PURPOSE: We assessed unenhanced helical computerized tomography (CT) secondary findings as predictors of renal obstruction as determined by diuretic scintirenography, and determined their reproducibility. MATERIALS AND METHODS: We performed a retrospective review of the records of 77 consecutive patients with unenhanced helical CT findings (stones and secondary findings, including renal ...

Calculi in the seminal vesicles (SV) are extremely rare. A patient having large bilateral star-shaped calculi in the SV is reported. They were seen on plain x-ray and confirmed by computed tomography. On the reconstructed CT scans the large stone on the right side measured about 35 X 35 X ...

We review the scanning techniques for cardiac CT imaging with single slice and multislice scanners. Combined with prospective triggering for transaxial scanning and retrospective gating for helical scanning the potential advantages and the basic limitations are discussed. Based on those theoretical considerations, the major conclusion is that high resolution data ...

PURPOSE: Unenhanced helical computerized tomography (CT) has proved to be an excellent diagnostic tool for evaluating acute flank pain with reported 95% to 100% sensitivity, 92% to 100% specificity, 96% to 100% positive and 91% to 100% negative predictive values. The diagnostic value of a new low dose protocol was ...

PURPOSE: We evaluated the accuracy of noncontrast spiral computerized tomography (CT) for determining urinary stone size compared with plain x-ray. MATERIALS AND METHODS: We retrospectively analyzed noncontrast helical CT and plain x-ray of the kidneys, ureters and bladder images of 39 patients with urolithiasis who underwent each study from July ...

The development of new imaging techniques and the refinement of established methods in uroradiological imaging is proceeding rapidly. In the last few years several important developments have been implemented in the routine diagnostic evaluation of urological patients.A milestone is the recent advent of multidetector helical computed tomography (CT), enabling the ...

Evaluation of patients with acute flank pain using helical computed tomography (CT) is a well-accepted, rapid, and safe procedure in the emergency setting. Various primary and secondary signs are described in the literature for evaluation of these patients. Our purpose is to demonstrate both the classical findings associated with ureteral ...

PURPOSE: To determine the sensitivity and specificity of cardiac gated electron-beam computed tomography (CT) and ungated helical CT in detecting and quantifying coronary arterial calcification (CAC) by using a working heart phantom and artificial coronary arteries. MATERIALS AND METHODS: A working heart phantom simulating normal cardiac motion and providing attenuation ...

OBJECTIVE: The purpose of this study was to compare the accuracy of unenhanced helical CT with combined sonography and unenhanced radiography in patients with acute flank pain suggestive of ureteral colic. SUBJECTS AND METHODS: From January 1997 to December 1999, 181 consecutive patients with acute flank pain underwent unenhanced radiography, ...

AIM: To assess the diagnostic power of three-dimensional computed tomography (3D CT), axial helical computed tomography (CT) and conventional tomography in the classification of acetabular fractures by interdisciplinary review. MATERIALS AND METHODS: Receiver operating characteristics (ROCs) were assessed for two radiologists and two surgeons blinded to the presence of acetabular ...

BACKGROUND: The purpose of this study was to investigate whether trained radiologists can distinguish minor differences among computed tomography (CT) images of extended helical pitches of 1.0 to 1.5. METHODS: Between September 2000 and February 2001, 72 patients were randomized into 1 of 3 equal groups: helical pitches of 1.0, ...

OBJECTIVE: To determine the value of unenhanced ultrafast computerized tomography (CT) in the diagnosis of acute flank pain in 43 patients evaluated for suspected stone disease. MATERIAL AND METHOD: Noncontrasted ultrafast CT was performed in 43 consecutive patients seen in the emergency department to evaluate acute flank pain. All CT ...

In the Eurasian Upper Paleolithic after about 35,000 years ago, abstract or depictional images provide evidence for cognitive abilities considered integral to modern human behavior. Here we report on two abstract representations engraved on pieces of red ochre recovered from the Middle Stone Age layers at Blombos Cave in South ...

OBJECTIVES: To compare CT virtual bronchoscopy (VB) to CT alone and to conventional bronchoscopy for evaluation of central airway stenoses in patients with Wegener's granulomatosis. DESIGN: Prospective observer study, in which 18 thin-section helical CT scans of the trachea and bronchi of 11 patients with Wegener's granulomatosis were obtained. VB ...

PURPOSE: The aim of this study was to determine the optimal amount of contrast agent for helical CT of the trunk during primary radiologic evaluation of polytraumatized patients. METHOD: Eighty-three patients with severe and multiple injuries (mean age 36.2 years) underwent standardized helical CT examination with administration of a single ...

PURPOSE: The purpose of this work was to compare the extent of pseudoenhancement (artifactual increase in measured attenuation of a simple cyst after contrast medium administration) in a phantom model on single detector and multidetector helical CT scanners. METHOD: The phantom consisted of four water-filled spheres varying in size from ...

Computer simulation of mass distribution within the model and Fourier transforms of images depicting mass distribution are explored for verification of two alternative modes of the myosin molecule arrangement within the vertebrate skeletal muscle thick filaments. The model well depicting the complete bipolar structure of the thick filament and revealing ...

OBJECTIVE: Prior studies using radiography have examined the relationship of ureteral stone size and location to the probability of spontaneous passage. Given the improved accuracy and new role of unenhanced CT in the diagnosis of acute ureterolithiasis, we studied the relationship of stone size and location as determined by unenhanced ...

Multislice CT (MSCT), which allows for shorter scan times and thinner slice sections than single-slice helical CT (SSHCT), will likely increase the demands on picture imaging and communication system (PACS) resources. Weekly averages for number of images per study (IPS) were collected from MSCT and SSHCT scanners from 1-01 to ...

PURPOSE: There is considerable interest in using radiological imaging to predict kidney stone fragility before patient treatment. Case series of shock wave lithotripsy show that shock wave lithotripsy is repeated and/or ancillary procedures are done to remove shock wave resistant stones in a significant number of cases. If the fragility ...

OBJECTIVE: This study was designed to assess interobserver variability in identifying the rim and comet-tail signs and to determine the clinical utility of these signs in determining whether or not the calcifications with which they are associated represent ureteral calculi. MATERIALS AND METHODS: Two radiologists and a radiology resident, unaware ...

OBJECTIVE: With single-slice helical CT, an increased pitch can decrease the radiation dose to the patient if all other parameters are constant. The purpose of this study was to determine whether the same relationship holds for a particular multislice helical CT system (Somatom Plus 4 VZ multislice helical CT scanner, ...

The aim of this prospective study was to determine whether anti-carcinoembryonic antigen (anti-CEA) scintigraphy is a useful additional technique in the diagnosis recurrence of colorectal cancer. Forty patients with suspected recurrence of colorectal cancer, underwent immunoscintigraphy (IS) and helical computed tomography (CT) in the 2 weeks before surgery. Surgical findings ...

Despite of the diagnostic potential of conventional CT (CCT), limitations being inherent in this technology reduce its diagnostic confidence and limit clinical CT applications as 3D imaging. Helical CT (HCT) has far overcome the limitations of CCT and has become the standard CT technology. After a short overview on the ...

PURPOSE: The goal of this work was to evaluate the diagnostic accuracy of transabdominal ultrasound (US), helical CT, and MRI in the diagnosis of adenomyomatosis (ADM) of the gallbladder. METHOD: Twenty patients with surgically proven ADM were included, all of whom underwent preoperative US, helical CT with 3 mm collimation, ...

Advancements in computed tomography (CT) have led to the development of noninvasive helical CT of the pulmonary arteries as a diagnostic tool in patients with suspected pulmonary embolism (PE). The first-generation, single-slice CT scanners were capable of acquiring one 3-mm-thick imaging section per second. As a further technical evolution of ...

OBJECTIVE: The purpose of this study was to assess the improvement in the detection of ureteral stones on abdominal radiographs when the stones were viewed on multislice helical CT scans and maximum-intensity-projection (MIP) images. SUBJECTS AND METHODS: The study included 72 patients with renal colic who underwent abdominal radiography and ...

RATIONALE AND OBJECTIVES: The authors performed this study to assess the effect of abdominal compression on opacification and distention of the proximal renal collecting system during helical computed tomography (CT). MATERIALS AND METHODS: Abdominal compression was applied during helical CT in 31 patients who were scanned 150 and 300 seconds ...

OBJECTIVE: The accurate detection of intraocular foreign bodies is critically important in treating ocular trauma. The purpose of this study was to evaluate the efficacy of CT, MR imaging, and sonography in detecting seven types of glass varying in size and placed in three locations in the globe, and to ...

Helical CT evaluation of the abdomen and pelvis can be challenging in the cancer patient. This pictorial essay illustrates the important sites of neoplastic dissemination in the abdomen and pelvis. We will emphasize the classic CT appearance of several selected sites and indicate, where appropriate, the primary lesions usually associated ...

The purpose of this study was to evaluate time management and workflow for multidetector-row helical CT (MDCT). Time for patient and data handling of at total of 580 patients were evaluated at two different time periods (December 1999, August 2000), each for the following baseline measurements: (a) change of clothes/instruction; ...

RATIONALE AND OBJECTIVES: The authors performed this study to determine whether exposure of renal calculi to radiographic contrast material has an effect on the attenuation values at computed tomography (CT) performed with varying collimation widths. MATERIALS AND METHODS: Renal calculi (23 stones of various composition) were scanned with 1-, 3-, ...

The aim of our study was to compare the accuracy of non-contrast spiral CT with ultrasound (US) for the diagnosis of ureteral calculi in the evaluation of patients with acute flank pain. 62 consecutive patients with flank pain were examined with both CT and US over a period of 9 ...

We report a 15-year-old girl with nutcracker syndrome (NCP) in whom three-dimensional helical computed tomography (3D helical CT) was useful for diagnosis; angiographic imaging using 3D helical CT provided fine outlines of the vascular structures in NCP, i.e., a compression of the left renal vein between the aorta and the ...

We report the triphasic helical computed tomographic (CT) and dynamic magnetic resonance imaging (MRI) findings in a unique case of biopsy-proven peliosis of the liver. Several reports have described the CT and MRI findings of this entity without specific appearance. This report discusses the usefulness of dynamic helical CT and ...

OBJECTIVE: We present preliminary results of a new method (hereinafter called 'CT-clearance') to measure single kidney contrast media clearance by performing multiphasic helical CT of the kidneys. CT-clearance was calculated according to an extension of the Patlak-Plot. In contrast to prior investigators, who repeatedly measured a single slice, this method ...

Over a 5-year period, 346 helical computed tomographic (CT) studies were performed in renal transplant recipients. Helical CT proved useful in this context by depicting parenchymal, perirenal, renal sinus, pyeloureteral, and vascular complications in great detail. CT often delineates fluid collections and their anatomic relationship to adjacent structures better than ...

OBJECTIVES: The present study was carried out to evaluate the accuracy of helical computed tomography (CT) and intravenous digital subtraction angiography (IV-DSA) on anatomical assessment of renal vasculature for living renal donors. METHODS: Forty-two healthy potential renal donors were prospectively evaluated and 35 subsequently underwent donor nephrectomy after helical CT ...

OBJECTIVE: The objective of this study was to investigate the relationship between duration of flank pain and the frequency of secondary signs of ureteral obstruction on unenhanced helical CT. SUBJECTS AND METHODS: The duration of flank pain was prospectively determined in 227 consecutive patients diagnosed with acute ureterolithiasis on unenhanced ...

Helical CT colography is improved by multislicing due to thinner slices. The case reported shows the potential of multislice HCT colography to demonstrate gas-filled cysts on axial images as well as on CT endoscopy, and consequently the extent of the disease exceeding the sigmoid, as was diagnosed by conventional coloscopy.

BACKGROUND: Helical computed tomography (CT) is commonly used to diagnose pulmonary embolism, although its operating characteristics have been insufficiently evaluated. OBJECTIVE: To assess the sensitivity and specificity of helical CT in suspected pulmonary embolism. DESIGN: Observational study. SETTING: Emergency department of a teaching and community hospital. PATIENTS: 299 patients with ...

OBJECTIVE: We tested breath-held 1-mm multislice helical CT for obtaining both contiguous and high-resolution CT sections of the chest from a single set of raw data. SUBJECTS AND METHODS: Seventy patients with suspected focal and diffuse lung disease were allocated into two groups for comparison. The first group (n = ...

This article describes pitfalls in the interpretation of multidetector-row helical CT (MDCT) images at the window width and level settings for lung parenchyma. On MDCT, linear artifacts, which look like black and white linear densities and are called "hurricane artifacts," radiate out from objects that have very different densities from ...

OBJECTIVE: To compare the diagnostic accuracies of Lipiodol computed tomography (CT) and helical biphasic CT as preoperative imaging modalities for hepatocellular carcinoma (HCC). SUMMARY BACKGROUND DATA: Lipiodol CT after digital subtraction angiography has long been used as a highly sensitive imaging modality for HCC. The recent advent of helical CT ...

OBJECTIVES: to evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) in the detection of type II endoleaks during follow-up after endovascular treatment of intra-renal aortic aneurysms. DESIGN: prospective study. MATERIAL AND METHODS: between March 1996 and November 1999, 31 patients with infra-renal aortic aneurysms who underwent stentgraft implantation ...

Important sites of metastasis from intrathoracic and extrathoracic primary neoplasms are depicted on helical CT of the neck and thorax. This pictorial essay reviews several of these key sites of dissemination. For each, we illustrate the typical or classic appearance on helical CT and note the commonly associated primary malignancies.

Helical CT has become a valuable imaging tool for detection of pulmonary embolism, deep venous thrombosis, ureteral colic, acute small-bowel obstruction, and acute appendicitis. Generally, helical CT has good sensitivity and specificity values, and scans can be performed more quickly than previous gold standard diagnostic examinations for the conditions mentioned. ...

OBJECTIVE: We evaluated the impact of delayed scans on the conspicuity of squamous cell carcinoma in helical CT of the head and neck. SUBJECTS AND METHODS: Twenty-seven patients with biopsy-proven squamous cell carcinoma of the head and neck underwent dual-phase helical CT examinations using 100 mL of nonionic contrast material. ...

As compared to single slice helical CT, multislice helical CT does not only improve the quality of the individual images (in terms of slice sensitivity profile and image artifacts) and the range of scan coverage, it also enforces the CT postprocessing possibilities. The advantage of post-processing thin collimation bowel CT ...

Tracheal involvement is an extremely rare manifestation in patients with neurofibromatosis type 1 (NF-1). We present a 33-year-old women with NF-1 suffering from progressive dyspnea. Multislice spiral CT revealed a neurofibroma located within the trachea with intratracheal extension. To our knowledge, this is the first report of an intratracheal neurofibroma ...