Spondylolysis and isthmic spondylolisthesis: impact of vertebral hypoplasia on the use of the Meyerding classification.

BACKGROUND: Spondylolysis and isthmic spondylolisthesis are common multifactorial disorders. The extent of slipping of the spondylolytic vertebra is considered a major predicator for prognosis and further follow-up. Vertebral hypoplasia is a common finding associated with spondylolysis. The purpose of this study is to evaluate the incidence of hypoplastic vertebral bodies in patients with spondylolysis and in the general population and to analyse the impact of the findings on the measurement and grading of spondylolisthesis. METHODS: 140 patients with 141 levels of spondylolysis identified by MRI were included in this study. The slippage of the spondylolytic vertebral body and the size in the midline sagittal image were measured and correlated. In addition, a randomised control group was evaluated to test the hypothesis that shortened, hypoplastic vertebral bodies can also be found in the general population. RESULTS: Shortened, hypoplastic vertebrae were found in 50 patients with spondylolysis and none was found in the control group. These shortened vertebrae mimicked spondylolisthesis and in 19 patients the slippage equalled the shortening, thus mimicking spondylolisthesis, although only spondylolysis was present. CONCLUSION: Sagittal shortening of the spondylolytic vertebra is common and may mimic spondylolisthesis. In order to define and measure spondylolisthesis the shortening of the spondylolytic vertebra has to be taken into account.

Features of positional magnetic resonance imaging in tethered cord syndrome.

PURPOSE: Tethered cord syndrome (TCS) is a clinical entity in which symptoms are induced through excessive tension on the spinal cord. The radiological method of choice to confirm TCS is magnetic resonance imaging (MRI), however limitations exist especially in patients with no underlying spinal dysraphism. MATERIALS AND METHODS: The positional MRI features of TCS in a series of four patients with suspected or proven TCS are described, especially with respect to contact of the myelon or the cauda equina with the dorsal elements of the lumbar spinal canal. The findings are correlated with the lordosis angle of the lumbar spine. RESULTS: In flexion contact of the myelon or the cauda equina with the dorsal elements of the lumbar spinal canal is reduced due to a straightening of the lumbar spine. With increasing lordosis of the lumbar spine, the degree of contact increases and detection of TCS is more difficult. The site of tethering could be identified in all four patients in flexion. CONCLUSION: Positional MRI can be useful to confirm or rule out TCS and helpful to identify the site of tethering. The value of positional MRI is limited to patients who are able to fully flex the lumbar spine and in patients without spinal canal stenosis and spondylolisthesis.

Position dependent changes of the cerebral venous drainage--implications for the imaging of the cervical spine.

PURPOSE: This study demonstrates the physiological changes of the cerebral venous outflow routes in healthy humans in the recumbent and the sitting position employing positional MRI. METHODS: In five volunteers, the internal jugular veins and the cervical vertebral plexus were analyzed in the supine and sitting position using an open MR system. Axial T2-weighted scans and axial T1-weighted flow sensitive gradient echo sequences were acquired. The findings were compared to previously published anatomic descriptions from cadaver preparations. RESULTS: In the supine position, the internal jugular vein is the main route for the cerebral venous outflow. The mean area was 100 mm (2) (±29 mm (2)) for both sides together. In the sitting position, the jugular vein collapses (mean area: 11 mm (2)±2 mm (2)) and the vertebral venous plexus becomes more prominent. CONCLUSION: The position dependent changes in cerebral venous outflow can be imaged using positional MRI. The vertebral venous plexuses may mimic pathologies and physicians reading positional MRI images of the cervical spine should be aware of the physiological changes occurring in the erect position.

[Pathomechanisms of spinal canal stenosis - upright MRI image gallery]. / Pathomechanismen der spinalen Enge - Upright-MRT-Bildergalerie.

AIM: Lumbar spinal canal stenosis is a common disease of the elderly patient, with a high prevalence and clinical importance. MRI is the established method of choice for the imaging of spinal canal stenosis. However, there is often a discrepancy between the clinical symptoms and the spinal canal stenosis as shown using MRI in a supine position. In such cases preoperative functional imaging is often warranted. METHODS: In an image gallery three cases of a functional spinal canal stenosis of the lumbar spine are shown. In all three patients a dynamic, positional MRI (upright MRI) was performed. RESULTS: The pathomechanisms of the spinal canal stenosis could be shown in all three cases. CONCLUSION: Using upright MRI a functional spinal canal stenosis can be shown. The pathomechanisms of the spinal canal stenosis are discussed. The possibilities and limitations of this new imaging modality are presented and analysed.

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.

[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.

31-P mr spectroscopy of a leg lymphangiosarcoma.

In a 64 year old man with a large, low grade lymphangiosarcoma of the right thigh, we correlated the results of in vivo 31-P-magnetic resonance spectroscopy (MRS), proton magnetic resonance imaging (MRI), and digital subtraction (DSA) with the pathologic specimen and histology. The 31-P MRS spectra of the tumor showed well-resolved peaks as follows: intense PCr (phosphocreatine), PDE (phosphodiester) and Pi (inorganic phosphate), and low PME (phosphomonoester). The Pi peak revealed an intratumor pH of 6.96 compared with 7.16 of normal skeletal muscle. The lower PME signal was consistent with low histopathologic mitotic activity of the tumor.

31-P MR spectroscopy and MRI of a testicular non-Hodgkin lymphoma recurrence to monitor response to irradiation. A case report.

PURPOSE: To monitor the metabolic changes during the radiation treatment of a recurrence of a high malignant non-Hodgkin lymphoma (NHL) of the left testis. PATIENTS AND METHODS: A 76-year old patients who presented a diffuse centroblastic high malignant NHL recurrence in the left scrotal sac was examined with 31-P magnetic resonance spectroscopy (MRS) and proton magnetic resonance imaging (MRI) before, during and after megavoltage radiotherapy to a total dose of 56 Gy. RESULTS: The 31-P MRS spectrum of the tumor showed before starting irradiation, intensive phosphomonoester (PME) and phosphodiester (PDE) signals that overlapped the inorganic phosphate (Pi) signal. After 26 Gy irradiation, the Pi peak appeared and revealed an intratumoral pH of 7.08 very close to that in the normal testis (pH of 7.02). After 56 Gy the tumor disappeared and a complete remission was achieved. CONCLUSIONS: 1. 31-P MRS is sensitive to the changes in the tumor metabolic activity after irradiation with a dose of 26 Gy. 2. Pi and PME peaks could be good pathological markers in the steady-state response to irradiation. 3. MRI could confirm the radiation induced tumor regression and the achieved clinical complete remission.

[MRI characteristics of the Sneddon syndrome]. / MRI-Charakteristik des Sneddon-Syndroms.

The report describes the MRI findings in a female patient with an established long course of a Sneddon's syndrome. Multiple ischaemic cerebral infarcts of a mainly macroangiopathic pattern are typical. In the beginning the corresponding clinical deficiencies often show a considerable regression.

Altered muscle metabolism in pustular psoriasis (Zumbusch type): demonstration by 31P magnetic resonance spectroscopy.

We report a patient with pustular psoriasis (Zumbusch type) with diffuse muscle pain. Evaluation of skeletal muscle metabolism during rest, graded levels of exercise and recovery was performed using 31phosphor magnetic resonance spectroscopy (31P MRS). Our results underline the systemic character of severe pustular psoriasis. The clinical improvement after drug therapy (prednisolone and etretinate) correlated well with the measurable changes in vivo of several metabolites and indices important in muscle contraction, such as phosphocreatine (PCr), inorganic phosphate (P(i)), intramuscular pH and the phosphorylation potential (PCr/Pi). Abnormal accumulation of sugar phosphates (phosphomonoester) as well as their slow resolution during recovery reflect profound alteration of metabolism in the sense of block in glycolysis. Our results show that 31P MRS is well suited to identify and measure subtle changes in the muscle metabolism occurring in pustular psoriasis.

[Syphilis and AIDS: a historical comparison]. / Sifilis y sida una comparacion historica.

The present work displays the analogies and differences among syphilis and AIDS concerning appearance, evolution, symptoms, treatment, prophylaxis, spreading, as well as their names' origin. A comparative analysis among both diseases in terms of causes, clinical evolution and therapeutic essays is established. Venezuelan health institutions' effectiveness in fighting these diseases is evaluated.

Magnetic resonance imaging and computer tomography of acute spinal cord trauma.

Spinal cord lesions are not detectable on roentgenograms and computed tomography (CT) scans. Magnetic resonance images (MRIs) are able to make soft-tissue lesions visible. Interpretations of MRIs, CT scans, and roentgenograms were compared in 25 patients and three postmortem specimens with spinal cord injuries. In 14 patients and one specimen with normal roentgenograms and CT scans, the MRI demonstrated ten soft-tissue injuries as minimal displacement of the vertebral bodies or as a high signal intensity in the disc space, indicating a hematoma. Seven of the ten patients demonstrating soft-tissue injuries also had an intramedullary lesion, while in five of the 15 patients with normal CT scans, only a medullary lesion was present on MRI. In 11 patients and two postmortem specimens, fractures were seen on roentgenograms and CT scans. In these patients, the CT was superior to the MRI in detecting small bony fragments, but the medullary lesions were visible only on the MRIs. An intramedullary low signal intensity corresponded to macroscopically visible hemorrhages in the three postmortem specimens. The MRI provided important information in patients with neurologic deficits. No obvious pathologic changes were evident on the roentgenograms and CT scans. The MRI also demonstrated intramedullary and extramedullary soft-tissue lesions and was useful in establishing a diagnosis and in choosing appropriate therapy. CT, on the other hand, was superior in detecting small bony fragments and fracture lines.

[Initial experience with the use of oral gadolinium-DTPA in nuclear magnetic resonance tomography of the pelvis]. / Erste Erfahrungen mit der Anwendung von oralem Gadolinium-DTPA bei der Kernspintomographie des kleinen Beckens.

The use of an oral contrast medium has so far not become a matter of routine in MR of the abdomen. In the present study the use of orally applied gadolinium-DTPA was examined in respect of tumorous diseases in the minor pelvis. 18 patients with tumours in the minor pelvis were examined before and after oral administration of gadolinium-DTPA (Gd-DTPA). 10 ml/kg body weight of a gadolinium DTPA solution were applied in a concentration of 1.0 mmol/l. T1-weighted and T2-weighted sequences were carried out before application and T1-weighted sequences after application. Oral application gadolinium-DTPA resulted in enhancing the signals of the filled intestinal portions. In 54% of the cases the sequences showed a sharper delineation between tumour and intestine. In 19% the delineation between pathological tissue and intestine on contrast examination was as well defined as in T2-weighted contrast images; in 27% of the cases oral administration of gadolinium-DTPA did not yield any additional information. No significant side effects were seen.

[Angiography diagnosis in the elderly--current indications in reduced complication rates and expanded therapeutic modalities]. / Angiographische Diagnostik beim alten Menschen--Aktualisierte Indikationsstellung durch reduzierte Komplikationsraten und erweiterte Therapiemodalitäten.

A potential higher rate of complications, recent developments in the technical procedures, and expanding modalities of interventional or operative therapy must be considered in evaluating angiographies in the aged patient. Most frequently, imaging of the pelvic and femoral arteries as well as the cerebral vessels was performed in patients older than 70 years, in 40% as out-patient angiography. The risk of puncture-site, vascular and catheter complications, as well as of neurological deficits was not found increased. A higher rate of cardiovascular problems however requires exact internal investigations and evaluation of the biological age. Angiographic information about vascular morphology as a basis for interventional therapy can be achieved today with an acceptable risk in the aged patient.

[A combination of generalized neurofibromatosis (Recklinghausen disease) and agenesis of the corpus callosum]. / Kombination von generalisierter Neurofibromatose (Morbus Recklinghausen) und Agenesie des Corpus callosum.

Whereas generalised neurofibromatosis is a relatively frequent disease its combined occurrence in conjunction with agenesia of the corpus callosum is extremely rare and probably a casual coincidence.

[Generalized brain edema and cerebral infarct in ergotamine abuse: imaging by computerized tomography, magnetic resonance tomography and angiography]. / Generalisiertes Hirnödem und Hirninfarkt bei Ergotamin-Abusus: Darstellung im Computertomogramm, Kernspintomogramm und in der Angiographie.

Abuse of ergotamine can release a generalised brain edema and brain infarctions. This can be visualized by CT, MR and angiography. The reason, however, can only be found in the patients history.