Extra-anatomic bypass from the ascending aorta for treatment of critical lower limb ischaemia.
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Aorta↗
Biomedical subjects
H Ahlström
Publications and source records attributed to H Ahlström.
Evaluation of new sclerotic bone metastases in breast cancer patients during treatment.
PURPOSE: According to the World Health Organization (WHO) criteria for response of bone metastases to therapy, new lesions indicate progressive disease. We intended to prove that a new sclerotic lesion on conventional radiography may also be a sign of a positive therapeutic response in a previously undetectable lytic metastasis. MATERIAL AND METHODS: In a previous placebo-controlled clinical trial of clodronate (Ostac) therapy, 139 breast cancer patients with bone metastases underwent both conventional radiography and bone scan every 6 months for 2 years with 99mTc before and during clodronate treatment. WHO criteria were applied for therapy response evaluation. RESULTS: In 24 patients, 52 new sclerotic lesions observed during therapy were selected for re-evaluation of conventional radiographs and bone scans. In 8 of the 24 patients, 17 of 52 new sclerotic lesions (33%) had showed positive uptake on previous bone scans. These lesions were possibly misinterpreted as new when applying WHO criteria. CONCLUSION: For better assessment of new sclerotic lesions during treatment, more sensitive techniques, e.g. bone scan, are needed as a complement to conventional radiography.
Adult↗
Residual mass in aggressive lymphoma--does size, measured by computed tomography, influence clinical outcome?
Residual masses are frequently found in patients with aggressive lymphomas, following therapy. A study was undertaken to determine whether initial tumour size, changes during treatment, or size of the residual mass could provide prognostic information. Computed tomography (CT) examinations were carried out before, midway and after completion of chemotherapy in 37 patients with aggressive lymphoma with residual mass after treatment. The tumours were measured for both the greatest diameter sizes and area. The size of the residual mass correlated with the tumour size at diagnosis. Neither a large tumour size before treatment nor a large residual mass after treatment correlated with an increase in rate of relapse. The initial tumour reduction (measured after completion of half of the planned chemotherapy) was less pronounced in relapsing patients compared to relapse-free patients. Using a cut-off level of 70% tumour reduction (measured after completion of half of the planned chemotherapy), 66% of patients with a tumour reduction of < 70% relapsed, compared with 22% (p < 0.05) in those with more marked tumour regression.
Adolescent↗
Sequence optimization in mangafodipir trisodium-enhanced liver and pancreas MRI.
To find an optimal magnetic resonance (MR) sequence for mangafodipir trisodium-enhanced liver and pancreas imaging, six healthy volunteers were studied using a 1.5 T MR system with different T1-weighted abdominal imaging sequences. These were turbo field (gradient)-echo (TFE), fast field (gradient)-echo (FFE), and spin-echo sequences before and after mangafodipir trisodium administration. Various parameter combinations were investigated within each sequence type, and then the best combination was found and compared with those of the other sequences. Signal intensity (SI) measurements were made in regions of interest in the liver, pancreas, and a reference marker with a known T1 value. Contrast index (CI, SItissue/SImarker) and contrast-to-noise ratio (CNR, [SItissue/SImarker]/SDbackground) were calculated, and percentage CI increase and CNR in the postcontrast images were used for the best sequence evaluation. Regarding CI, the TFE sequence with a TR/TE/flip angle of 15 msec/4.6 msec/20 degrees and inversion time of 300 msec had the largest pre- to postcontrast percentage increase. The FFE sequence with a TR/TE/flip angle of 140 msec/4.6 msec/90 degrees had the highest postcontrast CNR and is considered to be the optimal sequence for mangafodipir trisodium-enhanced MR imaging of the liver and pancreas.
Adult↗
MRI multiplanar reconstruction in the assessment of congenital talipes equinovarus.
BACKGROUND: Magnetic resonance imaging (MRI) has been shown to be a useful tool in the evaluation of the complex deformities which are present in congenital talipes equinovarus (clubfoot). OBJECTIVE: To evaluate MRI with the multiplanar reconstruction (MPR) technique as a new method for assessment of clubfoot. MATERIALS AND METHODS: Seven infants with 11 clubfeet were studied by using three-dimensional gradient-echo MR sequences. MPR was performed from the acquired image data in orthogonal, single and double oblique planes to demonstrate the complex deformities in clubfoot. Three angles (talar body-neck angle, talocalcaneal left-right angle and the talocalcaneal superior-inferior angle) were defined for measuring the medial angulation of the talar neck and the rotation of the calcaneus in relation to the talus. RESULTS: The method clearly demonstrated the pathological anatomy of the clubfeet, especially the talonavicular articulations. Dislocation of the navicular bone was observed in 9 of the 11 feet. The angle measurements were easily conducted with MPR, and these angles differed considerably among the patients. CONCLUSIONS: The information provided by this method is useful for classification of the severity of clubfoot deformities.
Clubfoot↗
Pharmacokinetics of bambuterol during oral administration to asthmatic children.
AIMS: To investigate dose proportionality, dosing frequency, and ethnic aspects of the pharmacokinetics of bambuterol in asthmatic children, and to discuss the relationship with previous observations in adults. METHODS: Forty-eight children in four different studies completed two double-blind bambuterol treatments each (daily doses of bambuterol hydrochloride): 12 preschool (5 mg x 2 vs 10 mg) and 12 school (10 mg vs 20 mg) Caucasians, 12 preschool (2.5 mg vs 5 mg), and 12 school (10 mg vs 20 mg) Orientals. Peak plasma concentrations and dosing interval area under curve (AUC) of bambuterol and the active metabolite terbutaline were assessed at steady state. Treatment differences were analysed statistically within each study. Differences between the studies and the relation to steady-state AUC in adults were described. RESULTS: Dose proportionality was seen for terbutaline but not for bambuterol. Twice-daily dosing (2 x AUC(0,12 h)) could not be shown to differ from once-daily dosing (AUC(0,24 h)) in the preschool Caucasians. Mean AUC of terbutaline was 128 and 242 nmol l-1 h in the preschool Caucasians (5 mg/12 h; 10 mg/24 h), 213 and 406 nmol l-1 h in the Caucasian school children (10 mg; 20 mg), 87.4 and 202 nmol l-1 h in the Oriental preschool children (2.5 mg; 5 mg), and 356 and 640 nmol l-1 h in the Oriental school children (10 mg; 20 mg). Oriental school children had higher plasma concentrations of bambuterol and terbutaline than Caucasian school children. The strict ethnic implication of the difference could not be elucidated, because demographic data were not perfectly matched. Terbutaline AUC was only moderately increased in the Caucasian school children compared with Caucasian adults. The increase was more pronounced in Oriental children and in some preschool Caucasians. The highest concentration of terbutaline, 58 nmol l-1, was seen in an Oriental school child after a 20 mg dose. CONCLUSIONS: Caucasian school children can be given bambuterol hydrochloride very much as Caucasian adults, 10 or 20 mg once daily, but Oriental preschool and school children plus preschool Caucasians should be given lower doses.
Administration, Oral↗
Use of novel bone biopsy system to study molecular effects of growth hormone in human bone--a pilot study.
In this study, we have examined whether a novel bone biopsy system combined with reverse transcription-polymerase chain reaction (RT-PCR) or differential display PCR (ddPCR) can be used to detect specific mRNAs induced by growth hormone (GH) in human bone. In a 58-year-old man with complete GH deficiency as a result of empty sella, bone biopsies were taken before, and 5 and 24 h after administration of 24 recombinant human GH. Insulin-like growth factor binding protein-3 (IGFBP-3) mRNA levels in this patient, measured in a semiquantitative RT-PCR assay, increased about 40% 24 h after GH administration. This increase was not seen in a healthy control who did not receive GH, suggesting that the increase was an effect of GH rather than of the biopsy itself. Several differentially expressed mRNAs were detected by ddPCR. Thus, this pilot study suggests that our novel bone biopsy system may be suitable for in vivo studies of the molecular effects of substances with essential functions in human bone.
Base Sequence↗
CT in malignancy grading and prognostic prediction of non-Hodgkin's lymphoma.
PURPOSE: The presence of tumor inhomogeneities in MR images of non-Hodgkin's lymphoma (NHL) provides information about malignancy grade and prognosis. The aim of this study was to determine whether CT images are also informative in these respects. MATERIAL AND METHODS: Sixty-three CT examinations in patients with NHL (32 high-grade and 31 low-grade tumors) were reviewed retrospectively by two senior radiologists. The tumor patterns were classified subjectively as homogeneous, slightly inhomogeneous or severely inhomogeneous and their relations to malignancy grade, clinical characteristics and prognosis were determined. RESULTS: Sixteen out of 17 patients with a severely inhomogeneous tumor pattern had high-grade NHL tumors while 21 out of 29 patients with a homogeneous tumor appearance had low-grade NHL tumors. Among chemotherapy-treated patients, those with the highest degree of inhomogeneity had a significantly worse prognosis (9 out of 11 patients died). This relationship was not found in patients treated with radiotherapy. CONCLUSION: A severely inhomogeneous tumor pattern on CT images was found to be associated with a high malignancy grade in NHL. This CT pattern was also compatible with a poor prognosis in patients treated with chemotherapy.
Antineoplastic Combined Chemotherapy Protocols↗
Skeletal metastases from breast cancer: uptake of 18F-fluoride measured with positron emission tomography in correlation with CT.
OBJECTIVE: To characterise the uptake of 18F in skeletal metastases from breast cancer using positron emission tomography (PET) and to relate these findings to the appearance on CT. PATIENTS AND DESIGN: PET with 18F and CT were performed in five patients with multiple skeletal metastases from breast cancer. The CT characteristics were analysed in areas with high uptake on the PET study. Dynamic PET imaging of the skeletal kinetics of the 18F-fluoride ion were included. RESULTS: The areas of abnormal high accumulation of 18F correlated well with the pathological appearance on CT. Lytic as well as sclerotic lesions had markedly higher uptake than normal bone, with a 5-10 times higher transport rate constant for trapping of the tracer in the metastatic lesions than in normal bone. CONCLUSION: PET with 18F-fluoride demonstrates very high uptake in lytic and sclerotic breast cancer metastases.
Aged↗
Positron emission tomography with 5-hydroxytryprophan in neuroendocrine tumors.
PURPOSE: Carcinoid tumors, especially those of midgut origin, produce serotonin via the precursors tryptophan and 5-hydroxytryptophan (5-HTP). We have evaluated the usefulness of positron emission tomography (PET) with carbon-11-labeled 5-HTP in the diagnosis and treatment follow-up evaluation of patients with neuroendocrine tumors. PATIENTS AND METHODS: PET using 11C-labeled 5-HTP was compared with computed tomography (CT) in 18 patients (14 midgut, one foregut, one hindgut carcinoid, and two endocrine pancreatic tumors [EPT]). In addition, 10 of 18 patients were monitored with PET examinations during treatment. RESULTS: All 18 patients, including two with normal urinary 5-hydroxyindole acetic acid (U-5-HIAA), had increased uptake of 11C-labeled 5-HTP in tumorous tissue as compared with normal tissue. Liver metastases, as well as lymph node, pleural, and skeletal metastases, showed enhanced 5-HTP uptake and PET could detect more lesions than CT in 10 patients and equal numbers in the others. Tumor visibility was better for PET than for CT due to the high and selective uptake of 5-HTP with a high tumor-to-background ratio. Binding studies indicated an irreversible trapping of 5-HTP in the tumors. Linear regression analyses showed a clear correlation (r = .907) between changes in U-5-HIAA and changes in the transport rate constant for 5-HTP during treatment. CONCLUSION: PET with 11C-labeled 5-HTP demonstrated high uptake in neuroendocrine gastrointestinal tumors and thereby allowed improved visualization compared with CT. The in vivo data on regional tumor metabolism, as expressed in 11C-5-HTP uptake and transport rate, provided additional information over conventional radiologic techniques. The close correlation between the changes in 11C-5-HTP transport rate and U-HIAA during medical treatment indicates the potential of 11C-5-HTP-PET as a means to monitor therapy.
5-Hydroxytryptophan↗
2D inflow MR angiography in severe chronic leg ischemia.
PURPOSE: The aim of this study was to compare 2D inflow MR angiography (MRA) with selective X-ray angiography (XRA) in patients with severe chronic leg ischemia. MATERIAL AND METHODS: In a blinded prospective study, 2D inflow MRA and XRA were compared with regard to evaluation of the arteries distal to the knee in 24 patients (median age 72 years) with severe ischemia; 23 of them had either rest pain or tissue loss. Statistics were calculated with XRA as the reference method. RESULTS: The interpretations of 2D inflow MRA and XRA showed moderate agreement in the calf arteries but poor agreement in the foot arteries. Of the discrepancies, two-thirds were observer-related and only one-third method-related. Of all the comparable arteries, 9% showed method-related differences between the two methods. An assessment of MRA using only maximum intensity projections (MIP) resulted in 19% of findings being judged inconclusive whereas all the arteries could be classified when the cross-sectional images were studied on the viewing console. CONCLUSION: The agreement between MRA and XRA was good in the calf but questionable in the foot.
Adult↗
3D surface rendering of images from multiple MR pulse sequences in the pre-operative evaluation of hepatic lesions.
PURPOSE: To develop a method for making three-dimensional (3D) reconstructions of liver vessels and hepatic lesions from different MR data sets. MATERIAL AND METHODS: To reduce the time required for segmentation and reconstructions, we used T1, T2 and phase contrast angiography, optimised for liver, lesion and vessels respectively. Following segmentation and reconstruction, the different volumes were combined on the same workstation and presented to the surgeon. RESULTS AND CONCLUSION: Segmentation and reconstruction took 1-2 h. To be able to combine the volumes from the different data sets, certain criteria had to be fulfilled: a) the field of view had to be constant; b) the same volume had to be scanned every time which meant that the slice thickness and the number of slices could be adjusted as long as the volume covered was the same; and c) the positioning of each volume had to be identical between every scan. The resulting 3D reconstruction gave the surgeon a clear appreciation of the different lesions and their relation to the different liver segments in the pre-operative planning of hepatic resections.
Angiography↗
Postpolio muscular dysfunction: relationships between muscle energy metabolism, subjective symptoms, magnetic resonance imaging, electromyography, and muscle strength.
Eleven patients with previous polio were studied. The concentration of energy-related metabolites and energy charge was measured from the vastus lateralis muscle, as was isometric muscle strength of knee extension. Cross-sectional area of the quadriceps femoris muscle was calculated from magnetic resonance imaging. Reinnervation was studied using macroelectromyography. Muscle weakness, pain, and newly acquired muscle weakness in the legs was estimated by the patients. The findings in the legs in which the patients experienced new loss of muscle function were compared with the stable legs. There were no significant differences between these groups in any of the objectively measured variables. Only hip pain correlated with new loss of muscle function. Creatine phosphate was decreased in 5 patients. The symptoms and subjective muscle strength did not correlate with any of the objective measurements. There were no significant relationships between energy-related metabolites and postpolio symptoms.
Adult↗
Magnetic resonance angiography in the resectability assessment of suspected pancreatic tumours.
The aim of this prospective study was to evaluate MRI, including MR angiography (MRA), in the preoperative assessment of the resectability of suspected malignancy of the pancreas. A total of 17 patients with suspected pancreatic carcinoma and planned surgery were investigated with conventional angiography, ultrasonography with Doppler technique, MRI and MRA. The MRA protocol included both 2D inflow angiography and 3D phase-contrast angiography. Surgery was carried out in 13 patients. The image quality of MRA was judged satisfactory in all cases. The findings with respect to vascular involvement agreed between the radiological methods in all but 3 cases. When the findings were correlated with the final diagnosis, one false-negative case was found for each of the three methods. The results suggest that MRI with MRA, including both the phase-contrast and inflow techniques, has a similar diagnostic value to that of conventional angiography and ultrasonography in the preoperative assessment of the portal venous system in patients with pancreatic carcinoma. Further studies are needed to establish the optimal diagnostic procedure.
Biopsy↗
Serial gadolinium-enhanced magnetic resonance imaging and assessment of facial nerve function in Bell's palsy.
Eleven patients with mild or moderate acute idiopathic peripheral facial palsy, so-called Bell's palsy, were serially examined by gadolinium-DTPA-enhanced MRI on mean days 11, 40, and 97 (third examination, n = 10) after the onset of palsy. Results of the clinical and neurophysiologic assessment of facial nerve function were compared with the gadolinium-enhanced MRI findings. Eight of the 11 patients demonstrated contrast enhancement of the facial nerve at the initial examination, but in 7 of them, the enhancement had disappeared by the time of the serial follow-up gadolinium-enhanced MRI scans. The disappearance of facial nerve enhancement was found to be related to clinical and neurophysiologic improvements in facial nerve function during recovery from Bell's palsy. The three patients whose scans were negative at the initial gadolinium-enhanced MRI examination had the same clinical severity of palsy, but initially they had milder neurophysiologic involvement than those who demonstrated enhancement; these three patients did not exhibit enhancement at serial follow-up scans. These findings indicate that the presence of enhancement at the initial MRI scan is not necessarily indicative of a poor prognosis for recovery.
Acute Disease↗
Positron emission tomography (PET) with 11C-5-hydroxytryptophan (5-HTP) in patients with metastatic hormone-refractory prostatic adenocarcinoma.
The discovery of neuroendocrine differentiation in hormone-refractory prostatic adenocarcinoma has opened a potentially new therapeutic approach in this group of patients with a poor prognosis and few effective therapy modalities. Based on previous findings of increased uptake of 11C-5-hydroxytryptophan (11C-5-HTP) in neuroendocrine tumours using the PET technique, this tracer was applied in the study of 10 patients with metastatic hormone-refractory prostatic adenocarcinoma. In three patients, the study was repeated after treatment. An increased uptake of 11C-5-HTP was observed in all investigated skeletal lesions, although the magnitude of the uptake was moderate. The difference between the standard uptake values (SUV) in normal bone and metastatic lesions was significant (p < 0.001). A kinetic analysis of the uptake of 11C-5-HTP demonstrates an increase during the first minutes followed by a wash-out and a stabilization of the tissue/blood ratio at about 2. The Patlak plots demonstrated a gradual increase in the transport rate during the first 20 to 30 min, after which a constant level was observed. The SUV varied between patients and between lesions over time and treatment. The uptake of 11C-5-HTP discriminates metastatic lesions from normal bone and may thus aid in the diagnosis and, potentially, in treatment monitoring of metastatic hormone-refractory prostatic adenocarcinoma. Uptake kinetics are characterized by a wash-out and cannot alone be used as proof of neuroendocrine differentiation in hormone-refractory prostatic adenocarcinoma.
5-Hydroxytryptophan↗
Dysprosium-enhanced MR imaging for tumor tissue characterization. An experimental study in a human xenograft model.
PURPOSE: To evaluate dysprosium-enhanced MR imaging for differentiation between morphologically intact and necrotic tumor tissue in a tumor model. MATERIAL AND METHODS: A human colon carcinoma was transplanted subcutaneously into 9 nude (immunodeprived) rats. MR imaging was performed before and after injection of the dysprosium agent Dy-DTPA-BMA. T1-, T2- and T2*-weighted sequences were acquired. The tumors were dissected, histological sections were prepared, and compared with corresponding MR images. RESULTS: In intact tissue, the MR signal intensity in the T2- and T2*-weighted images decreased after Dy injection and the delineation of the intact regions were sharp and corresponded well to the gross histological sections. CONCLUSION: Dy-enhanced MR imaging facilitated the differentiation between intact and necrotic tumor tissue.
Adenocarcinoma↗
Diagnostic efficacy of MnDPDP in MR imaging of the liver. A phase III multicentre study.
PURPOSE: To assess the diagnostic efficacy, safety and tolerability of mangafodipir trisodium (MnDPDP, Teslascan) in MR imaging of the liver. MATERIAL AND METHODS: Eighty-two patients from 4 centres underwent MR imaging with pre-contrast sequences including T1-weighted SE and GRE, and T2-weighted turbo SE sequences. MnDPDP at a dose of 5 mumol/kg b.w. was administered by slow i.v. infusion, and 20-60 min after infusion the T1-weighted SE and GRE sequences were repeated. Diagnostic efficacy was evaluated by counting the number of lesions and by evaluating whether more information for lesion characterisation was available in post-contrast images. Safety and tolerability were assessed by recording adverse events and infusion-related discomfort. RESULTS: Significantly more lesions were found in MnDPDP-enhanced T1-weighted SE and GRE images than in unenhanced images of the same sequences. More lesions were also found in these images compared with T2-weighted images at a level of marginal significance. More information was obtained from MnDPDP-enhanced images in 40 cases. Mild to moderate adverse events were experienced by 17% of the patients. CONCLUSION: MnDPDP-enhanced images can improve lesion detection in the liver and are helpful for lesion characterisation. To obtain optimal diagnostic information of liver lesions T2-weighted images are also valuable. MnDPDP is a safe contrast agent for MR imaging of liver lesions.
Adult↗