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Biomedical subjects

O Tervonen

Publications and source records attributed to O Tervonen.

At least 37 records · Page 2Linked to original sources
PubMed2001

The efficacy of a continuous quality improvement (CQI) method in a radiological department. Comparison with non-CQI control material.

OBJECTIVE: To study the efficacy of continuous quality improvement (CQI) compared to ordinary management in an on-duty radiology department. MATERIAL AND METHODS: Because of complaints regarding delivery of on-duty radiological services, an improvement was initiated simultaneously at two hospitals, at the HUCH (Helsinki University Central Hospital) utilising the CQI-method, and at the OUH (Oulu University Hospital) with a traditional management process. For the CQI project, a team was formed to evaluate the process with flow-charts, cause and effect diagrams, Pareto analysis and control charts. Interventions to improve the process were based on the results of these analyses. RESULTS: The team at the HUCH implemented the following changes: A radiologist was added to the evening shift between 15:00-22:00 and a radiographer was moved from the morning shift to 15:00-22:00. A clear improvement was achieved in the turn-around time, but in the follow-up some of the gains were lost. Only minimal changes were achieved at the OUH, where the intervention was based on traditional management processes. CONCLUSION: CQI was an effective method for improving the quality of performance of a radiology department compared with ordinary management methods, but some of this improvement may be subsequently lost without a continuous measurement system.

Finland↗
PubMed2000

Nerve root infiltration of the first sacral root with MRI guidance.

The purpose of this clinical trial was to describe the methodology and evaluate the accuracy of optical tracking-based magnetic resonance (MR)-guided infiltration of the first sacral (S1) root. Thirty-five infiltrations were performed on 34 patients with a 0. 23-T open C-arm magnet installed in a fully equipped operation room with large-screen (36 inches) display and optical navigator utilizing infrared passive tracking. T1 and T2 fast spin-echo (FSE) images were used for localizing the target and fast field echo for monitoring the procedure. Saline as contrast agent in single-shot (SS)FSE images gave sufficient contrast-to-noise ratio. Twenty-four patients had unoperated L5/S1 disc herniation, and 10 had S1 root irritation after failed back surgery. Needle placement was successful in 97% of the cases, and no complications occurred. Outcome was evaluated 1-6 months (mean 2.2 months) after the procedure and was comparable to that of other studies using fluoroscopy or computed tomography guidance. MR-guided placement of the needle is an accurate technique for first sacral root infiltration.

Bupivacaine↗
PubMed2000

Slow vasomotor fluctuation in fMRI of anesthetized child brain.

Signal intensity changes in fMRI during rest caused by vasomotor fluctuations were investigated in this work. Resting-state baseline fluctuations were evaluated in 12 children anesthetized with thiopental. Five subjects had fluctuations related to subvoxel motion. In seven subjects without significant motion, slow signal fluctuation at 0.025-0.041 Hz near one or more primary sensory cortices was observed. In each subject the amplitude and frequency of the fluctuations were stable. It is hypothesized that thiopental, which reduces blood pressure and flow in the cortex, alters the feedback in neurovascular coupling leading to an increase in the magnitude and a reduction in the frequency of these fluctuations. The use of anesthesia in fMRI may provide new insight into neural connectivity and the coupling of blood flow and neural metabolism.

Anesthesia, Intravenous↗
PubMed2000

Initial experience with a wireless personal digital assistant as a teleradiology terminal for reporting emergency computerized tomography scans.

A new type of terminal device, a wireless personal digital assistant (PDA) based on a GSM digital cellular phone, was used to transmit computerized tomography scans of 21 patients to a neuroradiologist. All transmitted images were suitable for a preliminary consultation and in one case a final report could be made. In 18 cases the findings were compatible with the reference film reading performed later and in three cases there were minor differences of no clinical importance. Transmission of a single image lasted 1 min 30 s and the transmission of a complete brain scan (14 images) took on average 21 min. The total process of transmission and interpretation of a brain examination series took on average 40 min. In this pilot study the neuroradiologist gained essential information in 24% of the cases and beneficial information in 62%. The neuroradiologist considered that the image consultation saved a hospital visit in 15 cases (71%). Although PDA technology is at an early stage of development and has numerous limitations, it is likely that future technical improvements will allow easier clinical consultations for neurosurgeons and neurologists.

Adolescent↗
PubMed2000

[Imaging the ear].

Explore the source record for details and available documents.

Diagnostic Imaging↗
PubMed1999

Association of atherosclerosis with low back pain and the degree of disc degeneration.

STUDY DESIGN: This was a cross-sectional observational study in which the abdominal aorta was evaluated for atheromatous lesions visible in computed tomographic scans in patients with and without low back pain. OBJECTIVES: To evaluate whether patients with low back pain have more atherosclerosis in the abdominal aorta than patients without low back pain and whether the severity of atherosclerosis in the abdominal aorta correlates with the grade of disc damage. SUMMARY OF BACKGROUND DATA: There are studies in which results indicate that insufficient blood supply may be a significant causative factor in disc degeneration. There are also studies in which smoking, one of the risk factors for arterial disease, has been correlated with low back pain. Calf pain has also been shown to correlate with low back pain. Results in a long-term follow-up study have further indicated an association between disc diseases and fatal ischemic heart disease. However, there seems to be only one postmortem study in which results show an association between atherosclerosis in the arteries of the lumbar area and disc diseases. METHODS: Computed tomographic images of 29 patients with low back pain, who had been evaluated with computed tomographic discography for diagnostic purposes, were evaluated for the quantity of atherosclerotic calcifications visible on computed tomographic scans of the abdominal aorta. A similar evaluation was performed in an age- and sex-matched control group of 52 patients without low back pain selected from among the patients referred for abdominal computed tomography. RESULTS: Sixteen (55%) of the 29 patients with low back pain had atherosclerotic calcifications visible on computed tomographic scans, whereas 11 (21%) of the 52 age-matched patients without low back pain were found to have aortic calcifications. Eleven (48%) patients with low back pain who were 50 years of age or less (n = 23) had aortic calcifications, whereas only 3 (8%) of the 36 control patients aged less than 50 years had aortic calcifications. There was no correlation between the amount of calcifications and the degree of disc degeneration assessed by computed tomographic discography. CONCLUSIONS: A significant association is indicated between atheromatous lesions in the abdominal aorta and low back pain.

Adult↗
PubMed1999

An allele of COL9A2 associated with intervertebral disc disease.

Intervertebral disc disease is one of the most common musculoskeletal disorders. A number of environmental and anthropometric risk factors may contribute to it, and recent reports have suggested the importance of genetic factors as well. The COL9A2 gene, which codes for one of the polypeptide chains of collagen IX that is expressed in the intervertebral disc, was screened for sequence variations in individuals with intervertebral disc disease. The analysis identified a putative disease-causing sequence variation that converted a codon for glutamine to one for tryptophan in six out of the 157 individuals but in none of 174 controls. The tryptophan allele cosegregated with the disease phenotype in the four families studied, giving a lod score (logarithm of odds ratio) for linkage of 4.5, and subsequent linkage disequilibrium analysis conditional on linkage gave an additional lod score of 7.1.

Adult↗
PubMed1999

MR imaging in tibial shaft fractures. A potential method for early visualization of delayed union.

PURPOSE: To evaluate the relationship between MR findings at the fracture site during the healing process and the outcome of patients with tibial shaft fracture. MATERIAL AND METHODS: Twelve consecutive patients with an uncomplicated tibial fracture treated conservatively were imaged by MR 1 to 3 days, 1 week, 3 weeks, 6 weeks and 12 weeks after the trauma. MR imaging consisted of sagittal/coronal T1-weighted, T2-weighted, proton density, short-tau inversion recovery, and contrast-enhanced T1-weighted spin-echo images. The images were analysed for the extent of signal pathology in the bone marrow adjacent to the fracture, the extent of soft tissue oedema, and the intensity and homogeneity of the contrast enhancement of the callus. RESULTS: The differences between normal (n=7) and delayed union (n=5) were observed within 3 to 6 weeks after the trauma, mainly in the homogeneity of the callus in T2-weighted and contrast-enhanced images. CONCLUSION: MR imaging is a potentially valuable method for early visualization of delayed union in tibial shaft fractures.

Adult↗
PubMed1998

Evaluation of humeral head erosions in rheumatoid arthritis: a comparison of ultrasonography, magnetic resonance imaging, computed tomography and plain radiography.

The value of ultrasonography (US), magnetic resonance imaging (MRI), computed tomography (CT) and plain radiography (PR) in detecting bone erosions on the humeral head was evaluated in a study of 26 in-patients (26 shoulders) with rheumatoid arthritis (RA). MRI depicted humeral erosions in 25 (96%), US in 24 (92%), CT in 20 (77%) and PR in 19 (73%) of the 26 shoulders. MRI and US were superior to CT in detecting small erosions. US was the most sensitive method to show surface erosions on the greater tuberosity. US, CT and MRI detected large erosions quite similarly. PR frequently missed small erosions. In the evaluation of early erosions in the rheumatoid shoulder, US and MRI are more sensitive methods than the traditionally used PR. US and MRI are suitable for the evaluation of soft-tissue involvement in the rheumatoid shoulder, but also for the detection of bone erosions of the humeral head.

Adult↗
PubMed1998

Digital wireless radiology consultations with a portable computer.

A wireless system for radiological subspecialist consultation based on a portable personal computer and a GSM cellular phone was tested. A link with secure access to the hospital image network was built. A total of 68 emergency computerized tomography (CT) examinations were transmitted. Transmission time via GSM for a single CT image was 1 min and for a complete head scan was 18 min. The transmitted images were acceptable for final diagnosis in 72% of the cases, the rest being acceptable for preliminary diagnosis. The diagnosis from the transmitted images did not change after a later review of the original images in 97% of cases. The wireless link saved a hospital visit by the senior radiologist in 24% of cases. The results show that a remote consultation link can be built with readily available technology and that the technique is useful in radiological subspecialist consultations for CT images.

Adolescent↗
PubMed1997

Epidural abscess after lumbar discography. A case report.

STUDY DESIGN: The patient who suffered from pain in both lower legs and in whom discography was performed experienced a rare complication after discography. The findings and method of discography is described, as is usefulness of magnetic resonance imaging to image this rare complication. OBJECTIVES: To establish the possibility of getting a spinal epidural abscess after discography, how to make the diagnosis, and how to treat the complication. SUMMARY OF BACKGROUND DATA: Discitis after discography is a well-known complication, but epidural abscess is rare. METHODS: C-reactive protein concentration was measured and was more than 100 mg/L. Infection was suspected, and antibiotic therapy was started immediately. Magnetic resonance imaging was performed, and the diagnosis became clear. A laminotomy was performed. RESULTS: Symptoms due to epidural abscess disappeared soon after laminotomy. CONCLUSIONS: Some harmful and unpleasant complications are possible after discography. Antibiotic prophylaxis and stiletted needles should be used. Magnetic resonance imaging is the best radiologic procedure to image the complication, and surgery must be performed as soon as possible.

Abscess↗
PubMed1997

Bony vibration stimulation test combined with magnetic resonance imaging. Can discography be replaced?

STUDY DESIGN: The results of two noninvasive methods, magnetic resonance imaging and a bony vibration test, were compared with discographic pain provocation findings. OBJECTIVES: To evaluate whether the combination of magnetic resonance imaging and vibration pain provocation tests could be used to replace discography in low back pain diagnostics. SUMMARY OF BACKGROUND DATA: Magnetic resonance imaging gives a wealth of visual information on anatomic changes of the spine with often unknown clinical significance. Discographic examination of the spine is still the only widely accepted diagnostic method that can relate the pathoanatomic changes to the patient's clinical pain. Internal anular rupture has been shown to be one of the sources of back pain. The bony vibration test of the spinal processes has been shown correlate well with discographic pain provocation tests in cases of internal anular rupture. METHODS: The three lowest lumbar discs of 33 patients with back pain were examined by means of magnetic resonance imaging and a bony vibration stimulation test, and the results were compared with those from computed tomography-discography. RESULTS: In cases of intradiscal magnetic resonance imaging findings, the vibration provocation test showed a sensitivity of 0.88 and a specificity of 0.50 compared with the discographic pain provocation test. If the patients with previous back surgery were excluded, the specificity was 0.75. In the cases of total anular rupture, the sensitivity was 0.50, and the specificity was 0.33. CONCLUSION: The combination of the two noninvasive methods, vibration stimulation and magnetic resonance imaging, gives more information on the origin of the back pain than magnetic resonance imaging alone. The pathoanatomic changes seen in magnetic resonance imaging can be correlated with the patient's disorder more reliably using the vibration provocation test in the cases of partial anular ruptures. The use of discography can be limited mostly to cases with total anular ruptures detected by magnetic resonance imaging.

Adult↗
PubMed1997

Image feature based automatic correction of low-frequency spatial intensity variations in MR images.

An automatic method of compensating for low-frequency variations in magnetic resonance images is presented. Small variations within a tissue type are modelled and a correction function is generated. The method is based completely on image features and does not need a phantom or user interaction to generate the compensation function. This image correction simplifies digital image analysis and may enhance clinical evaluation. As a result, the correction technique reduces inhomogeneity and improves contrast. Our results show that the radiofrequency response variation of coils can be reduced. The segmentation process, even with a simple threshold method, produces more reliable results when corrected images are used. The presented method is most useful for images acquired in the sagital and coronal planes with circular local coils, or using surface coils, e.g., spine coils.

Algorithms↗
PubMed1997

Sonography and MRI in the evaluation of painful arthritic shoulder.

We evaluated 31 painful shoulders of 30 patients with chronic arthritis by ultrasonography (US) and compared the results with those of magnetic resonance imaging (MRI). Both US and MRI revealed effusion in the subacromial-subdeltoid (SA-SD) bursa, biceps tendon sheath (BTS) and glenohumeral (GH) joint, but MRI was more accurate in depicting joint inflammation because of its ability to visualize synovial hypertrophy. US visualized biceps tendon ruptures equally well as MRI. MRI was better able to reveal full-thickness tear of the supraspinatus tendon, whereas US showed better other changes of the supraspinatus tendon (degeneration or partial-thickness tear). Both of the imaging methods were able to depict erosions of the humeral head, but the locations occasionally differed. Inexpensive and easily available US can be recommended as the first imaging method for the detection of soft-tissue changes in the arthritic shoulder, but in rotator cuff problems both methods may be needed.

Adult↗
PubMed1997

Ultrasound evaluation of the acromioclavicular joint.

OBJECTIVE: To evaluate the value of ultrasonography in assessing arthritic acromioclavicular (AC) joints. METHODS: One hundred twenty-six AC joints of 63 healthy subjects (2 groups) were prospectively examined by ultrasound to determine the-normal limits of capsular distention and the width of the joint space. Thirty-three AC joints of 32 patients with chronic arthritis were evaluated by ultrasound and, for comparison, by radiography, computed tomography (CT), and magnetic resonance imaging (MRI). RESULTS: The mean ultrasonographic distance of the joint capsule from the bone rim was 2.2 mm +/- standard deviation (SD) 0.5 mm in 21-32-year-old control subjects and 2.9 +/- 0.7 mm in 37-81-year-old control subjects. The mean width of the joint space was 4.1 +/- 0.9 mm and 3.5 +/- 0.9 mm in the same control groups, respectively. In detecting soft tissue changes in arthritic AC joints MRI was better than ultrasound. In revealing bony surface changes, CT was the best method and radiography was least sensitive but quite specific. Our most prominent finding was that ultrasound is able to exclude joint inflammation; when the ultrasonographic distance of the joint capsule from the bone rim was < 3 mm, there was no synovial hypertrophy or effusion on MRI scans. CONCLUSION: Ultrasound can detect AC joint changes reliably. It is able to exclude joint inflammation. Effusion in the AC joint may reflect inflammation, but may also be a sign of degeneration.

Acromioclavicular Joint↗
PubMed1996

Ultrasonic imaging of lumbar discs combined with vibration pain provocation compared with discography in the diagnosis of internal anular fissures of the lumbar spine.

STUDY DESIGN: The diagnostic information achieved by a combination of ultrasonographic imaging of discs and local bony vibration of lumbar vertebrae was compared to that obtained by discographic imaging and pain provocation. OBJECTIVES: The purpose of this study was to find a noninvasive method for spine diagnostics to replace expensive and invasive methods such as discography. SUMMARY OF BACKGROUND DATA: Internal anular fissures of the lumbar discs have been shown to be a source of back pain. Intradiscal changes associated with disc degeneration can be imaged by ultrasonography. The bony vibration test of spinal processes has shown to correlate well with discographic pain provocation tests in cases of internal anular ruptures. Discographic examination of the spine is the only widely accepted diagnostic method that combines pathoanatomic changes and patients' pain. METHODS: Patients with back pain in this study were examined by means of ultrasonography, bony vibration stimulation, and discography. The three lowest lumbar discs were examined. RESULTS: In the cases of intradiscal ultrasound findings, the vibration provocation test showed a sensitivity of 0.90 and a specificity of 0.75 compared to the discographic pain provocation test. In cases of total anular ruptures seen in ultrasound examination, the sensitivity and the specificity of the vibration pain provocation test were much lower, being 0.50 and 0.50, respectively. CONCLUSION: The combination of the two noninvasive methods provides a useful screening test for the evaluation of low back pain. The combination test can accurately depict painful disc degeneration with internal disc rupture and the use of discography can be limited to the cases suggesting total anular rupture in ultrasound examination.

Adult↗
PubMed1996

Circumferential measurement of thoracic wall using a standard respiratory belt.

Respiratory gating during imaging to reduce imaging artifacts involves the gathering of image data only at the end of the respiratory cycle. This is commonly performed by a pneumatic respiratory belt to monitor thoracic wall motion during respiration. Such gating has been used for magnetic resonance, computerized tomographic, and nuclear medicine imaging. The goal of this study was to measure the performance of a standard belt used for gating imaging studies. The standard respiratory belt system provided with the Magnetom 42 SP MRI scanner (Siemens AG, Erlangen, Germany) was selected. The belt was connected to a microcontroller-based pressure measurement unit that was connected to the standard RS-232C serial port of a computer. The signal was compared with that of a strain gauge respiration transducer. The response of the system was tested in vitro both for isometric and isotonic loading. The data measured from the pneumatic belt was linear with different weights of 50 to 1,400 grams with a coefficient of determination (R2) of 0.999. The system was linear for different amounts of stretching (R2 of 0.998) within the first 45 mm, which is enough for normal breathing. In vivo the pneumatic system seemed more accurate in measuring the constant stretching in apnea than the strain gauge respiratory belt. The results show that it is possible to use a standard pneumatic belt for accurate measurement of thoracic wall movement during imaging and for other purposes as well.

Anthropometry↗