[Changes in the anterior cerebral artery in relation to stenoses of the carotid arteries--a DSA study]

DSA of the supraaortal extracranial arteries and intracranial arteries was performed in 568 patients suffering from cerebrovascular insufficiency. The results of this study showed a relationship between the atherosclerotic stenosis of the extracranial arteries and the occlusion of the A 1 segment of the anterior cerebral artery.

[Nuclear magnetic resonance tomographic studies following experimental ligation of the renal artery in rats]

MR was carried out on 22 Han-Wistar rats in relation to ligature of the left renal artery; measurements were obtained before the operation and at two, four, eight and thirty-six hours afterwards. Significant increase in T2 relaxation of the left cortex was observed after thirty-six hours and increased T2 of the medulla on the operated side after two hours. T1 relaxation time in the cortex was also prolonged, but the medulla showed no definite change. Following the operation, there was an increase in the size of the opposite kidney after eight hours; on the operated side, the cortex increased, but the medulla decreased. The results indicate that MR is a very sensitive method for demonstrating renal artery occlusion at an early stage.

[Extravasation of contrast medium from kidney calices in overfilling of the urinary bladder]

The most frequent cause of contrast media extravasation from the renal pelvis is a nephrourolithiasis. There are frequent causes enumerated in the literature, that are also characterized by a mechanical obstruction of the contrast media excretion. The presented case reports are characterized by a technical dependency, namely a long angiographic investigation and an overfilling of the urinary bladder without any indication of an organical excretory impediment. The clinical consequence of such observations should be discussed. 150 ml contrast media should not be exceeded during one examination.

[Accuracy of computed tomographic densitometry in the neighborhood of the pelvic bones]

A phantom is described which makes it possible to correct for the change in CT values produced by soft tissues; these can be treated quantitatively. As a result of beam hardening, artefacts are produced in the soft tissues which may be hypodense or hyperdense. Rules have been established for routine densitometry in clinical use.

[Magnetic resonance tomography in injuries of the cervical spine]

Twenty patients who had suffered spinal trauma were examined by magnetic resonance tomography. Fifteen patients with first degree trauma in Erdmann's classification showed no abnormality. Magnetic resonance tomography of the cervical spine appears to be a suitable method for investigating patients with whiplash injuries. It is indicated following severe flexion injuries with subluxations and neurological symptoms, since it is the only method that can demonstrate the spinal cord directly and completely and show the extent of cord compression. For patients with thoracic trauma and rapidly developing neurological symptoms, magnetic resonance tomography is ideal for showing post-traumatic syringomyelia. Magnetic resonance tomography following whiplash injuries is recommended if plain films of the cervical spine show any abnormalities, as well as for the investigation of acute or sub-acute neurological abnormalities. The various findings are discussed.

[Demonstration of intra- and paracardiac space-occupying processes using magnetic resonance tomography]

Magnetic resonance tomography (in three planes) was performed on 21 patients in whom echocardiography, angiocardiography or a chest X-ray had indicated or was suspicious of intra- or paracardiac space-occupying lesions. MR imaging demonstrated bronchial carcinoma with aortic displacement in two (one of them also with vena cava occlusion); hypernephroma with displacement of the right atrium in one; paracardiac teratoma in two and lipoma in one; aortic aneurysm in two; atrial tumour in five; atrial thrombi in one; ventricular thrombi in four; and exclusion of intra-cardiac lesions in two. Thus the method distinguished between vascular and tumourous paracardiac space-occupying lesions and demonstrated origin and structural relationship of paracardiac tumours, especially to the great vessels. Size, shape and mobility of intracardiac tumours was also demonstrated. For both intra- and paracardiac space-occupying lesions there were the beginnings of structural differentiation.

[Chronic ethmoid and sphenoid sinusitis as an incidental finding in computerized tomography of the skull]

From 373 patients examined by cranial CT 60 had as accidental findings chronic ethmoidal and/or sphenoidal sinusitis. From 234 patients with pathologic brain CT findings 33 had chronic sinusitis (14%). By comparison 27 from 139 patients without pathologic brain CT had findings like sinusitis (19.4%). We suppose that often chronic sinusitis ethmoidalis and/or sphenoidalis suspense signs lead to cranial CT, although sinusitis was the only pathologic cause.

[Analysis of the NMR signal for biological information in spinal diagnosis]

Discs of 23 patients and volunteers were examined for the purpose of obtaining T1 and T2-relaxation times. First of all, the signal characteristics of the surface coil were evaluated. The relaxation times of 100 discs were then measured by using standard spin echo sequences. There was a correlation between age and T2-values for healthy discs (R = -0.744). This was not found in case of degenerated discs. The mean value of T1 for healthy discs was found to be 825 ms. The results show a possibility of using relaxation measurements in routine diagnosis for the early identification of disc degeneration.

[Value of digital subtraction angiography compared to conventional angiography in diagnosing hypernephroma]

The authors report on the application of intraarterial renal digital subtraction angiography in 82 patients and more than 122 conventional angiographies. The radiological criteria of renal carcinoma are discussed. The value of angiography in relation to other imaging methods is assessed and compared.

[Value of NMR tomography in the diagnosis and staging of prostatic neoplasms]

MR imaging (MRI) possesses good sensitivity in diagnosis of carcinoma of the prostate. It is often not possible to distinguish clearly between carcinoma of the prostate and prostate hypertrophy. MRI can assess the local extension of a prostate carcinoma with a high degree of accuracy (85%); this applies in particular to periprostatic infiltration. MRI possesses only moderate sensitivity in diagnosis of regional lymph node metastases in the minor pelvis.

[Results of nuclear spin tomography of facial bone tumors]

We examined 21 patients with tumours of the mouth, one with tumour involvement of the facial skeleton and three with lymph node involvement in the upper neck, by nuclear tomography. Twenty patients with carcinomas of the mouth were also examined by CT. Nuclear tomography was superior to CT in showing the extent of the tumour; in ten patients the extent of the tumour could not be accurately determined, since there was no clear demarcation from normal tissue. Amongst our patients, nuclear tomography was also superior for showing lymph node metastases. Computed tomography is better at showing bone infiltration. Our results indicate that nuclear tomography is better than CT for showing the tumour and lymph nodes. If there is a suspicion of bone involvement, CT should be used in addition.

[Disk hernia of the lumbar spine. Radiologic study with special reference to the technic and value of nuclear magnetic resonance tomography]

Degenerations of the spinal disc especially in the lumbar region are the most frequent degenerative diseases in orthopedics. As diagnostic proceedings to discover disc herniation myelography and computerized tomography have been proven to be very usefull. Each of those methods show a high sensitivity and accuracy. Computerized tomography seems to be the first procedure because of the lac of any risk. Myelography has been reserved for the second approach, if there is any doupt in diagnosis. This paper will especially discuss advantages and disadvantages of MRI-tomography for the diagnosis of disc herniation. In MRI-tomography we have no radiation, there is no risk for the patient and we have the possibility of slices in different orientations with the sagittal orientation having priority in diagnosis of disc herniation. A more pronounced contrast in MRI relatively to the computerized tomography with nearly the same spatial resolution is an other important fact in favour for MRI. The value of MRI diagnosis of the spine depends however mainly on the use of special surface coils and on the use of high magnetic fields which provides a good signal to noise relation and which would permit us to use a thin-slice technique.

[Value of nuclear magnetic resonance tomography in the diagnosis and stage determination of urinary bladder neoplasms]

We arrived at the following conclusions in our study on the ranking of magnetic resonance tomography in diagnosis and staging of urinary bladder neoplasms: MR tomography possesses high sensitivity but only low specificity in diagnosing the local spread of the tumour. Sensitivity of MR seems to be better in respect of determining the paravesical tumorous spread, than that of other methods. However, it is not possible to determine the tumour status of a space-occupying growth. No advantages of MR over other methods, especially computed tomography, were seen in the examination of lymph node metastases in the minor pelvis.

[Nuclear spin tomography in brain tumors. Evaluation of 40 confirmed cases]

Forty histologically confirmed primary and secondary cerebral tumours are described. These contained fifteen primary tumours, five adenomas of the hypophysis, four hamartomas or lipomas and craniopharyngiomas, three meningiomas and three vascular malformations. One malignant lymphoma, one chordoma and eight cerebral metastases were also included. In our series, the accuracy of CT and MR were the same, particularly since most patients coming for MR had abnormal CT findings. MR was superior in demonstrating vascular malformations and sometimes in the differential diagnosis of tumour versus infarct. MR is also more accurate in demonstrating the extent of a tumour and of infiltration, since it is possible to obtain images in several planes. Disadvantages of MR are related to the characterisation of primary brain tumours, since the signals from these tumours failed to show characteristic differences. Calcification cannot be recognised. In sixteen out of 36 patients, MR proved superior, whereas CT was superior in five. Tumour-related oedema was present in 18 cases and demonstrated by MR in seventeen. CT failed to differentiate tumour from oedema on one patient.

[Value of nuclear magnetic resonance tomography in lung tumors]

A total of 93 patients with pulmonary diseases were examined by means of magnetic resonance tomography. Of these, 39 had a bronchial neoplasm of varying histological structure and varying hilar and mediastinal extension. Compared with other imaging methods, magnetic resonance tomography offers advantages in the imaging of a malignant process and accurate definition of its spatial extension. MR and CT seem to be essentially of equal value in respect of the diagnostic problem of deciding whether lymph node metastases are present in the mediastinum and in the hilus. On the other hand, CT is presently still superior to MR with regard to verifying small-scale processes which are in the process of undergoing endobronchial growth, since CT provides better spatial resolution. Hence, in our opinion the special value of magnetic resonance tomography is the exact definition of the extension of an already identified neoplastic process. This method can supply accurate pointers towards the operability of a bronchial neoplasm. In this regard it is an ideal complement to mediastinoscopy. However, MR will not be an important tool--even in the foreseeable future--for effecting early diagnosis of a neoplasm. The value of diagnostic information supplied by this method may improve by the future use of breath triggering, and additional diagnostic advantages are envisaged by the use of contrast media and the future possibility of producing thinner layers. That is why the catalogue of indications prepared at this time should be seen as a kind of momentary snapshot which may have to be supplemented or extended after the prevailing technical and equipment parameters have undergone further optimisation.

[Initial experiences with MR in liver tumors]

We examined 21 patients with focal lesions of the liver. Routinely we used T1 weighted, proton weighted and T2 weighted measurement modes, mainly with repetition times of 1.6 sec and echo delay times of 35 or 120 msec. Using these parameters we can see characteristic changes of the signals of the liver tumours. Cystic lesions usually show a strong decrease of the signal in the T1 weighted images in comparison with the normal liver pattern, in the proton weighted images a weak decrease but also in some cases a weak increase of the signal; in the T2 weighted images they show signals of very great intensity. We can differentiate haemangioma of cystic lesions because of the very strong signal in the proton weighted images in comparison with the normal liver pattern, which we could not see in any other focal liver disease. Metastases and hepatoma produced low signal intensity in the T1 weighted image. The proton weighted and the T2 weighted images show signals with a slightly greater intensity compared with the normal pattern, i.e. a very good possibility to distinguish hepatoma and metastases from cystic lesions or haemangioma. The differentiation from hepatoma and metastases cannot be made with NMR up to now. We are also not able to differentiate the focal nodular hyperplasia (FNH) from metastases. We used a 0.35 T supraconductive magnetic system.

[Immediate effect of x-ray contrast media on thyroid hormone parameters]

Immediately after application of various contrast media a number of functional parameters of thyroid function were determined. Especially after application of Biliscopin which is strongly bound to plasma proteins, a significant rise of the free thyroid hormone fractions, a significant increase in the binding capacity of specific transport proteins and a decrease of the total concentration of thyroid hormones was noticed. It is therefore recommended that neither in the early phase within the first hour, nor in the late phase within 10 days after application of contrast media, blood for determination of parameters of thyroid function should be collected, since otherwise misleading results may be obtained.