MDCT of intraductal papillary mucinous neoplasm of the pancreas: evaluation of features predictive of invasive carcinoma.

Objective: The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT.

Materials And Methods: Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed.

Internet-based medical education: use of an "expert-corner" for disseminating radiologic information and determining users' educational interests.

Rationale And Objectives: A website dedicated to body computed tomography (CT) offers users the opportunity to submit any question to a national expert. The purpose of this study was to characterize inquiries submitted over a 1-year period.

Materials And Methods: A total of 408 questions posed by users between February 2003 and February 2004 were reviewed and categorized.

Comparison of coronary calcium and stress myocardial perfusion imaging in apparently healthy siblings of individuals with premature coronary artery disease.

Detection of subclinical coronary atherosclerosis is possible using exercise myocardial perfusion imaging for inducible ischemia or multidetector computed tomography for coronary artery calcium (CAC), which is used to detect subclinical coronary atherosclerosis. The extent to which these screening tests converge in an asymptomatic population that is at increased risk for coronary artery disease remains unknown. We compared the concordance of findings in 260 asymptomatic middle-age siblings of hospitalized index patients <60 years of age with documented coronary artery disease.

IV contrast selection for MDCT: current thoughts and practice.

Objective: The purpose of this article is to review studies evaluating how contrast concentration affects MDCT of the body and to report IV contrast infusion protocols from MDCT angiography and MDCT of abdominal tumors.

Conclusion: Higher concentrations (350 mg I/mL or greater) may improve visualization of small abdominal arteries. However, preliminary data comparing 300 mg I/mL to higher concentrations for MDCT of hypervascular hepatocellular carcinoma and pancreatic cancer have shown that higher concentrations may not increase tumor conspicuity.

Hemodialysis fistula occlusion: demonstration with 64-slice CT angiography.

The speed and resolution of 64-slice CT have resulted in new applications for CT angiography (CTA) owing to rapid data acquisition during the arterial phase, improved visualization of small vessels, and lengthened anatomic coverage. Extremity CT angiography is one such region. This case report shows the utility of multislice CTA for the evaluation of hemodialysis graft dysfunction.

Women with a low Framingham risk score and a family history of premature coronary heart disease have a high prevalence of subclinical coronary atherosclerosis.

Background: The Framingham risk estimation (FRE) serves as the basis for identifying which asymptomatic adults should be treated with aspirin and lipid-lowering therapy in primary prevention. However, the FRE generally yields low estimates of 10-year "hard" coronary heart disease (CHD) event risk with few women (< 70 years) qualifying for preventive pharmacologic therapy despite relatively high lifetime risk. We postulated that traditional risk factor assessment might fail to identify a sizeable portion of women with a sibling history for premature CHD as having advanced subclinical atherosclerosis.

Direct comparison of FDG PET and CT findings in patients with lymphoma: initial experience.

Purpose: To retrospectively compare fluorine 18 fluorodeoxyglucose (FDG) positron emission tomographic (PET) and computed tomographic (CT) findings at the same anatomic locations in patients with lymphoma by using a combined PET/CT scanner and to analyze the lesions on metabolic and anatomic bases to evaluate causes of discrepant findings between the two modalities.

Materials And Methods: The institutional review board allowed an exempt retrospective review of cancer PET database, and informed consent was waived. The study was HIPAA compliant.

Intraductal papillary mucinous neoplasm of the pancreas: can benign lesions be differentiated from malignant lesions with multidetector CT?

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a distinct clinicopathologic entity that is being recognized with increasing frequency. In 25%-44% of IPMNs treated with surgical resection, associated invasive carcinoma has been reported. Surgical resection is the treatment of choice for most IPMNs.

Three-dimensional computed tomographic imaging of complex congenital cardiovascular abnormalities.

Primary evaluation of congenital cardiac abnormalities traditionally relies upon echocardiography and conventional angiography, both of which have potential limitations. Echocardiography is an operator dependant study, limited by a small window and patient movement. Conventional angiography is an invasive procedure with an inherent risk of catheter complication such as vessel damage, bleeding, stroke and infection.

Musculoskeletal imaging with computed tomography and magnetic resonance imaging: when is computed tomography the study of choice?

Indications for computed tomography (CT) of the musculoskeletal system, especially with the advent of 16-slice multidetector CT (MDCT), are numerous. In addition to the evaluation of the trauma patient where CT is essential when imaging complex skeletal injuries, MDCT is particularly useful in patients who have had prior surgery. In postoperative cases, metal artifact typically prohibits magnetic resonance imaging evaluation, but volume-rendering of a MDCT axial database virtually eliminates streak artifact associated with hardware.

Initial experience with FDG-PET/CT in the evaluation of breast cancer.

Purpose: We retrospectively reviewed FDG-PET/CT images in patients with breast cancer to determine whether PET/CT improved the level of diagnostic confidence as compared with PET and to compare PET/CT and CT findings at the location of suspected malignancies.

Methods: The study included 75 patients with known breast cancer. The initial PET/CT study for each patient was retrospectively reviewed to determine whether improved diagnostic confidence (IDC) regarding lesion localization and characterization was observed with PET/CT as compared with PET alone.

Liver and biliary system: evaluation by multidetector CT.

CT commonly is indicated for the evaluation of suspected hepatic and biliary pathology. The recent introduction of multidetector CT (MDCT) provides unique capabilities that are valuable especially in hepatic volume acquisitions, combining short scan times, narrow collimation, and the ability to obtain multiphase data. These features result in improved lesion detection and characterization.

Distinction of long bone stress fractures from pathologic fractures on cross-sectional imaging: how successful are we?

Objective: The objectives of our study were to define CT and MRI features that distinguish pathologic fractures from stress fractures and to compare the performance of CT and MRI with radiography.

Materials And Methods: Two reviewers retrospectively reviewed 45 MR images, 37 CT scans, and 43 radiographs in 59 patients (30 biopsy-proven pathologic fractures and 29 stress fractures followed to resolution). The features observed on MRI were abnormal bone marrow (well-defined, ill-defined); intracortical, periosteal, or muscle T1 or T2 signal; endosteal scalloping; and a soft-tissue mass.

Median arcuate ligament syndrome: evaluation with CT angiography.

The median arcuate ligament is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The ligament usually passes superior to the origin of the celiac axis. However, in some people, the ligament inserts low and thus crosses the proximal portion of the celiac axis, causing compression and sometimes resulting in abdominal pain.

Lymphoepithelial cyst of the pancreas--evaluation with multidetector CT.

Lymphoepithelial cyst of the pancreas is a rare cystic pancreatic tumor. In this case report we provide the imaging perspective of the lesion including the role of multidetector CT (MDCT) and CT angiography and 3D imaging.

Multidetector 3D CT of pulmonary embolism of a peripheral intravenous line.

Embolization of foreign objects to the pulmonary circulation is an uncommon occurrence. Traditionally, plain radiographs have been used to detect larger, radiodense objects, with axial CT used to localize smaller, less radiodense objects. More recently, the use of multidetector CT has permitted the detection and accurate localization of smaller, relatively radiolucent objects.

Acute non-traumatic maternal illnesses in pregnancy: imaging approaches.

The imaging methods used to obtain diagnostic information for pregnant patients presenting with acute non-traumatic maternal illnesses have been reviewed. Conditions affecting the gastrointestinal tract, urinary tract, uterus, adnexae, central nervous system and chest have been investigated via a variety of imaging methods, which include ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), intravenous pyelography (IVP), angiography and fluoroscopy. The method of choice, application, and safety to the mother and fetus are considered for investigation of each condition.

Clinically significant incidental findings on the unenhanced CT portion of PET/CT studies: frequency in 250 patients.

Unlabelled: PET/CT technology is in rapid evolution. It remains unclear if the unenhanced CT portion, performed for attenuation correction and lesion localization, provides additional independent diagnostic information not apparent on PET alone. The objective of the current study was to evaluate the incremental added value and frequency of potentially clinically significant incidental findings from the independent reading of the unenhanced CT portion of PET/CT studies by an expert CT radiologist.

Combined PET/CT for detecting recurrent ovarian cancer limited to retroperitoneal lymph nodes.

Objective: To evaluate the utility of combined positron emission tomography/computed tomography (PET/CT) for detecting recurrent epithelial ovarian cancer limited to retroperitoneal adenopathy.

Methods: Fourteen patients (median age = 53 years) with rising serum CA125 levels, and negative or equivocal conventional CT imaging > or = 6 months after primary therapy were retrospectively identified as having recurrent disease limited to retroperitoneal lymph nodes by combined PET/CT and underwent surgical reassessment of targeted nodal basins. Fisher's Exact Test was used to measure the ability of PET/CT to predict isolated retroperitoneal nodal disease.

Focal FDG uptake in a pancreatic lipoma mimicking malignancy.

Positron emission tomography (PET) using the glucose analog 18-F-fluoro-2-deoxy-D-glucose (FDG) is commonly obtained to stage patients with cancer. Benign lesions can be a source of false-positive PET examinations, leading to incorrect staging and treatment of tumors. Computed tomography can aid in distinguishing between certain benign and malignant lesions.

Imaging of pelvic malignancies with in-line FDG PET-CT: case examples and common pitfalls of FDG PET.

The role of 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in combination with computed tomography (CT) in the evaluation of pelvic malignancies has been rapidly growing in recent years. FDG PET has proved to be valuable in the evaluation of a variety of pelvic malignancies, including colorectal cancer, uterine cervical cancer, ovarian cancer, endometrial cancer, and non-Hodgkin lymphoma. However, a number of pitfalls are commonly encountered at FDG PET, including normal physiologic activity in bowel, ovaries, endometrium, and blood vessels and focal retained activity in ureters, bladder diverticula, pelvic kidneys, and urinary diversions.

Multidetector CT of musculoskeletal disease in the pediatric patient: principles, techniques, and clinical applications.

Computed tomography (CT) plays an important role in the evaluation of musculoskeletal disease in the pediatric patient. With the advent of high-performance 16-section multidetector CT, images can be produced with subsecond gantry rotation times and with submillimeter acquisition, which yields true isotropic high-resolution volume data sets; these features are not attainable with older spiral CT technology. Such capabilities are particularly helpful in the evaluation of pediatric patients by virtually eliminating the need for sedation and minimizing dependence on patient cooperation.

Optimal contrast agents for vascular imaging on computed tomography: iodixanol versus iohexol.

Rationale And Objectives: Dimeric nonionic iodinated contrast has a lower osmolality than monomeric nonionic iodinated contrast but is available at lower iodine concentrations. Less dilution of intravascular fluid by influx from the extravascular space is proposed to occur with decreasing osmolality. The purpose of this study was to determine if a dimeric nonionic iso-osmolar contrast agent (iodixanol) gives equal vascular enhancement compared with a monomeric nonionic hyperosmolar contrast agent (iohexol).