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Biomedical subjects

L Kivisaari

Publications and source records attributed to L Kivisaari.

At least 109 records · Page 6Linked to original sources
PubMed1988

Pharmacokinetics of contrast medium in experimental pancreatography.

The pharmacokinetics of a contrast medium in experimental pancreatography of 17 piglets were studied by repeated radiographs of the pancreas and by measuring the concentration of I125-labelled CM in the portal vein, inferior vena cava and in the thoracic duct. Intraduodenal and portal vein injections were performed for comparison. Contrast enhancement of the pancreas after pancreatography was measured by CT. High concentrations of CM were seen in the portal vein 40 seconds after pancreatography, demonstrating direct absorption into the local veins. The concentration of CM in lymph exceeded the systemic concentration 15 minutes after injection, suggesting absorption into lymphatic vessels from the pancreas. CT revealed parenchymal filling of the pancreas even though no acinar filling was seen in normal radiographs. This suggests "invisible" parenchymal filling during normal pancreatography.

Animals↗
PubMed1988

Does dilution of contrast media affect contrast enhancement? An experimental study in rats.

The effect of contrast media (CM) dilution on contrast enhancement was studied using CM representing four structurally different molecular types at osmolalities ranging from 135 to 1340 mosm/kg. Diatrizoate (ionic monomer), iopamidol (nonionic monomer), ioxaglate (ionic dimer), and iodecol (nonionic dimer) were each given at a dose of 500 mgI/kg and at concentrations of both 300 and 150 mgI/mL. Contrast media concentrations were measured using iodine 125I. Tissue blood volumes were determined using human serum albumin labeled with 131I. For each of the four CM at each of the two concentrations and after each of five time intervals following injection (0, 15, 40, 120, and 300 seconds), five rats were killed (total = 200 rats). Blood and 14 other tissues were studied. Dilution of the CM did not lead to any lower iodine tissue concentrations, iodine distribution volumes, plasma volumes, or hematocrit. The authors conclude that lowering CM osmolality by dilution with water should improve tolerance without affecting CT contrast enhancement.

Animals↗
PubMed1988

Comparative pharmacokinetics of gadolinium DTPA and gadolinium chloride.

An intravenous injection of 153Gd-labeled gadolinium-DTPA or gadolinium chloride was given to 60 rats, which were killed either 15, 40, 120, 300, 900, or 3600 seconds later. Tissue concentrations of gadolinium in the blood, liver, spleen, stomach, pancreas, renal cortex, renal medulla, lungs, heart, adrenals, gluteal muscle, fat, skin, thymus, brain, thyroid, and parathyroids were measured. Five animals were killed at each time interval with gadolinium-DTPA, and at each of the latter four time intervals (15 and 40 seconds excluded) with gadolinium chloride. The pharmacokinetics of gadolinium-DTPA and chloride differ markedly in terms of tissue concentration, distribution volumes, and the time course of these parameters. Gadolinium, when injected as a chloride, evidently forms insoluble carbonate and phosphate precipitates in the blood, which are taken up by the reticuloendothelial system. The distribution of gadolinium-DTPA on dynamic MRI should closely parallel the distribution of iodinated contrast media on dynamic computed tomography.

Animals↗
PubMed1988

Contrast-enhanced computed tomography and microangiography of the pancreas in acute human hemorrhagic/necrotizing pancreatitis.

Five patients with severe acute pancreatitis had a low contrast enhancement (CE) of the pancreas in computed tomography (CT) and underwent subtotal pancreatectomy. Microangiography and histologic studies were performed on the resected pancreases, and the findings were related to those of CE. All patients had histologically documented hemorrhagic/necrotizing pancreatitis. The more disturbed the vascular anatomy in microangiography, the more hemorrhages and necroses were found in histology. The microangiographic and histologic findings corresponded closely to the low contrast-enhanced CT of the diseased pancreas in each patient. Thus, in the early phase of severe acute pancreatitis, one can detect by noninvasive means which areas of the gland are necrotic and which edematous by a dynamic study of contrast-enhanced CT of the pancreas.

Acute Disease↗
PubMed1988

Experimental pancreatography: a comparison of three contrast media.

Twenty-five piglets were subjected to experimental transduodenal pancreatography, using three contrast media (CM), namely sodium meglumine diatrizoate (Urografin), meglumine ioxaglate (Hexabrix), and iohexol (Omnipaque), all diluted to a concentration of 300 mg/ml of iodine. The emptying of CM from pancreatic ducts was studied by repeated roentgenograms, and pancreatic irritation by serum amylase and phospholipase A2 measurements. On the 3rd day after pancreatography the glands were removed for histologic examination of tissue damage. Hyperamylasaemia was seen in 53% of the animals 12 to 15 h after examination, to equal extents in each group. Minimal acinar destruction was seen on histologic examination in all cases. The changes were least when diatrizoate was used. The difference from the changes seen in the ioxaglate group was significant (p less than 0.05). Emptying of CM from the ducts was highly significantly (p less than 0.001) faster in the diatrizoate group than in the other groups. Rapid emptying may be an advantage in clinical endoscopic retrograde pancreaticocholangiography.

Animals↗
PubMed1988

Results and complications of percutaneous nephrostomy.

A series of 181 patients (158 with obstructive uropathy) treated by percutaneous nephrostomy (PN) in 1978-1987 is evaluated. In 8.3% of the patients PN did not succeed. The success rate of PN was lower when done outside normal working hours and before ultrasound guidance was used. Major complications occurred in 5.5% and minor ones in 10.5%. There was no direct mortality. The complications and the possible avoidance of them are discussed. In 68% of patients nephrostomy improved their clinical condition. The benefit of PN was closely related to the existing renal recovery potential following the relief of obstruction; a problem that has not yet been fully solved.

Adolescent↗
PubMed1988

Effect of pancreatitis on the absorption of contrast medium from the pancreatic duct.

The absorption of contrast medium (CM) from the pancreatic duct into blood and lymph was studied in piglets with oedematous (n = 5), haemorrhagic (n = 6) and chronic (n = 7) pancreatitis. Six healthy animals served as controls. In piglets with oedematous pancreatitis, lymphatic absorption was found to be delayed, whereas venous absorption remained almost normal. Haemorrhagic pancreatitis severely delayed both venous and lymphatic absorption, due to microvascular damage. CM absorption was also delayed in chronic pancreatitis. Absorption from the pancreatic interstitium was rapid in healthy and oedematously inflamed pancreas. The slow absorption during haemorrhagic pancreatitis means that the parenchyma is exposed to the effects of CM for a longer period.

Absorption↗
PubMed1987

Computerized tomography and transrectal ultrasound in the assessment of local extension of prostatic cancer before radical retropubic prostatectomy.

The value of computerized tomography and transrectal ultrasound in the demonstration of local extension of prostatic cancer was evaluated in 38 patients undergoing radical retropubic prostatectomy. Transrectal ultrasound proved to be reliable for the demonstration of local extension of cancer beyond the prostatic capsule (sensitivity 86 per cent, specificity 94 per cent and accuracy 90 per cent). Invasion of the seminal vesicles was demonstrated by ultrasound, with a sensitivity of 29 per cent, specificity 100 per cent and accuracy 77 per cent. The addition of transrectal ultrasound scanning to clinical evaluation increased sensitivity in relation to detection of extraprostatic involvement from 15 to 92 per cent. When computerized tomography scanning was added to clinical examination, the sensitivity increased from 15 to only 46 per cent. Transrectal ultrasound is valuable for the preoperative evaluation of patients in whom radical prostatectomy is being considered as treatment for clinically localized prostatic cancer.

Humans↗
PubMed1987

Free tunica vaginalis patch in urethroplasty. An experimental study.

The management of urethral strictures is a challenge for surgery. In the present study the value of tunica vaginalis tissue for urethroplasty was investigated. 30 male rabbits were divided into two groups. In group I (11 animals) a urethral defect was covered with a tunica vaginalis patch (n = 6) or was left uncovered (n = 5). In group II (19 animals) a preoperative urethral stricture was induced by electrocoagulation through a urethroscope. The strictured urethra was plastied with tunica vaginalis (n = 9) or preputial (n = 10) patches. The results were analyzed after a period of 2 weeks to 5 months with radiographic, macroscopic and microscopic methods. The tunica vaginalis graft showed its superiority over the preputial graft: only 1 postoperative short stricture from 15 plasties (6 normal and 9 strictured urethrae) was found in the plastied group, whereas 2 strictures from 10 plasties were seen in the preputial patch group. In the urethral defect group, strictures were seen in 2 of 5 animals. The mesenchymal tunica vaginalis epithelium was covered with thin transitiocellular-like epithelium resembling transitiocellular layers. The present study supports the earlier findings on the use of tunica vaginalis tissue in urethroplasty.

Animals↗
PubMed1987

Mammographic patterns in twin pairs discordant for breast cancer.

As part of a case-control study of breast cancer in pairs of twins selected from the population-based Finnish Twin Cohort, mammograms of 30 pairs (seven monozygotic (MZ), 23 dizygotic (DZ] discordant for breast cancer were analysed. The mammographic pattern in the unaffected breast of the cancer case was compared with the pattern in the ipsilateral breast of the healthy twin (control). There were no differences for MZ pairs, while among DZ pairs the cancer case had a prominent parenchymal pattern significantly more often than the control, as assessed by two radiologists independently and blindly. Thus, there is a relationship between parenchymal pattern and risk of breast cancer even when the controls are the twin sisters of breast-cancer cases and are themselves at high risk. The overall similarity, despite disease discordance, in parenchymal pattern of the twins (more evident among MZ than DZ pairs) suggests a familial, possibly genetic influence on parenchymal pattern.

Breast↗
PubMed1987

Computed tomography in staging of oesophageal carcinoma.

The computed tomographic (CT) findings in 45 patients with histologically proved oesophageal carcinoma are reviewed. In 20 of these patients the CT findings were correlated with findings at surgery (19 patients) or autopsy (1 patient). Correlation analysis showed that the accuracy of CT in assessing both invasion of adjacent organs and mediastinal and abdominal lymph node involvement is limited. Twenty-five patients were considered inoperable; in 15 of these the conclusion was based on CT findings of distant metastases (14 patients) or definite local invasion (1 patient). Ten patients were inoperable for other reasons (general health condition). We found the value of CT to be in detecting distant metastases, thus avoiding unnecessary radical surgery; it is not a reliable way of defining the primary tumour.

Aged↗
PubMed1986

Pervaginal cul-de-sac cytology and CT in the follow-up care of patients with advanced ovarian cancer.

Among 28 patients with advanced ovarian cancer (FIGO stage III) treated with cytotoxic chemotherapy there were 23 cases with residual malignant disease as revealed by "second-look" surgery. Preoperative studies including fine needle cul-de-sac washing samples (FD) for cytology and abdominopelvic computed tomography (CT) detected 13 tumors with residual disease. No false positive findings were encountered among preoperative studies. There were 2 cases in which both clinical examination and CT detected malignant growth. In 2 cases clinical examination revealed tumors not detected by CT. On the other hand in 3 cases CT found the residual disease. In 6 cases residual tumors were preoperatively detected only by FD cytology. Manually and radiologically undetectable tumors were greater than 1 cm in diameter in 7 cases, fine nodular involvements in 8 cases, and in 1 case the residual disease was only cytologically diagnosed.

Biopsy, Needle↗
PubMed1986

Pelvic hemangiopericytoma resembling a prostatic tumor.

A case of pelvic hemangiopericytoma resembling a prostatic tumor is presented. Radical prostatovesiculectomy with enblock tumor excision was performed. No metastases were found. The histopathologic picture was suggestive of the malignant form of hemangiopericytoma. Two years postoperatively the patient is in good condition without any signs of recurrence.

Diagnosis, Differential↗
PubMed1986

Hypovolemic shock and contrast-enhanced computed tomography of the pancreas.

The effect of profound hemorrhagic hypovolemia on cardiac output and pancreatic blood flow was studied in pigs with the thermodilution method and microsphere technique. Approximately 30-40% of the circulating blood volume was withdrawn slowly during 5 h. Cardiac output and pancreatic blood flow decreased by 35% and 32%, respectively. The animals underwent contrast-enhanced computed tomography (CT) before hypovolemia and at 5 h after its onset. The changes in systemic and local blood flow were related to the contrast enhancement of the pancreas. In spite of profound hypovolemia and a significant decrease in pancreatic blood flow (p less than 0.005), the contrast enhancement remained normal. The results of the present study indicate that pancreatic hypoperfusion caused by hypovolemia does not affect the contrast enhancement of the pancreas in CT.

Animals↗