bluuebunny/crossref_metadata_2025 huggingface dataset:
Zooplankton community structure within various macrophyte stands of a small water body in relation to seasonal changes in water level
Authors: Kuczyńska-Kippen Natalia , Nagengast Barbara , Celewicz-Gołdyn Sofia , Klimko Małgorzata
Published: October 2009

Zooplankton community structure within various macrophyte stands of a small water body in relation to seasonal changes in water level

Different morphological features of particular water bodies, physical and chemical factors of their waters and sediments will have an impact on the development of specific aquatic vegetation types, which in turn will affect the creation of specific communities of plankton organisms. Therefore the aim of this study was to analyse the quantity and quality changes of macrophyte structure in relation to the lowering of the water level. Furthermore, the relationship between zooplankton community densities and environmental parameters was studied. Another aspect of the study was to investigate the similarity of the zooplankton communities of particular sampling stations in the three examined seasons.

The study was carried out on Dąbrówka water body, a shallow and macrophyte-dominated pond, situated 10 km west of Poznań, Wielkopolska region, western Poland. The examination was conducted in the three seasons: spring, summer and autumn.

The results revealed that during one vegetative period, including three seasons — spring, summer and autumn, three different layouts of aquatic vegetation were obtained, which reflected a significant transformation in the macrophyte cover. Along with the lowering of the water level the structural changes, especially in the case of submerged vegetation were recorded, which in each season was represented by different dominating species.

Only three significant correlations between zooplankton densities and environmental factors observed. Negative relationship concerned total nitrogen and two positive related to biometric parameters of the macrophyte habitat (plant biomass plant stem volume). The plant biomass was a predictor of cladoceran abundance and plant stem volume referred to rotifers, which may reflect the complexity of the aquatic plant habitat, indirectly relating to the effectiveness of the macrophyte stand as anti-predator refuge.

The analysis of the similarity of the zooplankton communities of particular sampling stations in the three examined seasons did not reveal any clear relationship, either in relation to a particular season or a sampling station. The participation of eutrophic species was highest in the spring and lowest during the autumn season. The open water zone possessed the highest participation of these species compared to the macrophyte zones.
Percutaneous Transluminal Renal Artery Angioplasty Using the Coaxial Technique
Authors: Kløw N.-E. , Paulsen D. , Vatne K. , Rokstad B. , Lien B. , Fauchald P.
Published: October 2009

Purpose: To evaluate the angiographic and clinical results of all percutaneous transluminal renal angioplasties (PTRAs) performed at one centre in Norway since the introduction of the method. Most of the PTRAs were performed with the coaxial technique (guiding-catheter-assisted angioplasty).

Material and Methods: In 419 patients, 595 PTRAs of 552 stenoses were performed from 1982 to 1993. the cases included 295 patients with arteriosclerotic vascular disease (AVD), 49 with fibromuscular dysplasia (FMD), and 74 transplantation patients (TX). Angiographic and clinical follow-up were undertaken.

Results: Initial angiographic success was obtained in 92% of the patients and another 3% improved. the rates of immediate success were 92%, 98% and 84% for AVD, FMD and TX respectively. the corresponding rates for primary patency were 57%, 67% and 54%, and for secondary patency (after 1 to 6 angioplasties) 77%, 93% and 64%.

Lower long-term results were obtained for: recanalized vessels; long lesions; bifurcation stenoses; stenoses in patients with abdominal aortic aneurysm; smaller vessels; and segmental branches in native and TX kidneys. of 252 patients with hypertension, 8% were cured and another 58% improved. of 215 patients with reduced renal function, 38% were normalized or improved and 42% unchanged. Major complications including 2 deaths were seen in 2.9% of the procedures and other complications in 4.7%.

Conclusion: PTRA with a guiding catheter can be performed in most patients with a high success rate and a low complication rate. This study points to two major problems with PTRA: the high restenosis rate and the low response to treatment of hypertension. the careful selection of patients for PTRA is important for increasing the success rate, and follow-up to detect restenosis is mandatory.
Ultrasonography in the Differential Diagnosis of Achilles Tendon Injuries and Related Disorders
Authors: Paavola M. , Paakkala T. , Kannus P. , Järvinen M.
Published: October 2009

Purpose: To assess the value of US in the diagnosis of various Achilles tendon disorders.

Material and Methods: Pre-operative US was compared with surgical findings in 79 patients with an Achilles tendon complaint.

Results: US was highly reliable for verifying a complete Achilles tendon rupture: only one false-negative US examination was found in the 26 surgically verified cases. for diagnosing retrocalcanear bursitis, US was accurate: 6 out of the 8 cases of bursitis were found and there were no false-positive cases. There were also no false-positive US findings in patients with peritendinitis/tendinitis, but 7 false-negative US cases among the 40 surgically verified peritendinitis/tendinitis patients indicated that a negative US finding in a clinically suspected case of peritendinitis/tendinitis is unreliable. US also seemed to be inadequate for differentiating partial tendon rupture from a focal tendon degeneration. Nevertheless, the occurrence and location of such a lesion could be adequately determined by US.

Conclusion: US can reliably be used for locating the Achilles tendon abnormality, estimating its severity, and determining most of the conditions requiring surgical intervention. However, US is not completely reliable for diagnosing peritendinitis and tendinitis, and it cannot be used to differentiate partial tendon ruptures from focal degenerative lesions.
Bone Mineral Density in the Lumbar Spine as Determined by Dual-Energy X-Ray Absorptiometry
Authors: Nysom K. , Mølgaard C. , Michaelsen K. Fleischer
Published: October 2009

Purpose: To compare bone mineral in the lumbar spine as measured by either consecutive regional or whole-body dual-energy X-ray absorptiometry (DXA), and to develop models that predict regional results from whole-body results.

Material and Methods: In 180 children and young adults, bone mineral in the lumbar spine was measured by a Hologic QDR-1000/W DXA scanner, using either whole-body software (which can give data for the lumbar spine subregion) or dedicated lumbar spine software. Data on 139 persons were used to compare the two methods and to develop models that predict the result of a regional scan from the result of a whole-body scan. Data on the remaining 41 persons were used to control these models.

Results: Bone mineral content, bone area, and bone mineral areal density (BMDA) of the lumbar spine were measured significantly lower by whole-body scans than by regional scans ( p<0.0001). the difference was larger for the lower values of bone area and BMDA. We developed models that predicted lumbar spine BMDA from whole-body results. When these models were controlled in another group, the mean error between the methods was non-significant and the error was unrelated to the BMDA value. However, the variance of the error was only minimally reduced.

Conclusions: Lumbar spine bone mineral was measured significantly lower by whole-body DXA than by regional DXA. Based on local data, models were developed that removed the significant difference between the methods.
Broadband Ultrasound Attenuation of the Calcaneus
Authors: Tribl B. , Vogelsang H. , Pohanka E. , Grampp S. , Gangl A. , Hörl W. H.
Published: October 2009

Purpose: To evaluate broadband ultrasound attenuation (BUA) for the assessment of bone status and to correlate this to dual-energy X-ray absorptiometry (DXA) in haemodialysis patients.

Material and Methods: In 60 patients, BUA (dB/MHz) was determined for the calcaneus. the results were expressed as Z-scores and T-scores, i.e. units of standard deviations respectively from age- and sex- matched normal values and from sex-matched normal mean values in healthy young adults. Ultrasound data were correlated to relevant clinical, biochemical and DXA data (g/cm2), which were examined at the femoral neck and at the lumbar spine in 50 patients.

Results: the BUA Z-score was <−1 in 53% of the patients and <−2 in 22%. the BUA T-score was <−1 in 88% and <−2 in 62%. Moderate correlation was found for calcaneal BUA to DXA in men (r=0.47−0.48, p<0.01) and to DXA of the lumbar spine in women (r=0.51, p<0.05). the best correlation was observed for BUA to DXA of the femoral neck in women (r=0.61, p<0.01).

Conclusion: Calcaneal BUA is an additional tool for the surveillance of bone density in haemodialysed patients.
Coronary Arteriopathy after Heart Transplantation
Authors: Kløw N.-E. , Levorstad K. , Simonsen S. , Geiran O.
Published: October 2009

Purpose: To describe changes in the coronary artery following heart transplantation (HTx) in patients who survived for 1 year or more.

Material and Methods: Yearly ventriculography and coronary angiography were performed in 171 out of 172 patients aged over 12 years who survived HTx in Norway for 1 year or more after the first operation in 1983. Mean follow-up was 5.2 years ±2.8, range 1–12.

Results: Altogether 31 patients died in the follow-up period, 8 (26%) of them from coronary artery disease (CAD). Angiographic changes included coronary artery stenoses, diffuse changes with ectatic and narrowed segments of the major coronary vessels, peripheral changes with occlusions and tapering of the small vessels, and reduction in the left ventricular ejection fraction (EF). Significant stenosis developed in 43 patients and 19 of these developed an occlusion of one of the major coronary artery branches. the coronary arteries were without significant stenosis in 97% of the surviving 141 patients at 1 year after HTx and in 82% at 5 years. Completely normal findings were seen in 81% after 1 year and in 44% after 5 years. Progression to significant stenosis and occlusion was rapid once changes first appeared.

Conclusion: CAD contributed to a significant number of deaths. the stenoses could develop at any time after transplantation and usually progressed rapidly once the first changes appeared.
Doppler Ultrasound Assessment of Tips Patency and Function — the Need for Echo Enhancers
Authors: Skjoldbye B. , Wieslander S. , Struckmann J. , Court-Payen M. , Schlichting P. , Mygind T. , Burcharth F.
Published: October 2009

Purpose: the aim of this study was to illustrate the versatility of an i.v. administered echo enhancer for Doppler US assessment of TIPS patency and function.

Material and Methods: A total of 22 Doppler US evaluations of TIPS patency and function were performed in 5 patients with alcoholic cirrhosis and recurrent oesophageal bleeding who had been treated with TIPS. TIPS patency was evaluated by means of colour or power Doppler US. the volume flow (VF) was assessed in the TIPS and in the portal vein by spectral Doppler. the ratio of the VF in the TIPS to the VF in the portal vein (T/P ratio) was used to express the functional status of the TIPS. If Doppler signals were inconclusive or absent, echo-enhanced US was performed.

Results: In 22 follow-up Doppler US examinations, echo-enhanced Doppler US was required in 7 cases (29%). the Doppler enhancement persisted in the range of 3–5 min. No adverse effects were observed. An apparently normal TIPS function reflected a T/P ratio in the range of 0.44-1.10, median 0.78 ± 0.20 (2SD).

Conclusion: the i.v. administration of echo enhancers would seem to be indicated in the assessment of the TIPS function if conventional Doppler US fails to prove normal TIPS patency and function. the T/P ratio may be a convenient monitoring parameter for reflecting the TIPS function.
Abdominal Tuberculosis
Authors: Arslan A. , Çiftçi E. , Ceylan N. , Metin K. , Demirci A.
Published: October 2009

Tuberculous involvement of the abdominal parenchymatous organs is usually a diffuse process. the macronodular form of hepatosplenic tuberculosis and focal involvement of the pancreas are extremely rare. This report describes CT findings of abdominal parenchymatous organ involvement in a patient with pulmonary and vertebral tuberculosis.

Although CT does not confirm a diagnosis of abdominal tuberculosis, it is a valuable examination that can support the diagnosis and define the extent of disease.
Paediatric Mesenteric Lipoma, An Unusual Cause of Repeated Abdominal Pain
Authors: Kaniklides C. , Frykberg T. , Lundkvist K.
Published: October 2009

Fatty masses, especially solid lipomas, in the paediatric abdomen are very rare. We present such a case, that of an 11-year-old boy who was admitted with abdominal pain and distension. the pre-operative diagnosis of lipoma was suggested by US and CT. the diagnosis of simple lipoma arising in the leaves of the small bowel mesentery, without immature cells, was verified microscopically after the operation. the tumour was enucleated from the mesenterium leaving the intestine intact.

We underline the importance of US and CT as pre-operative diagnostic tools.
Proton MR Spectroscopy in Infants with Cerebral Energy Deficiency due to Hypoxia and Metabolic Disorders
Authors: Kugel H. , Heindel W. , Roth B. , Ernst S. , Lackner K.
Published: October 2009

Purpose: To investigate the similarities and differences of cellular energy deficiencies due to asphyxia and to impaired oxidative phosphorylation caused by enzyme deficiencies using localized 1H-MR spectroscopy of the brain.

Material and Methods: In 35 neonates and infants with a postconceptional age of 36.4–153 weeks, 1H-MR spectra were obtained from the basal ganglia. of the 35 children, 14 served as a control group, 12 suffered from hypoxicischemic disease (HIE), and 9 had congenital enzymatic disorders.

Results: Eleven of the 12 children with HIE showed low n-acetyl aspartate (NAA) to trimethylamine (TMA) ratios, indicating neuronal damage. Lactate (Lac) to TMA ratios correlated with the HIE grade. Children with congenital disorders of energy metabolism had NAA/TMA ratios ranging from severely decreased to normal, but 7 of the 9 had high Lac signals, even in brains with normal NAA/TMA.

Conclusion: High Lac/TMA even with normal NAA/TMA in children with enzyme deficiencies, in contrast to Lac/TMA that correlates with clinical grade and low NAA/TMA in asphyxic children, hints at different mechanisms of cell damage in the two disease groups.
Optimising Contrast-Enhanced Cranial CT for Detection of Brain Metastases
Authors: Sighvatsson V. , Ericson K. , Tómasson H.
Published: October 2009

Purpose: In order to optimise contrast-enhanced CT in the detection of brain metastases, we investigated how sensitivity was affected by an increase in contrast medium dose and a reduction in slice thickness.

Material and Methods: A total of 198 cases of known primary malignancy with suspected brain metastases were investigated in three consecutive contrast-enhanced CT examinations. the first was a standard CT examination with an injection of 100 ml contrast medium (300 mg I/ml) and a slice thickness of 10 mm. A further 100 ml contrast medium was given and the second examination was performed immediately afterwards with the same slice thickness as the first. This was followed by the third examination, which used a slice thickness of 5 mm. the standard contrast-enhanced CT images were compared with the double-dose images and with the images of reduced slice thickness (5 mm instead of 10 mm).

Results: the double-dose images demonstrated an 8–18% increase in the number of brain metastases detected compared to the standard contrast-enhanced CT; the images of the 5-mm-thick slices showed a further 22–33% increase. the comparison between the standard contrast-enhanced CT images and the images with both thinner slices and the double dose of contrast medium demonstrated a 32–55% increase in the number of metastases detected.

Conclusion: A considerable increase in sensitivity (32–55%) in contrast-enhanced CT can be obtained by reducing the slice thickness and increasing the contrast medium dose. This optimised technique should be the method of choice in patients with known primary malignancy and suspected brain metastases.
Renal Duplex Doppler Ultrasonography as a Predictor of Preclinical Diabetic Nephropathy in Children
Authors: Ökten A. , Dinç H. , Kul M. , Kaya G. , Çan G.
Published: October 2009

Purpose: To perform Doppler US in patients with insulin-dependent diabetes mellitus (IDDM) as a predictive method in diabetic nephropathy (DN).

Material and Methods: Twenty-five patients with type I diabetes mellitus underwent renal Doppler US examination. Children were divided into three age groups: group I, 3–7 years; group II, 8–10 years; and group III, 11–18 years. the age-matched control group consisted of 56 healthy children who underwent renal Doppler US only.

Results: the mean values of the resistive index (RI) were, respectively, 0.64 ± 0.03, 0.59 ± 0.04, 0.59± 0.02 in age groups I, II, and III for healthy children and 0.68 ± 0.03, 0.62 ± 0.04, 0.59 ± 0.04 in age groups I, II, and III of the diabetic patients. There were no significant differences between the diabetic and healthy subjects. the mean RI value was not different in the patients with glomerular hyperfiltration compared to patients with normal filtration rate. Additionally, there were no significant differences between the mean RI value in patients with or without microalbuminuria.

Conclusion: Renal Doppler US is not useful for prediction or for early diagnosis of DN.
Gadolinium-Enhanced MR Imaging of Normal Renal Transplants
Authors: Dupas B. , Bach-Gansmo T. , Blancho G. , Franconi J. M. , Havet T. , Léauté F.
Published: October 2009

Purpose: To evaluate the potential usefulness of dynamic MR with echo-planar imaging (EPI) in assessing the renal function in patients with renal allografts.

Material and Methods: Using a T1-weighted sequence, EPI was performed after injection of a Gd-chelate in 17 patients with normally functioning renal allografts. Time-intensity curves were plotted from the signal intensity (SI) measurements of the cortex and the medulla.

Results: the pattern of corticomedullar differentiation (CMD) observed after contrast enhancement was divided into four phases using the T1-EPI. After a rapid decrease in the SI of cortical structures, and a subsequent return to precontrast levels, a gradual fall in the SI of the medulla was observed. the average time between the two periods of signal loss was 60 s.

Conclusion: This study illustrated the potential use of dynamic T1-EPI to demonstrate contrast-induced CMD in renal allografts.
Radiological Diagnosis of Acute Stroke
Authors: Geijer B. , Brockstedt S. , Lindgren A. , Ståhlberg F. , Norrving B. , Holtås S.
Published: October 2009

Purpose: To compare conventional MR imaging, echo-planar diffusion-weighted imaging (EP-DWI) and spin-echo diffusion-weighted imaging (SE)-DWI at radiological diagnosis of acute stroke.

Material and Methods: Twenty-seven patients (30–85 years old) were examined. Clinical examination was performed before MR imaging. All MR examinations were assessed by an experienced neuroradiologist blinded to clinical findings.

Results: In EP-DWI, every patient had a lesion corresponding to the clinical findings. EP-DWI was used as the gold standard. In conventional PD + T2 imaging, 23/59 focal lesions were interpreted as acute, which was false in 11 lesions, and 36/59 lesions were considered to be old, 6 were in fact acute. Nine acute lesions were only detected retrospectively and 12 acute lesions were not detected at all on PD + T2. SE-DWI including the apparent diffusion coefficient correlated fairly well with EP-DWI but the procedure was impractical.

Conclusion: EP-DWI is reliable for diagnosis of early ischemic stroke, while SE-DWI performs reasonably well. Conventional PD + T2 imaging is not reliable for diagnosis of early ischemia.
Triggering in Quantitative Diffusion Imaging with Single-Shot EPI
Authors: Brockstedt S. , Borg M. , Geijer B. , Wirestam R. , Thomsen C. , Holtås S. , Ståhlberg F.
Published: October 2009

Purpose: the aim of this study was to evaluate any possible effects of brain motion, CSF pulsations and other possible sources of physiological motion in electrocardiographic (ECG) triggered and non-triggered single-shot echo-planar imaging (EPI) measurements of diffusion.

Material and Methods: Three different triggering protocols were evaluated in 6 healthy volunteers: 1) ECG triggering with time delay (TD) 100 ms; 2) ECG triggering with TD 400 ms; and 3) no triggering at all.

Results: the results obtained showed that white matter mean apparent diffusion coefficient (ADC) values were similar for all triggering protocols and that the reproducibility in ADC measurements using diffusion-weighted (DW) EPI was good. the average standard deviation of the ADC values was, however, higher for ADC maps obtained without ECG triggering.

Conclusion: the use of prospective diastolic ECG triggering significantly improves the accuracy of quantitative diffusion measurements but for routine clinical diffusion imaging, where quantitative data is of less importance, the accuracy obtained without ECG triggering can be considered adequate.
Effect of an Internal Carotid Stenosis on Orbital Blood Velocity
Authors: Päivänsalo M. , Riiheläinen K. , Rissanen T. , Suramo I. , Laatikainen L.
Published: October 2009

Purpose: To examine how an internal carotid artery (ICA) stenosis influences the orbital blood velocity and to determine which velocity parameters are most useful.

Material and Methods: the study group comprised 94 randomly selected patients examined with orbital US; most of the patients had a carotid artery stenosis. There were 58 men and 36 women, ranging in age from 22 to 88 years with a mean age of 63.1 years. the ICA stenosis grade was determined with carotid US. Peak systolic (Vp) and end-diastolic blood velocities, systolic acceleration, mean velocity, pulsatile index (PI) and resistance index (RI) were measured within the central retinal artery (CRA) and the ophthalmic artery (OA), and peak velocity was measured within the central retinal vein (CRV). the area under the ROC curve was used to compare the outcome of diagnostic tests.

Results: Only a severe (>80%) ICA stenosis decreased orbital blood velocity significantly, while milder stenoses did not cause significant flow decrease or side differences. According to ROC curve analysis, the threshold values giving the highest accuracy in detecting a >80% ICA stenosis were Vp <0.08 cm/s for the CRA and Vp <0.14 cm/s for the OA. the sensitivities for detecting a >80% ICA stenosis were 45% for Vp CRA and 60% for Vp OA. Systolic acceleration also decreased in severe stenoses, but RI, PI and velocity in the CRV did not correlate with ICA pathology. Reversal of OA flow was seen in 92% of ICA occlusion and in 47% of severe ICA stenosis.

Conclusion: Orbital Doppler combined with carotid Doppler can be helpful in the diagnosis of the ocular ischaemic syndrome and in the evaluation of whether the symptoms are related to occlusion of the ophthalmic or central retinal vessels or are a consequence of carotid artery stenosis.
MR Imaging of Squamous Cell Carcinoma of the Floor of the Mouth
Authors: Murakami Ryuji , Baba Y. , Nishimura R. , Baba T. , Nakaura T. , Ishikawa T. , Takahashi M.
Published: October 2009

Purpose: To determine the diagnostic value of MR imaging for tumors of the floor of the mouth and the effects of the tumors on the sublingual and submandibular glands.

Material and Methods: Thirty-seven patients with proven squamous cell carcinoma of the floor of the mouth underwent MR imaging, including unenhanced T1-weighted, T2-weighted, dynamic, and contrast-enhanced T1-weighted images. the appearance of the tumor and the sublingual and submandibular glands was assessed qualitatively and quantitatively.

Results: All tumors demonstrated replacement of the normal signal intensity in the adjacent sublingual gland. Twenty-one patients (57%) had abnormal signal intensity of the submandibular gland without tumor invasion, presumably secondary to submandibular duct obstruction by the tumor. Unenhanced T1-weighted images provided high contrast between tumor and sublingual gland. Tumors limited within the gland were well detected on unenhanced T1-weighted images. Large tumors extending beyond the gland were well delineated on dynamic images, but no better than on T2-weighted images.

Conclusion: At MR imaging for tumor of the floor of the mouth, one must carefully evaluate the appearance of the sublingual and submandibular glands. Contrast-enhanced studies are unnecessary when the tumor is limited within the sublingual gland on precontrast MR images.
NC100150-Enhanced 3D-SPGR MR Angiography of the Common Carotid Artery in a Pig Vascular Stenosis Model
Authors: Røhl L. , Øtergaard L. , Simonsen C. Z. , Vestergaard-Poulsen P. , Sørensen L. , Bjørnerud A. , Sæbø K. Briley , Gyldensted C.
Published: October 2009

Purpose: NC100150 is a new type of ultra-small iron oxide (USPIO) blood pool agent. the aim of this study was to compare NC100150-enhanced MR angiography (MRA) to time-of-flight (TOF) MRA, phase-contrast (PC) MRA, and digital subtraction angiography (DSA) in experimental stenoses in pigs, and furthermore to determine the optimal dose of the contrast agent.

Material and Methods: An experimental stenosis of the right and left common carotid artery (CCA) was applied surgically in 6 Yorkshire pigs. DSA was performed as the gold standard, followed by 3D-TOE 3D-PC, and NC100150-enhanced MRA.

Results: Eleven stenoses of the CCA were successfully applied. the degree of the stenosis, determined by NC100150-enhanced MRA, did not differ significantly from DSA, whereas TOF and PC MRA underestimated it. the image quality of the NC100150-enhanced MRA was superior to both TOF and PC MRA. the optimal dose of NC100150 was 5–6 mg Fe/kg, since higher doses did not further increase signal-to-noise ratio or contrast-to-noise ratio. There was a linear relationship between blood relaxation rate and contrast dose.

Conclusion: NCl00150-enhanced MRA has the potential for quantification of carotid stenoses and provides an alternative to DSA. the optimal dose of NC100150 was 5–6 mg Fe/kg.
Comparison of Iodixanol 270 with Iohexol 300 in Infrapopliteal Arteriography
Authors: Manninen H. I. , Yang X. M. , Söder H. , Matsi P. J. , Borch K. W. , Eide H.
Published: October 2009

Purpose: To compare iodixanol 270 mg I/ml with iohexol 300 mg I/ml in infrapopliteal arteriography by measuring digital densitometric vessel opacification and by visually assessing angiographic enhancement.

Material and Methods: In a double-blind, dual-balanced, 4-sequence crossover design, 50 claudicant patients received two contrast media injections (10 min interval) in the superficial femoral artery. Digital angiography was performed at 8 frames/s and time-density curves with a circular region of interest over a distal calf artery were generated. A mixed, linear model was used to identify effects influencing the density measurements. Subjective evaluation of the image quality was made independently by two observers.

Results: No statistically significant difference between the contrast media was revealed in the analysis of the densitometric measurements ( p = 0.14) nor in the subjective visual evaluation ( p = 0.74). However, the mean density at the time of maximum opacification was higher after the first injection than that after the second injection ( p = 0.02). There was a tendency towards lower intensity of warmth during injection of iodixanol 270 than during injection of iohexol 300.

Conclusion: In patients with severe occlusive atherosclerotic disease, iodixanol yielded the same image quality as iohexol in infrapopliteal arteriography, in spite of the 30 mg I/ml lower iodine concentration.
Clinical Impact of MR Arthrography of the Shoulder
Authors: Zanetti M. , Jost B. , Lustenberger A. , Hodler J.
Published: October 2009

Purpose: To evaluate the effect of MR arthrography of the shoulder on diagnostic thinking and therapeutic decisions by orthopedic shoulder surgeons.

Material and Methods: Orthopedic surgeons completed a questionnaire before and after MR arthrography for 73 consecutive patients. the main indications were suspected rotator cuff abnormalities. the clinical diagnosis, the degree of confidence in this diagnosis, and the therapeutic decision were noted before and after MR imaging. Surgical reports were available for 34 patients.

Results: Thirty-four percent of the pre-MR imaging diagnoses were withdrawn after MR imaging, and new diagnoses were made after MR imaging in 13% of the case & Confidence in the diagnosis increased significantly after MR imaging for supraspinatus and infraspinatus lesions ( p < 0.05). Changes of therapeutic decision after MR imaging were noted in 36 of the 73 patients (49%). In 23 patients, more invasive therapeutic procedures were initiated after MR imaging, and a more conservative treatment was implemented for 13 patients. Agreement of MR diagnoses with surgery was 94% for supraspinatus tears, 87% for infraspinatus tears, 77% for subscapularis tears, and 81% for biceps tendon lesions. Agreement of clinical diagnoses with surgery was 56%, 83%, 50%, and 64%, respectively.

Conclusion: MR arthrography of the shoulder has a major effect on diagnostic thinking and therapeutic decisions by orthopedic shoulder surgeons.
Sympathotropic Drugs and the Distribution of 99mTc-Hydroxymethylene Diphosphonate
Authors: Cronhjort M. , Jonsson C. , Jacobsson H.
Published: October 2009

Objective: the uptake of bone-seeking radiopharmaceuticals depends on the blood flow, which is influenced by the sympathetic nervous system. Our aim was to study the effect of sympathomimetic drugs on the distribution of bone-seeking agents.

Material and Methods: Various sympathomimetic and β-blocking drugs were injected in mice at different times in relation to the administration of 99mTc-HDP Three hours after this, venous blood and various organs were removed and their activities were related to the administered activity. A kinetic study of the whole-body activity retention after administration of terbutaline was also made.

Results: the biodistribution of 99mTc-HDP was similar after the administration of sympathomimetics and of β-antagonists. All drugs gave rise to an increased soft tissue activity and a decreased bone activity, corresponding to a lowered quality of the potential bone scan. Terbutaline gave rise to an increased excretion of 99mTc-HDP. the mechanisms behind the findings cannot be entirely explained.

Conclusion: Drug interference with the sympathetic nervous system causes undesirable effects on the biodistribution of 99mTc-HDP in the mouse. Studies in humans are necessary to evaluate whether clinical treatment with sympathotropic drugs affects the bone scintigram.
Determination of Tissue Volumes
Authors: Lönn L. , Starck G. , Alpsten M. , Ekholm S. , Sjöström L.
Published: October 2009

Purpose: To evaluate MR imaging for tissue volume measurements.

Material and Methods: Imaging was done with a spoiled gradient echo technique using the human lower leg as a simple model and CT as the reference technique. Areas of adipose tissue, muscle plus skin and bone tissue were evaluated in 5 volunteers using signal intervals (MR) and attenuation intervals (CT) defined by histograms. Volumes were determined from 7 images (MR-7, CT-7), from 70 contiguous images (MR-70), and also from a commercially-available 3D program based on a seeding technique applied according to the operators' judgment (MR-op).

Results: the sum of bone tissue, muscle plus skin and adipose tissue were similar for CT and MR. Compared to CT-7, MR-7 and MR-70 overestimated adipose tissue (0–8%) and muscle plus skin (11–15%), while bone tissue was underestimated (61–78%). Determinations based on the contiguous images or the 7 images were similar (standard error 2–5%). MR-op resulted in pronounced underestimation of muscle plus skin and bone tissue and a minor underestimation of adipose tissue.

Conclusion: Valid determinations of adipose tissue volume are possible with MR but further technical development is required for other tissue volumes. the technique applied according to the operators' judgement, as used for 3D surface rendition, is unreliable for tissue volume determinations.
Hepatic Alveolar Echinococcosis
Authors: Akin O. , Isiklar I.
Published: October 2009

Alveolar echinococcosis is a rare parasitic disease caused by Echinococcus multilocularis and most commonly involves the liver. Early diagnosis and precise evaluation of the localisation and the extent of the lesions are essential for treatment. In this report, we present US and CT findings in a patient with hepatic alveolar echinococcosis.
Diaphragmatic Haemangioma
Authors: Kaniklides C. , Dimopoulos P. A.
Published: October 2009

The case of a 4-year-old patient with a diaphragmatic haemangioma is reported. There were no symptoms and the only clinical finding was prominent subcutaneous vessels on the abdominal wall. the lesion was revealed by imaging and was excised. the findings and the differential diagnosis are discussed.
CT-Guided Fine-Needle Aspiration Biopsy of Spinal Lesions
Authors: Kang M. , Gupta S. , Khandelwal N. , Shankar S. , Gulati M. , Suri S.
Published: October 2009

Purpose: A retrospective study of CT-guided fine-needle aspiration biopsies (FNABs) of spinal lesions performed over a period of 6 years was carried out with the aim of assessing the safety and efficacy of the procedure and to analyse the various approaches used.

Material and Methods: Ninety-three FNABs were performed in 87 patients, 4–70 years of age, under CT guidance. Lytic or mixed vertebral lesions with or without a paraspinal soft tissue component were included in the study. the approach depended on the anatomic region and part of the vertebra involved.

Results: A definite cytological diagnosis was obtained in 77 patients (88.5%); of these, 47 patients had benign lesions and 30 patients had neoplasms. the most common pathologies encountered were tuberculosis (n=33) and metastases (n=17). There were 10 inconclusive FNABs; these showed blood only, necrotic material or scanty material insufficient for diagnosis. There were no procedure-related complications.

Conclusion: CT-guided FNAB is a safe and effective technique for the evaluation of spinal lesions and is helpful in planning therapy. Choosing the appropriate approach results in a low complication rate.
The Additional Value of us to Mammography in the Diagnosis of Breast Cancer
Authors: Skaane P.
Published: October 2009

Purpose: To assess the additional value of ultrasonography (US) to mammography in the diagnosis of malignant breast tumors.

Material and Methods: Prospectively recorded final assessment categories for mammography and US were compared for 327 (228 palpable and 99 nonpalpable) consecutive malignant tumors confirmed at histology. the additional value of US was assessed for a subpopulation of 71 of these 327 malignancies after excluding mammographically conclusive malignant findings, ductal carcinomas in situ (DCIS), and invasive carcinomas presenting with suspicious microcalcifications, since there is no indication for performing US in these patients.

Results: A total of 267 (82%) of the 327 malignant tumors were correctly diagnosed on both imaging modalities. Mammography correctly diagnosed 41 cancers with false-negative US findings as compared with 11 true-positive US diagnoses of malignant tumors with false-negative findings on mammography (McNemar test p<0.001). US correctly diagnosed (“upgraded”) 31 (10%) of the 327 malignant tumors with benign or indeterminate mammographic diagnoses. In the subpopulation, US upgraded 20 (42%) of 48 palpable and 10 (44%) of 23 nonpalpable malignant tumors.

Conclusion: the overall additional value of US to mammography in the diagnosis of breast cancer was rather limited in a population of mixed malignant tumors. Excluding cancers with mammographically conclusive diagnosis and suspicious microcalcifications as well as DCIS from analysis, US correctly upgraded more than 40% of palpable and nonpalpable malignant tumors.
New Classification of Small Pulmonary Nodules by Margin Characteristics on Highresolution CT
Authors: Furuya K. , Murayama S. , Soeda H. , Murakami J. , Ichinose Y. , Yauuchi H. , Katsuda Y. , Koga M. , Masuda K.
Published: October 2009

Purpose: To analyze margin characteristics of pulmonary nodules on highresolution CT (HRCT) in order to improve imaging diagnoses.

Material and Methods: HRCT images of 193 pulmonary nodules of less than 30 mm maximum diameter (113 primary cancers, 15 metastatic cancers, 55 inflammatory nodules, and 10 benign tumors) were reviewed and classified as to 6 types of margins: round, lobulated, densely spiculated, ragged, tentacle or polygonal and halo. the relationships of these imaging types to the diagnoses, the underlying pathological features, mainly those of tumor growth patterns in 93 neoplasms, and the pathological characteristics of 14 inflammatory nodules were investigated.

Results: Eighty-two percent of the lobulated, 97% of the densely spiculated, 93% of the ragged and 100% of the halo nodules were malignant. Eighty percent of the tentacle or polygonal nodules were inflammatory and 66% of the round ones were benign. the 6 types differed statistically as to the nature of the benignity/malignancy ( p<0.001). Pathologically, in case of neoplasms, most of the 6 types had a relationship to a particular tumor growth pattern.

Conclusion: This HRCT classification method is useful for determining the nature of small pulmonary nodules and reflects the underlying pathological characteristics.
Detection of Small Peripheral Lung Cancer by Digital Chest Radiography
Authors: Yang Z.-G. , Sone S. , Li F. , Takashima S. , Maruyama Y. , Hasegawa M. , Hanamura K. , Asakura K.
Published: October 2009

Purpose: To clarify whether processed digital chest radiography can improve the detection rate for small peripheral lung cancer.

Material and Methods: Five radiologists independently interpreted 54 digitized chest radiographs of 18 patients with small peripheral lung cancers measuring less than 20 mm, which were displayed following 3 types of digital processing: 1) an original version; 2) unsharp mask processing with a type 1 filter (very low-frequency-enhancing, mid-frequency-suppressing, and high-frequency-enhancing filter); and 3) unsharp mask processing with a type 2 filter (very low— and high-frequency-enhancing filter). A total of 1,620 pooled observations were evaluated by receiver operating characteristic (ROC) analysis.

Results: the mean area under the ROC curves was 0.68 for the type 1 filter, 0.68 for the type 2 filter, and 0.65 for the unprocessed (original) image. There were no statistically significant differences among these 3 kinds of image processing ( p>0.05). In all types of images, the small lung cancer with an alveolar lining tumor growth was less visible than a solid tumor growth ( p<0.01); the sensitivity increased with tumor size when the 3 groups of cancers, those measuring less than 10 mm, 11–15 mm, and 16–20 mm, were compared ( p<0.01).

Conclusion: Unsharp mask-image processing of digital chest radiography will not improve the detection rate of small peripheral lung cancer, probably due to a substantial drawback: the limited conspicuity of cancer lesions in the surrounding lung and superposition of structures.
Hypoperfusion in the Renal outer Medulla after Injection of Contrast Media in Rats
Authors: Liss P. , Nygren A. , Hansell P.
Published: October 2009

Purpose: the effect on regional renal blood was studied after injection of nonionic iso-osmolar iotrolan or ionic high-osmolar iothalamate.

Material and Methods: Laser-Doppler flowmetry was used to measure outer medullary (OMBF) and superficial cortical blood flow (CBF) simultaneously in anesthetized rats. Iotrolan (320 mOsm/kg H2O) was injected i.v. at a dose of 600 mg I/kg b.w. (normal dose) over 2 min or 1,600 (high dose) mg I/kg b.w. over 2 or 8 min. Iothalamate (2,580 mOsm/kg H2O) was injected i.v. at a dose of 1,600 (high dose) or 2,900 (extremely high dose) mg I/kg b.w. over 2 min.

Results: At the normal dose and 2-min injection of iotrolan, OMBF was reduced by 25±9% over 20 min. the high dose of iotrolan injected over 8 min resulted in a reduction in OMBF slightly smaller (17±9%) than that induced by the normal dose but lasting longer (30 min). Compared to the normal dose, the high dose and fast (2 min) injection of iotrolan resulted in a greater and more prolonged decrease in OMBF (32±6% lasting 50 min). After the high dose of iothalamate (1,600 mg I/kg) there was a decrease in OMBF by 21±6%, lasting 30 min. An extremely high dose (2,900 mg I/kg b.w.) gave a heterogeneous response with a mean increase in OMBF of 48 ±24% occurring 60 min after the injection.

Conclusion: Iso-osmolar and high-osmolar contrast media (CM), at normal and high doses, decrease OMBF, while an extremely high dose of iothalamate may result in an increase. the depression of outer medullary perfusion may have implications for CM-induced acute renal failure in view of the vulnerability of this region to a decrease in oxygen tension.
Long-Term follow-up in Patients with Malignant Biliary Obstruction after Percutaneous Placement of Uncovered Wallstent Endoprostheses
Authors: Kaskarelis I. S. , Papadaki M. G. , Papageorgiou G. N. , Limniati M. D. , Malliaraki N. E. , Piperopoulos P. N.
Published: October 2009

Purpose: Evaluation of the treatment of malignant obstructive jaundice by percutaneous insertion of uncovered stents.

Material and Methods: 51 patients (35 men, 16 women) with inoperable malignant biliary obstruction underwent percutaneous placement of uncovered Wallstent biliary endoprostheses. A total of 65 endoprostheses were inserted.

Results: the technical success rate was 98%, and the procedure-related complications rate was 10%. Early complications rate within the first 30 days was 2%. the clinical success rate within the first 30 days was 98% and the 30-day mortality rate was 2%. the late complications rate was 16%. the overall stent occlusion rate was 18% at a mean of 288.4 days. Mean survival time of the 50 patients was 214 days, and the mean total duration of hospital stay was 9.8 days.

Conclusions: the advantages of uncovered Wallstent endoprostheses justify their placement in patients with inoperable malignant obstructive jaundice since patients' quality of life is markedly improved. Stent insertion is associated with a low complication rate, most stents remain patent longer than the patients' survival time and patients' hospital stay is relatively short.
Impact of CT in Patients with Sepsis of unknown Origin
Authors: Barkhausen J. , Stöblen F. , Dominguez-Fernandez E. , Henseke P. , Müller R.-D.
Published: October 2009

Purpose: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin.

Material and Methods: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated.

Results: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1).

Conclusion: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a septic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery.
Bronchopulmonary Arterial Anastomosis at the Precapillary Level in Human Lung
Authors: Hasegawa I. , Kobayashi K. , Kohda E. , Hiramatsu K.
Published: October 2009

Purpose: To investigate the interrelationships between the bronchial and pulmonary circulations including the existence of precapillary bronchopulmonary arterial anastomoses.

Material and Methods: CT of bronchial arteriography (BAG-CT) was performed in 10 patients and BAG-CT during a pulmonary artery block test (PA-block) in 5 patients with lung cancer. Bronchial and pulmonary circulations were evaluated in 5 autopsied normal lungs by injecting silicone rubber with different colors into the bronchial and pulmonary arteries.

Results: BAG-CT correlated well with the findings at silicone rubber injection into lung autopsy samples. BAG-CT demonstrated inflow of contrast medium into the pulmonary artery during PA-block in all cases, while no inflow was observed before and following reversal of PA-block. Mixed silicone rubber was observed in the lobar to subsubsegmental bronchial arteries in all cases and in the subsubsegmental pulmonary artery in one case.

Conclusion: Precapillary bronchopulmonary arterial anastomoses may exist at the level of the lobar bronchi to the periphery. If either the pulmonary or bronchial circulation is disturbed, flow occurs inside the anastomoses to supplement the other flow, especially flow from the bronchial to the pulmonary arteries via the anastomoses, which occurs within 30 min.
Optimising Imaging Parameters for Post Mortem MR Imaging of the Human Brain
Authors: Blamire A. M. , Rowe J. G. , Styles P. , McDonald B.
Published: October 2009

Purpose: MR imaging of post mortem brains has the potential to yield volumetric information and define the extent of structural changes prior to pathological examination. Although standard T2-weighted clinical imaging sequences have been used for the examination of formalin-fixed brains, these protocols may not yield optimum contrast. We examined the effect of varying durations of formalin fixation on the transverse relaxation time (T2) and the tissue spin density.

Material and Methods: Three post mortem brains were examined weekly during formalin fixation from the unfixed state to 35 days fixation. Standard MR spin-echo imaging was used at 5 echo times (20–100 ms) to calculate transverse relaxation time (T2) and spin density.

Results: T2 decreased significantly (ANOVA, p<0.001) in both grey and white matter by 7 days fixation and there was a further (but non-significant) trend towards lower values between 7 and 35 days. Grey and white matter T2 times converged with fixation. Conversely, the grey to white matter spin density ratio increased from 1.19±0.01 to 1.54±0.06 over five weeks of fixation.

Conclusion: Our results suggest that spin density-weighted imaging sequences would provide improved grey to white matter contrast over T2-weighted sequences.