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Biomedical subjects

S Soimakallio

Publications and source records attributed to S Soimakallio.

At least 37 records · Page 2Linked to original sources
PubMed1996

Vascular manifestations of small solitary pulmonary masses. Angiographic-pathologic correlations and clinical significance.

RATIONALE AND OBJECTIVES: By performing pulmonary specimen angiographies, the authors attempted to determine the pathologic correlations of the vascular-related radiologic manifestations within, at the edge of, and adjacent to the small solitary pulmonary masses, and to evaluate their usefulness in differentiating small bronchogenic carcinomas from tuberculomas. METHODS: A total of 29 resected lobe specimens with 1.5- to 3.5-cm solitary pulmonary masses, including 24 carcinomas and 5 tuberculomas, were studied prospectively with preoperative radiographs, postoperative specimen arteriographies (in 19 carcinomas and 5 tuberculomas), and venographies (in 5 carcinomas), 10- to 15 micrograms-thick whole-mount sections, and 5-micrograms-thick slices for the examination of angiographic-pathologic correlation. Another series of chest radiographs and conventional tomographs of 100 patients with 1- to 3-cm peripheral pulmonary masses, including 60 carcinomas and 40 tuberculomas, were reviewed retrospectively and analyzed with the chi-square test. RESULTS: Specimen angiographies showed the intralesion avascularity, small arterial speculation, and lobulation or notch at the mass margin with arterial compression, as well as vascular convergence to the mass, in both carcinoma and tuberculoma groups. The irregular arterial wall (79.2%) and venous dilation distal to the mass (100%) were found in the carcinoma group only. Microscopically, arterial or venous fibrous hyperplasia was observed in both carcinomas and tuberculomas, whereas the arterial erosion by tumor tissue and tumor emboli within the vessels were found in carcinomas only. The retrospective review of the 100 patients showed that two radiologic signs of the vascular convergence to the mass and the vascular dilation distal to the mass occurred at similar frequencies (12%-13%) between the carcinoma and tuberculoma groups. CONCLUSIONS: In addition to compression of vessels by tumor and vessel occlusion by tumor embolus, pulmonary vascular fibrotic hyperplasia can cause intramass avascularity. Small vessels running vertically into or from the mass margin can construct the spiculation sign of the tuberculomas. Any evidence of pulmonary vascular irregularity will indicate a bronchogenic carcinoma. The vascular convergence to the mass and the vascular dilation distal to the mass are not specific radiologic signs for small solitary bronchogenic carcinomas.

Adenocarcinoma↗
PubMed1996

Site and size of rotator-cuff tear. Findings at ultrasound, double-contrast arthrography, and computed tomography arthrography with surgical correlation.

RATIONALE AND OBJECTIVES: The authors discuss findings of ultrasound (US), double-contrast arthrography (AG), and contrast computed tomography arthrography (CTA) in assessing precise site and size of rotator-cuff tears. METHODS: Eighty-six patients were compared prospectively in a masked fashion; the results of surgery were studied in 25 patients and the results of arthroscopy were studied in 61 patients. RESULTS: Ultrasound detected 80% (8 of 10) of the partial-thickness tears and 90% (18 of 20) of the full-thickness tears. Arthrography and CTA had identical results with 70% sensitivity (7 of 10) in partial-thickness tears; AG showed 90% (18 of 20) and CTA 95% (19 of 20) of the full-thickness tears. Arthrography had two false-positive findings, and US and CTA had one each. The size of a tear could be evaluated correctly with AG in 30% (9 of 30), with US in 70% (21 of 30) and with CTA in 76% (23 of 30). More extensive tears were encountered at US than had been found at surgery in 2% (2 of 86) and less extensive tears in 9% (8 of 86); CTA depicted more extensive tears in 2% (2 of 86) and less extensive tears in 6% (6 of 86), respectively. The site of a tear could be evaluated with AG in 30% (9 of 30); US and CTA showed the site correctly in every patient in which the tear could be diagnosed. CONCLUSION: Ultrasound and CTA were equally accurate in diagnosing and evaluating the size and site of rotator-cuff tears. Double-contrast AG was less accurate in the diagnosis of tears and the size and site of tears clearly could be assessed worse.

Adult↗
PubMed1996

Thyroid ultrasound findings 7 years after the Chernobyl accident. A comparative epidemiological study in the Bryansk region of Russia.

AIMS: The accident at the Chernobyl nuclear power station occurred in April 1986. We report on a comparative epidemiological study on thyroid abnormalities in the contaminated and uncontaminated populations of the Bryansk region, South-West Russia, in 1993, 7 years after the accident. MATERIAL AND METHODS: The study material consisted of all inhabitants aged 3-34 years in the contaminated village of Mirnyi and in the uncontaminated village of Krasnyi Rog, excluding those who had moved to the villages after the accident. The total material comprised 302 inhabitants in Mirnyi and 200 in Krasnyi Rog. RESULTS: No pathological US findings in either village were found in children born after the accident. In the age group 0-9 years old at the time of the accident, the prevalence of thyroid abnormalities was 8.1% in the contaminated village compared to 1.6% in the uncontaminated village. In the age group 10-27 years the corresponding figures were 18.8% and 17.7%. Only 55% of the pathological US findings were detected by physical palpation. CONCLUSION: The total prevalence of thyroid abnormalities was higher among children in the contaminated village. We recommend an active screening of young contaminated subjects with US, supplemented with fine needle biopsy.

Adolescent↗
PubMed1996

Radiological diagnosis of pneumonia in children.

During 12 months in 1981-82, 201 children were hospitalized due to radiologically verified definite or probable pneumonia. In 1985, 194 chest radiographs (anteroposterior views) were re-evaluated jointly by two radiologists, and classified into three categories: alveolar, interstitial and probable pneumonia. In 127 cases definite pneumonia was diagnosed on both occasions, alveolar in 48 cases and interstitial in 79 cases. Variation between the two evaluations 3 years apart was observed in 46 (24%) of the 194 cases; the adjusted kappa (0.47) was in the modest region. Factors contributing to this variation were young age, less than 12 months, and the presence of interstitial infiltration, bronchial obstruction and low C-reactive protein. Factors associated with less marked variation were the presence of alveolar infiltration, auscultatory fine rates and elevated C-reactive protein. The microbial aetiology of infection, assessed by viral and bacterial antigen and antibody assays, showed no association with diagnostic variation. A lateral view of the chest radiograph was obtained from 158 patients; it was positive in 99 (91%) of the 109 cases with definite pneumonia. In only three cases the diagnosis was based on the lateral view alone. Our results show that the radiological diagnosis of pneumonia is difficult in children, especially in young children with interstitial pneumonia.

Adolescent↗
PubMed1995

Radiation-induced changes in human brain metabolites as studied by 1H nuclear magnetic resonance spectroscopy in vivo.

PURPOSE: External radiation therapy for brain tumors exposes healthy areas of brain to considerable doses of radiation. This may cause cognitive and psychological impairment, which indicate neuronal dysfunction. 1H-magnetic resonance spectroscopy (MRS) was used to study brain metabolites in the adjacent regions 0.5-13 years after exposure to therapeutic irradiation. METHODS AND MATERIALS: Eight patients with irradiated brain tumors were examined by means of in vivo 1H-MRS using a point-resolved spectroscopy (PRESS) sequence with echo times of 60 or 270 ms. The metabolites were quantified by using brain water concentration as internal reference. The volume of interest (VOI) was positioned in irradiated brain areas excluding, however, scar and recurrent tumor. The respective radiation doses were measured based on radiation therapy plans, simulator films, and localization MR images. RESULTS: The concentration of the neuron-specific metabolite N-acetyl-L-aspartate (NAA) was 13.2 +/- 1.4 mmol/l in controls, whereas it was reduced in the brains of treated patients to 8.6 +/- 0.9 mmol/l (total radiation dose 59-62 Gy). Concentrations of creatine and choline-containing compounds were unchanged. The T2 of water was longer in irradiated than in unexposed brain areas. CONCLUSION: Therapeutic brain irradiation causes neuronal damage, which is reflected by reduction of N-acetyl-L-aspartate (NAA) concentrations. 1H-MRS could serve clinically as a means of evaluating adverse effects in the central nervous system, enabling intervention and rehabilitation.

Adult↗
PubMed1995

Carotid artery stenosis: clinical efficacy of MR phase-contrast flow quantification as an adjunct to MR angiography.

PURPOSE: To assess the utility of magnetic resonance (MR) flow quantification in the evaluation of suspected carotid artery stenosis. MATERIALS AND METHODS: Fifty-five patients referred for angiography and 10 healthy volunteers underwent Doppler ultrasound, three-dimensional time-of-flight MR angiography, and MR phase-contrast flow quantification to measure peak systolic velocity (PSV) and volumetric flow rate (VFR) in the common and internal carotid arteries distal to the stenosis. RESULTS: PSV and VFR were significantly lower in the severely (> or = 70%) stenosed internal carotid arteries (P < .05). The VFR ratio (internal carotid artery-common carotid artery) achieved 91% overall accuracy for detection of severe stenosis. Combination of flow data with results of MR angiography yielded sensitivity of 100% (95% confidence interval, 78%-100%) with a modest loss in specificity. Doppler and MR measurements of PSV in the common carotid artery showed significant correlation: volunteers, r = .73; patients, r = .64. CONCLUSION: MR flow quantification provides information about the hemodynamic significance of carotid stenosis. As an adjunct to MR angiography, it may be useful in enabling differentiation of occlusions from critical stenoses.

Adult↗
PubMed1995

Rotator cuff calcifications: treatment with US-guided technique.

PURPOSE: The authors developed and tested a technique to treat calcific tendinitis in the rotator cuff with multiple needle punctures, aspiration, and lavage under ultrasonographic (US) guidance. MATERIALS AND METHODS: Atraumatic pain in the shoulders of a 46-year-old woman and a 42-year-old man was resistant to conservative therapy. With local anesthesia and continuous three-dimensional US visualization, the tips of two 18-gauge needles were placed within the calcification in the rotator cuff. Saline solution was injected and aspirated with the needles until the aspirate was free of calcific particles. RESULTS: Both patients experienced complete relief of pain and recovery of full range of motion, one on the 3rd day after treatment and one within 15 minutes. CONCLUSION: Use of this US-guided technique is successful to treat calcific tendinitis in the rotator cuff without the radiation exposure of fluoroscopic guidance.

Adult↗
PubMed1995

Medial displacement of the biceps brachii tendon: evaluation with dynamic sonography during maximal external shoulder rotation.

PURPOSE: To determine the value of the sonographic subluxation test--dynamic scanning of a shoulder during maximal external rotation--in the evaluation of medial displacement of the biceps tendon. MATERIALS AND METHODS: The subluxation test was performed during shoulder sonography in 1,210 patients, 284 of whom subsequently underwent surgery (152 men and 132 women aged 24-77 years [mean, 52 years]). Subluxation or displacement of the biceps tendon was surgically confirmed in 21 of the 284 patients (16 men and five women aged 35-57 years [mean, 48 years]). The sonographic and surgical findings in these 21 patients were analyzed. RESULTS: The subluxation test helped detect 12 of 14 (86%) cases of subluxation. Static scanning (without the subluxation test) depicted six of seven (86%) cases of dislocation. The test failed or could not be performed in 18 of the 284 (6%) patients; however, no false-positive findings occurred. CONCLUSION: The subluxation test is reliable in the diagnosis of subluxation of the biceps tendon and should be performed during shoulder sonography.

Adult↗
PubMed1995

Carbon dioxide in vascular imaging and intervention.

Angiography with iodinated contrast agents is bound up with the risks of contrast-induced nephrotoxicity and hypersensitivity, which led to the idea of using carbon dioxide (CO2) gas as a negative contrast medium to eliminate these drawbacks. During the last decade, refinements and experiences have proved carbon dioxide digital subtraction angiography (CO2-DSA) to be an accurate, safe, and clinically promising vascular imaging modality, with the advantages of no hypersensitivity and no nephrotoxicity as well as minimal patient discomfort. In this article, we have reviewed the history, physical and chemical aspects, techniques, and pathophysiologic changes with the use of CO2-DSA as well as some clinical trials. Applications of CO2 gas in vascular interventions and other imagings, and the advantages and limitations of using CO2 gas in DSA are also discussed.

Angiography↗
PubMed1995

Defecography.

Defecography, a dynamic imaging modality, plays an important role in the diagnosis of functional and morphologic abnormalities of the anorectal region. We have here summarized the principle and techniques as well as observations of defecography, with special emphasis on morphologic measurements, clinical relevance, and limitations. The application of MR imaging in examination of anorectal function has also been addressed.

Barium Sulfate↗
PubMed1995

Imaging of carotid artery stenosis: clinical efficacy and cost-effectiveness.

PURPOSE: To determine the most accurate, safe, and cost-effective imaging protocol for selecting patients for carotid endarterectomy. METHODS: The actual costs of carotid angiography, ultrasound, and MR angiography were calculated. The diagnostic accuracy with different confidence levels was assessed for carotid ultrasound and MR angiography in 45 patients. The cost-effectiveness and theoretical impact on patient outcome of hypothetical screening models were compared. RESULTS: Ultrasound before angiography is more effective and considerably cheaper than performing angiography in all patients presenting with transient ischemic attacks ($25 216 versus $48 708 imaging costs per one prevented stroke). When the more costly MR angiography was used to select patients for angiography the slightly higher diagnostic accuracy did not result in a greater number of prevented strokes. As the only preoperative scrutiny, the combination of ultrasound and MR angiography would have resulted in a greater number of prevented strokes than invasive angiography (27.9 versus 23.3) but at the expense of unnecessary surgery (6.6% of all surgeries). CONCLUSIONS: Ultrasound followed by confirmatory angiography is a cost-effective way to image patients suspected of carotid artery stenosis. MR angiography may become cost effective and lead to a better final patient outcome only when it can reliably replace invasive angiography as the preoperative examination.

Angiography, Digital Subtraction↗
PubMed1994

Reproducibility of five anorectal morphologic measurements in defecography.

RATIONALE AND OBJECTIVES: We evaluated the inter- and intraobserver reproducibility of measuring five morphologic parameters of the anorectum in defecography (evacuation proctography). METHODS: Measurements from 42 defecographic studies were statistically analyzed. The parameters measured during resting, squeezing, and straining included two anorectal angles (posterior and axis), maximal width of the anal canal, maximal width of the rectal lumen, and size of the rectocele. RESULTS: The results demonstrated only fair interobserver agreement (kappa = 0.22-0.38) for almost all measurements of the five morphologic parameters. There were high correlations (kappa = 0.62-1.00) among most intraobserver measurements. CONCLUSION: For defecographic measurement, the five parameters we studied have relatively poor clinical value because of high inter- and intraobserver inconsistency.

Adult↗
PubMed1994

Comparison of angiographic opacification of ioxaglate and iodixanol by digital region-of-interest processing technique in an experimental circulation model.

RATIONALE AND OBJECTIVES: By using digital ROI (region of interest) processing techniques, we measured and compared directly the angiographic opacification of ioxaglate and iodixanol in an experimental circulation model. METHODS: A pulsatile pump circulated water into a 2-mm plastic tube for digital subtraction angiography (DSA). Altogether, 90 digital imaging series were registered during injections of two contrast media with 320, 300, and 270 mg/mL iodine concentrations. By selecting a "vessel" ROI and a subtracted background ROI, a time-density curve (TDC) was created. From the TDC, the average density of contrast media and the appearance time of contrast media into the selected ROI were measured. RESULTS: The average density was statistically different (P < .01) among three various iodine concentrations of the contrast media, but no difference was found between the two contrast media. The appearance times of ioxaglate with 320 mg/mL iodine concentration were statistically shorter (P < .01) than those of iodixanol. In both contrast medium groups, the appearance times were statistically shorter (P < .05) with 270 mg/mL iodine concentration than with two higher iodine concentrations. CONCLUSION: The current experimental set-up facilitates reproducible measurement of angiographic opacification during the injection of contrast media. The average densities between ioxaglate and iodixanol are the same, but are significantly different among three iodine concentrations. The different appearance times of the two CM and the three iodine concentrations may be caused by the various viscosities of the contrast media.

Angiography, Digital Subtraction↗
PubMed1994

Influence of carbon dioxide gas perfusion to thermal distribution of sapphire probe. A comparative study with saline.

RATIONALE AND OBJECTIVES: A previous study confirmed that the direct laser-thermal conduction of the sapphire probe with carbon dioxide gas perfusion increased the width of the laser-recanalized channel. This caused us to further investigate the thermal distribution characteristics of the sapphire probe when lasing with CO2 gas perfusion. METHODS: The surface temperature of a sapphire probe in a circulation model using 37 degrees C flowing whole blood was measured. Two hundred and sixteen measurements were obtained by directly contacting a flexible thermocouple wire onto the sapphire probe at different sites: 1) metal connector; 2) lateral side of the sapphire crystal; 3) top of the sapphire crystal; and 4) 3 mm in front of the sapphire probe. During lasing with a neodymium-yttrium-aluminum garnet (Nd-YAG) laser, the CO2 gas or saline was infused through the sapphire probe at different flow rates. RESULTS: The lateral side of the sapphire crystal was heated up to 75 degrees C when lasing without any perfusion, but up to 220 degrees C when lasing with CO2 gas perfusion. At all four sites, the mean temperature increases were statistically higher (P < .01) with CO2 gas than with saline perfusion. The mean peak temperatures increased with increasing flows of CO2 gas perfusion and decreased with increasing flows of saline perfusion. CONCLUSIONS: The thermal conduction from the sapphire probe can be significantly enhanced by increasing flows of CO2 gas perfusion. This may play an important role in creating a greater diameter of the recanalized channel and in better delaying the formation of restenosis or re-occlusion after laser recanalization of atheromatous arteries.

Aluminum Oxide↗
PubMed1994

Femoropopliteal angioplasty in patients with claudication: primary and secondary patency in 140 limbs with 1-3-year follow-up.

PURPOSE: To determine the usefulness of percutaneous transluminal angioplasty in the femoropopliteal arteries in patients with claudication. MATERIALS AND METHODS: In a prospective study of 106 claudicants (71 men and 35 women, aged 41-90 years [mean, 67 years]), a total of 208 lesions in 140 limbs were treated. The patients were followed up for 12-36 months. The patency rates were based on determination of the ankle-brachial index. RESULTS: The hemodynamic success rate for all the treated limbs was 89%, 99% for femoropopliteal stenoses (n = 71) and 80% for femoropopliteal occlusions (n = 69). In multiple logistic regression analysis, a smaller number of diseased vessels (one to two vs three to seven) and milder lesion severity (stenosis vs occlusion) correlated favorably with early success. Survival analysis with the Kaplan-Meier method according to established criteria revealed 1-, 2-, and 3-year primary patency rates of 47% (27 of 57 limbs), 41% (14 of 34 limbs), and 43% (three of seven limbs), respectively. CONCLUSION: In selected cases, good primary success and acceptable long-term results can be achieved with femoropopliteal angioplasty in claudicants.

Adult↗
PubMed1994

Prophylaxis for the prevention of venous thromboembolism after total knee arthroplasty. A comparison between unfractionated and low-molecular-weight heparin.

We compared the efficacy and safety of low-molecular-weight heparin with that of low-dose unfractionated heparin in the prevention of venous thromboembolism after total knee arthroplasty in a prospective, randomized, multicenter trial. One hundred and eighty-five patients were randomly assigned to two groups: ninety-two received low-molecular-weight heparin (forty milligrams of enoxaparin the evening before the operation and once a day subsequently) and ninety-three received unfractionated heparin (5000 international units the evening before the operation and three times a day thereafter). The prophylaxis was continued until bilateral ascending venography was performed six to nine days after the operation or, if venography was not done, until the eighth postoperative day. Venography revealed a prevalence of deep-vein thrombosis of 27 per cent (twenty-five of ninety-three patients) in the group that received unfractionated heparin and 23 per cent (twenty-one of ninety-two patients) in the group that received low-molecular-weight heparin. The difference was not significant (p = 0.6). Five patients (5 per cent) who received unfractionated heparin and 3 patients (3 per cent) who received low-molecular-weight heparin had a deep-vein thrombosis in the proximal veins. Two patients who received unfractionated heparin and one who received low-molecular-weight heparin had clinical symptoms suggestive of a pulmonary embolism. None of these three patients had a positive ventilation-perfusion scan. There were no deaths, major bleeding episodes, or wound hematomas necessitating operative intervention or discontinuation of the anticoagulation in the series.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Accuracy of digital videodensitometry in quantitating contrast medium concentration.

To evaluate the accuracy of digital videodensitometric technique in directly quantitating concentration of contrast medium, iohexol 300 mg I/ml was injected into a 2-mm-diameter plastic tube, in which clean water was circulated at a 190 ml/min flow, for digital subtraction angiography. Altogether 27 injections were performed with 3, 4 and 5 ml volumes at 3-, 4- and 5-ml/s flows of the contrast medium. A time-density curve was achieved by selecting a "vessel" region of interest (ROI) and a background ROI. Then, a frame corresponding to the maximum opacification of the contrast medium could be calculated. Finally, the average density and the time to peak density of the contrast medium were obtained. The average density was statistically higher (p < 0.01) with 5 ml/s flow than with 4- and 3-ml/s flows. Times to peak density reduced as injection flows or volumes increased. The results support the conclusion that digital videodensitometric technique is an accurate method for quantitation of contrast medium concentration during angiography. The angiographic opacification may be improved by injecting the iodine contrast medium with higher flows or larger volumes.

Absorptiometry, Photon↗