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We report on a male epileptic patient, presently 27 years old, who has suffered complex-partial attacks for 19 years. Under treatment with carbamazepine the seizures were completely controlled. In addition, the patient exhibited partial hypopituitarism. CT and MRI revealed the presence of 2 lipomas, one located within the optico-chiasmatic cistern and the other one in the medial temporal lobe. To our knowledge, this combination of the generally rare lesions has not been described yet.

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A 51-year-old diabetic showed symptoms of a hypertensive crisis with a systolic blood pressure above 300 mmHg. The antihypertensive therapy failed and the Doppler-pressure values were also too high for all limb arteries. Duplex-sonography and soft-x-ray examination showed a mediasclerosis of arms and legs. The true pressure, measured at the still compressable arteries of the fingers was relatively low. There was symptomatic improvement after completion of the antihypertensive therapy.

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BACKGROUND: Aortic dissection requires prompt and reliable diagnosis to reduce the high mortality. The purpose of this study was to assess the reliability of both ECG-triggered magnetic resonance imaging (MRI) and transesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) for the diagnosis of thoracic aortic dissection and associated epiphenomena. METHODS AND RESULTS: Fifty-three consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol in random order; imaging results were compared and validated against the independent morphological "gold standard" of intraoperative findings (n = 27), necropsy (n = 7), and/or contrast angiography (n = 53). No serious side effects were encountered with either imaging method. In contrast to a precursory screening transthoracic echogram, the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta irrespective of its location. The specificity of TEE, however, was lower than the specificity of MRI for a dissection (TEE, 68.2% versus MRI, 100%; p less than 0.005), which resulted mainly from false-positive TEE findings confined to the ascending segment of the aorta (TEE, 78.8% versus MRI, 100%; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation, or pericardial effusion. CONCLUSIONS: Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. TEE, however, is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE as a semi-invasive diagnostic procedure after a precursory screening transthoracic echogram in suspected aortic dissection, but they establish MRI as an excellent method to avoid false-positive findings. Anatomic mapping by MRI may emerge as the most comprehensive approach and morphological standard to guide surgical interventions.

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To correlate the appearance of poststenotic jets on gradient echo images with features of localized Doppler spectra of the jets, we studied an in vitro model of steady flow-through stenoses of 86, 96, and 99% area reduction. As fluids, water and a 40% glycerol solution in water were used. MRI was performed with a 1.5 T whole body imager and gradient echo images were obtained in planes parallel to the direction of flow. Doppler spectra were acquired separately from the MR measurements at 1 cm intervals for a distance of 10 cm downstream from the stenosis. Poststenotic signal void was observed for water and for the 40% glycerol solution only if the mean velocity within the stenosis exceeded a limit of 50-60 cm/sec. On the MR images, the jets could be divided into two segments: A proximal jet segment of uniform width equal to the diameter of the stenosis, followed by a distal jet segment which was characterized by broadening and then dissipating signal void. Except for the 99% stenosis, a high signal intensity core was present within the proximal jet segment. In the proximal jet segment, the Doppler measurements showed a low temporal fluctuation of the maximal flow velocity and only little flow opposite to the main flow direction. In the distal jet segment, the velocity fluctuation and the intensity of reverse flow increased sharply. The high signal intensity core of the jet was associated with a poststenotic zone of constant maximal flow velocity. The results demonstrate a close relationship between characteristic features of poststenotic jets in MRI and pulsed Doppler sonography.

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The morphology of the minor fissure, i.e., the shape of the upper surface of the middle lobe, was studied in 10 specimens and in 60 thoracic CT's. In 8 specimens and 54 CT's there was the arrangement typical for the right lung consisting of 3 distinct lobes. The upper surface of the middle lobe had a convex upward shape against the base of the upper lobe in all anatomical preparations and in 52 of the CT's. The position and shape of the convexity was, however, quite variable. In 2 cases the upper surface of the middle lobe was flat. In 78% the minor fissure was incomplete and in 2 cases it was absent.

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By employing the so-called inversion recovery technique, one has a nuclear magnetic resonance method at hand that allow discrete imaging of lesion in the intraorbital portion of the optic nerve in patients with optic neuritis. In our series, signal rich areas were visible in affected optic nerves in 15 of 18 patients. The areas of increased signal intensity involved the middle or the proximal third of the nerve and were still demonstrable following recovery of visual function. On the other hand, inversion recovery studies of the affected optic nerves following long inflammation free periods after an attack were within normal limits. Inflammatory edema or alterations in glial tissue may be considered as the causes of the increased signals.

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The CT findings in the lungs of 52 patients with histologically confirmed sarcoidosis are described. In addition to a nodular pattern, reticulo-nodular, reticular, diffuse infiltrative and streaky shadowing due to fibrosis could be recognised. Pleural lesions, bronchial ectasis and mediastinal and hilar lymph node changes could be diagnosed. The high sensitivity of CT contrasted with its relatively low specificity. At present CT is useful for analysing the pulmonary pattern when planning lung biopsy or lavage. In some cases, the diagnosis of pulmonary sarcoidosis can be made by CT, but the exact criteria for diagnosis and differential diagnosis must be borne in mind.

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Inversion recovery sequences with short inversion periods (STIR sequences) are particularly suitable for the examination of the intra-orbital and intracanalicular portion of the optic nerve, since they selectively suppress interference from neighbouring fat. This technique makes possible direct demonstration of retrobulbar neuritis that had to be diagnosed exclusively by clinical criteria up to now. As evidence of inflammatory changes in 15 out of 18 patients with acute retrobulbar neuritis, there were areas of increased signal intensity in the affected nerve; in six cases the nerve was also swollen. In eight normals and five patients with healed retrobulbar neuritis, the signal and calibre of the optic nerves were normal.

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Acetabular fractures are caused by high kinetic energy, and satisfactory management requires differentiation of the fracture types. The basic radiological examinations consist of the A-P pelvic view, the obturator, and the iliac oblique view. Plain radiography proves to be insufficient, particularly for visualization of the posterior column and the posterior acetabular lip. In comparison, axial CT scans give exact and complete information about the acetabular fracture and associated injuries. In summary CT is the method of choice in evaluating dislocated or non-dislocated fractures, even when two- and three-dimensional reformation is involved.

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Percutaneous embolization using detachable balloons was successfully performed in a series of nine patients with intracranial carotid aneurysms. The clinical progress and the results of MR examination are reported. Up to 4 months after treatment, MR imaging did not show any significant change in size of the artificially thrombosed aneurysms. Complete resorption cannot be expected in less than 6-8 months, but resorption does eventually occur. The intensity pattern observed in the evolution of the thrombus was similar to that of intra- and extra-cranial hematomas.

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Magnetic resonance imaging (MRI) at 1.5 T was performed in 25 extracranial haematomas using spin-echo (SE) and fast-field-echo (FFE) sequences. The age of the haematomas was in 11 cases less than 2 days and in 9 cases more than 14 days. Fresh haematomas were isointense to skeletal muscle on T1-weighted SE images. With T2-weighted SE sequences, fresh haematomas had high signal intensity on the first day, but became inhomogeneous with predominantly low signal intensity on the following days. Areas of low signal intensity could be demonstrated by T2-weighted FFE sequences already on the first day after bleeding. Subacute haematomas were recognised by their high signal intensity on the T1-weighted SE images. Also with T2-weighted SE and FFE sequences, subacute haematomas showed increasingly high signal intensity. The characteristic appearance of haematomas facilitates their identification with MRI.

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Thirty-four patients with known Paget's disease were examined by CT in order to characterise the appearances of the bones on transverse sections. The typical findings have been related to their anatomical localisation and frequency. The differential diagnosis from conditions with similar CT appearances, such as osteoplastic metastases, fibrous dysplasia or osteomyelosclerosis, is discussed. The CT appearances of Paget's disease are typical in the same way as conventional radiographs.

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The lacrimal drainage systems of 92 patients were examined by a digital subtraction technique; 30 patients were examined additionally by a conventional technique, using films obtained during screening for the contrast injection. The digital subtraction dacryocystogram provided excellent demonstration of the lacrymal sac and of the tear ducts, but there is little diagnostic gain when compared with the conventional technique. Both methods are highly reliable. In view of its low radiation dose and rapid and simple course, conventional dacryocystography is regarded as the method of choice for routine examinations. The digital subtraction technique should be reserved for special problems.

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Thirty patients with histologically confirmed malignant schwannomas were examined. In five patients the lesions were malignant neurofibromas, as part of von Recklinghausen's disease, the others were solitary malignant schwannomas. CT appearances of malignant schwannomas are variable. Shape, structure and attenuation vary considerably. Most malignant schwannomas present with the CT criteria of benign tumours. Altogether neither the solitary schwannomas, nor those associated with von Recklinghausen's disease show specific diagnostic features, whether for the primary tumour or for recurrences. Reliable information on the nature of these lesions is possible in a few cases only.

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Twenty-six patients with suspected bronchiectasis were examined by bronchography and CT and the CT appearances of normal and abnormal bronchi are described. Like bronchography, CT will distinguish between cylindrical and cystic bronchiectasis. Lobar and segmental localisation can be reliably achieved by both methods; there was agreement between these methods in 109 out of 114 lobes and in 391 out 468 segments. In our experience the sensitivity of CT in the diagnosis of bronchiectasis is 93% and specificity is 96%. It is possible to obtain the necessary information, i.e. the existence and localisation of bronchiectasis by means of CT.

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