bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological fluctuation of 99mtc-sestamibi uptake in normal mammary glands: a systematic investigation in female rats
Authors: Larson M. , Larson M. , Li Zhixin , Larson M. , Li Zhixin , Hall C. L. , Jensen E. , McAllister D. M. , Kalyanaraman B. , Zhao Ming 
Published: December 2009

Background: Scintimammography is an imaging tool for the diagnosis and management of primary breast tumors. There remains a significant knowledge gap regarding the physiological fluctuations in the basal level of 99mTc-sestamibi uptake in normal mammary tissues with respect to the female reproductive cycle. Purpose: To systematically characterize 99mTc-sestamibi uptake in normal mammary tissues in female Sprague Dawley (SD) rats in different estrous phases. Material and Methods: The exact phase of the reproductive cycle was determined in 18 female SD rats. Each rat was sacrificed at 20 min after 99mTc-sestamibi injection (14.8 MBq/kg). The mammary glands were dissected, and the radioactivity uptake was measured by gamma counting. Results: Tc-99m-sestamibi uptake oscillates by about twofold and reaches a maximum at the proestrous phase of the rat reproductive cycle. Conclusion: Tc-99m-sestamibi uptake fluctuates significantly in normal mammary tissues in synchrony with the female reproductive cycle, and peaks in the proestrous phase in rats, which is equivalent to the early to mid-follicular phase in the human menstrual cycle. This finding will likely benefit the detection of breast lesions that may otherwise be obscured by fluctuating background signals in surrounding normal breast tissues.
Efficient use of automatic exposure control systems in computed tomography requires correct patient positioning
Authors: Gudjonsdottir J. , Svensson J. R. , Campling S. , Brennan P. C. , Jonsdottir B. 
Published: December 2009

Background: Image quality and radiation dose to the patient are important factors in computed tomography (CT). To provide constant image quality, tube current modulation (TCM) performed by automatic exposure control (AEC) adjusts the tube current to the patient's size and shape. Purpose: To evaluate the effects of patient centering on tube current–time product (mAs) and image noise. Material and Methods: An oval-shaped acrylic phantom was scanned in various off-center positions, at 30-mm intervals within a 500-mm field of view, using three different CT scanners. Acquisition parameters were similar to routine abdomen examinations at each site. The mAs was recorded and noise measured in the images. The correlation of mAs and noise with position was calculated using Pearson correlation. Results: In all three scanners, the mAs delivered by the AEC changed with y-position of the phantom ( P<0.001), with correlation values of 0.98 for scanners A and B and −0.98 for scanner C. With x-position, mAs changes were 4.9% or less. As the phantom moved into the y-positions, compared with the iso-center, the mAs varied by up to +70%, −34%, and +56% in scanners A, B, and C, respectively. For scanners A and B, noise in two regions of interest in the lower part of the phantom decreased with elevation, with correlation factors from −0.95 to −0.86 ( P<0.02). In the x-direction, significant noise relationships ( P<0.005) were only seen in scanner A. Conclusion: This study demonstrates that patient centering markedly affects the efficacy of AEC function and that tube current changes vary between scanners. Tube position when acquiring the scout projection radiograph is decisive for the direction of the mAs change. Off-center patient positions cause errors in tube current modulation that can outweigh the dose reduction gained by AEC use, and image quality is affected.
Pitfalls in interpreting rat knee joint magnetic resonance images and their histological correlation
Authors: Wang Hao-Hao , Wang Yi-Xiang J. , Griffith J. F. , Sun Yan-Lin , Zhang Ge , Chan Chun-Wai , Qin Ling , Ahuja A. T. , Teng Li-Song 
Published: December 2009

Background: Magnetic resonance (MR) imaging has been increasingly used as an investigational tool for assessing the structure and function of animal joint disease models, while to date MR tomographic knowledge of laboratory animal skeletal microanatomy remains limited. Purpose: To describe pitfalls in interpreting rat knee joint MR images and their histological correlation. Material and Methods: MR scans of the right knee of five 3-month-old Sprague-Dawley (SD) rats were carried out using a 4.7T magnet, using a fat-suppressed three-dimensional (3D) gradient echo sequence with a spatial resolution of 59×117×234 µm. Histology assessment with hematoxylin and eosin staining and Safranin O staining was carried out in the five 3-month-old SD rats and two SD rats of 1 month and 6 months old, respectively. MR images were analyzed by a radiologist, and histology data were assessed by a radiologist and a pathologist. Results: Though the MR images were acquired in normal rats, many signs unfamiliar to radiologists were noted, including notch-like bright signal areas in the epiphysis, gray signal areas in the epiphysis, and fuzzy joint surface of the epiphysis of the femur and tibia. Detailed inspection of the histology specimen showed more unfamiliar features of rat knee microanatomy, including curvy or dipped surface of the femur/tibia epiphysis, areas composed of a mixture of cartilage and bone components, normal notch structure, cyst-like structure, and cavity between cortical lamellae under the joint cartilage. Conclusion: There are a number of normal microstructures of the rat knee joint that can be potentially misinterpreted as arthritic changes on MR images. Recognizing these rat knee microstructures can help correct image reading during biomedical research.
Diagnostic value of early-phase-enhanced computed tomography for the differentiation of pulmonary metastases from hepatocellular carcinoma and primary lung cancer
Authors: Choi Joon-Il , Choi Hyuck Jae , Jung Dae Chul , Kim Min-Ju , Hong Eun Kyung , Park Joong-Won , Jang Yun-Jin , Kim Chang-Min 
Published: December 2009

Background: The lung is the most common site of distant metastases from hepatocellular carcinoma. Correct differentiation between metastatic hepatocellular carcinoma of the lung and primary lung cancer is sometimes difficult without biopsy. Purpose: To evaluate the usefulness of measuring the attenuations of pulmonary nodules on early-phase contrast-enhanced computed tomography (CT) for the differentiation of pulmonary metastases from hepatocellular carcinoma and primary lung cancer. Material and Methods: Thirteen patients with pulmonary metastases from hepatocellular carcinoma (nine men, four women; age 53.9±14.2 years, range 16–70 years) and 25 patients with primary lung cancer (14 men, 11 women; age 62.2±9.4 years, range 43–72 years) were retrospectively evaluated. Contrast-enhanced scans were obtained 35 s after commencing intravenous injection of contrast medium. Attenuation values and the size of the pulmonary nodules were measured on contrast-enhanced CT scans. CT and clinical features were analyzed with regard to age, sex, body surface area of the patients, the attenuation values and size of the nodules, and CT machines using univariate analysis (Fisher's exact test for binary data sets and the Mann-Whitney U test for continuous data sets). Multiple linear regression analysis was used to eliminate confounding factors. Results: The mean attenuation value of metastatic pulmonary nodules from hepatocellular carcinoma (75.7±24.9 HU) was higher than that of primary lung cancer nodules (45.8±14.4 HU) ( P<0.01). Other variables such as age, sex, body surface area of the patients, CT device, and nodule size were not significant variables on multiple regression analysis. When a cut-off value of 75 HU was applied, the positive predictive value for diagnosing metastatic nodules from hepatocellular carcinoma was 100%. Conclusion: Pending confirmation in a large study, our findings suggest that there is a difference in contrast enhancement between pulmonary metastases from hepatocellular carcinoma and primary lung cancer.
Progression of emphysema evaluated by MRI using hyperpolarized 3he (hp 3he) measurements in patients with alpha-1-antitrypsin (a1at) deficiency compared with CT and lung function tests
Authors: Stavngaard T. , Søgaard L. Vejby , Batz M. , Schreiber L. M. , Dirksen A. 
Published: December 2009

Background: The progression of emphysema is traditionally measured by pulmonary function test, with forced expiratory volume in 1 s (FEV1) being the most accepted and used measurement. However, FEV1 is insensitive in detecting mild/slow progression of emphysema because of low reproducibility as compared to yearly decline. Purpose: To investigate the progression of emphysema over a period of 2 years using diffusion-weighted hyperpolarized (HP) 3He magnetic resonance imaging (MRI) in patients with alpha-1-antitrypsin (A1AT) deficiency. Material and Methods: Nine patients with severe A1AT deficiency were studied over a period of 2 years (baseline, year 1, and year 2) with HP 3He MRI using apparent diffusion coefficient (ADC), lung function tests (FEV1 and carbon monoxide lung diffusion capacity [DL,CO]), and computed tomography (CT) using densitometric parameters (15th percentile density [CT-PD15] and relative area of emphysema below -910 HU [CT-RA-910]). Results: Seven patients were scanned three times, one patient two times, and one patient only at baseline. The mean increase in ADC values from first to last HP 3He MR scanning was 3.8% (0.014 cm2/s [SD 0.024 cm2/s]; not significant). The time trends for FEV1, DL,CO, CT-PD15, and CT-RA-910 were all statistically significant. We found a high correlation between ADC and DL,CO ( P<0.001). Conclusion: This pilot study indicates the possible use of nonionizing HP 3He MRI for monitoring the progression of emphysema. However, in the future, larger studies are needed to confirm these preliminary results.
T2 relaxation time mapping of proximal tibiofibular cartilage by 3-tesla magnetic resonance imaging
Authors: Kwack Kyu-Sung , Min Byoung-Hyun , Cho Jae Hyun , Kim Jun Man , Yoon Seung-Hyun , Kim Sun Yong 
Published: December 2009

Background: The proximal tibiofibular joint (PTFJ) can be considered the fourth compartment of the knee joint. However, there have been no studies of the T2 values (T2 relaxation time) of PTFJ cartilage. Purpose: To assess the T2 values of PTFJ cartilage at 3T magnetic resonance imaging (MRI), and to show the clinical utility of T2 values of PTFJ cartilage for the diagnosis of osteoarthritis (OA). Material and Methods: 118 patients who had knee MR imaging and knee radiography were enrolled. MRI was performed using a 3T MRI scanner, and T2 maps were calculated from a sagittal multi-echo acquisition. Two regions of interest (ROIs) were positioned within PTFJ cartilage and medial femoral condyle (MFC) cartilage. The average T2 value and standard deviation (SD) of each ROI were recorded. Using PTFJ cartilage as a standard reference, the T2 index (( MFC/ PTFJ)×100) and T2SD index (( MFCSD/ PTFJSD)×100) were calculated. A paired t test was performed to compare the mean and SD of ROIs within PTFJ and MFC cartilage. Correlation analyses were performed among the parameters age, Kellgren–Lawrence (KL) score, means and SDs of ROIs within PTFJ and MFC cartilage, T2 index, and T2SD index. Results: PTFJ cartilage had a significantly shorter T2 value than did MFC cartilage ( P<0.0001). ROIs within PTFJ cartilage showed significantly smaller SDs than did those within MFC cartilage ( P<0.0001). The average T2 value and SD of MFC and the T2SD index showed a positive correlation to the KL score ( P<0.05). The correlation coefficients for the average T2 value, SD, and T2SD index of MFC were R=0.203, 0.254, and 0.268, respectively. However, there was no significant correlation between T2 values of PTFJ cartilage and KL score ( P=0.643). Conclusion: PTFJ cartilage showed shorter and more homogeneous T2 values with a small SD than did MFC cartilage, regardless of the degree of OA at femorotibial compartments. PTFJ cartilage may be a useful internal standard reference to diagnose OA and would be a good candidate as a standard reference for cartilage imaging.
Dobutamine stress cardiovascular magnetic resonance imaging in patients after invasive coronary revascularization with stent placement
Authors: Heilmaier C. , Bruder O. , Meier F. , Jochims M. , Forsting M. , Sabin G. V. , Barkhausen J. , Schlosser T. W. 
Published: December 2009

Background: High-dose dobutamine stress magnetic resonance (DSMR) is a well-established imaging technique for the detection of coronary artery disease (CAD). Purpose: To investigate the value of DSMR for the detection of in-stent restenoses (ISR) in patients with prior coronary stenting, using invasive coronary angiography (ICA) as the standard of reference. Material and Methods: 50 patients with 74 stents and without wall motion abnormalities at rest were examined on a 1.5T MR scanner and underwent ICA for clinical reasons within 14 days after DSMR examination. A dobutamine/atropine stress protocol was employed until age-predicted heart rate was achieved, and imaging was performed in at least three long- and three short-axis views using a segmented steady-state free precession sequence (repetition/echo time [TR/TE] 3/1.5 ms, flip angle 60°). All examinations were read by an experienced cardiologist and radiologist in consensus, with myocardial ischemia being defined as a new stress-induced wall motion abnormality in at least one myocardial segment. Statistical analysis was performed on a per-vessel (left circumflex artery [LCX], left anterior descending artery [LAD], and right coronary artery [RCA]) basis and with regard to the number of affected vessels (one-, two- or three-vessel disease). Results: ICA yielded seven ISR, of which one was missed by DSMR (sensitivity 86%, 95% confidence interval [CI] 0.42–0.99). Sixty-seven coronary arteries showed no ISR in ICA; however, due to new wall motion abnormalities, seven ISR were suspected in DSMR (2×RCA, 3×LCX, and 2×LAD; sensitivity 86%, specificity 90%, positive predictive value 46%, negative predictive value 98%, and diagnostic accuracy 89%). The per-vessel analysis of the three main coronary arteries revealed highest sensitivity (100%), specificity (93%), and diagnostic accuracy (94%) for the LAD. Conclusion: High-dose DSMR is an accurate, noninvasive technique for the detection of ISR and reliably allows identification of patients who need to undergo control ICA.
Role of manual aspiration in treating pneumothorax after computed tomography-guided lung biopsy
Authors: Yamagami T. , Terayama K. , Yoshimatsu R. , Matsumoto T. , Miura H. , Nishimura T. 
Published: December 2009

Background: Pneumothorax is the most common complication after computed tomography (CT)-guided lung biopsy. The presence of a pneumothorax per se does not complicate patient management, but an increasing pneumothorax, making chest tube placement necessary, is highly problematic. Purpose: To evaluate the efficacy and limitations of simple aspiration of air from the pleural space to prevent increased pneumothorax and avoid chest tube placement in cases of pneumothorax following CT-guided lung biopsy. Material and Methods: The subjects of our study were 642 consecutive lung lesions in 594 patients for which percutaneous needle lung biopsies were performed using CT guidance. While patients were on the CT scanner table, percutaneous manual aspiration was performed in all patients with a non-small pneumothorax demonstrated on post-biopsy chest CT images. The frequency of pneumothorax, management of each such case, and factors influencing the incidence of worsening pneumothorax that finally required chest tube placement were evaluated. Results: Post-biopsy pneumothorax occurred in 243 of 642 (38%) procedures. Of the 243 cases, 112 were treated with manual aspiration immediately after biopsy. In 210 (86.4%), the pneumothorax had resolved completely on follow-up chest radiographs without chest tube placement. Only 33 patients required chest tube placement. Requirement of chest tube insertion significantly increased in parallel with the degree of pneumothorax as shown on post-biopsy CT images. The rate of chest tube insertion was statistically higher in subjects with values for aspirated air above 543 ml. Conclusion: Percutaneous manual aspiration of biopsy-induced pneumothorax performed immediately after biopsy may prevent worsening of pneumothorax and avoid chest tube placement. The amount of aspirated air can be predictive of the requirement for chest tube placement.
Lcd versus crt monitors for digital mammography: a comparison of observer performance for the detection of clustered microcalcifications and masses
Authors: Cha Joo Hee , Moon Woo Kyung , Cho Nariya , Lee Eun Hye , Park Jeong Seon , Jang Mi Jung 
Published: December 2009

Background: There are two types of soft-copy display of digital mammograms, cathode-ray tube (CRT) and liquid-crystal display (LCD) monitors, and these present different resolutions and noise characteristics. Purpose: To compare observer performances for the detection of clustered microcalcifications and masses in digital mammograms, using LCD and CRT monitors. Material and Methods: Four radiologists evaluated 100 digital mammograms. Of these, 28 mammograms depicted clustered microcalcifications (12 benign, 16 malignant), 18 depicted masses (10 benign, eight malignant), and 54 depicted no apparent abnormality. The images were stored uncompressed as Digital Imaging and Communications in Medicine (DICOM) files and randomized for two sessions of soft-copy reading. The readers independently read all cases displayed on two 5-megapixel LCD and two CRT monitors with an interval of 3 months. Observers were asked to rate using a five-point scale the likelihoods of microcalcifications and masses independently. Receiver operating characteristic analysis was used to analyze results. Results: For the LCD and CRT monitors, average area-under-the-curve (Az) values for microcalcification detection were 0.977 (0.976, 0.970, 0.980, and 0.983 for the four readers) and 0.958 (0.910, 0.990, 0.976, 0.956), respectively. Corresponding Az values for masses were 0.971 (0.955, 0.990, 0.949, 0.989) and 0.944 (0.928, 0.966, 0.955, 0.925). No statistically significant difference was detected between the two monitor types (P>0.05). Conclusion: The LCD and CRT monitors are comparable in terms of detecting clustered microcalcifications and masses in digital mammograms.
Multidetector-row computed tomographic angiography findings of musculoskeletal tumors: retrospective analysis and correlation with surgical findings
Authors: Argin M. , Isayev H. , Kececi B. , Arkun R. , Sabah D. 
Published: December 2009

Background: Although magnetic resonance imaging (MRI) is a valuable method in staging musculoskeletal tumors, it may not give enough information on the association between the tumor and the main vascular structures adjacent to the tumor. In this respect, computed tomographic angiography (CTA) may be a useful alternative imaging technique. Purpose: To evaluate the effectiveness of CTA in determining vascular invasion in patients with musculoskeletal tumors and suspected vascular invasion by MRI, and to correlate the CTA findings with the surgical findings. Material and Methods: Twenty patients who had musculoskeletal tumors and lacked a fat plane between the tumor and adjacent vessels by MRI were included in this study. All patients were evaluated with CTA, and the CTA findings were reviewed by two radiologists to determine the presence of vascular invasion. Statistical analysis was carried out by using surgical findings as the gold standard. Results: There were nine women and 11 men (mean age 31 years) with either bone ( n=9) or soft-tissue ( n=11) tumors. Twelve patients without invasion according to the CTA examination were also surgically negative (true-negative cases). Of the eight patients with invasion shown by CTA, only three had adhesions and were considered surgically negative (false-positive cases). Five had invasions proven by surgery and were considered surgically positive (true-positive cases). Compared to the surgical findings, CTA had 100% sensitivity, 80% specificity, 62.5% positive predictive value, 100% negative predictive value, and 80% accuracy. Conclusion: CTA is a more accurate imaging technique than MRI in evaluating vascular invasion of musculoskeletal tumors, and provides valuable preoperative data.
Inflammatory response in patients undergoing uterine artery embolization as compared to patients undergoing conventional hysterectomy
Authors: Brøchner A.C. , Mygil B. , Elle B. , Toft P. 
Published: December 2009

Background: Uterine fibroids are benign tumors seen in 20-40% of women of childbearing age, and these fibroids are usually treated by hysterectomy. During the last decade, embolization of the uterine arteries with polyvinyl alcohol microparticles has become an alternative treatment. Purpose: To investigate whether uterine artery embolization generates a reduced inflammatory response as compared with conventional hysterectomy. Material and Methods: 40 women, 20 in each group, entered this prospective, non-randomized study. The two groups were comparable concerning age, comorbidity, and body-mass index (BMI). Results: We found a significant difference between the inflammatory responses in women undergoing embolization compared with the inflammatory response in women having an abdominal hysterectomy. Women undergoing embolization were subjected to a much smaller inflammatory burden, their total morphine consumption was lower, and their return to work was faster than women subjected to conventional hysterectomy. Conclusion: Uterine artery embolization generates a reduced inflammatory response compared with conventional hysterectomy.
Percutaneous preoperative portal vein embolization using a combination of gelatin sponge and histoacryl glue
Authors: Bae Ji Hea , Kim Kab Cheol , Ryeom Hyeun Kue 
Published: December 2009

Background: Inadequate remnant liver volume is a major cause of postoperative liver failure. Preoperative portal vein embolization (PVE) is used clinically to prevent postoperative liver insufficiency. Purpose: To evaluate the efficacy and safety of preoperative portal vein embolization, by using a combination of gelatin sponge and histoacryl to induce hypertrophy of future liver remnant (FLR) in patients with a hepatobiliary malignancy. Material and Methods: PVE using a combination of gelatin sponge and histoacryl glue was performed in 11 patients (nine men, two women; mean age 60 years, range 46–70 years). These patients were diagnosed with a hepatobiliary malignancy before surgery and their FLR volumes were judged as insufficient to allow for safe resection (FLR <25% in patients with a normal liver or FLR <40% in patients with a chronic liver disease). Liver volume changes, levels of biochemical markers, complications related to PVE, and postoperative complications were retrospectively evaluated. Results: PVE was successful in all patients, and there were no procedural complications. The enlargement of nonembolized liver lobe was 30% (mean 118 cm3). A planned hepatectomy was cancelled in four patients due to the presence of a late-detected extrahepatic metastasis. Seven of the 11 patients underwent hepatectomy without complications. Conclusion: Preoperative PVE with a combination of gelatin sponge and histoacryl glue is a safe and effective procedure to induce hypertrophy of nonembolized parts of the liver.