PubMed Health⌕ Search

Biomedical subjects

S Bondestam

Publications and source records attributed to S Bondestam.

At least 37 records · Page 2Linked to original sources
PubMed1994

Diagnostic performance of low field MRI in acute knee injuries.

The diagnostic performance of low field (0.1 T) magnetic resonance imaging (MRI) was studied prospectively and double-blindly among 33 patients with acute knee injuries. The subsequent arthroscopy was the golden standard. For lesions of the medial meniscus low field MR had a sensitivity of 88% and a specificity of 80%; for lesions of the lateral meniscus the sensitivity was 25% and the specificity 97%. For anterior cruciate ligament tears, low field MRI had a sensitivity of 83% and a specificity of 85%. The specificity for posterior cruciate ligament tears was 97%. The performance of low field MRI equalled that reported earlier for high field MRI, the only exception being the sensitivity for lateral meniscus lesions.

Acute Disease↗
PubMed1994

Hepatosplenic yeast infection in patients with acute leukemia: a diagnostic problem.

The occurrence of hepatosplenic candidiasis following prolonged neutropenic periods has emerged as a major problem for patients with leukemia. In order to evaluate the diagnostic value of various available procedures, we analyzed our findings regarding 26 leukemic patients with hepatosplenic candidiasis. A significantly increased level (> 50 mg/L) of serum C-reactive protein (S-CRP) was significantly more common than a daily fever (for which the mean temperature peak was > 37.5 degrees C) or raised levels of liver enzymes (serum alanine transferase, aspartate transferase, or alkaline phosphatase). Focal changes in the liver, spleen, or kidneys were detected in > 90% of the patients examined by computed tomography (CT) but in < 50% of those examined by ultrasonography. Seventeen diagnoses were based on the findings from microscopy of samples obtained invasively, whereas a positive fungal culture was the basis of the diagnosis for only five patients. In conclusion, monitoring the S-CRP level after a patient's recovery from neutropenia is useful in that its elevation is cause for early suspicion of hepatosplenic candidiasis. In detection of the hepatosplenic foci, CT is superior to ultrasonography. For establishing the specific diagnosis, aggressive collection of samples for microscopy is essential.

Acute Disease↗
PubMed1994

Infectious liver foci in leukemia: comparison of short-inversion-time inversion-recovery, T1-weighted spin-echo, and dynamic gadolinium-enhanced MR imaging.

PURPOSE: To assess the performances of three different magnetic resonance (MR) imaging techniques in the evaluation of patients with leukemia and suspected hepatic candidiasis. MATERIALS AND METHODS: Twelve patients with acute leukemia and definite or clinically suspected hepatic candidiasis were imaged at 1.0 T with a T1-weighted spin-echo (SE) technique, a short-inversion-time inversion-recovery (STIR) fat-suppression technique, and a dynamic gadolinium-enhanced fast low-angle shot (FLASH) technique. The conspicuity of hepatic lesions was evaluated semiquantitatively and ranked on a three-point scale. RESULTS: Multiple liver lesions were seen as high-signal-intensity foci with the STIR sequence; other sequences showed equivocal results. In the semiquantitative evaluation, STIR was significantly (P < .001) superior to both T1-weighted SE and contrast-enhanced FLASH techniques. Multiple red blood cell transfusions affected lesion conspicuity. CONCLUSION: STIR imaging is recommended as the MR technique of choice at 1.0 T in the evaluation of infectious liver foci in patients with acute leukemia.

Acute Disease↗
PubMed1994

Magnetic resonance imaging of transfusional hepatic iron overload.

The transfusional iron overload in 11 adult patients suffering from haematological malignancy was studied in 14 consecutive 1.0 Tesla magnetic resonance imaging (MRI) studies. Routine T1- and T2-weighted spin echo sequences and a fat suppressed sequence (STIR) were used. The ratio from a region of interest of the liver parenchyma and from a manganese chloride reference phantom was measured. There was a definite difference between the signal ratio from the haematological patient group and the control group (p = 0.0001). The patients showed a diminished signal ratio in all pulse sequences used. There was a statistically significant inverse linear correlation between the number of transfused red cell units and the signal ratio in the T1-weighted (p = 0.03) and the T2-weighted (p = 0.03) images. A definite decrease of the effect is found after 20-30 red cell unit transfusions in T2-weighted and STIR images.

Adult↗
PubMed1994

Compression sonography in the diagnosis of deep venous thrombosis of the leg.

The value of compression sonography was assessed to reduce the number of phlebographies otherwise necessary when deep venous thrombosis (DVT) is suspected among hospital patients. Compression sonography was used to study 119 prospective hospital patients who were suspected of having DVT of the lower extremity. The results were compared to those by phlebography. There were 44 DVTs detected by phlebography; ten of these were located only in the calf, below the knee. Of the remaining 34 femoropopliteal DVTs 33 were detected by the compression sonography technique. It is concluded that the use of compression sonography for primary investigation of suspected DVT reduces the number of patients who require phlebography to those whose results by compression sonography are negative. In our study, this would have represented a decrease of 28%, corresponding to a reduction of the total diagnostic costs by 10%.

Adolescent↗
PubMed1994

A low pH 111In-bleomycin complex: a tracer for radiochemotherapy of head and neck cancer.

Bleomycin (BLM) is a well known natural antibiotic. It is toxic to dividing cells and has been used for the treatment of several forms of cancer. BLM has been labeled with various cations, but most of them have turned out be unstable in in-vivo experiments. In-BLM demonstrated high bone marrow uptake, but using 111In-bleomycin complex (BLMC) formed at low pH, the low in vivo stability and high bone marrow seeking behavior of the molecule could be avoided. The idea of using BLMC in combined radiotherapy and chemotherapy is intriguing. In this study we examined the effects of 111In-A'2a-c-BLMC in the treatment of 31 head and neck cancer patients. Findings were compared with those of surgery, and pre-operative radiology. The injected activity was 85-110 MBq, and the specific activity was approximately 100 MBq/mg. The half-life of 111In activity in serum varied from 1.5 to 3.1 hours. Maximum activity in the urine was achieved in all patients within 3 hours, and the average half-life in urine was 2 hours. In most patients 50% was excreted within 3 hours, in some 70%; in all patients > 95% of the activity was excreted within 22 hours. In surgical samples from 24 patients the best tumor-to-tissue ratios were: fat 60:1, bone 17:1, muscle 12:1, blood 3.6:1. All patients were examined on the injection day with ultrasonography of the neck. Using 111In-BLMC we missed a few small lymph nodes in 2 patients, but there were no false positive findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Bleomycin↗
PubMed1994

Quality assurance of the bedside chest radiography process.

The bedside chest radiography process was analyzed in terms of modern quality management guidelines and the sources of quality problems were identified. In order to analyze systematically the various quality factors, the process was described in a top-down fashion with the aid of data flow diagrams. Two internal quality control points and one external point were found in the process. Means to measure quality at the quality control points including questionnaires and a formula for calculating the internal quality index were developed.

Humans↗
PubMed1993

Observed lung markings in normal chest roentgenograms.

The digital chest posterior-anterior roentgenograms of 42 healthy individuals were ranked twice (interval of at least 5 days) in the order of increasing lung parenchymal markings. The evaluations were made by three radiologists, two residents, a medical student and a radiographer. All observers regardless of their radiological experience showed good intraobserver correlations between their two subsequent rankings (p < 0.05-0.001). The interobserver agreement on rankings was generally poor, even if the radiologists were considered. Radiologic training seemed to eliminate the influence of false leading factors (the object's respiration and body constitution). "The golden standard of evaluation" (= the added-up rankings by the radiologists) did not correlate either with the patient's ages (19-54 years) or smoking habits (0-45 pack-years, mean 4.2).

Adult↗
PubMed1992

Correlations of liver echo intensity with cytology and chemical measurements of fat, water and protein content in live burbots (Lota lota).

Six live burbot fish (Lota lota) were examined on the 1st, 7th and 15th day after capture. The echo intensity of the liver tissue was correlated with chemically measured fat and water content and with the tissue cytology. At the end of the study, the collagen and total protein contents of the livers were also measured. The increasing size of fat droplets and clustering of droplets correlated well with the echo intensity (p = 0.0012), but there was no statistically significant correlation between echo intensity and chemically measured fat concentration (p = 0.1989). These results indicate that the echogenicity is a function of the liver histomorphology. No significant correlation was found between the echo intensity and liver collagen, total protein content, or amounts of water. The burbots tolerated transport and repeated anesthesia and appear well suited for experimental ultrasound studies.

Animals↗
PubMed1992

Tissue characterization by image processing subtraction: windowing of specific T1 values.

A method for windowing specific T1 values is presented. A 1.0 T imager with two routine pulse sequences was employed: A T1-weighted spin echo (SE) sequence and a short tau inversion recovery STIR sequence (fat-suppressed IR). A T1 window for fat was obtained by subtracting the STIR image from the SE image. Negative values were coded black. The method was tested on a normal human thigh, on a human liver with confirmed fatty infiltration, and on the livers of four live burbots. The fat-containing tissues of the two human volunteers were well depicted. The differences in fat concentration among the burbot livers were also clearly shown. The fat intensity seen in the images correlated well with the chemically measured fat concentration. This subtraction method for windowing T1 values proved feasible for fat. The method could be used for tissues with other short T1 values as well.

Adipose Tissue↗
PubMed1992

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↗
PubMed1992

The needle tip echo.

The echo of the needle tip used in sonographically guided needle aspiration biopsies was studied in A mode. The biopsy transducer was placed in a water tank and needles parallel to the beam axis were used. The beveled needle tip produced two echoes, which were probably generated by diffraction at the edge of the far end of the tip and by the sharp edge of the needle tip opening. The distal echo was more intense than the proximal one. When a stylet was inserted the proximal echo disappeared as the diffracting edges decreased to a single echo. Inserting a stylet did not enhance the echoes. Roughening of the needle shaft did not enhance echogenicity, whereas side ports in the shaft produced a greater number of echo peaks.

Biopsy, Needle↗
PubMed1991

Determination of fat content of burbot (Lota lota) liver with low field MR imaging (0.04 T).

A reconstructed separate fat image was used for studying the fat content of the liver of 12 dead and six living fasting burbots (Lota lota) in a 0.04 T magnetic field with olive oil as a reference. The correlation between the MR intensities and the results of the cytological, histological and chemical fat measurements, as well as chemically measured water, collagen and total protein contents were examined. The MR signal intensity in reconstructed fat images correlated well with the changes in fat content of the liver in living fish (r = 0.69, P = 0.0014). Also the contents of water (r = -0.66, P = 0.003) and total protein (r = -0.91, P = 0.013) correlated significantly with the MR signal intensity. The reconstructed fat image is thus a reliable method for following the changes in tissue fat content. The living burbot is an applicable test animal for studying the hepatic fat content with MR.

Animals↗