Diagnostic Value of Spinal Computer Tomography in Patients with Intraspinal Metastases Causing Complete Block on Myelography

The value of post-myelographic spinal computer tomography (CT) was evaluated in cancer patients with spinal metastases causing complete myelographic block. In 22 out of 25 lumbar myelographies (88%) showing complete blockade, sufficient contrast medium had leaked proximally to allow determination of the cranial limit of the metastasis on the CT-scan. It is concluded that the post-myelographic spinal CT can replace a supplementary cervical myelography in the majority of patients with epidural metastasis, causing a complete myelographic block.

Relationship between bone mineral content and frequency of postmenopausal fractures

To elucidate the relationship between bone mineral content (BMC) and the frequency of postmenopausal fractures, we performed an epidemiologic investigation in a representative sample of 70-year-old women. Anamnestic data concerning postmenopausal fractures due to minor trauma were recorded and lateral X-rays of the spine were taken for evaluation of spinal fractures. BMC was measured by 125I photon absorptiometry. The 285 women studied were allocated into quintiles according to their BMC value. In 77 women, there were 131 definite osteoporotic fractures (i.e., spinal crush, and fracture of the hip, proximal humerus, and distal forearm), and in 48 women, there were 162 other non-violent fractures (i.e., spinal wedge and other long bone fractures). The frequencies of osteoporotic fractures varied inversely with the mean BMC values for each quintile (r = 0.959, p less than 0.01). The difference in frequency of osteoporotic fractures between the first and fifth quintiles was highly significant (p less than 0.001). In contrast, other non-violent fractures appeared to be unrelated to BMC. It is concluded that low BMC levels predispose to osteoporotic fractures.

MRI of the arthritic small joints: comparison of extremity MRI (0.2 T) vs high-field MRI (1.5 T)

The aim of this study was to compare the diagnostic capabilities of extremity MRI (E-MRI) with high-field MRI in arthritic small joints, and to evaluate the patients' acceptance and perceptions of the two MR systems. One hundred three patients (group 1 = 28 patients with RA < 3 years, group 2 = 25 patients with reactive and psoriatic arthritis and mixed connective tissue disease, group 3 = 25 patients with rheumatoid arthritis (RA) more than 3 years and group 4 = 25 patients with arthralgia) underwent dedicated E-MRI and high-field MRI of the wrist and finger joints. Coronal short tau inversion recovery and transversal 3D T1-weighted images before and after gadodiamide (Gd) were performed in both cases to outline the volume of the synovial membrane (Vsm) and to evaluate joints with enhancement, effusion, bone edema, and erosions. Investigators blinded to the clinical findings evaluated the images. Patients' compliance and acceptance of E-MRI and high-field MRI were evaluated. The median Vsm obtained on E-MRI did not differ significantly from that obtained on high-field MRI. Vsm = 1 ml (E-MRI) and 1.1 ml (high-field MRI) before Gd and Vsm = 0.1 ml (E-MRI) and 0 ml (high-field MRI) after Gd (Wilcoxon test, p > 0.05). The difference in agreement was 8% for joint enhancement, 2% for joint effusion, 3% for bone edema, and 4% for bone erosions. Of the patients, 64% preferred E-MRI due to more comfortable positioning and less claustrophobia and noise. Extremity MRI of the small arthritic joints is comparable to high-field MRI and more readily accepted than high-field MRI by this patient group.

Magnetic resonance imaging of the wrist and finger joints in patients with inflammatory joint diseases

OBJECTIVE

To study magnetic resonance imaging (MRI) features in the wrist and metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints in 4 patient groups: early rheumatoid arthritis (RA) (< 3 yrs); established RA (> 3 yrs); other arthritis; arthralgia.

METHODS

MRI was obtained before and after contrast (gadodiamide) injection of the wrist and finger joints in 103 patients and 7 controls. The study included: (1) 28 patients with disease duration < 3 yrs who fulfilled the American College of Rheumatology (ACR) criteria for RA; (2) 25 patients with RA disease duration > 3 yrs who fulfilled the ACR criteria. (3) 25 patients with reactive arthritis, psoriatic arthritis, or mixed connective tissue disease; and (4) 25 patients with arthralgia. The following MRI variables were assessed: number of joints with enhancement after contrast injection, number of joints with joint fluid, and number of bones with edema in the wrist and fingers. The volume of the enhancing synovial membrane after contrast injection in the MCP, PIP, and DIP joints was manually outlined. MR images were scored independently under blinded conditions.

RESULTS

Bone marrow edema was found in 68% of the patients with established RA, and the number of bones with edema was significantly higher in patients with established RA compared to patients with early RA, other arthritis, and arthralgia (Mann-Whitney p < 0.04). Bone edema was not found in patients with arthralgia. There was marked overlap within and between the patient groups. No differences in MRI features were found between patients with early RA and patients with other arthritis. The volumes of the synovial membrane in the MCP, PIP, and DIP joints were significantly higher in patients with arthritis compared to patients with arthralgia.

CONCLUSION

Although there was marked overlap between the arthritis patient groups, MRI determined bone marrow edema and synovial membrane volumes provided additional information about disease activity and may be used as a marker of it. Bone marrow edema appeared with the highest percentage in patients with long duration of RA (> 3 yrs) and is probably secondary to changes in inflammatory activity.

MRI of the plantar structures of the foot after falanga torture

Falanga is an ancient form of punishment or torture but is still commonly reported by our refugees. The late result of caning the heel and ball of the foot is a chronic painful condition with few clinical signs. The aim of the present study was to assess, by MRI, possible morphologic characteristics of the heel and ball of the foot, related to falanga and pain in correlation to clinical findings. Magnetic resonance imaging of the foot was obtained in 12 victims exposed to falanga torture and 9 healthy volunteers. Sagittal T1-weighted spin-echo images (TR 616-840 ms, TE 20 ms), T2-weighted spin-echo images (TR 1900 ms, TE 90 ms), and short tau inversion recovery (STIR) images (TR 1200 ms, TE 15 ms, TI 100 ms) were performed. The central portion of the plantar aponeurosis was generally significantly thicker in victims exposed to falanga torture as compared with that of controls (P < 0.05). In all except one of the victims, MRI demonstrated two layers of the thickened plantar aponeurosis: a deeper portion with normal homogeneous low signal intensity (SI) appearance, and a superficial layer with characteristic areas of mixed SI on both T1- and T2-weighted images. There were no signs of chronic muscular compartment syndromes, and the thickness of the plantar pad did not differ between the two groups. Magnetic resonance imaging may demonstrate morphologic characteristics of the plantar aponeurosis which may confirm falanga torture. Further imaging with more specific sequences is warranted to demonstrate the supposed injuries in the compartmental fat tissue chambers and the vascularity of the ball pad of the foot.

Long-term genetic modification of rhesus monkey hematopoietic cells following transplantation of adenoassociated virus vector-transduced CD34+ cells

We have explored the potential of recombinant adenoassociated virus (AAV) vectors for gene transfer of the human beta-globin gene and the genetic modification of primate pluripotent hematopoietic stem cells (P-PHSCs). Transduction of P-PHSCs was tested in a preclinical bone marrow transplantation model in rhesus monkeys. CD34+ cells were transduced ex vivo and autologously transplanted without prior selection into irradiated rhesus monkeys. Vector-transduced peripheral blood mononuclear cells and granulocytes were present in the circulation for more than 15 months after transplantation. Approximately 1 in 10(5) cells in the circulation was vector modified. The vector was detected in the bone marrow, in granulocytes, and in purified populations of B and T cells, thus demonstrating multilineage repopulation by vector-transduced stem cells. Comparison of transduction protocols suggested that short-term culture of P-PHSCs enhances transduction and subsequent repopulation by rAAV-transduced cells. These results demonstrate that rAAV vectors can be used for the permanent genetic modification of a rhesus monkey hematopoietic system in the absence of selective pressure.

Determinants of musculoskeletal flexibility: viscoelastic properties, cross-sectional area, EMG and stretch tolerance

Cross-sectional area, stiffness, viscoelastic stress relaxation, stretch tolerance and EMG activity of the human hamstring muscle group were examined in endurance-trained athletes with varying flexibility. Subjects were defined as tight (n = 10) or normal (n = 8) based on a clinical toe-touch test. Cross-sectional area was computed from magnetic resonance imagining (MRI) images. Torque (Nm) offered by the hamstring muscle group, electromyographic (EMG) activity, knee joint angle and velocity were continuously monitored during two standardized stretch protocols. Protocol 1 consisted of a slow stretch at 0.087 rad/s (dynamic phase) to a pre-determined final angle followed by a 90-s static phase. In the dynamic phase final angle and stiffness was lower in tight (28.0+/-2.9 Nm/rad) than normal subjects (54.9+/-6.5 Nm/rad), P<0.01. In the static phase tight subjects had lower peak (15.4+/-1.8 Nm) and final torque (10.8+/-1.6 Nm) than normal subjects (31.6+/-4.1 Nm, 24.1+/-3.7 Nm, respectively)(P<0.01), but torque decline was similar. Protocol 2 consisted of a slow stretch to the point of pain and here tight subjects reached a lower maximal angle, torque, stiffness and energy than normal subjects (P<0.01). On the other hand, stiffness was greater in tight subjects in the common range (P<0.01). Cross-sectional area of the hamstring muscles and EMG activity during the stretch did not differ between the groups. However, lateral hamstring cross-sectional area was positively related to mid-range stiffness (P<0.05), but inversely related to final stiffness, peak torque and the toe-touch test (P<0.01). Final angle and peak torque in protocol 1 combined to improve the predictability of the toe-touch test (R2=0.77, P<0.001). These data show that the toe-touch test is largely a measure of hamstring flexibility. Further, subjects with a restricted joint range of movement on a clinical toe-touch test have stiffer hamstring muscles and a lower stretch tolerance.

Radiologic features compared to clinical findings in a prospective study of 153 patients with metastatic spinal cord compression treated by radiotherapy

Plain radiography, myelography and post-myelographic CT-scan are described and related to clinical findings in a prospective study of 153 consecutive patients with myelographic signs of spinal cord compression. The majority of the metastatic tumours arise in the vertebral body or the pedicles. In 80% of the patients with total blockage to the contrast medium on myelography the post-myelographic-CT showed passage of the contrast medium. Ambulatory function at time of diagnosis was correlated to the degree and the localization of the epidural block. In 64 patients who underwent a second myelography, the post-treatment findings of sensory function were correlated to radiological regression.

[Magnetic resonance imaging compared to myelography and CT. Diagnostic value in patients with suspected medullary spinal compression syndrome]

Comparison between myelography (MY) and magnetic resonance imaging (MRI) was carried out in 36 patients with clinical suspicion of spinal cord or root compression due to metastatic disease in the spinal canal. In three patients metastatic lesions were visualized on MY but not on MRI, while there were no cases with a negative MY and a positive MRI. In 44% of the cases MY alone or combined with postmyelographic CT (pm-CT) showed a larger tumour extension than did MRI, while the opposite occurred in 25%. As for detection of bony metastases and tumour masses localized outside the spine there was no difference between MRI and MY + pm-CT. The results indicate that the choice between MRI and MY + pm-CT still can be based on the availability and quality of the procedure at a given institution.

Comparison of myelography combined with postmyelographic spinal CT and MRI in suspected metastatic disease of the spinal canal

Comparison between myelography (MY) and magnetic resonance imaging (MRI) was carried out in 36 patients with clinical suspicion of spinal cord or root compression due to metastatic disease in the spinal canal. In 3 patients metastatic lesions were visualized on MY but not on MRI, while there were no cases with a negative MY and a positive MRI. In 44% of the cases MY alone or combined with postmyelographic CT (pm-CT) showed a larger tumor extension than did MRI, while the opposite occurred in 25%. As for detection of bony metastases and tumor masses localized outside the spine there was no difference between MRI and MY + pm-CT. The results indicate that the choice between MRI and MY + pm-CT still can be based on the availability and quality of the procedure at a given institution.

Diagnostic value of spinal computer tomography in patients with intraspinal metastases causing complete block on myelography

The value of post-myelographic spinal computer tomography (CT) was evaluated in cancer patients with spinal metastases causing complete myelographic block. In 22 out of 25 lumbar myelographies (88%) showing complete blockade, sufficient contrast medium had leaked proximally to allow determination of the cranial limit of the metastasis on the CT-scan. It is concluded that the post-myelographic spinal CT can replace a supplementary cervical myelography in the majority of patients with epidural metastasis, causing a complete myelographic block.

Thrombolytic therapy of cerebral arterial occlusion with recombinant tissue plasminogen activator

This report describes three patients, with acute cerebral arterial occlusion, treated with recombinant tissue plasminogen activator (rt-PA). In one patient with basilar artery occlusion thrombolytic treatment was initiated 12 h after onset of the symptoms. In two patients with angiographically verified occlusion of the middle cerebral artery, the treatment was initiated approximately 4.5 h after onset of the symptoms. Recombinant tissue plasminogen activator 80-120 mg, was infused intra-arterially over 90-100 min via a catheter the tip of which was close to the occlusion. This regimen resulted in recanalization in all the patients; however, in two patients it was verified by repeat CT scan only. In two patients the thrombolytic treatment was successful (the patients improved clinically); the third patient died of massive cerebral infarct-related oedema. In none of the patients did significant bleeding or other obvious side-effects occur. From this preliminary report it is concluded that angiographically proven thrombolytic recanalization in acute cerebrovascular occlusion is possible with rt-PA. In some patients, however, the treatment is initiated too late. Further investigation of the possible indication for thrombolytic therapy in stroke is needed.

Unbiased and efficient estimation of total ventricular volume of the brain obtained from CT-scans by a stereological method

Using a simple stereological method the estimation of the ventricular volume in ten hydrocephalic children and adults based on ordinary CT-scans is presented. The volume estimates are compared with "ventricular size" expressed as Evans' ratio. The differences between the two estimates are discussed.

Measurement of anteversion of the femoral neck. Ultrasound and computerised tomography compared

Anteversion of the femoral neck of 30 unpaired dry bones was measured directly, by ultrasound, and by computerised tomography. The angles measured directly corresponded well with the angles found by CT scan, but there was poor correlation between these and the angles measured by ultrasound. At present ultrasound seems to be unsuitable for the measurement of anteversion of the femoral neck.

Intracerebral haemorrhage after carotid endarterectomy

Among 662 consecutive carotid endarterectomies eight cases of postoperative ipsilateral intracerebral haemorrhage were identified, occurring into brain areas which, preoperatively were without infarction. As blood pressures across the stenosis were routinely measured during surgery, the internal carotid artery (ICA) perfusion pressure could be related to the occurrence of haemorrhage. In addition, cerebral blood flow (CBF) was studied with the intravenous xenon-133 technique in four patients and histopathologic examination of the brain was available in four patients who died subsequent to their haemorrhage. All eight patients had a high grade of ICA stenosis and a marked reduction of ICA perfusion pressure (average of 40%) which was significantly greater than that observed (average of 6%) in the other patients undergoing carotid surgery (P less than 0.0001). Relative hyperperfusion of the ipsilateral hemisphere was seen in the four patients studied postoperatively. In at least two cases the haematoma was preceded by an asymptomatic postoperative ischaemic infarct. Histologic examination did not confirm previous findings of changes resembling those seen in malignant hypertensive encephalopathy. These results substantiate the view, that patients at risk of haemorrhage after endarterectomy are those with a low preoperative cerebral perfusion pressure and postoperative hyperperfusion. Postoperative silent brain infarction is an additional risk factor.

Does 1,25(OH)2D3 accelerate spinal bone loss? A controlled therapeutic trial in 70-year-old women

The progress of spinal bone loss was monitored by measurements of the vertebral body height of T6 to L5 in seventy 70-year-old women who participated in a controlled, double-blind therapeutic trial. They were treated for one year by 1,25(OH)2D3, 0.50 micrograms a day (or less if hypercalcemia occurred) and cyclical estrogen/gestagen, alone or combined, or placebo. Sufficient calcium intake was ensured in all. The vertebral body height decreased significantly, by 1%, in both of the 1,25(OH)2D3 groups, whereas it remained unchanged in the hormone and the placebo + calcium group. This observation does not encourage the use of 1,25(OH)2D3 for prevention or treatment of postmenopausal bone loss.

Validity in diagnosing osteoporosis. Observer variation in interpreting spinal radiographs

Observer variation in interpreting radiograph of the spine in 70-year-old Danish women has been examined. The women joined a general health investigation as part of an epidemiologic screening for osteoporosis. Two experienced radiologists examined independently 280 sets of lateral radiographs of the spine to disclose fractures. The radiographs were examined four times, each examined at two different occasions by each radiologist. Overall intra-observer agreement was 88% and 87% when asked for presence or absence of fractures, irrespective of fracture localization. When accidental occurrence of agreement was taken into account (kappa analysis) intra-observer variation was reduced to 64% and 62%. The overall inter-observer agreement was 75%, but reduced to 47% when accidental occurrence of agreement was noted. Kappa analysis in testing observer variation indicates that a considerable part of agreement can be ascribed to chance alone. This seriously questions the hitherto used definition of osteoporosis.

Epidemiology of postmenopausal spinal and long bone fractures. A unifying approach to postmenopausal osteoporosis

The incidence of spontaneous postmenopausal fractures and their relationship to menopausal age and bone mass were determined in a representative sample of 70-year-old Danish women. Two hundred and eighty-five women (1.2% of all women in that age group) were examined by case history, by 125I photon absorptiometry in both forearms (BMC), by metacarpal index (CA/TA), and by lateral radiographs of the spine. Twenty-four per cent of the participants had sustained single fractures, and 20% multiple fractures. Nineteen per cent had fractures of the lower forearm, 5% of the proximal humerus, 4% of the hip, and 5% crush fractures of the spine. These comprise Group I fractures, the most definite expressions of osteoporosis. The remaining other long bone fractures (7%) and spinal wedge fractures (18%) comprise Group II fractures. Group I cases were characterized by an earlier onset of the menopause and a definite decrease in bone mass, as judged from BMC and CA/TA, as compared with the nonfracture group. Group II cases did not display this distinction. Of Group I cases, those with multifractures differed from those with single fractures by having a five-year earlier occurrence of first fracture, a further decrease in bone mass, and a slightly raised serum alkaline phosphatase level. Serum calcium and phosphate levels were the same in all groups.