bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of Area at Risk during Coronary Occlusion and Reperfusion by Means of MR Perfusion Imaging
Authors: Szolar Dieter H. , Saeed M. , Wendland M. , Sakuma H. , Stiskal M. A. , Derugin N. , Higgins C. B. 
Published: January 2010

Purpose: Considerable clinical interest has focused on the size of ischemic myocardium. Fast MR imaging in conjunction with MR contrast media has the potential to identify hypoperfused and infarcted myocardium. This study used MR perfusion imaging to detect and quantify reperfused ischemic myocardium during a brief coronary occlusion and reperfusion, and to characterize the spatial extent of ischemic and reperfused ischemic myocardium relative to the “true” size of the area at risk as defined in histochemical morphometry at post mortem. Material and Methods: The left circumflex (LCX) coronary artery in 8 dogs was occluded for 15 min followed by reperfusion in order to produce regional reversible myocardial ischemia. Perivascular Doppler probes were used to measure blood flow in the left anterior descending (LAD) and LCX coronary arteries. Fast inversion recovery-prepared gradient-recalled-echo images were acquired to delineate the ischemic area during occlusion, and the area of reversible ischemic injury at 1 and 30 min of reperfusion. The size of ischemic and reperfused ischemic myocardium were compared with the area at risk as determined by histochemical morphometry at post mortem. Results: During LCX occlusion, LCX flow decreased from 16±1 to 0.2± 0.1 ml/min. On contrast-enhanced images, ischemic myocardium was evident as a zone of relatively low signal intensity (SI) compared to normal myocardium. The size of the ischemic region was significantly smaller (30± 2%) than at post mortem (36± 3%; p<0.05). Immediately after reperfusion, LCX flow increased to 83±11 ml/min and the contrast medium caused greater enhancement in the reperfused ischemic region than in the normal myocardium (69± 3 vs 42± 3 arbitrary units; p<0.05). The increase in regional SI correlated closely with the increase in regional blood flow (r=0.73). At 1 min of reperfusion, the size of the reperfused ischemic myocardium was larger (48± 3%, p<0.05) than the area at risk measured at post mortem. At 30 min of reperfusion, when the flow returned to baseline values (16± 2 ml/min), contrast bolus produced no differential enhancement between the 2 myocardial territories. Conclusion: MR perfusion imaging has the potential to detect and quantify the size of ischemic myocardium and the region of post-occlusive hyperemia in the early reperfusion period. There is a significant direct linear relationship between the regional contrast enhancement of reperfused ischemic myocardium and the blood flow during post-occlusive hyperemia. The difference in the size of the area at risk at MR perfusion imaging and at histochemical morphometry may reflect an influence of coronary collateral circulation.
Diagnostic Accuracy of Mammography and Contrast-Enhanced MR Imaging in 238 Histologically Verified Breast Lesions
Authors: Boné B. , Péntek Z. , Perbeck L. , Veress B. 
Published: January 2010

Purpose: To determine the sensitivity and specificity of X-ray mammography and of MR imaging in 238 consecutively operated breasts, and to correlate the findings to histopathological diagnosis. Material and Methods: Over 15 months, 220 patients scheduled for breast surgery were examined consecutively, before surgery, by means of both mammography and MR imaging. of the 220 patients, 18 underwent bilateral breast surgery. The entire breast was examined by means of T1-weighted transversal images using a 3D fast low-angle shot (FLASH) sequence. One pre— and 2 post-contrast scans were performed. Each breast was examined by means of mammography and 3 views were applied as routine. All palpable and mammographically suspect lesions were examined on additional images as microfocus magnification or spot compression. The two methods were evaluated independently of each other. Results: In total, 145 malignant and 93 benign lesions were found at histopathological examination. The sensitivity of mammography was 89% and MR imaging 92%. The specificity was 72% in both methods. When the results of the 2 methods were combined, a sensitivity of 99% and a specificity of 55% was achieved. Conclusion: Mammography and MR imaging seemed to complement each other to produce a high sensitivity. Unfortunately it is impossible at present to supplement mammography with MR imaging in each patient as a routine owing to the current technical and financial limitations.
Computed Radiography for Characterisation of the Weight-Bearing Knee
Authors: Sanfridsson J. , Svahn G. , Jonsson K. , Ryd L. 
Published: January 2010

Purpose: A new method for examining and measuring the weight-bearing knee in computed radiography (CR) and picture archiving and communication systems (PACS) has recently been developed on examination equipment used in QUESTOR Precision Radiography (QPR). QPR is a method for the standardised examination of the knee, and generates 9 angles (e.g. hip-knee-ankle (HKA) angle) and 10 distances, corrected for parallax and magnification. The aim of this present study was to evaluate the reproducibility of this newly developed method and to determine intra- and interobserver variation in its measurements. Material and Methods: The images were generated on a CR system, archived, and transferred to a multimodality work-station that had a monitor with a resolution of 1280x1024 (1kx1k). Photostimulable phosphor plates were used to generate images with a matrix of 1760x2140 pixels (pixel size 0.2 mm, corresponding resolution 2.5 1p/mm). Ten volunteers without knee problems were examined twice, bilaterally, by 2 different radiology technologists. Results: The total reproducibility of the method was good, offering an HKA reproducibility of ±2.64± in slight flexion and ± 1.62± in extension, at 95% confidence. The intra— and inter-observer variations were low with a reduction of the intra-observer variations in all measurements (except one) by a factor of 2.8 on average compared with the original QPR method for conventional film-screen radiography. Conclusion: When QPR is modified for CR, it fulfils the requirement of reproducibility in measurements of the weight-bearing knee.
Width of the Medial Tibiotalar Joint
Authors: Fiirgaard B. , Iversen J. K. , de Carvalho A. 
Published: January 2010

Purpose: To determine the extent to which the width of the space in the medial tibiotalar joint depends on plantar flexion. Material and Methods: Thirty healthy volunteers were studied by means of a.p. roentgenograms of the left ankle both in a neutral position and in plantar flexion. Results: The medial joint space showed significant widening (average 0.65 mm) between the neutral position and plantar flexion. Conclusion: When ankle joint injuries are studied on radiographs, the position of the foot must be taken into consideration.
Dynamic Scintigraphy of Bone and Bone Marrow in Multiple Myeloma Patients with Bone-Marrow Transplants
Authors: Ågren B. , Rudberg U. , Aspelin P. 
Published: January 2010

Purpose: To determine whether dynamic registration at bone and bone-marrow scintigraphy produces additional information compared to subsequent static registrations of bone-marrow transplants in multiple myeloma patients. Material and Methods: In a prospective study, 8 dynamic bone and 6 dynamic bone-marrow scintigraphies were performed in 10 patients. The dynamic scintigraphies were compared with conventional radiography, MR images, and static scintigraphies of bone and bone marrow. Results: No additional information was revealed by the dynamic registration method; on the contrary, 4 of the 8 known lesions were not discerned at dynamic registration. An incidental observation was that the time-activity curves of both radiopharmaceuticals had a specific pattern. Conclusion: Dynamic registration at bone and bone-marrow scintigraphy was not useful for detecting disease in multiple myeloma lesions.
Dual-Energy X-Ray Absorptiometric Densitometry in Osteoarthritis of the Hip
Authors: Preidler K. W. , White L. S. , Tashkin J. , McDaniel C. O. , Brossmann J. , Andresen R. , Sartoris D. 
Published: January 2010

Purpose: The aim of this study was to evaluate the influence of buttressing on bone densitometry measurements in the femoral neck, in Ward's triangle, and in the greater trochanter. In addition, we attempted to establish the length of the femoral axis (FAL) and the true length of the femoral neck (FNL) as potential correlates with osteoarthritis (OA) or with buttressing. Material and Methods: Our study comprised 101 hips in 68 adult patients. Conventional radiographs of the hip joints were obtained in order to assess the presence and extent of OA by means of the 6-step grading system introduced in 1990 by Croft et al., and in order to measure the cortical thickness at the medial aspect of the femoral neck. In addition, FAL and FNL were measured. All patients underwent dual energy x-ray absorptiometry so that bone density could be assessed in the femoral neck, in Ward's triangle, and in the greater trochanter. The Spearman rank correlation was used to compare the measurements. Results: Statistical analysis showed a significant positive correlation between cortical thickness and bone density in the femoral neck and in Ward's triangle. No correlation was found between cortical thickness and bone density in the greater trochanter, nor between cortical thickness and OA, FNL, and FAL, nor between OA and bone density, FNL, and FAL. Conclusion: Buttressing influenced our bone density measurements in the femoral neck and in Ward's triangle. It did not affect the region of the greater trochanter which may therefore be the best region of interest for a long-term follow-up of bone density in patients with OA.
Blunt Pancreatic Trauma
Authors: Procacci C. , Graziani R. , Bicego E. , Mainardi P. , Bassi C. , Andreis I. A. Bergamo , Valdo M. , Guarise A. , Girelli M. 
Published: January 2010

Purpose: To define the evolution patterns of blunt pancreatic trauma, and to point out the CT features most significant for the diagnosis. Material and Methods: Ten cases of pancreatic trauma, observed over a period of about 10 years, were analyzed in retrospect. The cases were divided into 3 groups according to the time that had elapsed between trauma and first CT: early phase (within 72 h: n=3/10); late phase (after 10 days: n=3/10); and following pancreatic drainage (n=4/10). Results: In the early phase, one case showed a blood collection surrounding the pancreatic head and duodenum, and displacing the mesenteric vessels to the left. In the 2 other cases it was possible to demonstrate a tear in the pancreas at the neck, perpendicular to the main pancreatic axis. In the late phase in all 3 cases, one cystic lesion was present at the site of the tear, either surrounding the gland or embedded - more or less deeply - within the parenchyma. One of the lesions subsided spontaneously; the 2 others required surgery. In the postoperative phase, an external fistula was demonstrated in 2 cases following percutaneous drainage of pancreatic cysts; the fistula was fed by a cystic lesion in the pancreatic neck. In the 2 other cases a pseudocyst developed. Conclusion: Early demonstration of a parenchymal tear was difficult. At a later stage the diagnosis was easier owing to the demonstration of cystic lesions within the parenchyma at the site of the tear. The surgical drainage of this lesion does not usually lead to healing since an external fistula or a pseudocyst may develop.
Transjugular Intrahepatic Portosystemic Shunt (Tips)
Authors: Siegerstetter V. , Krause T. , Rössle M. , Haag K. , Ochs A. , Hauenstein K.-H. , Moser H. E. 
Published: January 2010

Purpose: To compare the thrombogenicity and patency of the Palmaz stent and the Wallstent, and to evaluate the effect of periprocedural heparin therapy in cirrhotic patients with maintained coagulation capacity who receive a transjugular intrahepatic portosystemic shunt (TIPS). Material and Methods: Twenty-four patients were randomized into 4 groups of 6 patients. Each received a Palmaz-stent or Wallstent TIPS with or without periprocedural heparin therapy. The groups receiving periprocedural heparin were given 24 U/ kg b.w. just before stent placement, followed by 24 h therapeutic i.v. heparin. After 24 hours, all patients received i.v. heparin for 1 week followed by subcutaneous treatment with low-molecular-weight heparin (0.3 ml/day) for another 4 weeks. Stent thrombogenicity was determined scintigraphically after i.v. injection of 120-290 mBq of 99mTc-labeled platelets at the time of stent placement and expressed as the stent/heart ratio. Shunt patency was assessed by duplex sonography and confirmed radiologically. Results: The aggregation ratio was highest 90 min after stent implantation. Wall-stents showed a significantly higher ratio than Palmaz stents. Heparin reduced the ratio in patients with a Wallstent (-41%) but had no effect on Palmaz stents. Patients with a Wallstent without heparin had a higher rate of early shunt insufficiency (66.6%) than the other patients (0-16.6%). Primary assisted long-term patency was similar in the 4 groups. Conclusion: Wallstents were more thrombogenic than Palmaz stents and gave a significantly higher risk of early shunt insufficiency in cirrhotic patients with maintained coagulation capacity. Periprocedural heparin was effective in the prevention of shunt insufficiency and is therefore indicated in such patients.
Optimal MR Protocol for Hepatic Hemangiomas
Authors: Kim T. K. , Choi B. I. , Han J. K. , Jang H.-J. , Han M. C. 
Published: January 2010

Purpose: To compare conventional spin-echo (SE) sequences with T2-weighted turbo SE and serial gadolinium-enhanced T1-weighted FLASH sequences in the detection and characterization of hepatic hemangiomas, and to describe the enhancement characteristics of the lesions on dynamic MR imaging. Material and Methods: Forty-two patients with 66 hemangiomas were studied at 1.0 T or 1.5 T by using conventional SE sequences (T1-weighted, T2-weighted, and heavily T2-weighted), T2-weighted turbo SE sequences, and breath-hold T1-weighted FLASH sequences acquired before, immediately after, and 1, 2, 3, 5, and 10 min after injection of a bolus of gadopentetate dimeglumine. Images were quantitatively analyzed for lesion-to-liver contrast-to-noise (C/N) ratios, and qualitatively analyzed for lesion conspicuity. The enhancement pattern and the rapidity of enhancement were analyzed in small (<15 mm), medium (15-39 mm), and large (>39 mm) hemangiomas. Results: In T2-weighted images, T2-weighted turbo SE and heavily T2-weighted SE images had higher C/N ratios than T2-weighted SE images (p=0.003). Lesion conspicuity was not significantly different in these 3 sequences (p=0.307). In T1-weighted images, T1-weighted FLASH images had higher C/N (p<0.001) and also better lesion conspicuity (p<0.001) than T1-weighted SE images. Immediate uniform enhancement was seen in 43% of small hemangiomas (9 of 21 lesions), and persistent central hypo-intensity was seen in 73% of large hemangiomas (11 of 15 lesions). Rapid enhancement was seen in 62% of small hemangiomas (13 of 21 lesions) and in 31% of medium or large hemangiomas (14 of 45 lesions). Conclusion: Further clinical study is needed for evaluating the differential diagnostic advantages of turbo SE T2-weighted imaging compared to the calculation of T2-values by means of a SE T2-weighted sequence. However, the results of the present study suggest that T2-weighted turbo SE imaging and precontrast and serial gadolinium-enhanced FLASH imaging have the potential to replace conventional SE imaging in the evaluation of hepatic hemangiomas.
Defaeco-Peritoneography in the Diagnosis of Rectal Intussusception and Rectal Prolapse
Authors: Bremmer S. , Udén R. , Mellgren A. 
Published: January 2010

Purpose: The aim of the present study was to evaluate the use of defaeco-peritone-ography in diagnosing rectal intussusception as distinct from mucosal folds in the rectum, and rectal prolapse as distinct from mucosal prolapse. Material and Methods: Fifty-seven patients with defaecation disorders were examined by means of defaeco-peritoneography. Results: Twenty-three patients had rectal intussusception and 7 patients had rectal prolapse at defaeco-peritoneography. All these patients had a rectal peritoneocele in the serosal ring-pocket of the rectal intussusception or in the rectal prolapse. Twenty-seven patients had neither rectal intussusception nor rectal prolapse and none of these patients had a rectal peritoneocele. Conclusion: The present study demonstrated that only patients with a rectal intussusception or rectal prolapse have a rectal peritoneocele. Defaeco-peritoneography therefore offers correct diagnosis of rectal intussusception as distinct from mucosal folds in the rectum, and of rectal prolapse as distinct from mucosal prolapse.
MR Evaluation of CSF Fistulae
Authors: Gupta V. , Goyal M. , Mishra N. , Gaikwad S. , Sharma A. 
Published: January 2010

Purpose: To evaluate the role of MR imaging in the localisation of cerebrospinal fluid (CSF) fistulae. Material and Methods: A total of 36 consecutive unselected patients with either clinically proven CSF leakage (n=26) or suspected CSF fistula (n=10) were prospectively evaluated by MR. All MR examinations included fast spin-echo T2-weighted images in the 3 orthogonal planes. Thin-section CT was performed following equivocal or negative MR examination. MR and CT findings were correlated with surgical results in 33 patients. Results: CSF fistula was visualised as a dural-bone defect with hyperintense fluid signal continuous with that in the basal cisterns on T2-weighted images. MR was positive in 26 cases, in 24 of which the fistula was confirmed surgically. In 2 patients the CSF leakage was directly demonstrated on MR. MR sensitivity of 80% compared favourably with the reported 46-81% of CT cisternography (CTC). No significant difference in MR sensitivity in detecting CSF fistula was found between active and inactive leaks Conclusion: MR is recommended as the first investigation for detecting a CSF fistula owing to its efficacy and to its freedom from the potential complications encountered with CTC.
MR Imaging of Experimental Subdural Bleeding
Authors: Orlin J. R. , Thuomas K.-Å. , Pontén U. , Bergström K. , Zwetnow N. N. 
Published: January 2010

Purpose: To evaluate morphological and physiological changes during acute lethal subdural bleeding in 2 models of anaesthetized dogs. Material and Methods: In model I, blood from the aorta was led into a collapsed subdural rubber balloon while in model II, the blood was directed into the subdural compartment over the left cerebral frontoparietal lobe. Eight vital physiological parameters were continuously registered. MR imaging visualized the compression and displacement of cerebral tissue, and assessed the dynamic changes in cerebral tissue water. Results: In model I, tissue herniation and compression of cerebral ventricles led to death at a haematoma volume corresponding to 8% of the intracranial volume. In model II, the extravasated blood progressed infratentorially and into the spinal sac with a volume that was 3 times larger than that of the lethal haematoma. Tissue water increased almost linearly during bleeding in both models. Conclusion: The high level of mortality after acute subdural haematoma is caused by a reduction in intracranial volume tolerance with a critical decrease in cerebral perfusion pressure, resulting in a fatal cerebral ischaemia.
Joint-space width in the axial view of the patello-femoral joint
Authors: Boegård T. , Rudling O. , Petersson I. F. , Sanfridsson J. , Saxne T. , Svensson B. , Jonsson K. 
Published: January 2010

Purpose: to validate a bony landmark on the dorsal aspect of the patella for measurement of the interbone distance in the axial radiogram of the patello-femoral joint (PFJ); to assess the reproducibility of this radiogram and the minimal joint-space (MJS) width measurements in the medial and lateral compartments of the PFJ in this view; and to relate the MJS of the PFJ to MR-detected cartilage defects in the same joint Material and Methods: Fifty-seven individuals with chronic knee pain (aged 41–58 years, mean 50 years) were examined with an axial view of the PFJ in the standing position. the MJS was measured with a mm-graded ruler. on the same day, an MR examination was performed with proton density- and T2-weighted turbo spin-echo sequences on a 1.0 T imager. We noted the cartilage defects in the PFJ in axial and sagittal MR images, and the shape of the sub-chondral cortex of the medial and lateral articular surfaces of the patella in sagittal MR images Results and Conclusion: the bony landmark was found on all articular surfaces. the axial view of the PFJ and the MJS measurements were reproducible. an MJS of < 5 mm showed high specificity for MR-detected cartilage defects. Thus an MJS of 5 mm proved to be a limit in the diagnosis of joint-space narrowing in the PFJ in middle-aged individuals with chronic knee pain
Bone fragility induced by x-ray irradiation in relation to cortical bone-mineral content
Authors: Nyaruba M. M. , Yamamoto I. , Kimura H. , Morita R. 
Published: January 2010

Purpose: A large single dose of irradiation to bone tissue causes bone fragility, and such bone will be susceptible to fracture even without trauma. the purpose of this study was to investigate the effects of fractional irradiation on the biomechanical properties of bone in the rat in relation to the cortical bone-mineral content (BMC), and to compare these effects with those brought about by single-dose irradiation Material and Methods: Seventy-five veteran female Wistar rats were divided into 4 groups. Group 1 was the control group. the left tibiae of the remaining rats were exposed to irradiation. Group 2 received one single dose of X-rays at 10–60 Gy. Groups 3 and 4 received fractional irradiation up to different cumulative doses (10–60 Gy): group 3 received 2.5 Gy once a day; group 4 received 1.25 Gy twice a day. Twenty-four weeks after irradiation, the rats were killed and the BMC in each tibial diaphysis was determined by dual-energy X-ray absorptiometry (DXA). the bones were then loaded to failure in a three-point bending test Results: the control group showed no difference (p<0.05) between left and right tibiae, neither in BMC nor in the maximum load at fracture. Single-dose irradiation caused a 16% ( p = 0.0366) decrease in the maximum load at 40 Gy, and a 19% ( p = 0.008) decrease at 60 Gy. the once-daily fractional dose of irradiation caused a 10% ( p = 0.0022) decrease in the maximum load of the irradiated tibiae at 60 Gy when compared to the intact contralateral tibiae. the twice-daily fractional dose of irradiation had no observable effect on the maximum load of the irradiated tibiae. Neither fractional irradiation modality had an effect on BMC Conclusion: the study suggested that bone fragility induced by single fractional irradiation doses (given once daily up to high cumulative doses) was not associated with change in the cortical BMC. It also confirmed the preference for twice-daily fractional irradiation as compared to once-daily fractional irradiation and the total single dose