Magnetic resonance imaging (MRI) scans

A Research Network Based in London, Ont., aims to improve hospital care by having hospitals share information. The research points out the ways some hospitals do things differently. Dr. William Sibbald, who heads the network, says that if hospitals overcome some of the variations between them, they may be "able to save money and become more efficient."     

Magnetic resonance imaging in cervical spinal cord compression

In patients with cervical spondylotic myelopathy MRI sometimes shows increased signal intensity zones on the T2-weighted images. It has been suggested that these findings carry prognostic significance. We studied 56 subjects with cervical spinal cord compression. Twelve patients showed an increased signal intensity (21.4%) and a prevalence of narrowing of the AP-diameter (62% vs 24%). Furthermore, in this group, there was evidence of a longer mean duration of the symptoms and, in most of the patients, of more serious clinical conditions. The importance of these predisposing factors remains, however, to be clarified since they are also present in some patients without the increased signal intensity.     

Magnetic resonance imaging of experimental subacute spinal cord compression

STUDY DESIGN: Subacute compression of the spinal cord was applied to rats. The animals were chronologically observed using magnetic resonance imaging for more than 8 weeks after surgery and were killed for histopathologic examination. OBJECTIVES: To investigate the correlation of changes in signal intensity on magnetic resonance images with those observed in histopathologic study and with the degree of spinal cord compression and paralysis. SUMMARY OF BACKGROUND DATA: No consensus has been reached concerning the correlation of magnetic resonance images to clinical symptoms of compressive myelopathy. Few reports are available in which magnetic resonance imaging findings are compared with histopathologic features in chronic or subacute experiments. METHODS: In rats under general anesthesia, the T11 lamina was thinned and a slow increase in volume was applied. Hind limb paralysis appeared 1 week after the procedure and spontaneously subsided thereafter. The degree of spinal compression and signal intensity was observed chronologically using magnetic resonance imaging. The signal intensity on the final MR images was rated on a four-point scale and compared with histopathologic findings. RESULTS: As spinal compression increased, the incidence of high signal intensity on long spin-echo images became higher. Low signal intensities on short spin-echo images were visible in animals in which compression and paralysis were the most severe. In these animals, cavitation and a dilated central canal were visible. High signal intensities on long spin-echo images reflected various pathologic changes. CONCLUSIONS: Changes in signal intensity on MR images are visible after the induction of myelopathy by high-pressure compression. These signal intensities may be useful in predicting the outcome of compressive myelopathy.     

Frequency and severity of headache after lumbar myelography using a 25-gauge pencil-point (Whitacre) spinal needle

A 77-year-old man had been suffering from stress urinary incontinence for 2 years since he had received transurethral resection of prostate (TUR-P) for benign prostatic hypertrophy. A 60-min pad test yielded 3 g of urine. Prostatic urethra was widely open and the external sphincteric injury was suggested because of the short membraneous urethra on the urethrogram. Urethral pressure profile indicated his maximal urethral closing pressure (MUCP) of 24 cmH2O and functional urethral length of 1.6 cm and cystometry demonstrated an underactive bladder, indicating that his incontinence was caused by sphincteric injury. Autologous fat injection therapy was performed in the lithotomy position under spinal anesthesia. Fifteen ml of subcutaneous fat was obtained from his lower abdomen by liposuction through a 15G needle, and 10 ml was injected submucosally from the perineum at 6 o'clock area of the prostatic apex under the guidance of transrectal echography using a 15G needle. The patient became completely dry after the procedure. MUCP and FUL increased to 35 cmH2O and 1.9 cm, respectively, although longer follow up is necessary. The advantage of autologous fat injection to the prostate for post-TUR-P SUI patients is briefly discussed.     

Magnetic resonance (MR) imaging of the chest: state-of-the-art

To date, magnetic resonance (MR) is established as an imaging modality in the diagnosis of chest diseases. Because of its excellent distinction of vessels and soft tissue, MR can be performed as the primary imaging procedure before computed tomography in patients with suspected vascular lesions, mediastinal masses, hilar lesions, and pathological changes of the pleura and the chest wall. In these cases, MR is able to provide all the necessary diagnostic information. In other patients, a limited number of MR images may be helpful in cases of equivocal or confusing CT or clinical findings. More detailed information can be obtained, using surface coils or special imaging sequences, i.e. high resolution MR images of the pleura or angiographic images of mediastinal and pulmonary vasculature. From a clinical viewpoint, the most important task for thoracic magnetic resonance nowadays is the pretherapeutic evaluation of intrathoracic masses, the differential diagnosis of benign versus malignant lesions, and the accurate documentation of tumour extent in malignancies including three-dimensional-display to improve surgical or radiation planning. Future directions in thoracic magnetic resonance will be predominantly influenced by postprocessing approaches, specialized imaging techniques, and magnetic resonance-guided interventional applications.     

Magnetic resonance in HTL-I associated myelopathy. Leukoencephalopathy and spinal cord atrophy

Cerebral white matter lesions and spinal cord atrophy have been frequently reported in patients with HTLV-I associated myelopathy (HAM). The exact frequency and the clinical relevance of these findings still remain to be elucidated. Twenty-nine patients with HAM were studied by magnetic resonance imaging of the brain and spine. Cerebral white matter lesions equal or over 3 mm in diameter were considered abnormal. The spinal cord size was evaluated using an index we have called "spinal cord index". The radiological findings were correlated to the clinical features of the myelopathy. Cerebral white matter lesions occurred in 52% of the patients, and spinal cord atrophy in 74%. There was no significant correlation between these abnormalities and the clinical features studied. These findings suggest that the resonance imaging is a useful method for detection of cerebral and spinal cord abnormalities in HAM patients. The absence of correlation between cerebral white matter lesions and either patient age or risk factors for cardiovascular disease suggests a possible association between the leukoencephalopathy and the infection.     

Bilateral femoral neck fractures as a complication of myelography

This paper discusses two cases of bilateral subcapital fracture of the proximal femur as a complication of myelography with Conray 60. The literature is reviewed.     

The caloric vestibular examination: a simplified technique and its normal values (author's transl)

A simple modification of caloric vestibular stimulation and its documentation is described to improve the coordination of vestibular investigation in clinics and practice. A volume of 50 cc. 30 degrees and 44 degrees C water is used to irrigate the ear and is administered within a 10 s period. The patient is then evaluated for the rate and duration of nystagmus, using Frenzel lenses. 1182 patients were investigated in this manner and their results were computerized. It was then shown that irrigation with 30 degrees C water was followed by a greater nystagmus reaction (including vertigo and vegetative signs) than with the 44 degrees water.     

Magnetic resonance tomographic angiography of the arterial circle (of Willis)

The efficacy of two different types of commercial competitive exclusion (CE) products against Salmonella was studied in three chicken assay trials. Chicks were treated on the day of hatch and challenged one day later either with Salm. infantis (Trials 1 and 2) or a combination of Salm. infantis and Salm. enteritidis (Trial 3). The caeca of the birds were examined for Salmonella five days after challenge. The mean logarithmic counts of Salmonella were from 3.4 to 5.7 in the groups treated with product. A derived from the whole caecal contents of an adult bird, from 0.0 to 1.2 in the groups treated with product B, a highly selected product that does not contain any clostridia, and from 6.3 to 7.6 in the control groups. None of the challenge organisms superseded the other in Trial 3, and neither did the double challenge affect the protective capacity of the treatment materials.     

Magnetic resonance cholangiopancreatography (MRCP) versus endoscopic retrograde cholangiopancreatography (ERCP): diagnostic usefulness

Human stem cell growth factor (SCGF) produced by a myeloid cell line, KPB-M15, exhibits species-specific hematopoietic activities. However, KPB-M15-conditioned medium induced colony formation of mouse bone marrow cells. KPB-M15-derived colony-stimulating activity (CSA) was purified through Butyl-Toyopearl 650c and Cu2+ chelating-Sepharose 6B chromatography. TSK-G3000SW gel filtration of the purified preparation presented 3 distinct peaks around Vo, 150 kD and 85 kD. Gel fractions extracted from SDS-PAGE had macrophage colony-stimulating factor (M-CSF)-specific amino acid sequences. PCR, Northern hybridization and ELISA demonstrated that KPB-M15 cells secreted a significant amount of M-CSF and IL-6. Anti-M-CSF but not anti-IL-6 antibody abrogated CSA in KPB-M15-CM. IL-6 hardly synergized with M-CSF to enhance colony formation. Collectively, M-CSF is a sole CSA for murine hematopoietic progenitor cells in KPB-M15-CM. This is the first report of a human myeloid cell line, KPB-M15, constitutively producing M-CSF in addition to SCGF and IL-6. It can be useful in investigating the mechanism of production of M-CSF.     

Magnetic resonance arteriography as a method for diagnosing arteriosclerosis of the lower extremities

The purpose of our study was the evaluation of usefulness of Magnetic Resonance Angiography in diagnostic process in patients with arteriosclerosis of lower extremities and complications such as aneurysms and pseudoaneurysms. 105 patients were examined using 2D TOF method. We concluded the results were very similar as in radiological examinations. The MRA is a very helpful method in evaluation of constriction and occlusion of iliac and femoral arteries and aorta.     

Magnetic resonance imaging (MRI) of a cookie in comparison with time-lapse photographic analysis (TLPA) during baking process

Magnetic Resonance Imaging (MRI) has been used to study the baking of a cookie. The structural and dynamic changes occurring during baking have been monitored, including changes in the internal moisture saturations and distribution. The images reveal the moisture distribution is initially uniform, and during baking a gradient in moisture develops from the interior to the edge. Changes in physical dimensions calculated from the data are consistent with those obtained from time-lapsed photography.     

Magnetic resonance imaging of a mediastinal ependymoma

Ependymomas typically occur in the brain and spinal cord, and represent 5% and 16% of primary intracranial and spinal cord tumors respectively. Ependymomas arising outside the central nervous systems are uncommon and when they do occur are usually seen in the sacrococcygeal region. Other reported sites include the pelvis, spinal nerve roots, and lung. An extraspinal mediastinal ependymoma is a rare occurrence, with only two previously reported cases to our knowledge. In both instances, the lesion arose in the posterior mediastinum, and were imaged with either chest radiographs alone or chest radiographs and computed tomography. In our case, plain radiography was followed by magnetic resonance imaging. This report documents the clinical, pathological, and magnetic resonance imaging findings in a case of a posterior mediastinal ependymoma. Primary mediastinal ependymomas are rare lesions that may be considered in the differential diagnosis of a posterior mediastinal mass.     

Magnetic resonance imaging of Long-Evans cinnamon rats as a new model of hepatocellular carcinoma

A case of recurrent and metastatic nonfunctioning adrenocortical carcinoma in a 40-year-old woman is reported. The patient received 4 laparotomies and 1 thoracotomy for recurrent and metastatic disease after removal of the primary adrenal tumor. She has been alive for over 18 years following multiple surgery for diseases after the first adrenalectomy. In selected patients with recurrence and/or metastasis, repeated surgical resection offers the possibility of a cure or extended palliation.     

Thoracic and lumbar myelography with metrizamid (author's transl)

With the new x-ray medium Metrizamid it is possible to perform almost complication-free lumbar and thoracic myelography. In an experience the type of complications arising were reduced to moderate headaches, mild nausea occasional dissiness. No convulsions were seen. The number of complications are less than with other watersoluble contrast medium.     

Prospective study of 163 retinal detachments operated by episcleral technique (preoperative examination)

The predominance of retinal breaks in the superior temporal quadrant is well known. This predominance was found to be related to age and refraction (p < 0.01). The distribution of breaks plotted across the 12 meridians shows a predilection for the superior temporal quadrant and half of the inferior temporal and superior nasal one. However, in this area the distribution is irregular (p > 0.001) with a predominance in the 10-11 and 12-1 o'clock section (if we consider the right eye). The H/T ratio (holes/tears for each case) is positive for patients under 40 years of age and becomes negative after 50 years.     

External ear resonance as a screening technique in children with otitis media with effusion

External ear resonance can be quickly and accurately measured using real ear insertion gain equipment. It has been previously shown that external ear resonance characteristics are often altered by the presence of middle ear fluid. The external ear resonance characteristics of 84 children with a history of chronic middle ear disorder were determined. Results were compared to other audiological data and otological findings recorded during surgery. External ear resonance peak amplitude was significantly correlated with the presence or absence of middle ear fluid. It was found that peak amplitude of > or = 24 dB was associated with only 15% of dry ears and peak amplitude of < or = 22 dB associated with 79% of ears without fluid. The use of external ear resonance measures as a potential screening procedure is discussed.     

Side reaction after lumbar myelography with dimer-x (author's transl)

The existence of several very impressive spinal paroxysms after lumbar myelography with Dimer-X1 caused us to make a retrospective investigation of 327 patients with 355 myelographies. In 7.1% of the investigations we have found partly heavy, but mostly reversible neurological complications. The latter cannot be classified, contrary to prevailing statements, in spinal, meningeal or cerebral reactions, since mostly all 3 anatomical structures are being concerned. Corresponding casuistical information are being presented and with their neurological symptomatic discussed. The spinal paroxysms appeared approximately 6 hours after the myelography and lasted over 8-10 hours, in spite of intensive therapeutical efforts. The pathogenesis points to a multifactorial occurrence caused by the coincidence of an increased dosage of the contrast media, too bed rest time, rising of the contrast media in the spinal cord zone and disturbed liquor fluid circulation and contrast media resorption. Pathophysiologically is in connection with spinal cramps an epileptic mechanism probable. Additional spinal reflexive components could be an explanation for the little therapeutical effect of Diacepam (Valium), which is contrary to the statement in the literature. We have seen a better effect in particular cases with Phenothiazine. With strict observance of specific precautionary measures, the Dimer-X seems to be a good media for the presentation of the lumbar subarachnoid space. A further development in this field is desirable.     

Magnetic resonance imaging-documented extravasation as an indicator of acute hypertensive intracerebral hemorrhage

OBJECT: The aim of this study was to determine the usefulness of magnetic resonance (MR) imaging-documented extravasation as an indicator of continued hemorrhage in patients with acute hypertensive intracerebral hemorrhage (ICH). METHODS: The authors studied 108 patients with acute hyperintensive ICH. Imaging modalities included noncontrast-enhanced computerized tomography (CT) scanning, gadolinium-enhanced MR imaging, and conventional cerebral angiography obtained within 6 hours after the onset of hemorrhage. A repeated CT scan was obtained within 48 hours to evaluate enlargement of the hematoma. Findings on MR imaging indicating extravasation, including any high-intensity signals on T1-weighted postcontrast images, were observed in 39 patients, and 17 of these also showed evidence of extravasation on cerebral angiography. The presence of extravasation on MR imaging was closely correlated with evidence of hematoma enlargement on follow-up CT scans (p < 0.001). CONCLUSIONS: Evidence of extravasation documented on MR imaging indicates persistent hemorrhage and correlates with enlargement of the hematoma.