Familial risk ratios for high and low physical fitness levels in the Canadian population

PURPOSE: To estimate the familial risk of being physically fit or unfit in Canada. METHODS: The sample consisted of 11,680 participants from 4144 nuclear families of the 1981 Canada Fitness Survey. Indicators of physical fitness included estimated physical working capacity at a heart rate of 150 beats x min(-1) derived from a step test (PWC150), hand grip strength, sit-ups, and trunk flexibility. Probands were defined as reference individuals who were physically fit (95th, 85th, and 75th percentiles) or physically unfit (25th, 15th, and 5th percentiles) for each fitness indicator, respectively. RESULTS: Standardized risk ratios, adjusted for age and sex (SRR), for spouses and first-degree relatives of probands exceeding the 95th percentile are 1.63 and 1.81 for PWC150, 2.38 and 3.16 for grip strength, 2.63 and 3.98 for sit-ups, and 2.59 and 3.56 for trunk flexibility, respectively, whereas the SRR for spouses and first-degree relatives of probands below the 5th percentile are 1.54 and 1.34 for PWC150, 1.83 and 1.85 for grip strength, 1.13 and 1.53 for sit-ups, and 1.42 and 1.84 for trunk flexibility, respectively. The familial risks tend to be greatest at the extremes (95th and 5th percentiles) and the risks for first-degree relatives of physically fit probands are generally greater than those for spouses for grip strength, sit-ups and trunk flexibility, whereas those for PWC150 show no clear pattern. CONCLUSION: There is significant familial risk for being physically fit or unfit in the Canadian population. The pattern of SRR suggests that the familial risk for indicators of strength and flexibility may be due, in part, to genetic factors, whereas the shared family environment is largely contributing to the familial risk for PWC150.     

Within-patient variability of (18)F-FDG: standardized uptake values in normal tissues.

The aim of this study was to evaluate the test-retest variability of standardized uptake values (SUVs) in normal tissues and the impact of various methods for measuring the SUV. METHODS: SUVs were determined in 70 cancer-free patients (40 female and 30 male) on 2 occasions an average of 271 d apart. Mean values for body weight and height, blood glucose level, injected dose, and uptake period did not change between the 2 groups of studies. Four regions of interest (ROIs) were placed-on the liver, lung, mediastinum, and trapezius muscle. Mean and maximum SUVs normalized for body weight were obtained, and normalizations were then applied for lean body mass (LBM), LBM and blood glucose level, body surface area (BSA), and BSA and blood glucose level. RESULTS: In the lungs and muscle, metabolic activity within the ROIs was significantly different in the 2 studies, no matter which method was used for the SUVs. The differences ranged from 0.02 to 0.1 for SUV normalized for body weight and SUV normalized for LBM and from 0.001 to 0.002 for SUV normalized for BSA. In the liver, results were similar for all SUVs, except for maximum SUV corrected for LBM and maximum SUV corrected for LBM and blood glucose level. The metabolic activity measured in the mediastinum was also comparable in the 2 studies, regardless of the type of SUV. When investigating whether any normalization method for SUVs reduces variability and improves test-retest concordance, we found no significant superiority for any. The best intraclass correlation coefficients were obtained with the SUV normalized for body weight, in both the liver and the mediastinum, but the coefficients of variation were similar for all 3 mean SUVs that were not corrected for glucose level (range, 10.8%-13.4%). However, normalizing for blood glucose level increased the variability and decreased the level of concordance between studies. CONCLUSION: The SUVs measured in normal liver and mediastinum in cancer-free patients are stable over time, no matter which normalization is used. Correcting for blood glucose level increases the variability of the values and should therefore be avoided. Normalizing for BSA or LBM does not improve the reproducibility of the measurements.     

Low-dose multidetector-row CT angiography of the infra-renal aorta and lower extremity vessels: image quality and diagnostic accuracy in comparison with standard DSA

To investigate the possibility of reducing X-ray exposure during multidetector-row spiral computed tomographic (MDCT) angiography and to compare the image quality and diagnostic accuracy of different dosages with digital subtraction angiography (DSA) in the evaluation of the infra-renal aorta and lower extremities vessels. Seventy-five patients, randomly divided into three groups of 25 patients each, were evaluated for atherosclerotic disease with four-row spiral CT angiography (4×2.5 mm) and DSA. MDCT scanning parameters were kept constant, except for milliamperage (mAs): group A: 50 mAs; group B: 100 mAs; group C: 130 mAs. Images were analysed by two vascular radiologists in consensus. DSA represented the standard of reference. The diagnostic value of MDCT and total radiation exposure were evaluated for each data set. The simulated effective dose was 3.7 mSv for 50 mAs, 8.2 mSv for 100 mAs and 13.7 mSv for 130 mAs for men, and 4 mSv for 50 mAs, 8.9 mSv for 100 mAs and 14.8 mSv for 130 mAs for women. The dose reduction was 74% for group A and 40% for group B. The evaluation of the presence and degree of stenoses revealed a sensitivity, specificity, accuracy, PPV and NPV of 96%, 94%, 95%, 83% and 99% for Group A (50 mAs), 96%, 96%, 96%, 89% and 99% for Group B (100 mAs) and 98%, 96%, 97%, 91% and 100% for the standard dose protocol, Group C (130 mAs). Low-dose scanning is thus a feasible and accurate option for four-row CT angiography of the peripheral vessels. This technique provides substantial reduction of the radiation dose delivered to the patient while maintaining optimal diagnostic accuracy.     

Different approaches to bone densitometry.

From 1990 to 2000, several effective new treatments were introduced for the prevention of osteoporotic fractures; these treatments were proven effective in large, international, clinical trials. At the same time, there was rapid technologic innovation, with the introduction of new radiologic methods for the noninvasive assessment of patients' bone density status. These developments led to the publication of guidelines for the clinical use of bone densitometry that include criteria for the referral of patients for investigation as well as recommendations for intervention thresholds for the initiation of preventive treatment of osteoporosis. Dual-energy x-ray absorptiometry scanning of the spine and hip remains the technique of choice for bone densitometry studies, although there is now a wider appreciation of the need for smaller, cheaper devices for scanning the peripheral skeleton if the millions of women most at risk of a fragility fracture are to be identified and treated. This article reviews these developments, concentrating in particular on the advantages and disadvantages of the different types of equipment available for performing bone densitometry investigations, the guidelines for the referral of patients, and the principles for the interpretation of the scan findings.     

Acute multiple trauma: Analysis of the spectrum of radiologic workup and time requirement

As part of a prospective study of 140 patients who had sustained multiple trauma and were treated in the emergency department, we recorded the times needed for conventional radiography, sonography, and/or computed tomography (CT) for each patient, including the diagnostic-free intervals comprising the times for transporting and moving the patient and for waiting. Conventional radiography (on average, 8.5 radiographic films per patient) was performed in 98.6% of the patients, sonography in 78.6%, and CT in 67.8%. The average duration was 20.3 minutes (range, 1–80 minutes) for conventional radiography, 6.5 minutes (range, 2–15 minutes) for sonography, and 16.9 minutes (range, 12–135 minutes) for CT. The average cumulative total time consumed for diagnostic imaging in the emergency department was 78.4 minutes for all modalities (including CT) and 49.1 minutes for conventional radiography and sonography (excluding CT). The cumulative diagnostic-free time (i.e., time passing without actual performance of the imaging procedure) for all imaging modalities (including CT) was 31.9 minutes and for conventional radiography and sonography (without CT) 19.2 minutes of the total time. The average time for transporting the patient to and from the CT scanner and for positioning the patient for the CT examination was 14.5 minutes. When CT is added to the workup in the emergency department, transportation and waiting considerably prolong the time needed for diagnostic imaging.     

关节镜技术在关节外手术的临床应用

应用关节镜技术镜技术行关节外手术45例，其中关节镜下双侧臂肌挛缩射频汽化松解14例，关节镜监视下腕横韧带松解治疗腕管综合征15例，肱骨大结节骨折关节镜下经皮复位内固定3例，股骨干钢板取出5例，Guo窝囊肿关节镜下射频汽化8例，肱骨大结节骨折关节镜下经皮复位空心钉内固定3例均达解剖复位，骨折愈合，肩关节功能恢复良好，关节镜监视下腕横韧带切开减压治疗腕管综合征，术后15例神经压迫症状解除，感觉运动功能恢复恢复正常，双臀肌挛缩关节镜下射频汽化松解14例，术后髋关节弹响消失，下肢交腿试验阴性，双膝并拢下蹲功能恢复正常，Guo窝囊肿关节镜射频汽化术后无复发，无血管神经损伤和感染等并发症，说明关节镜下手术为微创操作，安全可靠，不仅适用于关节内关节，而且可选择性地用于关节外手术。     

Communicating the results of the BI-RADS categories to patients in senology

Clinical practice guidelines for psychological care and examples of announcing results are proposed for different categories of Breast Imaging Reporting and Data system (BI-RADS) of the American College of Radiology (ACR). Interpretation and recontextualization are explained for lesions category 2, management of paradox and doubt (probably benign and surveillance) for category 3, acceptance and emotions of patients for the category 4 or 5, psychological distress for the category 6. These models of exchange in doctor-patient relationship have to be modulated and adjusted to the women's profile and attitudes. A meaningful communication is necessary for the comprehension of information, for mammography adherence, for patient satisfactions and in the short and long term, it allows an adapted psychological adjustment for breast cancer.     

Validation of the telephone and in-person interview versions of the 7-day PAR

PURPOSE: To validate the 7-d Physical Activity Recall (PAR) telephone interview version and its activity intensity categories. METHODS: Seventy-four adults (47 women, 27 men), ranging in age (18-67) and activity levels, were interviewed by phone and in-person using the same PAR protocol. Each participant wore a TriTrac-R3D accelerometer for 10 d. Validity was assessed by comparing the phone and in-person PAR interviews with the TriTrac-R3D data. RESULTS: Sixty-nine adults (44 women, 25 men) were used for all statistical analyses. Intraclass correlations between the two PAR interviews for total minutes per week of activity were r = 0.96, and r = 0.94 for moderate, r = 0.97 for hard, and r = 0.97 for very hard intensity activities. Pearson product moment correlations between the phone PAR and TriTrac-R3D for total minutes per week of physical activity were r = 0.43, and r = 0.31 for moderate, r = 0.39 for hard, and r = 0.78 for very hard intensity activities. Pearson correlations between the in-person PAR and TriTrac-R3D for total minutes per week of physical activity were r = 0.41, and r = 0.33 for moderate, r = 0.43 for hard, and r = 0.74 for very hard intensity activities. Participants overestimated the amount of physical activity in both interviews as compared with the TriTrac-R3D. CONCLUSION: The phone and in-person versions of the PAR are equivalent measures for self-reported physical activity. Regardless of age, body mass index, or physical activity level both interview methods had similar estimates for total minutes per week of moderate, hard, and very hard activity. Correlations between each interview method and the TriTrac-R3D were lower for moderate and hard activities as compared with very hard activities.     

Radiation therapy for brain metastases from breast cancer by histological classification

One hundred thirteen patients with metastatic brain tumor from breast cancer who were treated with external irradiation between 1989 and 1997 at Cancer Institute Hospital were studied. The patients were all histopathologically proven to have invasive ductal carcinoma (scirrhous type 54 cases, papillotubular type 18, solid-tubular type 41). The patients were evaluated for efficacy and histopathological subtypes. The time interval between the diagnosis of breast cancer and brain metastases was 53.6 months for the scirrhous type, 75.0 months for the papillotubular type, and 35.5 months for the solid-tubular type. The time interval between the diagnosis of initial distant metastases and brain metastases was 14.3 months for the scirrhous type, 22.5 months for the papillotubular type, and 12.5 months for the solid-tubular type. Efficacy rates (CR + PR) for external irradiation of the brain metastases were 40.0% for the scirrhous type, 66.7% for the papillotubular type, and 36.6% for the solid-tubular type. The papillotubular type had a favorable efficacy rate compared with the other two types. Median survival time (MST) from the start of treatment for brain metastases and one-year survival rate were 5 months and 11.1% for the scirrhous type, 7 months and 41.5% for the papillotubular type, and 4 months and 28.3% for the solid-tubular type, respectively. No statistically significant difference between survival rates was observed among the histopathological types. Univariate analysis showed performance status, number of metastatic tumors, and existence of extracranial metastases without bony metastasis to be significantly related to prognosis. Multivariate analysis showed only extracranial metastases without bony metastases to be related to prognosis.     

Efficacy and Safety of Transjugular Intrahepatic Portosystemic Shunt Creation for Budd-Chiari Syndrome: A Systematic Review and Meta-Analysis

PurposeTo assess the critical role of transjugular intrahepatic portosystemic shunt (TIPS) in the management of Budd-Chiari syndrome (BCS), as the data with respect to the safety and outcome of TIPS in patients with BCS are scarce because of the rarity of the disease.Materials and MethodsA comprehensive search of literature of various databases from 2000 to October 2021 was conducted for studies evaluating the outcome of TIPS in patients with BCS. The primary outcomes of the analysis were technical and clinical success, adverse events and mortality associated with TIPS, dysfunction of TIPS, need for TIPS revision, need for liver transplantation (LT), and 1-year survival.ResultsA total of 33 studies (1,395 patients) were included in this meta-analysis. The pooled rates and 95% confidence intervals of various outcomes were 98.6% (97.6–99.7) for technical success, 90.3% (86.0–94.6) for clinical success, 10.0% (6.5–13.6) for major adverse events, 0.5% (0.2–1.0) for TIPS-related mortality, 11.6% (7.8–15.4) for post-TIPS hepatic encephalopathy (HE), 40.1% (32.5–47.7) for TIPS dysfunction, 8.6% (4.9–12.4) for the need for TIPS revision, 4.5% (2.8–6.2) for the need for LT, and 94.6% (93.1–96.1) for 1-year survival. Publication bias was seen with all outcomes except for post-TIPS HE, TIPS dysfunction, and the need for LT.ConclusionsThe existing literature supports the feasibility, safety, and efficacy of TIPS in the treatment of BCS. Deciding the optimal timing of TIPS in BCS needs further studies.     

Prospects of computed tomography in radiation therapy

Computerized tomography has become an essential element in the staging of tumors and in the localization of the tumor and neighboring normal tissues for treatment planning. It offers the potential for more accurate delivery of higher doses with improved therapeutic ratio, for the identification of and correction for tissue inhomogeneities, and for three-dimensional treatment planning. For treatment planning purposes only minor changes are required in the current generation of scanners. Possibilities for the future include dynamic radiation treatment, combined CT scanners, simulators, and treatment planning computers, and a potential for significant cost saving through improvements in the results of cancer therapy.     

Application of European Commission reference dose levels in CT examinations in Crete, Greece

The purpose of this study was to apply European Commission reference dose levels (EC RDLs) to routine CT examinations. The dosimetric quantities proposed in the European Guidelines (EG) for CT are weighted computed tomography dose index (CTDI(w)) for a single slice and dose-length product (DLP) for a complete examination. Patient-related data as well as technical parameters for brain, chest, abdomen and pelvis examinations were collected for four CT scanners in the Euromedica Medical Center. Computed tomography dose index (CTDI) measurements were performed on each scanner and CTDI(w), DLP and effective dose E were estimated for each type of examination for a random sample of 10 typical patients. Mean values of CTDI(w) had a range of 27.0-52.0 mGy for brain and 13.9-26.9 mGy for chest, abdomen and pelvis examinations. Mean values of DLP had a range of 430-758 mGy cm for brain, 348-807 mGy cm for chest, 278-582 mGy cm for abdomen and 306-592 mGy cm for pelvis examinations. Mean values of E were 1.4 mSv for brain, 10.9 mSv for chest, 7.1 mSv for abdomen and 9.3 mSv for pelvis examinations. Results confirm that the Euromedica Medical Center meets EC RDLs for brain, abdomen and pelvis examinations, in terms of radiation dose and examination technique. As far as chest examination is concerned, although CTDI(w) of each scanner is within proposed values, the DLP is consistently exceeded, probably because of the large irradiation volume length L. It is anticipated that a reduction of L, or product mAs, or their combination, will reduce DLP without affecting image quality.     

以腹水待查入院的结核性腹膜炎116例诊断体会

目的分析结核性腹膜炎（tuberculosis peritonitis,TBP）的临床特点和实验室检查．探讨各种诊断方法在TBP诊断中的应用。方法回顾分析116例以腹水待查人院并得到确诊的TBP病例,对其临床特点、实验室检查及诊断方法进行总结分析。结果各项检查的阳性率分别为PPD53．5％（38／71）,TB－Ab15．4％（2／13）。CA12592．4％（61／66）,CEA29．1％（23／79）,CA1991．7％（1／60）,ADA83．3％（20／24）,腹膜活检47．6％（10／21）,腹腔镜80％（4／5）,剖腹探查100％（10／10）。各种诊断方法诊断的例数所占比例分别为诊断性治疗77．6％（90／116）,淋巴结活检1．7％（2／116）,腹膜活检8．6％（10／116）,腹腔镜3．4％（4／116）,剖腹探查8．6％（10／116）。结论诊断性治疗是TBP确诊的主要方法。腹膜活检、腹腔镜及剖腹探查对TBP诊断的阳性率高,在有适应证的前提下应适时、及早进行。     

Gadopentetate dimeglumine-enhanced MR imaging of the musculoskeletal system

Contrast-enhanced MR imaging with gadopentetate dimeglumine has been used in the evaluation of musculoskeletal disorders only in recent years, and for the most part it is still under investigation. Review of the literature identified potential uses for this technique: (1) in the spine, for differentiation between scar tissue and recurrent disk herniation and for evaluation of epidural tumors; (2) in musculoskeletal tumors, for differentiation between tumor necrosis and peritumoral edema and for characterization and evaluation of tumors before and after treatment; (3) in the joints for delineation of cartilage and tendon tears, with intraarticular injection, and for differentiation between pannus and joint effusion, with IV injection; and (4) for delineation of infectious processes. Further studies are needed to confirm most of these potential indications. It is unlikely that gadopentetate dimeglumine-enhanced MR imaging will become a routine part of musculoskeletal MR imaging, and its use will be reserved for specific circumstances.     

Perceptibility curve test for digital radiographs before and after correction for attenuation and correction for attenuation and visual response

OBJECTIVE: Two digital image processing methods, correction for X-ray attenuation and correction for attenuation and visual response, have been developed. The aim of the present study was to compare digital radiographs before and after correction for attenuation and correction for attenuation and visual response by means of a perceptibility curve test. MATERIAL AND METHODS: Radiographs were exposed of an aluminium test object containing holes ranging from 0.03 mm to 0.30 mm with increments of 0.03 mm. Fourteen radiographs were exposed with the Dixi system (Planmeca Oy, Helsinki, Finland) and twelve radiographs were exposed with the F1 iOX system (Fimet Oy, Monninkyl?, Finland) from low to high exposures covering the full exposure ranges of the systems. Radiographs obtained from the Dixi and F1 iOX systems were 12 bit and 8 bit images, respectively. Original radiographs were then processed for correction for attenuation and correction for attenuation and visual response. Thus, two series of radiographs were created. Ten viewers evaluated all the radiographs in the same random order under the same viewing conditions. The object detail having the lowest perceptible contrast was recorded for each observer. Perceptibility curves were plotted according to the mean of observer data. RESULTS: The perceptibility curves for processed radiographs obtained with the F1 iOX system are higher than those for originals in the exposure range up to the peak, where the curves are basically the same. For radiographs exposed with the Dixi system, perceptibility curves for processed radiographs are higher than those for originals for all exposures. Perceptibility curves show that for 8 bit radiographs obtained from the F1 iOX system, the contrast threshold was increased in processed radiographs up to the peak, while for 12 bit radiographs obtained with the Dixi system, the contrast threshold was increased in processed radiographs for all exposures. When comparisons were made between radiographs corrected for attenuation and corrected for attenuation and visual response, basically no differences were found. CONCLUSION: Radiographs processed for correction for attenuation and correction for attenuation and visual response may improve perception, especially for 12 bit originals.     

A comparison of film-screen, CR and DR: a community hospital time-motion study

The purpose of this study was to compare technologist efficiency for conventional radiography, computed radiography (CR) and direct radiography (DR) for two types of general x-ray examinations. The study was performed at St. Joseph's Health Centre, in Toronto, Canada. The study spanned eight calendar months. Two views of the chest and three views of the ankle were chosen as representative examinations for analysis. Patient examination times were recorded on the radiology information system for both types of studies for conventional radiography, CR and DR. There was a significant difference in average time of examination for all three types of imaging formats for chest studies and between conventional radiography and CR or DR for ankle radiographs. There was no significant difference between examination times for ankle studies when CR and DR were compared. The median time of examination of the chest was 18 minutes, eight minutes and six minutes for conventional radiography, CR and DR respectively. The median time of examination for ankle radiographs were 22 minutes, seven minutes and five minutes for conventional radiography, CR and DR respectively. Technologists efficiency is significantly improved with the implementation of a DR system and CR system when compared to conventional radiography. DR may not deliver significant improvements in efficiencies for certain types of examinations.     

肺结核咯血患者非支气管动脉出血的介入治疗

目的:分析34例肺结核咯血患者支气管动脉及非支气管动脉栓塞的临床资料,探讨非支气管动脉栓塞在肺结核咯血患者临床止血中的意义。方法:经皮穿刺行支气管动脉造影,同时对相关的非支气管动脉进行造影,发现病变一并进行栓塞。结果:34例血管造影显示支气管动脉合并肋间动脉出血8例,支气管动脉合并肋间动脉和胸廓内动脉出血10例,支气管动脉合并胸廓内动脉和胸外侧动脉出血6例,支气管动脉合并胸廓内动脉和甲状颈干分支出血7例,支气管动脉合并肋间动脉和肺动脉出血3例。对所有破损的血管逐一进行栓塞。结论:在肺结核咯血的患者行支气管动脉栓塞过程中,应常规对相关的非支气管动脉造影,对提高栓塞在肺结核中量及大量咯血治疗中的效果、减少复发有重要的临床意义。     

Acute pyelonephritis: comparison of diagnosis with 99mTc-DMSA, SPECT, spiral CT, MR imaging, and power Doppler US in an experimental pig model

PURPOSE: To compare the sensitivity and specificity of technetium-99m dimercaptosuccinic acid (DMSA) single photon emission computed tomography (SPECT), spiral computed tomography (CT), magnetic resonance (MR) imaging, and power Doppler ultrasonography (US) for the detection and localization of acute pyelonephritis by using histopathologic findings as the standard of reference. MATERIALS AND METHODS: Bilateral vesicoureteric reflux was surgically created in 35 piglets (70 kidneys). One week later, a liquid bacterial culture of Escherichia coli was injected into the bladder. Three days after induction of urinary infection, imaging studies were performed, and the kidneys were removed for histopathologic examination. SPECT images were obtained 2-3 hours after injection of 99mTc-DMSA. Transverse and coronal MR images were obtained with gadolinium-enhanced fast inversion recovery. Transverse CT images were obtained before and after injection of contrast agent. Power Doppler US was performed in longitudinal, transverse, and coronal planes. Each kidney was divided into three zones for correlation of findings. RESULTS: Histopathologic examination revealed pyelonephritis in 102 zones in 38 kidneys. Sensitivity and specificity for detecting pyelonephritis in the kidneys were 92.1% and 93.8% for SPECT, 89.5% and 87.5% for MR imaging, 86.8% and 87.5% for CT, and 74.3% and 56.7% for US. Sensitivity and specificity for detecting pyelonephritis in the zones were 94.1% and 95.4% for SPECT, 91.2% and 92.6% for MR imaging, 88.2% and 93.5% for CT, and 56.6% and 81.4% for US. The pairwise comparison of these modalities showed no statistically significant difference among them except for US. CONCLUSION: 99mTc-DMSA SPECT, spiral CT, and MR imaging appear to be equally sensitive and reliable for the detection of acute pyelonephritis; power Doppler US is significantly less accurate.     

Differentiation of benign from malignant solid breast masses: conventional US versus spatial compound imaging

PURPOSE: To compare prospectively the diagnostic performance of radiologists who used conventional ultrasonography (US) with that of radiologists who used spatial compound imaging for the differentiation of benign from malignant solid breast masses. MATERIALS AND METHODS: The study was approved by the institutional review board, and informed consent was obtained. Before excisional or needle biopsy was performed, conventional US and spatial compound images were obtained in 67 patients (age range, 25-67 years; mean age, 45 years) with 75 solid breast masses (21 cancers and 54 benign lesions). Three experienced radiologists who did not perform the examinations independently analyzed US findings and indicated the probability of malignancy. Results were evaluated with kappa statistics and receiver operating characteristic (ROC) analysis. RESULTS: For US findings, the presence of calcifications was the most discordant feature (kappa = 0.372) between conventional US and spatial compound imaging, followed by echotexture (kappa = 0.439), boundary echo (kappa = 0.496), orientation (kappa = 0.518), echogenicity (kappa = 0.523), shape (kappa = 0.526), margin (kappa = 0.569), and posterior acoustic transmission (kappa = 0.669). The area under the ROC curve for conventional US was 0.79 for reader 1, 0.88 for reader 2, and 0.82 for reader 3, and the area under the ROC curve for spatial compound imaging was 0.85 for reader 1, 0.88 for reader 2, and 0.89 for reader 3. The partial area index for conventional US was 0.29 for reader 1, 0.69 for reader 2, and 0.39 for reader 3, and the partial area index for spatial compound imaging was 0.29 for reader 1, 0.65 for reader 2, and 0.39 for reader 3. The difference between the diagnostic performances of the two techniques was not significant (P > .05). CONCLUSION: The performance of the radiologists with respect to the characterization of solid breast masses was not significantly improved with spatial compound imaging.     

Correction of partial volume effects in myocardial SPECT

Background  Marked partial volume effects occur in myocardial single photon emission computed tomographic (SPECT) studies because of limited resolution in imaging the myocardial wall and contractile motion of the heart. Little work has been undertaken to develop correction techniques for SPECT except for efforts to improve the reconstructed resolution. Our purpose was to examine the extent of the problem and propose a correction method. Methods and Results  A potential correction method, developed initially for positron emission tomography, involved estimation of extravascular density by means of subtracting vascular density derived in a blood pool study from total density derived from a transmission study. Provided partial volume errors are the same for transmission and emission data, activity per gram of extravascular tissue can be obtained by means of dividing the perfusion regional data by extravascular density for the same region. Simulations were designed to assess the importance of partial volume errors and the use of extravascular density to correct the errors. Recovery coefficients for the myocardium were estimated by means of simulation of the beating heart on the basis of published values for ventricular dimensions. Resolution for transmission with a scanning line source system was compared with emission resolution. The effect of spillover on measured partial volume losses was assessed, and a method for matching spillover for emission and extravascular density was demonstrated. Correction for partial volume effects was demonstrated for a phantom with variable wall thickness. Significant variation in recovery coefficient was demonstrated between posterior and septal walls for individual patients independent of heart size. Filtering was necessary to account for the difference in transmission resolution measured in the axial direction. Spillover effects has a significant influence on the measured recovery for small objects; however, for a specific reconstruction algorithm and defined region size, correction was implemented to match the spillover effects for emission and extravascular density. Use of extravascular density for correction of partial volume loss, for ordered subsets expectation maximization reconstruction with compensation for resolution, was demonstrated to be accurate to within 10%. Conclusions  The feasibility of correcting partial volume effects with extravascular density was demonstrated. Correction is effective provided care is taken to match both resolution and spillover for emission and extravascular density. Supported in part by a grant from the National Health and Medical Research Council of Australia (NHMRC grant no 920036).