Bone health in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED): findings in 25 adults.

OBJECTIVE: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is characterized by chronic mucocutaneous candidiasis and autoimmune destruction of endocrine organs. The resulting endocrinopathies and their treatment may impact bone health. The purpose of our study was to assess bone health and its correlates in adult patients with APECED. PATIENTS AND METHODS: Twenty-five adults (12 males) with APECED were prospectively assessed. Data on their previous medical history were collected from hospital records. Areal bone mineral density (aBMD) for the lumbar spine (L1-L4), femoral neck and whole body as well as volumetric BMD (vBMD) for the lumbar spine (L2-L4) were measured with dual-energy X-ray absorptiometry (DXA). RESULTS: Mean age was 34 years (range 21-59 years). All patients had 1-4 autoimmune endocrinopathies, the most common being adrenocortical failure (20 patients) and hypoparathyroidism (18 patients). Osteopaenia or osteoporosis was present in 28%. The median (range) aBMD Z-scores were for the lumbar spine -0.3 (-2.3 to +3.3) and for the femoral neck, -0.1 (-2.2 to +2.0). The BMD Z-scores tended to be higher in patients with hypoparathyroidism than in patients with normal parathyroid function (at the lumbar spine +0.4 vs.-1.2, P = 0.016, and at the femoral neck +0.3 vs.-0.4, P = 0.090). Adrenocortical failure had a negative impact on BMD. Six patients had had low-impact fractures and three were diagnosed with compression fractures. CONCLUSIONS: Despite the complex endocrine problems, the overall prevalence of symptomatic osteoporosis is low in adults treated for APECED. Osteopaenia is frequently observed and warrants follow-up. Treated hypoparathyroidism may have a positive, and adrenocortical failure a negative, impact on bone health.

The effect of haemosiderosis and blood transfusions on the T2 relaxation time and 1/T2 relaxation rate of liver tissue.

Patients with chronic anaemia need repeated blood transfusions, which eventually lead to iron overload. The excess iron from blood transfusions is deposited in the reticuloendothelial system and in the parenchymal cells of the liver, spleen and other organs. Cellular damage is likely to occur when iron overload in the liver is pronounced. Liver biopsy is still necessary to evaluate the degree of haemosiderosis or haemochromatosis. To avoid this invasive procedure, methods have been sought to determine the concentration of iron in liver tissue and to estimate the effect of the treatment of haemosiderosis or haemochromatosis. In this MRI study, the T2 relaxation time and the 1/T2 relaxation rate of liver were determined in 23 patients who had undergone repeated blood transfusions for chronic anaemia. The first 60 transfusions had the greatest influence on the measured T2 relaxation time, with T2 relaxation time decreasing as haemosiderosis progresses. The 1/T2 relaxation rate increases significantly in a linear fashion when the number of blood transfusions increases up to 60. After 60 transfusions the influence of additional blood transfusions on the T2 value was minimal; the same response, although in reverse, was seen in the 1/T2 relaxation rate curve. One possible explanation for this may be that the MR system could detect the effect of only a limited amount of iron excess and any concentration over this limit gives a very short T2 relaxation time and a very weak signal from the liver, which is overwhelmed by background noise. However, in mild and moderate haemosiderosis caused by blood transfusions, T2 relaxation time and 1/T2 relaxation rate reflect iron accumulation in liver tissue.

Comparison of absorbable poly-L-lactide and metallic intramedullary rods in the fixation of femoral shaft osteotomies: an experimental study in rabbits.

An osteotomy of the distal femoral diaphysis was fixed with an intramedullary self-reinforced poly-L-lactide (SR-PLLA) rod in 22 and with a metallic rod in 38 skeletally mature rabbits. Histomorphometric and quantitative computed tomography (QCT) were performed to assess time-related changes in the consolidation process of the osteotomy of cortical bone and development of the external callus. The follow-up times were 8, 16, 24, and 48 weeks for radiologic and 16, 24, and 48 weeks for histologic studies; 19/22 of the SR-PLLA and 34/38 of the metallic fixed osteotomies healed during the observation periods. On microscopic evaluation, no difference was found in histologic parameters such as external callus area and fraction, and endosteal callus area and fraction between SR-PLLA and metallic fixed osteotomies. The total external callus area increased up to 16 weeks and subsequently decreased linearly over time in both experimental groups. However, the mean endosteal bone area and fraction decreased after 16 weeks in metallic fixated femora, while in the SR-PLLA fixated femora, both these values increased, being greater in the SR-PLLA group. The mean external callus QCT density decreased after 8 weeks in both experimental groups, the decrease being greater in the SR-PLLA group. Nevertheless, no significant difference was detected between SR-PLLA and metallic fixed femora in any of the follow-ups. These results suggest that both SR-PLLA and metallic rods are suitable in the fixation of femoral shaft osteotomies in rabbits. Furthermore, SR-PLLA rod fixation seems to have a minor stress-shielding effect.

A novel method for monitoring liver ethanol injections: activity tissue distribution in rat liver using digital quantitative autoradiography and CH3(14)CH2OH.

Accurate ethanol microdistribution during percutaneous ethanol injections (PEI) have not previously been reported by in vivo monitoring methods (e.g. by using ultrasound or other flow methods). Any real-time imaging method is insufficient to show the gradual diffusion of ethanol and its ultimate spread. Therefore a novel method to study the microdistribution and radiopharmacokinetics of labeled ethanol in rat liver was developed. Rats were injected with C-14-labeled ethanol into the right liver lobe. Liver slices were investigated at 1, 5, 15, and 30 min using a novel digital quantitative autoradiographic (DQAR) method. Tissue slices at 1 and 5 min demonstrated increased activity of C-14-labeled ethanol around the injection site, resulting in a uniform distribution at 15 min. At 30 min, a weak elimination was observed. Our results indicate that in PEI treatment, toxic effects may be found outside the primary injection site. Our DQAR method shows the dynamic spread of ethanol with great anatomical detail. It may therefore be used in future studies on ethanol kinetics in the liver and tumor tissues to optimize the antitumor effect of PEI while minimizing the potential for adverse spread and complications.

Perfusion CT of the brain in the assessment of flow alterations during brachytherapy of meningioma.

PURPOSE: The aim was to investigate the use of perfusion CT of the brain in the assessment of flow alterations during brachytherapy of meningiomas. MATERIAL AND METHODS: Six patients with an intracranial meningioma were investigated during brachytherapy treatment by stereotactic implantation of I-125 seeds. Cerebral blood flow (CBF) in the tumour centre and the tumour periphery as well as in the normal brain parenchyma was determined by perfusion CT. Follow-up examinations were performed during the first year after the implantation. The CBF of the normal brain parenchyma was used as control. RESULTS: In the beginning of therapy, the mean+/-SEM blood flow in the tumour centre was 231.4+/-58.1 ml/100 g/min and in the periphery 223.5+/-53.8 ml/100 g/min. Within three months after the iodine seed implantation, the tumour blood flow had decreased 41%. At the one-year follow-up, the tumour blood flow in the centre had decreased to 68.7+/-45.9 ml/100 g/min. In the periphery of the tumour, it remained nearly unchanged (199.3+/-101.0 ml/100 g/min). The CBF values obtained from normal brain parenchyma did not decrease during the treatment. Throughout the study, the mean CBF for the normal grey matter was 38.5+/-2.9 ml/100 g/min, and 22.3+/-1.2 ml/100 g/min for the normal white matter. CONCLUSION: Perfusion CT seems to enable accurate monitoring of the blood flow of meningiomas during brachytherapy, and could be used in clinical situations where blood flow changes in brain and tumours should be investigated.

Familial occurrence of abdominal aortic aneurysm.

BACKGROUND: A family history of abdominal aortic aneurysm has been reported to increase the risk for developing the disease. OBJECTIVE: To determine the risk for abdominal aortic aneurysm in first-degree relatives of patients with the disease. DESIGN: Cross-sectional ultrasonographic screening study. SETTING: University Central Hospital, Helsinki, Finland. PATIENTS: 238 of 325 living first-degree relatives of patients having surgery for abdominal aortic aneurysm (age > 50 years; 98 men and 110 women) and 281 controls (135 men and 149 women) without a family history of abdominal aortic aneurysm. MEASUREMENTS: Ultrasonography was used to measure aortic diameter in 101 male relatives and 140 female relatives (241 of the 325 persons at risk [74%]) and in 281 controls. RESULTS: Three siblings had already undergone surgery for abdominal aortic aneurysm. Eleven siblings (all brothers) (11 of 101 [10.9%]) had ultrasonographic evidence of abdominal aortic aneurysm (aortic diameter > 30 mm). In the control group, 2 men (1.5%) and 2 women (1.3%) had an aneurysm. Thirty siblings and no controls had dilatation of the abdominal aorta (aortic diameter, 20 to 29 mm). Neither the age nor the sex of the proband affected risk for developing abdominal aortic aneurysm among first-degree relatives. Family history increased the risk for an aneurysm by 4.33-fold (95% CI, 1.32-fold to 14.23-fold), male sex increased the risk by 12.21-fold (CI, 2.63-fold to 56.64-fold), and age (by decade) increased the risk by 1.93-fold (CI, 1.15-fold to 3.25-fold). CONCLUSION: Aging brothers of patients with known abdominal aortic aneurysm have the highest risk for developing the disease; the prevalence of the disease in siblings older than 60 years of age is 18%.

Spin lock and magnetization transfer MR imaging of local liver lesions.

The present study was designed to evaluate tissue contrast characteristics obtained with the spin-lock (SL) technique by comparing the results with those generated with a magnetization transfer(MT)-weighted gradient echo [GRE, echo-time (TE)=40 ms] sequence. Twenty-eight patients with hepatic hemangiomas (n=14), or metastatic liver lesions (n=14) were imaged at 0.1 T by using identical imaging parameters. Gradient echo, single-slice off-resonance MT, and multiple-slice SL sequences were obtained. SL and MT-effects were measured from the focal liver lesions and from normal liver parenchyma. In addition, tissue contrast values for the liver lesions were determined. Statistically significant difference between the SL-effects of the hemangiomas and metastases, and also between the MT-effects of the lesions was observed (p < 0.02). Tissue contrast values for the lesions proved to be quite similar between the SL and MT techniques. Our results indicate that at 0.1 T multiple-slice SL imaging provides MT based tissue contrast characteristics in tissues rich in protein with good imaging efficiency and wide anatomical coverage, and with reduced motion and susceptibility artifacts.

Intramedullary fixation of distal femoral diaphyseal osteotomies with absorbable self-reinforced poly-L-lactide and metallic intramedullary rods assessed by plain radiographs, quantitative computed tomography, and magnetic resonance imaging: an experimental study in rabbits.

Osteotomies of distal femoral diaphysis were fixed intramedullary with self-reinforced poly-L-lactide acid (SR-PLLA) rods in 19 and with metallic rods in 34 adult rabbits. The follow-up times were 8, 16, 24, and 48 weeks. Plain radiographs, computed tomography (CT), quantitative computed tomography (QCT), and magnetic resonance imaging (MRI) were used to evaluate the bone changes at two different levels of the osteotomy region. There were no significant differences in cortical bone density compared to the intact in the SR-PLLA fixed femurs at the osteotomy site. In the metallic-fixed femurs, the density values were significantly lower as compared to the contralateral femurs. There was a significant reduction of the cortical bone density values in SR-PLLA fixed femurs compared to the intact control side outside the osteotomy area at 8 (p = 0.01), at 16 (p = 0.0001), and at 24 weeks (p = 0.0003). In the metallic-fixed femurs significant reductions at 8 weeks (p = 0.02), at 16 weeks (p = 0.01), at 24 weeks (p = 0.009), and at 48 weeks (p = 0.002) were found compared with the intact control. MRI depicted well the SR-PLLA cases allowing studies without removal of the implant. On the contrary, abundant disturbing metallic artifacts were detected during investigation of the metallic-fixed femurs. In conclusion, our results indicated that CT is useful to evaluate the quality of reduction and internal fixation. Furthermore, the constant presence of internal metallic fixation seems to eventually cause osteoporosis in the cortical region of the femur. However, this stress protection effect of intramedullary fixation on the femoral diaphysis seems to be avoided by using an absorbable SR-PLLA rod, thus resulting in a better quality of bone when the osteotomies are healed.

Effect of fasting and food intake on magnetization transfer of human liver tissue.

Magnetization transfer (MT) technique is a promising method in differential diagnosis of diseases in parenchymal tissues. Basic knowledge about circumstances and elementary factors that influence MT and its parameters is still insufficient, however. Having a meal before the magnetic resonance (MR) examination could change liver MT parameters compared to fasting state through alteration in liver perfusion, blood flow, and content of portal blood (proteins and other derivates from a meal). If MT parameters can be altered by a meal, then MR liver studies should always be performed after fasting. Before MRI examinations we examined three healthy volunteers after a high-fat meal with Doppler ultrasound technique to find out duration and magnitude of changes in portal blood flow. Duration of > or = 50% increased peak-flow value compared to fasting state in portal vein was > 90 min, which is enough for our MR examination. With a low-field 0.1-T MR imager we examined 10 healthy volunteers after a short (range from 3 h 45 min to 17 h 30 min) fast and also immediately after a high-fat meal. Magnetization transfer parameters, magnetization transfer ratio (MTR) and magnetization transfer rate Rwm of liver tissue were determined. MTR changed significantly (Student paired two-tailed t-test, p = .0044) after a meal, but Rwm did not (p = .0952). We recommend a 4 h fast before MR examination that aims to determine the MTR of liver tissue.

Detection of pseudomyxoma peritonei by radioimmunohistochemistry and radioimmunoscintigraphy.

Pseudomyxoma peritonei (PP) is a local slowly progressing disease with typical abdominal swelling. Treatment is uneffective and the long-term prognosis is poor. Conventional radiology provides usually only a delineation of low density area relating gelatinous masses accumulating in the peritoneal cavity. In this study, immunohistochemistry based on digital quantitative autoradiography utilizing radiolabelled monoclonal antibody B72.3 (MoAb) recognizing TAG-72 antigen on epithelial carcinomas was used for diagnosis of pseudomyxoma (7 patients). The PP patients were studied with radioiodinated I-131-labeled MoAb after intravenous (2 patients) and intraperitoneal (7 patients) injections. Radioactivities of MoAbs varied considerably in the tumors. Both intra- and extracellular staining pattern was observed by immunohistochemistry. Gamma imaging at 1, 3, 7 and 14 days after i.v. injection (2 patients) revealed targeting of all known lesions. The intraperitoneally injected MoAb (7 patients) retained long time in the peritoneal cavity, specific tumour targeting was seen up to 16 days by an antibody-SPECT, while maximum blood radioactivity was measured between 8-12 hrs. Radiolabelled B72.3 MoAb recognizing TAG-72 antigen is also present within pseudomyxoma cells. It can be used for radioimmunohistochemistry of PP. Accurate imaging of PP is possible by MoAb suggesting earlier diagnosis and more accurate location of residual disease after operations, and evaluating treatment response. Estimated tumour dose for intraperitoneal tumour (MIRD formalism) was 13 mGy/MBq. This indicates that the radioiodinated B72.3 antibody can be used for in vivo targeting and therapeutic applications of intraperitoneal pseudomyxoma.

Imaging and staging of head and neck cancer using a low pH In-111-bleomycin complex.

Bleomycin (BLM), a natural antibiotic toxic to dividing cells has been used for treatment of several forms of cancer. BLM has been labelled with various cations but most have turned out to be unstable in vivo. In-BLM has demonstrated high bone marrow uptake, but by using an In-111-bleomycin complex (BLMC) formed at low pH, the low in vivo stability and high bone marrow uptake can be avoided. Our premise is to combine radiotherapy and chemotherapy by using radionuclide-BLMC. In this study we used In-111-A'2a-c-BLMC in 28 head and neck cancer patients. Scintigraphic findings were compared to those of surgery, pre-operative radiology and proliferation markers. The injected patient activity was approximately 85 MBq, 100 MBq/mg. The half-life of In-111 activity in serum varied from 1.5 to 3.1 h, and in urine from 1.4 to 3.7 h. More than 95% of the urine activity was excreted within 24 h. From biopsies obtained from surgical specimens of 22 patients the absolute uptakes in tumour tissues varied between 0.10 and 0.95 x 10(-3)% ID/g. Uptakes in normal tissues varied from 0.01 to 0.32 x 10(-3)% ID/g, and were always lower than in malignant tissues of the same patients. All patients were examined on the injection day with ultrasonography of the neck. Using In-111-BLMC we missed small metastatic lymph nodes (< 1 cm) in 2 patients, but there were no false positive findings. The critical organ from the dosimetric point of view was the kidney. The absorbed radiation doses with these injected activities were 19 mGy in liver, 75 mGy in kidney and 1.0 mGy in whole body (5 h mean residence time). Our results indicate that In-111-BLMC targets head and neck cancer, and identifies metastatic spread. It could possibly be applied with higher activities for adjuvant Auger-electron therapy of head and neck cancer.

Magnetic resonance imaging is superior to computed tomography and ultrasonography in imaging infectious liver foci in acute leukaemia.

We conducted a prospective study in order to compare ultrasonography, computed tomography and magnetic resonance imaging in the detection of liver foci in patients with acute leukaemia and clinical suspicion of hepatic candidiasis. 28 adult patients fulfilling set entry criteria after recovery from neutropenia were studied. Lesions in the liver were detected by at least one imaging modality in 21 patients: by ultrasonography in 7 (33% of detected cases), computed tomography in 12 (57%) and by magnetic resonance imaging in 20 patients (95%). Magnetic resonance imaging was significantly more sensitive than ultrasonography (p<0.001) and computed tomography (p<0.02). The difference between computed tomography and ultrasonography was not statistically significant (p=0.1). Invasive procedures performed in 10 patients provided definite proof of candidiasis in 5 patients, and nodes on the liver surface, compatible with yeast infection, were seen during laparoscopy in 3 other patients without proof of fungal infection. We confirm that magnetic resonance imaging is superior to ultrasonography and computed tomography in imaging liver foci in leukaemic patients recovering from neutropenia with persistent non-specific signs of infection or hepatic involvement.

Spin lock magnetic resonance imaging in the differentiation of hepatic haemangiomas and metastases.

Spin lock (SL) imaging technique, generating T1 rho-weighted images, was applied to the differentiation of hepatic haemangiomas from metastatic focal liver lesions. 17 haemangiomas and 16 metastases in 32 patients were imaged at the field-strength of 0.1 T using a multiple slice SL technique and a conventional gradient-echo (GRE) sequence with identical timing parametres. Spin lock effects of the hepatic lesions and different abdominal tissues were calculated. Images with adequate coverage of the liver and of good quality with few motion induced artefacts were acquired. A definite, statistically significant, difference was found between the SL-effects of hepatic haemangiomas and a liver metastases. Haemangiomas showed an SL effect of 46.6 +/- 3.4% and metastases of 56.2 +/- 5.8% (mean +/- SD, p < 0.0001). The multiple slice SL technique showed potential in distinguishing haemangiomas from metastatic liver lesions and should be considered as an alternative to the conventional T2 and magnetization transfer (MT) based methods.

Bone changes after experimental osteotomies fixed with absorbable self-reinforced poly-L-lactide screws or metallic screws studied by plain radiographs, quantitative computed tomography and magnetic resonance imaging.

The healing of the distal femoral osteotomy fixed with self-reinforced poly-L-lactide (SR-PLLA) or metallic screws in 16 rabbits was evaluated with plain radiographs, quantitative computed tomography and magnetic resonance imaging (MRI). At 36 weeks in the metallic fixation there was significantly more external callus than in the SR-PLLA fixation. On the metallic fixation side the cortical bone mineral density was significantly lower than on the non-operated side at 6 weeks as well as at 36 weeks. This decrease was not found in the SR-PLLA fixation. On the MRI on T1-weighted images a dark zone (signal void), and on the T2-weighted images a bright zone (increased signal intensity), was seen surrounding the screws, indicating oedema. At 36 weeks these oedematous zones were significantly smaller in the SR-PLLA fixation group than in the metallic one. The results give indirect evidence towards a more rapid and better osteotomy healing with the more physiologically elastic SR-PLLA screws than with the metallic screws. Fixation with SR-PLLA screws may prevent stress-protection atrophy and weakening of the fixed bone usually caused by the rigid metallic fixation.

Efficient memory management strategy in hypermedia with interactive MR images.

When composing hypermedia with interactive image sets the main problem is to allocate minimal memory of random access memory (RAM). The stand-alone product should be accessible to the public and not require too much memory to maintain interaction between the images and the text. We designed a new hypermedia application using SuperCard and image stacks in PICS format running on a Macintosh LC computer. Memory use was effective since the images were kept in external files outside the application. On browsing cards the images were requested from the image file and each image was displayed within about 1 second as a floating frame on top of the card in the top window. Interactivity when presenting, for example, anatomical parts was achieved by bitmap objects which were activated through the image by pointing at them through the image. By pointing at a text object the corresponding anatomical bitmap object was visualised through the image. The stand-alone version of the application with up to 100 cards runs on a 2 Mb RAM set-up. The maximum sizes of the external image stacks are not dependent on the RAM size.

Artifacts in MR imaging caused by small quantities of powdered iron.

The MR image artifacts caused by minute metallic particles were investigated by imaging small powdered iron quantities from 0.01 mg to 1.7 mg in water phantoms. Images with T1-weighted GRE 3-D and T2-weighted SE 2-D sequences were reconstructed with 5 MR imagers: at 0.04 T, 0.1 T (2 scanners), 1.0 T and 1.5 T. In GRE 3-D images the artifacts were round, clearly demarcated black areas, whereas in SE 2-D images artifact areas were elliptic and surrounded by a bright irregular rim with ghost veils in the direction of frequency encoding. The area of the artifact increased slightly up to 0.1 mg of iron, but grew clearly with larger samples. It appeared to behave independently on the MR imager system for all iron samples. This study shows that even microscopic magnetic particles cause a notable distortion in the MR image independently of the MR equipment used.

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)

Detection of focal liver lesions with superparamagnetic iron oxide: value of STIR and SE imaging.

OBJECTIVE: We assessed the value of superparamagnetic iron oxide (SPIO) particles on the detection of focal liver lesions by MRI. MATERIALS AND METHODS: Twenty patients with one to five focal liver lesions, primarily detected with ultrasonography and/or contrast-enhanced CT, were evaluated further with unenhanced and iron oxide-enhanced MRI at 1.0 T. Superparamagnetic iron oxide particles were administered intravenously as a slow infusion. Then T1-, T2-, and proton density-weighted SE images were obtained. In addition, the performance of a short TI inversion recovery (STIR) sequence was evaluated. RESULTS: The iron oxide contrast medium had marked effects on liver signal-to-noise (S/N) and tumor-to-liver contrast-to-noise (C/N) ratios but only minimal effects on tumor S/N ratios in cases of malignant tumor foci. Lesion-to-liver contrast, expressed as differences between the tumor and liver S/N ratios, improved very significantly after SPIO infusion with all four pulse sequences. Contrast enhancement of the liver parenchyma was best in T2-weighted SE images, but the tumor-to-liver C/N values were highest with the postcontrast STIR sequence. The SPIO enhancement revealed a number of additional focal lesions (31%), also foci under 1 cm in diameter. In three benign focal lesions, SPIO infusion produced a definite reduction in the S/N ratio of the lesions in contrast to the minimal change measured in malignant foci. The favorable performance of the STIR sequence contradicts the disappointing results previously obtained at 0.6 T. CONCLUSION: Superparamagnetic iron oxide is a promising new contrast medium for MR examinations of the liver, increasing the conspicuity and reducing the detectability threshold of focal hepatic lesions.

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%.