘤的CT和MRI诊断

本文总结了经手术和病理证实的脑室星形胶质细胞瘤共３１例，其中１级１９例，Ⅱ级３例Ⅲ级９例，位于侧脑室者１４例，位于第三脑室者８例，位于第四脑室者９例，作者阐述了肿瘤与患者年年，部位的关系，分析了肿瘤边界，肿瘤囊变坏死，钙出，出血，肿瘤血管，瘤周水肿，占位效应及造影剂增强后表现对肿瘤分级的价值，并讨论了本病与其他脑室肿瘤的鉴别诊断。     

CT and MRI: prognostic tools in patients with AIDS and neurological deficits

Summary To determine the prognostic value of CT and MRI in AIDS we studied the survival of patients with neurological involvement, in relation to the initial imaging results. Twenty-six initial CT and 15 MRI examinations of 41 patients were reviewed for the presence of cerebral atrophy and/or focal lesions. The mean survival time of patients with initially normal imaging was longer (700±89 days) than that of patients with isolated cerebral atrophy (326±65) or isolated focal lesions (202±97). The shortest survival (78±44 days) was found in patients with both cerebral atrophy and focal lesions. The risk of death in patients with focal lesions alone 6.4 times higher, and in patients with both changes 19.3 times higher than in patients with initially normal imaging. Cerebral imaging with CT and/or MRI thus allows identification of AIDS-related cerebral changes and may contribute to assessment of prognosis.     

Amyloidoma of the skull: plain radiographs,CT and MRI

Amyloidomas involving bone are rare. The 67-year-old man reported here had a large amyloidoma of the left frontal, parietal, sphenoid (greater wing) and temporal bones causing neural compression. Plain radiographs CT and MRI are shown.     

Cerebrotendinous xanthomatosis: cranial CT and MRI studies in eight patients

Summary We report the findings on cranial computed tomography (CT) and magnetic resonance imaging (MRI) and their correlation with the clinical manifestations, disease severity and biochemical abnormalities in eight patients with cerebrotendinous xanthomatosis. CT revealed cerebral atrophy in seven cases, cerebellar atrophy in four and focal low density lesions in the cerebral white matter in two. T2-weighted MRI showed high signal lesions in the cerebral white matter, focal in four cases and diffuse in one, and in the globus pallidus in three patients, two of whom also had lesions in the cerebellar white matter. While severely affected patients showed variable CT and MRI abnormalities, our cases did not show the dramatic findings expected from the neurological manifestations. Diffuse lesions in the cerebral and cerebellar white matter have been emphasized in previous reports, but in our study the focal lesions in the cerebral white matter were also present; the globus pallidus was frequently involved.