Showing papers in "Radiology in 2002"
TL;DR: Mammographic sensitivity for breast cancer declines significantly with increasing breast density and is independently higher in older women with dense breasts, which significantly increases detection of small cancers and depicts significantly more cancers and at smaller size and lower stage than does PE, which detects independently extremely few cancers.
Abstract: PURPOSE: To (a) determine the performance of screening mammography, ultrasonography (US), and physical examination (PE); (b) analyze the influence of age, hormonal status, and breast density; (c) compare the size and stage of tumors detected with each modality; and (d) determine which modality or combination of modalities optimize cancer detection. MATERIALS AND METHODS: A total of 11,130 asymptomatic women underwent 27,825 screening sessions, (mammography and subsequent PE). Women with dense breasts subsequently underwent screening US. Abnormalities were deemed positive if biopsy findings revealed malignancy and negative if findings from biopsy or all screening examinations were negative. RESULTS: In 221 women, 246 cancers were found. Sensitivity, specificity, negative and positive predictive values, and accuracy of mammography were 77.6%, 98.8%, 99.8%, 35.8%, and 98.6%, respectively; those of PE, 27.6%, 99.4%, 99.4%, 28.9%, and 98.8%, respectively; and those of US, 75.3%, 96.8%, 99.7%, 20.5%, and 96.6%,...
1,591 citations
TL;DR: In patients with unresectable HCC, chemoembolization significantly improved the overall 2-year survival compared with nonactive treatment, but the magnitude of the benefit is relatively small.
Abstract: PURPOSE: To review the available evidence of chemoembolization for unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Computerized bibliographic searches with MEDLINE and CANCERLIT databases from 1980 through 2000 were supplemented with manual searches, with the keywords “hepatocellular carcinoma,” “liver cell carcinoma,” “randomized controlled trial [RCT],” and “chemoembolization.” Studies were included if patients with unresectable HCC were enrolled and if they were RCTs in which chemoembolization was compared with nonactive treatment (five RCTs) or if different transarterial modalities of therapy (13 RCTs) were compared. Data were extracted from each RCT according to the intention-to-treat method. Five of the RCTs with a nonactive treatment arm were combined by using the random-effects model, whereas all 18 RCTs were pooled from meta–regression analysis. RESULTS: Chemoembolization significantly reduced the overall 2-year mortality rate (odds ratio, 0.54; 95% CI: 0.33, 0.89; P = .015) c...
772 citations
TL;DR: Treatment of patients with acute pancreatitis is based on the initial assessment of disease severity and individual laboratory indexes (markers of pancreatic injury, markers of inflammatory response), while promising, have not yet gained clinical acceptance.
Abstract: Treatment of patients with acute pancreatitis is based on the initial assessment of disease severity. Severe pancreatitis occurs in 20%-30% of all patients with acute pancreatitis and is characterized by a protracted clinical course, multiorgan failure, and pancreatic necrosis. Early staging is based on the presence and degree of systemic failure (cardiovascular, pulmonary, renal) and on the presence and extent of pancreatic necrosis. Individual laboratory indexes (markers of pancreatic injury, markers of inflammatory response), while promising, have not yet gained clinical acceptance. Numeric grading systems with sensitivities of about 70% are commonly used today as indicators of organ failure and disease severity. Contrast material-enhanced computed tomography is used in addition to help evaluate local pancreatic morphology and the presence and extent of pancreatic necrosis. Advantages and limitations of the clinical, laboratory, and imaging prognostic indexes are analyzed and discussed.
732 citations
TL;DR: Measurements of water diffusivity and cellularity suggest that higher cellularity contributes to more restricted diffusion within lymphomas and high-grade astrocytomas.
Abstract: PURPOSE: To determine if water diffusivity within lymphomas and high-grade astrocytomas correlates with cellularity. MATERIALS AND METHODS: Echo-planar diffusion-weighted magnetic resonance (MR) images obtained in 11 patients with brain lymphomas (19 lesions) and in 17 patients with astrocytomas (19 lesions) were retrospectively reviewed. Regions of interest were drawn on apparent diffusion coefficient (ADC) maps in enhancing tumor. ADC values were normalized by dividing ADC values of tumors by those of normal-appearing regions and expressing the quotient as a ratio. Histologic samples from 11 patients with astrocytomas (11 lesions) and seven patients with lymphoma (seven lesions) were reviewed. Cellularity was measured by calculating the percentage of nuclear area and the percentage of cytoplasmic area and expressing the results as the nuclear-to-cytoplasmic (N/C) ratio. The ADC and N/C ratios of both tumor types were compared by using a two-tailed t test. RESULTS: Mean ADC ratio of lymphomas was 1.15 (S...
657 citations
TL;DR: At equivalent specificity, FDG PET is the most sensitive noninvasive imaging modality for the diagnosis of hepatic metastases from colorectal, gastric, and esophageal cancers.
Abstract: PURPOSE: To perform a meta-analysis to compare current noninvasive imaging methods (ultrasonography [US], computed tomography [CT], magnetic resonance [MR] imaging, and 18F fluorodeoxyglucose [FDG] positron emission tomography [PET]) in the detection of hepatic metastases from colorectal, gastric, and esophageal cancers. MATERIALS AND METHODS: A MEDLINE literature search and review of article bibliographies and our institutional charts of patients with colorectal cancer identified data with histopathologic correlation or at least 6 months of patient follow-up. Two authors independently abstracted data sets and excluded data without contingency tables or data published more than once. Summary-weighted estimates of sensitivity were obtained and stratified according to specificity of less than 85% or 85% and higher. A covariate analysis was used to evaluate the influence of patient- or study-related factors on sensitivity. RESULTS: Among 111 data sets, nine US (509 patients), 25 CT (1,747 patients), 11 MR im...
593 citations
TL;DR: With a combination of unenhanced and delayed enhanced CT, nearly all adrenal masses can be correctly categorized as adenomas or non-adenomas.
Abstract: PURPOSE: To assess the accuracy of a dedicated adrenal computed tomographic (CT) protocol MATERIALS AND METHODS: One hundred sixty-six adrenal masses were evaluated with a protocol consisting of unenhanced CT, and, for those with attenuation values greater than 10 HU, contrast material–enhanced and delayed enhanced CT Attenuation values and enhancement washout calculations were obtained An adenoma was diagnosed if a mass had an attenuation value of 10 HU or less at unenhanced CT or a percentage enhancement washout value of 60% or higher RESULTS: The final diagnosis was adenoma in 127 masses and nonadenoma in 39 Masses measuring more than 10 HU on unenhanced CT scans were confirmed at biopsy (n = 28) or were examined for stability or change in size at follow-up CT performed at a minimum interval of 6 months (n = 33) Thirty-six (92%) of 39 nonadenomas and 124 (98%) of 127 adenomas were correctly characterized The sensitivity and specificity of this protocol were 98% and 92%, respectively This protoc
592 citations
TL;DR: Although conventional MR imaging characteristics of solitary metastases and primary high-grade gliomas may sometimes be similar, perfusion-weighted and spectroscopic MR imaging enable distinction between the two.
Abstract: PURPOSE: To determine whether perfusion-weighted and proton spectroscopic MR imaging can be used to differentiate high-grade primary gliomas and solitary metastases on the basis of differences in vascularity and metabolite levels in the peritumoral region. MATERIALS AND METHODS: Fifty-one patients with a solitary brain tumor (33 gliomas, 18 metastases) underwent conventional, contrast material–enhanced perfusion-weighted, and proton spectroscopic MR imaging before surgical resection or stereotactic biopsy. Of the 33 patients with gliomas, 22 underwent perfusion-weighted MR imaging; nine, spectroscopic MR imaging; and two underwent both. Of the 18 patients with metastases, 12 underwent perfusion-weighted MR imaging, and six, spectroscopic MR imaging. The peritumoral region was defined as the area in the white matter immediately adjacent to the enhancing (hyperintense on T2-weighted images, but not enhancing on postcontrast T1-weighted images) portion of the tumor. Relative cerebral blood volumes in these r...
527 citations
TL;DR: RF ablation and PMC thus far have had equivalent therapeutic effects, complication rates, and rates of residual foci of untreated disease, however, RF tumor ablation can be achieved with fewer sessions.
Abstract: PURPOSE: To evaluate the effectiveness of radio-frequency (RF) ablation and percutaneous microwave coagulation (PMC) for treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Seventy-two patients with 94 HCC nodules were randomly assigned to RF ablation and PMC groups. Thirty-six patients with 48 nodules were treated with RF ablation, and 36 patients with 46 nodules were treated with PMC. Therapeutic effect, residual foci of untreated disease, and complications of RF ablation and PMC were prospectively evaluated with statistical analyses. RESULTS: The number of treatment sessions per nodule was significantly lower in the RF ablation group than in the PMC group (1.1 vs 2.4; P < .001). Complete therapeutic effect was achieved in 46 (96%) of 48 nodules treated with RF ablation and in 41 (89%) of 46 nodules treated with PMC (P = .26). Major complications occurred in one patient treated with RF ablation and in four patients treated with PMC (P = .36). During follow-up (range, 6–27 months), residu...
526 citations
TL;DR: Lung cancer screening with low-dose CT demonstrated a prevalence of asymptomatic cancers in 1.3% of a smoking population, including a high proportion of early tumor stages and a 20% rate of invasive procedures for benign lesions.
Abstract: PURPOSE: To present prevalence screening data from a nonrandomized screening trial by using low-dose computed tomography (CT) and a simple algorithm based on the size and attenuation of detected nodules to guide diagnostic work-up. MATERIALS AND METHODS: Eight hundred seventeen asymptomatic volunteers (age range, 40-78 years; median age, 53 years; median tobacco consumption, 45 pack-years) underwent spiral low-dose CT of the chest without contrast material enhancement. We regarded all noncalcified pulmonary nodules greater than 10 mm in diameter as potentially malignant and recommended histologic examination or follow-up after 3, 6, 12, and 24 months to exclude growth. For noncalcified pulmonary nodules of 10 mm or smaller, repeat low-dose CT was recommended to exclude growth. RESULTS: In 43% (350 of 817) of individuals, 858 noncalcified pulmonary nodules were found. Thirty-two nodules in 29 subjects were larger than 10 mm. Biopsy of 15 lesions revealed lung cancer in 12 lesions in 11 subjects (prevalence for all ages, 1.3% [11 of 817 subjects]; >50 years of age, 2.1% [11 of 519 subjects]; >60 years of age, 3.9% [eight of 206 subjects]), with a high proportion of early tumor stages (seven tumors, stage I; two, stage II; and three, stage III); three lesions were benign. In 17 nodules larger than 10 mm, follow-up with low-dose CT for a minimum of 24 months did not demonstrate growth. CONCLUSION: Lung cancer screening with low-dose CT demonstrated a prevalence of asymptomatic cancers in 1.3% of a smoking population, including a high proportion of early tumor stages and a 20% (three of 15) rate of invasive procedures for benign lesions.
518 citations
TL;DR: The clinical applications of cerebral blood volume maps obtained with perfusion MR imaging in the differential diagnosis of intracranial mass lesions, as well as the pitfalls and limitations of the technique are discussed.
Abstract: Dynamic contrast agent-enhanced perfusion magnetic resonance (MR) imaging provides physiologic information that complements the anatomic information available with conventional MR imaging. Analysis of dynamic data from perfusion MR imaging, based on tracer kinetic theory, yields quantitative estimates of cerebral blood volume that reflect the underlying microvasculature and angiogenesis. Perfusion MR imaging is a fast and robust imaging technique that is increasingly used as a research tool to help evaluate and understand intracranial disease processes and as a clinical tool to help diagnose, manage, and understand intracranial mass lesions. With the increasing number of applications of perfusion MR imaging, it is important to understand the principles underlying the technique. In this review, the essential underlying physics and methods of dynamic contrast-enhanced susceptibility-weighted echo-planar perfusion MR imaging are described. The clinical applications of cerebral blood volume maps obtained with perfusion MR imaging in the differential diagnosis of intracranial mass lesions, as well as the pitfalls and limitations of the technique, are discussed. Emphasis is on the clinical role of perfusion MR imaging in providing insight into the underlying pathophysiology of cerebral microcirculation.
498 citations
TL;DR: US measurements of AVF at 2-4 months in patients undergoing hemodialysis are highly predictive of fistula maturation and adequacy for dialysis.
Abstract: PURPOSE: To compare various objective ultrasonographic (US) criteria for native arteriovenous fistula (AVF) maturation with subsequent fistula outcomes and clinical evaluation by experienced dialysis nurses. MATERIALS AND METHODS: US fistula evaluation results were analyzed retrospectively in 69 patients within 4 months after AVF placement; adequacy for dialysis was known in 54. Measurements included minimum venous diameter and blood flow rate. Experienced dialysis nurses examined 30 fistulas clinically. Predictors of fistula adequacy were analyzed with univariate and multivariate logistic regression. Mean fistula diameters and blood flow rates were compared by using analysis of variance or unpaired Student t tests. RESULTS: Fistula adequacy for dialysis doubled if the minimum venous diameter was 0.4 cm or greater (89% [24 of 27]) versus less than 0.4 cm (44% [12 of 27]; P < .001). Fistula adequacy for dialysis was nearly doubled if flow volume was 500 mL/min or greater (84% [26 of 31]) versus less than 5...
TL;DR: Diffusion-tensor MR imaging results indicate that white matter maturation assessed at different ages involves increases in both white matter density and organization during childhood and adolescence.
Abstract: PURPOSE: To evaluate differences in white matter diffusion properties as a function of age in healthy children and adolescents. MATERIALS AND METHODS: Echo-planar diffusion-tensor magnetic resonance (MR) imaging was performed in 33 healthy subjects aged 5–18 years who were recruited from a functional imaging study of normal language development. Results of neurologic, psychologic, and structural MR imaging examinations were within the normal range for all subjects. The trace of the apparent diffusion coefficient and fractional anisotropy in white matter were correlated as a function of age by using Spearman rank correlation. RESULTS: Statistically significant negative correlation of the trace of the apparent diffusion coefficient with age was found throughout the white matter. Significant positive correlation of fractional anisotropy with age was found in the internal capsule, corticospinal tract, left arcuate fasciculus, and right inferior longitudinal fasciculus. CONCLUSION: Diffusion-tensor MR imaging ...
TL;DR: A significant number of lipomas will have prominent non-adipose areas and will demonstrate an imaging appearance traditionally ascribed to well-differentiated liposarcoma, including thin septa and regions of increased signal intensity on fluid-sensitive MR images.
Abstract: PURPOSE: To review the reliability of computed tomographic (CT) and magnetic resonance (MR) imaging features in distinguishing lipoma and well-differentiated liposarcoma. MATERIALS AND METHODS: CT (n= 29) and MR (n = 40) images and radiographs (n = 28) of 60 patients with histologically verified fatty tumors (35 lipomas and 25 well-differentiated liposarcomas) were retrospectively reviewed in 31 females and 29 males (mean age, 56 years; age range, 1-88 years). Images were assessed for adipose tissue content, and nonfatty component was classified (thin and/or thick septa and nodular and/or globular components) as absent, mild, moderate, or pronounced. Also assessed were signal intensity and tissue attenuation of the fatty components and nonadipose elements. RESULTS: Statistically significant imaging features favoring a diagnosis of liposarcoma included lesion larger than 10 cm (P < .001), presence of thick septa (P = .001), presence of globular and/or nodular nonadipose areas (P = .003) or masses (P = .001...
TL;DR: The prevalence of pancreatic cysts at single-shot fast spin-echo (SE) magnetic resonance (MR) imaging-especially cysts with a diameter smaller than 10 mm-is similar to that of pancreas at autopsy and higher than that of Pancreas with malignant pancreatic tumors at transabdominal ultrasonography.
Abstract: PURPOSE: To evaluate single-shot fast spin-echo (SE) magnetic resonance (MR) imaging for depiction of pancreatic cysts in a large number of patients and to analyze cyst prevalence with respect to patient age and sex and other clinical information. MATERIALS AND METHODS: Single-shot fast SE images of the pancreas were obtained in 1,444 patients. The images were reviewed for presence of pancreatic cysts, which were classified as simple and nonsimple types, and cyst diameters were measured. κ statistic, Fisher exact, McNemar Q, and Pearson product moment correlation tests were performed. RESULTS: Two hundred eighty-three (19.6%) patients had at least one pancreatic cyst. The prevalence of pancreatic cysts increased with age (r = 0.96). The percentages of male and female patients with pancreatic cysts (20.4% vs 18.8%) were not significantly different. Two hundred seventy-one (18.8%) patients had simple cysts, and 147 (10.2%) had nonsimple cysts. Of 283 patients with pancreatic cysts, 158 (55.8%) had only one ...
TL;DR: Comparing different reconstruction thicknesses of thin-collimation multi-detector row spiral computed tomographic (CT) data sets of the chest for the detection of subsegmental pulmonary emboli results in substantially higher detection rates and greater agreement between different readers than the use of thicker sections.
Abstract: PURPOSE: To compare different reconstruction thicknesses of thin-collimation multi-detector row spiral computed tomographic (CT) data sets of the chest for the detection of subsegmental pulmonary emboli. MATERIALS AND METHODS: A multi-detector row spiral CT protocol for the diagnosis of pulmonary embolism was used that consisted of scanning the entire chest with 1-mm collimation within one breath hold. In 17 patients with central pulmonary embolism, the raw data were used to perform reconstructions with 1-mm, 2-mm, and 3-mm section thicknesses. For each set of images, each subsegmental artery was independently graded by three radiologists as open, containing emboli, or indeterminate. RESULTS: For the rate of detection of emboli in subsegmental pulmonary arteries, use of the 1-mm section width yielded an average increase of 40% when compared with the use of 3-mm-thick sections (P < .001) and of 14% when compared with the use of 2-mm-thick sections (P = .001). With the use of 1-mm sections versus 3-mm secti...
TL;DR: Aneurysm formation appears to be related to tumor size, and large aneurysms confer a higher probability of rupture, and multiple regression analysis indicated that aneurYSm size was the most important factor linked to rupture.
Abstract: PURPOSE: To evaluate the relationships between tumor size, aneurysm formation, and spontaneous rupture in renal angiomyolipomas. MATERIALS AND METHODS: Twenty-three patients with renal angiomyolipoma were examined with angiography and computed tomography (CT). The single largest lesion in each kidney was evaluated. Tumor size was measured at CT, and aneurysm size was measured at renal angiography. Tumor and aneurysm sizes were compared between the group with ruptured angiomyolipoma and the group with unruptured angiomyolipoma. Multiple regression analysis was performed to identify factors affecting rupture. RESULTS: Twenty-nine kidneys with angiomyolipoma were identified. Eight angiomyolipomas were hemorrhagic; the remaining 21 were not hemorrhagic. Tumor size was larger than 4 cm and aneurysm size was 5 mm or larger in all hemorrhagic lesions. There were significant differences in mean tumor size (11.4 cm ± 5.5 [SD] vs 5.0 cm ± 3.1, P < .02) and mean aneurysm size (13.3 mm ± 6.2 vs 2.4 mm ± 2.9, P < .02)...
TL;DR: Injury to the medial retinaculum, MPFL, and VMO may be identified at MR imaging after acute LPD, and concave impaction deformity of the inferomedial patella is a specific sign of prior LPD.
Abstract: PURPOSE: To assess magnetic resonance (MR) imaging findings after acute lateral patellar dislocation (LPD) with emphasis on the medial patella restraints and to describe a medial patellar impaction deformity. MATERIALS AND METHODS: Knee MR images obtained within 8 weeks after LPD were evaluated for medial retinacular and medial patellofemoral ligament (MPFL) disruption, vastus medialis obliquus (VMO) edema and/or elevation, and other derangements. One hundred patients with no evidence of prior LPD were evaluated as controls. The Student t test was used for statistical comparisons. RESULTS: Eighty-two examinations were performed in 81 patients with LPD (mean age, 20 years; age range, 9–57 years). Seventy-six percent (62 of 82 examinations) showed medial retinacular disruption at its patellar insertion; 30% (25 of 82), at its midsubstance. The MPFL femoral origin was identified in 87% (71 of 82); of these, 49% (35 of 71) showed injury. Forty-eight percent (39 of 82) showed more than one site of injury to th...
TL;DR: In nine subjects with carotid atherosclerosis, double-oblique, contrast material-enhanced, double inversion-recovery, fast spin-echo magnetic resonance (MR) images were acquired through atheroma in the proximal internal carotids artery, contrast enhancement helped discriminate fibrous cap from lipid core with a contrast-to-noise ratio as good as or better than that with T2-weighted MR images.
Abstract: In nine subjects with carotid atherosclerosis, double-oblique, contrast material–enhanced, double inversion-recovery, fast spin-echo magnetic resonance (MR) images were acquired through atheroma in the proximal internal carotid artery. Fibrocellular tissue within atheroma selectively enhanced 29% after administration of gadolinium-based contrast agent. Contrast enhancement helped discriminate fibrous cap from lipid core with a contrast-to-noise ratio as good as or better than that with T2-weighted MR images but with approximately twice the signal-to-noise ratio (postcontrast images, 36.6 ± 3.6; T2-weighted images, 17.5 ± 2.1; P < .001). © RSNA, 2002
TL;DR: A replaced LHA was less common than has been previously reported, and in two cases, the PHA arose from the SMA, which is comparable to results of seminal angiographic studies in which the cut-film technique was used.
Abstract: PURPOSE: To evaluate and describe the prevalence of hepatic arterial variants seen at digital subtraction angiography in a large series of patients. MATERIALS AND METHODS: Data were collected prospectively by using an arterial anatomy database questionnaire that was completed at the time each visceral angiographic examination was performed from May 1996 to October 2000. RESULTS: Six hundred patients underwent at least one visceral angiographic examination at one institution during the study period. Three hundred sixty-eight (61.3%) patients had the standard hepatic arterial anatomy. One hundred nineteen (19.8%) patients had variant left hepatic arteries (LHAs), and 89 (14.8%) had variant right hepatic arteries (RHAs). Twenty-eight (4.7%) patients had a variant anatomy involving both the LHA and the RHA. Twenty-four (4.0%) patients had a variant origin of the common hepatic artery (CHA) arising from either the superior mesenteric artery (SMA) or the aorta. In two patients, the proper hepatic artery (PHA) w...
TL;DR: In the diagnosis of stroke in the early period (<6 hours after presentation to emergency department), DW MR imaging is superior to conventional MR imaging and CT.
Abstract: PURPOSE: To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance (MR) imaging in a consecutive series of patients at presentation to the emergency department with symptoms of acute stroke. MATERIALS AND METHODS: Clinical data and images obtained in 691 consecutive patients with suspected acute stroke were examined. Results of first and second head CT and brain diffusion-weighted (DW) and conventional MR imaging were compared with each other and with the final neurologic discharge diagnosis. RESULTS: Five hundred seventy-three patients underwent CT at presentation, with 42% sensitivity (95% CI: 37%, 46%) and 91% specificity (95% CI: 82%, 96%). A total of 173 patients underwent a second CT examination, with 77% sensitivity (95% CI: 70%, 84%) and 79% specificity (95% CI: 49%, 95%). Of 498 MR images, 411 were DW, with 94% sensitivity (95% CI: 1%, 96%) and 97% specificity (95% CI: 88%, 100%), and 87 were conventional, with 70% sensitivity (95% CI: 58%, 81%) and 94% specificity (95...
TL;DR: In this study, US was more sensitive than supine chest radiography and as sensitive as CT in the detection of traumatic pneumothoraces.
Abstract: PURPOSE: To prospectively compare the accuracy of ultrasonography (US) with that of supine chest radiography in the detection of traumatic pneumothoraces, with computed tomography (CT) as the reference standard. MATERIALS AND METHODS: Thoracic US, supine chest radiography, and CT were performed to assess for pneumothorax in 27 patients who sustained blunt thoracic trauma. US and radiographic findings were compared with CT findings, the reference standard, for pneumothorax detection. For the purpose of this study, the sonographers were blinded to the radiographic and CT findings. RESULTS: Eleven of 27 patients had pneumothorax at CT. All 11 of these pneumothoraces were detected at US, and four were seen at supine chest radiography. In the one false-positive US case, the patient was shown to have substantial bullous emphysema at CT. Sensitivity and negative predictive value of US were 100% (11 of 11 and 15 of 15 patients, respectively), specificity was 94% (15 of 16 patients), and positive predictive value ...
TL;DR: The authors describe the initial application for tumor staging with an in-line system with a positron emission tomographic (PET) scanner and a multi-detector row helical computed tomography (CT) scanner combined in one machine.
Abstract: The authors describe the initial application for tumor staging with an in-line system with a positron emission tomographic (PET) scanner and a multi-detector row helical computed tomographic (CT) scanner combined in one machine. Fifty-three patients underwent imaging with four CT tube currents and PET emission and transmission data acquisition. Stepwise analysis of coregistered images revealed a significant (P <.05, McNemar test) improvement in lesion classification between PET images alone and coregistered images from the PET-CT examination.
TL;DR: The average fetal radiation dose with helical CT is less than that with ventilation-perfusion lung scanning during all trimesters.
Abstract: PURPOSE: To calculate mean fetal radiation dose from helical chest computed tomography (CT) by using maternal-fetal geometries obtained from healthy pregnant women and to compare the calculated CT doses with the fetal doses reported with scintigraphy. MATERIALS AND METHODS: Maternal-fetal geometries were determined in 23 pregnant women with varying body mass index and fetal gestational age. Monte Carlo techniques were used to estimate the dose that would be received by each fetus from CT scanning performed with the following parameters: 120 kVp; 100 mA; scanning time, 1 second per section; collimation, 2.5 mm; pitch of 1. Craniocaudal extent of the scan was 11 cm, with the most caudal section edge being 5 mm inferior to the xiphoid process. RESULTS: For helical CT, estimated mean fetal doses in micrograys at varying gestational ages were as follows: 3.3–20.2 μGy, first trimester; 7.9–76.7 μGy, second trimester; and 51.3–130.8 μGy, third trimester. These values were all less than mean fetal doses reported ...
TL;DR: Hyperpolarized (3)He diffusion MR imaging demonstrated potential for use in evaluating the global and regional severity of emphysema and whether apparent diffusion coefficients (ADCs) measured with MR imaging correlate with spirometric indexes.
Abstract: PURPOSE: To quantitatively evaluate hyperpolarized helium 3 (3He) diffusion magnetic resonance (MR) images of the lung in patients with emphysema and to determine whether apparent diffusion coefficients (ADCs) measured with MR imaging correlate with spirometric indexes. MATERIALS AND METHODS: Hyperpolarized 3He diffusion MR imaging was performed in 16 healthy volunteers and 11 patients. Coronal diffusion-sensitized MR images were obtained during suspended respiration after inhalation of laser-polarized 3He gas, and images of the ADC were calculated. Spirometry was performed immediately before imaging. The mean and SD of the ADCs were compared between subject groups and were correlated with spirometric indexes. RESULTS: ADC images were homogeneous in volunteers, but demonstrated regional variations in patients. The mean and SD of the ADCs for patients were significantly larger (P < .002) than those for volunteers. The mean ADCs for all subjects correlated with the percentage of predicted forced expiratory ...
TL;DR: FT offers the patient a well-tolerated preparation and improves specificity, with improved differentiation of polyps from residual stool, in a comparison with standard colonic cleansing with regard to patient acceptance, sensitivity, and specificity.
Abstract: PURPOSE: To compare reduced colonic cleansing based on dietary fecal tagging (FT) with standard (non-FT) colonic cleansing with regard to patient acceptance, sensitivity, and specificity. MATERIALS AND METHODS: In 50 patients (FT group), FT was performed by means of diet, magnesium citrate, and a barium suspension. In another 50 patients (non-FT group), preparation was based on polyethylene glycol administration. All patients underwent conventional colonoscopy after computed tomographic (CT) colonography. Sensitivity and specificity for polyp detection were calculated by using conventional colonography as the reference standard. At CT colonography, fecal residue was evaluated. Patients were interviewed to determine discomfort, side effects, sleep quality, final opinion on examination comfort, and whether they would be reluctant to undergo the same examination again. RESULTS: FT left more fecal residue but improved differentiation from polyps (FT specificity, 88% [30 of 34 patients]; non-FT, 77% [23 of 30 ...
TL;DR: Spiral CT is accurate in the depiction of peritoneal metastases from ovarian cancer, although sensitivity is reduced in patients with tumor implants 1 cm or smaller.
Abstract: PURPOSE: To determine the accuracy of spiral computed tomography (CT) in the depiction of peritoneal metastases by using surgical findings in patients with ovarian cancer as the standard of reference. MATERIALS AND METHODS: Three independent readers reviewed the preoperative CT scans obtained in 64 patients who underwent primary surgery for ovarian cancer. Readers rated the likelihood of peritoneal metastases on a five-point scale and recorded the presence or absence of ascites, parietal peritoneal thickening or enhancement, and small-bowel wall thickening or distortion. Peritoneal metastases were identified as nodular, plaquelike, or infiltrative soft-tissue lesions in the peritoneal fat or on the peritoneal surface. Area under the receiver operating characteristic curve was calculated for each reader. Interreader agreement was evaluated with the κ statistic. Descriptive statistical data were determined with dichotomized ratings (1–3 = absent; 4–5 = present). RESULTS: Areas under the receiver operating c...
TL;DR: Despite the small number of patients, CT and MR imaging may depicted all local regrowth at 4 months or sooner, and MR Imaging may have an edge over CT in the early detection of local reg growth.
Abstract: PURPOSE: To describe the appearance of hepatic tumors treated with radio-frequency (RF) ablation on computed tomographic (CT) and magnetic resonance (MR) images and the pattern of residual tumor at the site of RF ablation and to assess prospectively the sensitivity, specificity, and positive and negative predictive CT and MR imaging values in the evaluation of RF treatment. MATERIALS AND METHODS: Thirty-one patients with 50 tumors (nine hepatocellular carcinomas and 41 metastases) treated with RF ablation underwent CT and MR imaging on the same day at 2, 4, and 6 months; CT was performed every 3 months thereafter. CT and MR findings were interpreted separately and prospectively by two reviewers with consensus. For both imaging techniques, appearance of the treated area, treatment efficacy, and complications were assessed at each time. Sensitivity and specificity were determined by using the McNemar test. RESULTS: After a mean follow-up of 19 months, nine tumors showed local regrowth. At 2 months, MR imagi...
TL;DR: FISP produces small but significantly higher left ventricular volume measurements, as compared with FLASH imaging, and FLASH Imaging and FISP have similar reproducibility.
Abstract: PURPOSE: To compare fast imaging with steady-state precession (FISP) and fast low-angle shot (FLASH) magnetic resonance acquisitions to quantify left ventricular volumes, mass, and function and to determine if the two techniques are comparable. MATERIALS AND METHODS: Left ventricular volume studies were performed in 10 patients with heart failure and in 10 healthy subjects by using FISP and FLASH imaging. Identical section positions were used for section-by-section contour comparisons. Manual analysis was performed by two experienced observers. The study was repeated on a different day and interobserver and interstudy reproducibility assessed. RESULTS: With FISP, end-diastolic volume was larger (healthy subjects: +18 mL [13%], P < .001; patients: +6 mL [3%], not significant), end-systolic volume larger (healthy subjects: +9 mL [17%], P = .001; patients: +8 mL [6%], P = .001) and left ventricular mass smaller (healthy subjects: −25 g (19%), P < .001; patients: −21 g (11%), P < .001). There were no signific...
TL;DR: With no visible tumor-pancreas contrast for isoattenuating tumors, indirect signs such as mass effect, atrophic distal parenchyma, and an interrupted duct sign are important indicators for the presence of tumor.
Abstract: PURPOSE: To assess the frequency of isoattenuating pancreatic adenocarcinoma with multi–detector row computed tomography (CT) and determine whether there are specific secondary signs that aid in detection. MATERIALS AND METHODS: Fifty-three patients with pancreatic adenocarcinoma underwent contrast material–enhanced biphasic multi–detector row CT with curved planar reformation. Tumors were initially deemed isoattenuating or hypoattenuating to normal pancreatic parenchyma on the basis of visual inspection, and the degree of attenuation was confirmed by calculating the mean attenuation differences between normal pancreatic parenchyma and tumor (tumor-pancreas contrast) during the pancreatic phase. Indirect signs of pancreatic tumor were tabulated in patients with an isoattenuating tumor. RESULTS: Of the 53 patients, six (11%) had isoattenuating tumors with a mean tumor-pancreas contrast of 9.25 HU ± 11.3 during the pancreatic phase and 4.15 HU ± 8.5 during the portal venous phase. The secondary signs of pan...
TL;DR: F DOPA PET is highly sensitive and specific for detection of pheochromocytomas and has potential as the functional imaging method of the future.
Abstract: PURPOSE: To evaluate fluorine 18 (18F) dihydroxyphenylalanine (DOPA) whole-body positron emission tomography (PET) as a biochemical imaging approach for detection of pheochromocytomas. MATERIALS AND METHODS:18F DOPA PET and magnetic resonance (MR) imaging were performed in 14 consecutive patients suspected of having pheochromocytomas (five sporadic, nine with von Hippel-Lindau disease); metaiodobenzylguanidine (MIBG) scintigraphy was performed in 12 of these patients. The individual imaging findings were assessed in consensus by specialists in nuclear medicine and radiologists blinded to the results of the other methods. The findings of the functional imaging methods were compared with those of MR imaging, the reference standard. Histologic verification could be obtained in eight patients with nine tumors. RESULTS: Seventeen pheochromocytomas (11 solitary, three bifocal; 14 adrenal, three extraadrenal) were detected with MR imaging. 18F DOPA PET and MR imaging had concordant results in all 17 tumors. In c...