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Biomedical subjects

M Taavitsainen

Publications and source records attributed to M Taavitsainen.

At least 37 records · Page 2Linked to original sources

Ultrasound monitoring of experimental ethanol injection into pig liver.

RATIONALE AND OBJECTIVES: In percutaneous ethanol injection therapy, uncontrolled spread of ethanol sometimes causes complications. This study tested the accuracy of ultrasonography in showing the spread of ethanol during injection in normal postmortem pig livers. METHODS: Methylene blue-stained 96% (vol) ethanol (0.5-2 ml) was injected into pig livers under sonographic control. The volumes of the sonographically determined areas infiltrated by the injections and the corresponding pale lesions seen after dissecting the livers were measured and compared. The locations of the stained areas were determined. RESULTS: Uncontrolled spread of ethanol was often seen sonographically as hyperechoic lines spreading centrifugally from the injection site. After dissection, nearly all vessels and ducts were stained blue, indicating a major escape of ethanol from the injection sites. The volumes of the sonographically determined injection areas were significantly larger (P < 0.001) than the lesions found after dissection. CONCLUSIONS: Ultrasonography may overestimate the spread of ethanol, making the survival of peripheral tumor cells possible.

Administration, Cutaneous↗

Diagnosis of pancreatic lesions using fine needle aspiration cytology: detection of K-ras point mutations using solid phase minisequencing.

AIMS: To improve the diagnostic value of fine needle aspiration biopsy of pancreatic lesions using a simple mutation detection method based on the polymerase chain reaction (PCR). METHODS: Fine needle aspirates from 21 suspected pancreatic lesions were analysed for K-ras codon 12 point mutations using solid phase minisequencing. RESULTS: A point mutation in codon 12 of the K-ras gene was detected in 14 of 17 cases of pancreatic carcinoma. No false positive results were recorded. The concordance of the result with routine cytology was 78%. All patients diagnosed as having malignant disease on cytology also had a K-ras point mutation. Additional information on the presence of malignancy was obtained using molecular genetic analysis in two cases. CONCLUSIONS: PCR based minisequencing is a promising method for the analysis of cytological material. K-ras point mutation analysis was modified to enable it to be carried out in a clinical laboratory. Advantages of the method include its simplicity and speed. Adequate sampling guidance is important but analysis can be performed even with small amounts of cellular material.

Adult↗

Percutaneous interstitial laser hyperthermia in clinical use.

Twelve patients were treated with laser-induced hyperthermia. Eight had liver metastases from breast cancer or colorectal cancer, and four were treated for a primary tumour, two in the liver, one in the biliary tract and one in the pancreas. The mean diameter of the metastases was 2.5 cm and of the primary tumours 4 cm. One patient was given ethanol injections before the treatment, and seven were treated with chemotherapy before and two after the treatment. At the time of writing this report, all the patients are still alive. The follow-up times vary from six months to five years. Treatment was technically possible in all cases. The smallest metastasis disappeared totally and, with the exception of a few larger tumours, they were reduced in size. There were no serious complications. The patients were treated percutaneously under ultrasonographic imaging in real time. Only minor side effects were seen, and the method is safe. Technically, laserthermia is easy to perform. A skillful radiologist is needed, and the presence of an anaesthetist makes it possible to safely treat tumours that can be reached only when respiration is controlled mechanically. Controlled, randomized studies are now needed to evaluate the method in comparison with other palliative treatment modalities.

Adult↗

Sonography of Achilles tendon correlated to operative findings.

Ultrasound examination (US) with a 5 MHz linear array probe was used to examine 30 patients (34 Achilles tendons) with overuse injuries. The results were compared with surgical findings in all cases. Most of the patients had two or more sonographical findings. In this study US had an overall sensitivity of 0.96 in the detection of Achilles tendon pathology. Partial Achilles tendon rupture was suspected in ten tendons. During an operation ruptures were found in eleven tendons, of which two were fibrotic scars. Changes in inflammatory tendopathy (tendinitis, paratenonitis and paratenonitis with tendinosis) were found by US in 28 tendons and in the operation in 27 tendons. US showed tendinitis in 21 cases, of which four had a positive operative finding. In the seventeen negative cases, the surface of the tendon looked normal during the operation. Most of these cases (14 out of 17) were classified as paratenonitis during the operation. In three cases, paratenonitis with tendinosis was classified as paratenonitis in the operation and in one case the findings were similar in US and in surgery. US was underdiagnostic in paratenonitis and overdiagnostic in tendinitis. Bursitis was detected during the operation in ten cases, but only in three cases by US. False positive bursitis was diagnosed three times in US compared to the operative finding. In chronic bursitis, the bursa can be small, thickened by its wall and undetectable by US. High-resolution sonography is a relatively reliable diagnostic method in Achillodynia and mainly useful as a preoperative study to differentiate a partial rupture from inflammatory states.

Achilles Tendon↗

Localization of hepatic metastases by radiolabelled anti-carcinoembryonic antigen antibody and meta-iodobenzylguanidine in a patient with medullary thyroid carcinoma.

Sonography, computed tomography and magnetic resonance imaging examinations did not detect recurrence or metastases of medullary thyroid carcinoma (MTC) in a patient with a rapidly rising serum calcitonin concentration after total thyroidectomy. Scintigraphy with technetium-99m labelled anti-carcinoembryonic antigen antibody, 99mTc-colloid and iodine-131 metaiodobenzylguanidine indicated liver metastases. The three scintigrams were to some extent discrepant but from the combined information the diagnosis of hepatic metastases could be established; it was subsequently verified by sonography and aspiration biopsy. This case demonstrates the usefulness of applying nuclear medicine imaging methods for the localization of hepatic MTC metastases.

3-Iodobenzylguanidine↗

Fatal liver necrosis following percutaneous ethanol injection for hepatocellular carcinoma.

A 76-year-old man underwent an injection of 5 ml of ethanol for the treatment of a hepatocellular carcinoma 3 cm in diameter. Shortly after the procedure, he had an attack of abdominal pain. His condition soon deteriorated and he died 5 days later. Massive hepatic necroses distant from the injection site and a myocardial infarction were found at autopsy. To our knowledge, this is the first fatality associated with percutaneous ethanol injection therapy.

Aged↗

Thoracic lesions: diagnosis by ultrasound-guided biopsy.

We reviewed the results of US-guided fine-needle biopsies of peripheral pulmonary, pleural, mediastinal and chest wall lesions in 200 patients. Sufficient material for cytological analysis was obtained in 95%, 92%, 96% and 100%, respectively. Sensitivity was 88%, 94%, 96%, 100% and specificity 89%, 100% and 100%, respectively. The ratio of false-negative results was 7%. A cutting needle biopsy was additionally performed in 24 patients. All but two of the histological samples (92%) were adequate for diagnostic purposes and a correct diagnosis was established in 86% (19/22) of these. 8 patients (4%) with pleural or pulmonary targets had minor complications (5 pneumothorax, 3 haemoptysis), which did not require treatment. Cutting needle biopsies and biopsy of mediastinal lesions proved safe. Due to the many advantages US may be considered for guidance in peripheral larger-sized pulmonary lesions, particularly those abutting the pleura, and also in pleural, thoracic wall and mediastinal masses.

Adolescent↗

Intra- and peri-hepatic effects of ethanol injections in the pig liver.

We studied the intrahepatic (spread and scarring) and perihepatic effects of percutaneous ethanol injection therapy and its dose-necrosis relationship in normal pig livers. Ethanol (99.5%) was injected in volumes of 0.5-2.0 ml into the livers of six pigs during laparotomy. The livers were dissected and studied histopathologically 30 min and 2 weeks after the injections. Ethanol-induced liver necrosis, the diameter of which could roughly be calculated by dividing the injected dose by 2 (inversely: volume (ml) = 2 x diameter (cm)). Two weeks after the injections all pigs showed intra-abdominal adhesions and severe intrahepatic scar formation, unlike three control pigs similarly operated on without ethanol injections. The 30-min lesions showed thin projections extending into the neighboring liver tissue. Major escape of ethanol outside the needle tip area in the liver occurred twice. Uncontrolled spread of ethanol may be a potential hazard of this treatment.

Animals↗

Technetium-99m-HMPAO-labeled leukocytes and technetium-99m-labeled human polyclonal immunoglobulin G in diagnosis of focal purulent disease.

To evaluate the usefulness of 99mTc-HMPAO-labeled leukocytes and 99mTc-labeled polyclonal human immunoglobulin G (Technescan HIG) in the diagnosis of focal purulent disease, 31 comparative scintigraphies were done in 30 patients with known or strongly suspected focal infection. Focal purulent disease was the final diagnosis in 19 patients. Technetium-99m-labeled leukocytes showed 16 true-positive, no false-positive, 11 true-negative and 3 false-negative findings. The corresponding figures for 99mTc-labeled HIG were 11, 2, 9 and 8. The sensitivity and specificity of imaging with labeled leukocytes were 84% and 100%, respectively, and with labeled HIG, 58% and 82%, respectively. The overall accuracy of the leukocyte scan was significantly better than that of the HIG scan (90% versus 67%, p < 0.001). Thus, if focal infection is suspected, scintigraphy with 99mTc-labeled leukocytes is the preferable method. No cases exhibited a better imaging result with 99mTc-HIG scintigraphy than with 99mTc-labeled leukocytes.

Female↗

Technetium-99m hexamethyl propylene amine oxine leucocytes in the assessment of disease activity in inflammatory bowel disease.

The inflammatory activity in 108 bowel segments of 40 patients with suspected or known inflammatory bowel disease was assessed macroscopically by endoscopy, histology and technetium-99m hexamethyl propylene amine oxine (99mTc-HMPAO) leucocytes using a numerical grading system (scores 0-3). A 4-h series of scintigrams showed a significant correlation with both histological and macroscopical assessment of disease activity (rho = 0.850, P less than 0.001 and rho = 0.773, P less than 0.001, respectively). Sensitivity, specificity and accuracy of scintigraphy in detecting active inflammatory segments were 85%, 92% and 89%, respectively. A normal scintigram did not completely exclude mild inflammatory activity, especially in the rectosigmoid area. 99mTc-HMPAO leucocytes offer an accurate and non-invasive alternative for the assessment of disease activity in ulcerative colitis and Crohn's disease.

Adult↗

Technique of renal biopsy by ultrasound guided percutaneous puncture with a spring loaded "gun".

The study consisted of 89 consecutive patients (mean age = 41.5, range = 16-82, 64 men, 25 women) referred for renal biopsy because of clinical suspicion of renal parenchymal disease. Neither transplant kidneys nor tumour evaluation were included. A biopsy "gun" (Biopty) and 14 (2.0 mm) and 18 (1.2 mm) gauge needles were used with ultrasound guidance. Sixtyseven renal biopsies were guided using a freehand technique 42 using a fixed angle guide attachment. The mean glomerular yield was 9.4 glomeruli. Almost 25% of the 18 gauge needle biopsies (n = 57) had to be repeated and 29.3% of the 14 gauge needle biopsies (n = 75). The yield difference was not statistically significant (Chi-squared = 0.37, p = 0.54). There was no statistically significant difference between the distributions of failure to obtain a significant material for evaluation caused by the biopsy technique used (Chi-squared = 0.08, p = 0.78). When analysing cases of single successful pass the thinner needle produced 6.7 glomeruli (n = 36, SD = 5.08) and the thicker needle 13.8 glomeruli (n = 18, SD = 6.82). No serious complications occurred.

Adolescent↗

Splenic abscess. Imaging and intervention.

We reviewed the imaging findings of 14 splenic abscesses in 13 patients. All patients underwent chest radiography, 12 ultrasonography (US), 9 CT, 4 plain abdominal radiography, 2 99mTc-HMPAO leukocyte scan and 2 99mTc-HIG scan. Three patients were treated with percutaneous catheter drainage, and 5 with diagnostic or therapeutic fine-needle aspiration (FNA). At US the abscess was hypoechoic (n = 9), anechoic (n = 2), or anechoic with gas-bubbles (n = 1), or the entire spleen was inhomogeneous with gas-bubbles (n = 1). At CT the abscesses appeared as low density (18-30 HU) lesions with (n = 2) or without (n = 7) gas. In 2 cases 99mTc-HMPAO leukocyte scan, and in one case 99mTc-HIG scan showed an intrasplenic defect, and in one case 99mTc-HIG scan was considered normal. At plain abdominal radiography extraintestinal gas was suggested in 2 patients, and the findings were normal in 2. US-guided FNA confirmed infectious etiology of the lesion in 4 patients, and a necrotic specimen suggested infection in one. One patient was cured with repeated aspirations. Catheter drainage was successful in all 3 patients who underwent the procedure. We conclude that US and CT are accurate in detecting splenic abscesses. Our results in splenic interventions advocate wider use of the procedures.

Abscess↗

Scintigraphy with 99mTc-HMPAO labeled leukocytes in acute cholecystitis.

99mTc-HMPAO labeled leukocyte scanning was performed on 38 patients with clinically suspected acute cholecystitis (AC) to evaluate its diagnostic value. The typical finding was an increasing accumulation of the tracer in the gallbladder wall in a 4 hour series of scintigrams. Leukocyte scan was positive in 16 of 17 patients with surgically and histologically confirmed AC. There were no false-positive findings. The sensitivity, specificity, and accuracy of scintigraphy were 94, 100, and 96%, respectively. In 2 patients with acute acalculous cholecystitis true-positive findings were observed. Scintigraphy with 99mTc-HMPAO labeled leukocytes is a valuable new imaging method in AC.

Acute Disease↗

Radiologic findings in renal oncocytoma.

The imaging findings of 36 renal oncocytomas in 32 patients were evaluated retrospectively. Twenty-two patients underwent ultrasound (US), 16 CT, 25 angiography, 19 urography, and 6 fine-needle biopsy. At US 8 of the oncocytomas were isoechoic, 7 hyperechoic, and 7 hypoechoic. The structure was homogeneous in 59% and nonhomogeneous in 41%. At plain CT 12 oncocytomas were homogeneously hypodense, 3 isodense, and one hyperdense. Contrast enhancement was homogeneous in 10 and inhomogeneous in 4 cases. A stellate scar was detected in one case, and in one case a contrast study was not performed. At angiography the oncocytomas were hypervascular in 21, hypovascular in 3 cases, and one was not detected. Nineteen of the tumors were well delineated. A spokewheel arterial pattern was detected in 3 tumors. The cytologic diagnosis was benign renal oncocytoma in 4 cases and highly suggestive of oncocytoma in 2 cases. We conclude that the homogeneity of a renal tumor at US and at CT may suggest the possibility of oncocytoma. US-guided fine-needle biopsy is a useful diagnostic tool in patients who need a precise presurgical diagnosis.

Adenoma↗