Spondylolisthesis and posterior instability.

We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.

Direct evidence for the incorporation of univalent indium into high-silica zeolite, H-ZSM-5, by thermal auto-reductive solid-state ion exchange.

In mechanical mixtures of H-ZSM-5 and In2O3 thermal auto-reductive solid-state ion exchange (AR-SSIE) was found to proceed upon treatment in high vacuum at 840 K resulting in the incorporation of In+ ions into, and in an increase of the thermal stability of, the zeolitic component.

MR imaging in multiple sclerosis: comparison with clinical, CSF, and visual evoked potential findings.

MR examinations of 136 patients with multiple sclerosis (MS) were evaluated to correlate the results with clinical, CSF, and visual evoked potential (VEP) findings. In addition, 22 of the 136 patients were studied several times during a 5-month follow-up period. It was demonstrated that MR is superior to CSF and VEP findings in establishing cerebral alterations in MS. A relationship between the results of CSF and VEP examinations and the MR results could not be detected. Negative CSF and VEP results corresponded to positive MR imaging and vice versa. In our series, five negative MR results were obtained in patients with clinically proved MS. The extent of alterations shown up by MR corresponds to the duration of the disease; in particular, more confluent abnormalities in the periventricular region were found in patients with long-standing disease. More plaques were found in patients with a primary relapsing/remitting course of the disease than with the primary chronic progressive form. The clinical course and the grade of disability did not correspond to differences in MR imaging. Follow-up demonstrated that most lesions remain unchanged (72-79%); increases and decreases in the size of the plaques seem to depend on the clinical course. These results suggest that MR is the most sensitive technique for establishing the diagnosis of MS.

[The in-vitro-effects of loxaglate (Hexabrix) on coagulation, fibrinolysis and complement system (author's transl)]. / In-vitro-Wirkung von Ioxaglat (Hexabrix) auf Gerinnung, Fibrinolyse und Komplementsystem.

Ioxaglate causes a dose dependent prolongation of thrombin time, thrombin coagulase time, partial thromboplastin time and calcium thromboplastin time. A substantial activation of fibrinolysis, assayed by a dose dependent decrease of plasminogen concentrations, does not take place. Higher concentration of ioxaglate (more than 25 mg iodine/ml) cause a complement activation. No C-3 split products could be detected by two-dimensional immunoelectrophoresis. Ioxaglate induced changes of global coagulation tests are interpreted as being caused by interference of fibrin polymerization. The demonstration of complement activation by high concentrations of ioxaglate has no practical consequences.

[Nuclear spin tomography in brain tumors. Evaluation of 40 confirmed cases]. / Kernspintomographie bei Hirntumoren. Auswertung von 40 gesicherten Fällen.

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.

[Nuclear magnetic resonance tomographic studies following experimental ligation of the renal artery in rats]. / Kernspintomographische Untersuchungen nach experimenteller Nierenarterienligatur bei der Ratte.

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.

[Spin-echo sequences and rapid image sequences in a comparison of spinal diseases]. / Spinechosequenzen und schnelle Bildsequenzen im Vergleich bei Erkrankungen der Wirbelsäule.

Rapid image sequences of the spine were compared with proton and T2-weighted spin-echo sequences in 30 patients concerning their diagnostic value and image contrast. The rapid series was carried out with an angle of rotation of 30%, TR of 21 and TE of 12 msec., the spin-echo sequences with a TR/TE of 2,000/20/80 msec. The quality and contrast of the rapid series was markedly inferior to the spin-echo sequences; this was particularly marked for demonstrating disc and bone degeneration. At present, the routine use of rapid sequences cannot be recommended as a substitute for spine-echo examinations.

[Importance of contrast medium administration in determining the age of traumatic renal hemorrhage by NMR tomography--experimental results]. / Bedeutung der Kontrastmittelgabe zur Altersbestimmung einer traumatischen Nierenblutung mit der Kernspintomographie--experimentelle Ergebnisse.

In eleven Han-Wistar rats, experimental renal haematomas were produced and scanned by magnetic resonance tomography at two hours to 21 days. Bleeding during the first three or four days showed prolongation of T1 and T2 relaxation times. On subsequent days there was shortening of the T1 and T2 times. Gadolinium DTPA produced a marked effect in the second to fourth day following the trauma, if the examination was carried out 90 to 120 minutes after the administration of contrast medium. Gadolinium can be used in determining the age and clarifying the differential diagnosis of an bleeding if there is clinical support.

[Results of nuclear spin tomography of facial bone tumors]. / Ergebnisse der Kernspintomographie bei Tumoren des Gesichtsschädels.

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.

[Initial experiences with MR in liver tumors]. / Erste Erfahrungen mit MR bei Lebertumoren.

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.

[Nuclear spin tomography and computerized tomography in malignant hypernephroma]. / Kernspintomographie und Computertomographie des malignen Hypernephroms.

Forty patients with histologically confirmed hypernephromas were examined by MR and CT. As regards T-staging, MR had an accuracy of 97% and CT of 91%; for N-staging, MR had an accuracy of 85% and CT of 91% and, with regard to infiltration of the renal vein, MR was correct in 88% of cases and CT in 81%. MR was most accurate in the pre-operative assessment of tumour spread, demonstrating caval involvement in 100% and lymph node metastases in 97%. On the other hand, infiltration of the renal pelvis could be assessed in only 65% of cases; in 27% the assessment was not possible and in 8% one could not be certain. CT proved to be at its best for staging of lymph nodes, but in 15% it was not possible to identify infiltration of the renal vein. MR was not greatly superior to CT in the preoperative diagnosis and staging of hypernephromas.

[NMR tomographic studies in experimental renal vein ligation]. / Kernspintomographische Untersuchungen bei experimenteller Nierenvenenligatur.

Experimental ligation of the renal veins in rats indicate highly significant and characteristic changes within two hours, consisting of significant prolongation of T2 relaxation time in the cortex and T2 shortening in the medulla. In addition, there is a considerable increase in the size of the kidney, due to swelling of the cortex. T2 prolongation of the cortex is most marked between 30 hours and two to four days after ligation of the vein. In the following weeks there is a return to normal. T2 of the medulla at two to three weeks after ligation shows highly significant reduction compared with the normal side and, at this time, the size of the experimental kidney is significantly less than the opposite kidney. These results indicate that magnetic resonance tomography is a highly sensitive method for the early demonstration of renal vein thrombosis.

[Accuracy of computed tomographic densitometry in the neighborhood of the pelvic bones]. / Die Messgenauigkeit der computertomographischen Densitometrie in der Nachbarschaft des Beckenskeletts.

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]. / Kernspintomographische Befunde beim Halswirbelsäulentrauma.

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.

[Analysis of the NMR signal for biological information in spinal diagnosis]. / Analyse des NMR-Signals auf biologische Information in der Diagnostik der Wirbelsäule.

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.

[Cine-MRT in the functional and morphological diagnosis of the heart after a myocardial infarct/ A comparison with angiocardiography, 2-dimensional echocardiography, intracardiac scintigraphy and enzymatic infarct size estimation]. / Cine-MRT in der funktionellen und morphologischen Diagnostik des Herzens nach Myokardinfarkt. Vergleich zur Angiokardiographie, zweidimensionalen Echokardiographie, Herzbinnenraumszintigraphie und enzymatischen Infarktgrössenbestimmung.

PURPOSE: The aim of the study was to test the reliability of cine magnetic resonance imaging (cine-MRI) on the infarction heart with its altered geometry. MATERIAL AND METHODS: 61 patients (17 women, 44 men, 36-83 years, 32 with anterior, 29 with posterior wall infarction) received Cine-MRI in the true long and short axis of the heart and two-dimensional echocardiography one and 4 weeks post infarction. Two-level angiocardiography (ACG) and radionuclide ventriculography (RNV) were performed 4 weeks p.i. The size of myocardial infarction was determined enzymatically with the CK integral method. Left ventricular volume indices (EDVI, ESVI, SVI), ejection fraction (EF) and infarction weight (IW) were compared. RESULTS: Excellent correlations existed between cine-MRI in the long and short axis for the volume indices and EF. Between cine-MRI in the short axis and ACG all correlations were excellent as well. They were significantly less satisfactory between cine-MRI and 2DE due to the inhomogeneity of echo quality. Cine-MRI and RNV produced similar EF results (r = 0.884), and a comparison of IW in cine-MRI and CK integral method also showed a good correspondence (r = 0.967). CONCLUSION: Cine-MRI is a reliable method for the morphological and functional examination of post-myocardial infarction.

[Exposure technics for computed scintigrams]. / Untersuchungen zur Belichtungstechnik von Computerszintigrammen.

The technique of making copies on radiographic films or on multiformat cameras from computer scintigrams, computer tomograms, digital radiographs or other similar digital images should be carefully studied in order to make the best use of the characteristics of the film. Contrast transfer was studied using a nuclear medicine camera computer system with registration on radiographic film. Possible difficulties in obtaining copies and a simple software arrangement are described, which would influence contrast transmission.

[Causative investigations of heparin-induced rise on thyroid hormone serum levels (author's transl)]. / Untersuchungen zur Ermittlung der Ursachen der heparin-induzierten Konzentrationsanhebung der Schilddrüsenhormone im Serum.

Intravascular application of heparin causes a significant rise of free and total thyroid hormone concentrations in serum together with a concomitant drop of the TSH-levels. A causal relationship between these two findings has been firmly established by a number of investigators. The decline of TSH concentrations in serum after heparin injection might just be a physiological reaction of the pituitary gland to the heparin-triggered rise of serum thyroid hormone levels. The present investigations demonstrate a diminution of affinity of thyroid hormone receptors of liver cells. This result confirms the hypothesis that the rise of total thyroid hormone in blood is mainly due to a depletion of liver stores of thyroid hormones. In concordance with clinical findings the binding affinity of cellular pituitary thyroid hormone receptors was found to increase.

[Immediate effect of x-ray contrast media on thyroid hormone parameters]. / Einflussnahme von Röntgenkontrastmitteln auf Schilddrüsenhormonparameter als Soforteffekt.

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.

[Varying results of different procedures for determining the FT4 concentration in serum before and after heparin administration]. / Unterschiedliche Ergebnisse verschiedener Bestimmungsverfahren der FT4-Konzentration im Serum vor und nach Gabe von Heparin.

After application of heparin FT4 was determined by various methods in patients undergoing hemodialysis, and the results were compared with those obtained before application of heparin. Using ultrafiltration (Amicon) and the Dow-Lepetit test a significant increase in FT4 concentration could be registered at all times after heparin application. By use of the Corning test a non-significant increase in FT4 concentration was found one hour after heparin application. When the Amerlex method was employed no change in FT4 concentrations was detectable. Most probably, the observed increase in FT4 concentration after heparin application does, in fact, occur.