PURPOSE: To clarify whether the benefit of a reduced effective scan width obtained using a smaller pitch outweighs the disadvantage of increased noise in the application of a subsecond helical CT to mass screenings for lung cancer. MATERIALS AND METHODS: Twenty-two helical CT scans of the lung were obtained in ...

The objective of this study was to assess the efficacy of contrast-enhanced ultrasonography (CEUS) with SonoVue to evaluate the response to percutaneous treatment (ethanol injection/radiofrequency) of hepatocellular carcinoma in comparison with spiral computed tomography (CT) immediately and 1 month after treatment. Forty-one consecutive cirrhotic patients with early stage tumor (not ...

OBJECTIVES: We compared the diagnostic reliability of cone beam computed tomography (3DX) and helical computed tomography (helical CT) for the detection of osseous abnormalities of the mandibular condyle, using macroscopic observations as the gold standard. METHODS: Twenty-one temporomandibular joint autopsy specimens underwent imaging with 3DX and helical CT. The specimens ...

PURPOSE: We evaluated the incidence and clinical relevance of alternate or additional findings on unenhanced CT in patients with acute flank pain and suspected urinary calculi. MATERIALS AND METHODS: A consecutive series of 1,500 patients underwent unenhanced CT due to acute flank pain. The absence or presence of urinary tract ...

Previous studies suggested that the non-contrast-enhanced computerized tomography (CT) scan is a highly reliable tool for the diagnosis of analgesic-associated renal disease. However, this issue has not been addressed in the US population. A total of 221 incident patients with ESRD from different regions of the United States underwent a ...

AIM: To retrospectively evaluate helical computed tomography (CT) findings in a series of consecutive patients with Budd-Chiari syndrome. METHODS: Patterns of enhancement observed at contrast-enhanced helical CT in 10 consecutive patients (six women, four men; aged 27-51 years) with either acute, subacute or chronic Budd-Chiari syndrome were retrospectively evaluated along ...

OBJECTIVE: To evaluate, in a prospective study, the efficiency of helical computed tomography (CT) and endoluminal ultrasonography (ELUS) for detecting significant crossing vessels, a major cause of bleeding complications when treating patients with pelvi-ureteric junction (PUJ) obstruction, and to compare our results using ELUS with those of an earlier multicentre ...

The technological development of multidetector CT offers new possibilities for better imaging of organic structures that can be used in diagnosis of the kidney. The thinner slices allow a better spatial resolution, and slice fusion allows improved contrast resolution. The isotropic voxel has been realized in the latest 64-channel scanners. ...

We evaluated Feldkamp artifacts, which are specific to cone-beam computed tomography (CT), in phantom and clinical studies using the 256-multidetector-row CT (256MDCT), and compared the reconstruction accuracy of axial and helical scans. Image noise, slice sensitivity profile (SSP) and artifacts with the 256MDCT were evaluated using a phantom, and the ...

INTRODUCTION: A pilot study to evaluate helical computer tomography (CT) as a diagnostic tool for acute lower gastrointestinal tract (GIT) bleeding. CT was compared to conventional angiography (CA) and colonoscopy for the diagnosis and detection of bleeding site in suspected cases of acute lower GIT bleeding. METHODS: Seven patients presenting ...

PURPOSE: Percutaneous nephrolithotomy effectively treats large volume renal calculi but relies on postoperative imaging to judge success. We evaluated the effectiveness of maximizing intraoperative imaging through combined high resolution fluoroscopy and flexible nephroscopy. MATERIALS AND METHODS: Percutaneous nephrolithotomy was performed cooperatively with a radiologist in an interventional radiology suite equipped ...

Methods to predict fragmentation efficiency are still needed for extracorporeal shock wave lithotripsy (ESWL). Imaging studies of kidney stones could be a useful tool to guide ESWL. Artificial and real kidney stones were analyzed using standard clinical CT imaging procedures. The objective was to compare CT image properties of phantom ...

OBJECTIVE: The aim of this study was to evaluate the image quality of high-resolution CT (HRCT) reconstructed from volumetric data with 16-channel multidetector-row CT (MDCT). SUBJECTS AND METHODS: Eleven autopsy lungs that were diagnosed histopathologically were scanned by 16-channel MDCT with the step-and-shoot scan mode and three helical scan modes. ...

While respiration-correlated CT is gaining acceptance in clinical radiotherapy, the effect of scanning parameters on the image quality has yet to be addressed. The intent of this study was to characterize the effects of gantry rotation and table speed on various image quality characteristics in multi-slice, helical, retrospectively-gated CT images. ...

The current use of multidector row helical CT (MDCT) and imaging postprocessing techniques represents an additional step forward in the use of helical CT for detection and staging of pancreatic carcinoma. Although no large series have been published detailing the accuracy of MDCT compared to single detector row helical CT, ...

PURPOSE: To prospectively evaluate and compare the diagnostic accuracy of unenhanced helical computed tomography (CT) for patients with nontraumatic acute abdominal pain with that of traditional abdominal radiography. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained; this study was completed before implementation of the HIPAA. Ninety-one ...

PURPOSE: The classification of cystine stones into rough and smooth varieties has been suggested as an aid to choosing treatment for these difficult stones. Since the surface of stones is difficult to visualize preoperatively, we tested the hypothesis that the surface morphology of cystine stones correlates with their internal structure, ...

OBJECTIVE: High reproducibility of coronary artery calcium (CAC) scoring is a key requirement for monitoring the progression of coronary atherosclerosis. The purposes of this study were to compare electron beam CT and 16-MDCT scanners in the variability of repeated CAC measurements and to assess the factors influencing this variability. MATERIALS ...

BACKGROUND AND PURPOSE: Stone size forms the basis of management pathways in patients with urolithiasis. We carried out a questionnaire-based audit to find out how stone size is routinely measured by radiologists in the UK. MATERIALS AND METHODS: A series of 831 anonymous questionnaires concerning how stone size is assessed ...

Guaifenesin is a commonly used expectorant whose use may lead to the occasional formation of guaifenesin urinary stones. We herein describe a patient who was taking 2400 mg Guaifenesin per day as part of his treatment for asthma. He had a past history of a guaifenesin stone removed ureteroscopically. His ...

PURPOSE: To determine retrospectively whether there had been any change between 1998 and 2002 in the use and outcome of computed tomography (CT) performed in the emergency department for patients presenting with symptoms of renal colic. MATERIALS AND METHODS: Approval from the Research Ethics Board was obtained, and informed consent ...

OBJECTIVE: To compare ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in the diagnosis and determination of resectability of pancreatic adenocarcinoma. METHODS: Articles reporting US, CT, or MRI data of patients with known or suspected pancreatic adenocarcinoma and at least 20 patients verified with histopathology, surgical findings, or ...

Extracorporeal shockwave lithotripsy (ESWL) is a commonly used non-invasive treatment for urolithiasis. Helical CT scans provide much better and detailed imaging of the patient with urolithiasis including the ability to measure density of urinary stones. In this study we tested the hypothesis that density of urinary calculi as measured by ...

Untreated paired helical filaments (PHFs) and pronase-digested PHF-core filaments were stereoscopically imaged with a freeze-drying vertical platinum-carbon replication preparation method for TEM. The untreated PHF have an average wide region (W) = 22.8 +/- 2.4 nm, a narrow region (T) = 10.6 +/- 1.7 nm, and a helical turn period ...

OBJECTIVE: Localized low attenuated areas (pseudolesions) in the medial segment of left liver lobe are not rarely seen in the screening of abdomen using helical CT. The purpose of this study was to determine the prevalence of pseudolesions in the routine helical CT of abdomen and to evaluate the morphologic ...

PURPOSE: We investigated whether identification of the segmental artery feeding the anterior spinal artery (ASA) is possible by single-slice helical CT. MATERIAL AND METHODS: Enhanced CT and angiography were performed in 14 patients with retroperitoneal, liver, or bone tumor. A single-slice helical CT scanner with 7 mm collimation and a ...

OBJECTIVE: To describe in vitro CT features of intrahepatic stones and to correlate CT attenuation with chemical composition. MATERIALS AND METHODS: Of the patients who underwent choledochoscopic intrahepatic stone removal between 1998 and 2001, 54 patients with stones larger than 3 mm were enrolled in this study. In each case, ...

OBJECTIVES: To measure the vocal fold length (VFL) during inspiration and phonation and to determine the vertical difference of the vocal folds during phonation in patients with unilateral vocal fold immobility. DESIGN: Prospective study. SETTING: University hospital. Patients Thirty patients with unilateral vocal fold immobility. INTERVENTIONS: Each subject was asked ...

The objective of the study was to assess the clinical validity of a non-invasive diagnostic strategy for acute pulmonary embolism using clinical assessment combined with both ELISA D-dimer and complete lower limb ultrasound (US) examination of proximal and distal veins, before single-detector helical computed tomography (CT) of pulmonary arteries. We ...

PURPOSE: To retrospectively assess the accuracy of four-section multi-detector row computed tomography (CT) in the evaluation of renal transplant donors when scans are read by one of multiple readers with varied levels of expertise, by using surgery as the reference standard. MATERIALS AND METHODS: This retrospective study was approved by ...

AIM: To retrospectively establish the diagnostic criteria of gallstone ileus on CT, and to prospectively apply these criteria to determine the diagnostic accuracy of CT to confirm or exclude gallstone ileus in patients who presented with acute small bowel obstruction (SBO). Another purpose was to ascertain whether the size of ...

Our aim was to compare the quality of pelvicalyceal visualization on computed tomography (CT) urography using a small intravenous contrast material dose, hydration, and high-resolution multidetector CT (MDCT) with that of conventional helical CT. The test (MDCT) group (49 consecutive patients, 98 kidneys) was scanned 5 min following an intravenous ...

PURPOSE: To perform meta-analysis of literature about the role of helical computed tomography (CT) and ventilation-perfusion (V-P) scanning in detection of acute pulmonary embolism (PE) by using summary receiver operating characteristic (ROC) curve analysis. MATERIALS AND METHODS: V-P scanning articles published from January 1985 to March 2003 and helical CT ...

OBJECTIVE: In our department, most high-resolution CT (HRCT) scans of the lungs are performed in conjunction with a standard helical examination to assess the entire chest. This requires scanning the patient twice. The goal of this study was to determine if the radiation dose could be decreased by performing a ...

Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for subsegmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of >99% : a normal perfusion lung scan and a normal ...

We proposed a data sufficiency condition (DSC) for four-dimensional-CT (4D-CT) imaging on a multislice CT scanner, designed a pitch factor for a helical 4D-CT, and compared the acquisition time, slice sensitivity profile (SSP), effective dose, ability to cope with an irregular breathing cycle, and gating technique (retrospective or prospective) of ...

BACKGROUND AND PURPOSE: High recurrence rates and early recurrence have been reported for juvenile nasopharyngeal angiofibroma (JNA) involving the skull base. The purpose of this study was to evaluate the diagnostic accuracy of contrast-enhanced CT scanning for the detection of residual disease (RD) in the early postoperative course after surgical ...

BACKGROUND PURPOSE: Image transmission is an integral part of telemedicine, allowing evaluation of patients at remote sites. We developed a simple method of wireless transmission of digital images to a hand-held computer (PDA) and evaluated its feasibility and diagnostic accuracy in patients with acute renal colic or renal trauma. MATERIALS ...

PURPOSE: To evaluate whether, in principle, the mean CT attenuation values of kidney stones could predict fragmentation by shockwaves. MATERIALS AND METHODS: Four types of artificial kidney stones having different CT attenuation values were tested. Artificial stones were weighed and exposed to 700 shockwaves at 21 kV at the focus ...

AIM: To define the value of different radiologic modalities in determining the patients who believed to be stone-free after extracorporeal shock wave lithotripsy (SWL) with plain abdominal X-ray, by evaluating the same patients with ultrasonography (USG) and helical computed tomography (CT). PATIENTS AND METHODS: Between March 2002 and February 2003, ...

This is a preliminary demonstration of volumetric cine imaging of cardiovascular circulation in domestic pigs using a prototype 256-detector row computed tomography (CT) scanner. The scan range is approximately 120 mm in the craniocaudal direction, with a 0.5-mm slice thickness. The thin sections can be used to create cine loops ...

Gantry-tilted helical multi-slice computed tomography (CT) refers to the helical scanning CT system equipped with multi-row detector operating at some gantry tilting angle. Its purpose is to avoid the area which is vulnerable to the X-ray radiation. The local tomography is to reduce the total radiation dose by only scanning ...

BACKGROUND: An attempt was made to visualize minute intraductal lesions using helical CT in patients with abnormal nipple discharge. METHODS: Galactography was performed, immediately followed by CT (ductal CT examination). Based on the image data obtained, ductal images were constructed on a workstation using a Pegasus viewer (ductal CT imaging). ...

Our aim in this prospective study was to determine the best diagnostic method for discriminating between patients with and without osteochondral lesions of the talus, with special relevance to the value of MRI compared with the new technique of multidetector helical CT. We compared the diagnostic value of history, physical ...

For fast and exact CT reconstruction, we have conceptualized a triple-source helical cone-beam scanning mode, and formulated a backprojected-filtration (BPF) algorithm for that imaging geometry. The algorithm uses data from the three inter-helix PI-arcs related to the inter-helix PI-lines and the minimum detection windows defined for the triple-source configuration. The ...

To determine the accuracy of computed tomographic intravenous cholangiography (CT-IVC) for detection of choledocholithiasis. Sixty-five patients undergoing endoscopic retrograde cholangiography (ERC) underwent CT-IVC prior to ERC, using a single detector helical CT following intravenous infusion of 100 ml iotroxate. Patients with bilirubin levels >3 times normal were excluded. ERC was ...

BACKGROUND: Micro computed tomography (micro CT) has been shown to provide exceptionally high quality imaging of the fine structural detail within urinary calculi. We tested the idea that micro CT might also be used to identify the mineral composition of urinary stones non-destructively. METHODS: Micro CT x-ray attenuation values were ...

PURPOSE: To evaluate the utility of relatively low-dose megavoltage computed tomography (MVCT) images from a clinical helical tomotherapy system for setup verification purposes. METHODS AND MATERIALS: Cross-sectional kilovolt computed tomography (kVCT) images were obtained for treatment planning purposes on a diagnostic third-generation CT scanner, followed by MVCT images from a ...

BACKGROUND: Pulmonary metastasectomy is well accepted in patients with isolated metastases from an extrathoracic malignancy. The standard approach involves careful intraoperative palpation of the lungs because more metastases are frequently found than were seen by preoperative conventional computed tomography (CT). Helical CT detects more nodules than conventional CT, raising the ...

Helical CT has become the preferred method to diagnose urinary calculi in patients presenting with abdominal or flank pain. Recent in vitro studies have shown that CT also can display the internal structure in stones with remarkable detail. Because some stones respond better to SWL than others, knowing stone structure ...