This study was performed for evaluation of high- and low-contrast resolution in multidetector-row CT (MDCT) with 16 detector rows. For evaluating high-contrast resolution, a phantom was scanned ten times at 100 mA s with 24 patterns of scan parameters under several X-ray beam widths, X-ray tube voltages, X-ray tube rotation ...

Cystine stones are often highly resistant to shock wave lithotripsy (SWL), but it has been reported that cystine stones of "rough" morphology are actually quite susceptible to SWL. Based on the observation that rough cystine stones contain void regions that are visible by helical computed tomographic (CT) imaging, we hypothesized ...

The effectiveness of contrast-enhanced ultrasonography (CEUS) in the evaluation of patients with acute renal infarcts was investigated, using contrast-enhanced helical computed tomography (CT) as the reference imaging procedure. Twenty-seven consecutive patients with acute renal infarcts detected with contrast-enhanced helical CT underwent CEUS. Digital cine-clips of CEUS were evaluated by two ...

We describe a new celiac plexus block approach in a patient with cholangiocarcinoma who was referred to the Pain Clinic due to uncontrollable abdominal pain. The patient was initially programmed for a neurolytic celiac plexus block using the anterior approach with helical computerized tomography (CT) guidance. The CT scan revealed ...

AIM: To evaluate a new imaging pathway for the investigation of patients presenting with suspected acute renal colic. MATERIALS AND METHODS: A retrospective review of 500 consecutive cases of suspected acute renal colic was undertaken to evaluate the initial results of a new imaging pathway introduced at our institution, which ...

OBJECTIVES: To retrospectively assess the usefulness of the measurements on preoperative computed tomography (CT) of patients with urinary stone disease for planning the access site using vertical angulation of the C-arm. METHODS: Of the patients who underwent percutaneous nephrolithotomy from November 2001 to October 2006, 41 patients with superior calix ...

OBJECTIVE: This study was designed to determine whether discontinuous CT of the lower extremities for the detection of deep venous thrombosis (DVT) yields results similar to those of complete helical imaging using cases from the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II). MATERIALS AND METHODS: In PIOPED II, ...

PURPOSE: The aim of this study was to improve the contrast-to-noise ratio on noncontrast head computed tomography (CT) images, which are crucial for assessing patients with acute ischemic stroke. We applied a technique combining volume helical scanning with a three-dimensional (3D) denoising filter. MATERIALS AND METHODS: We scanned phantoms for ...

PURPOSE: We determined the value of automated coronal reformation using 64-detector computerized tomography for the detection of urinary stones. MATERIALS AND METHODS: A total of 72 patients underwent unenhanced 64-detector computerized tomography to diagnose urinary stones. Two radiologists independently reviewed coronal reformations and axial images at separate reading sessions. The ...

PURPOSE: We prospectively compared the sensitivity of antegrade pyelography (AGP), plain film radiography (KUB film), and noncontrast thin-slice abdominal CT for detecting residual stones after percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS: We prospectively evaluated 50 patients (53 renal units) who underwent PCNL for radiopaque renal pelvic stones with noncontrast abdominal ...

The diagnostic approach to ureteric colic has changed due to the introduction of new radiological imaging such as non-contrast CT. The role of intravenous urography, which is regarded as the gold standard for the diagnosis of ureteric colic, is being challenged by CT, which has become the first-line investigation in ...

The purpose of this study was to provide an atlas of the normal anatomy of the canine abdomen using helical computed tomographic (CT) images of the abdomen in four mature cross-breed dogs. The dogs were supported in sternal recumbency under general anaesthesia and scans were performed with 5 mm collimation ...

Calcium oxalate monohydrate (COM) stones are often resistant to breakage using shock wave (SW) lithotripsy. It would be useful to identify by computed tomography (CT) those COM stones that are susceptible to SW's. For this study, 47 COM stones (4-10 mm in diameter) were scanned with micro CT to verify ...

PURPOSE: To determine the diagnostic accuracy values of sonography in the detection of renal stones using noncontrast CT as the gold standard. In addition, we correlated the accuracy of sonography with stone size, the kidney affected (right versus left), and body mass index (BMI). METHODS: Fifty patients underwent 2 separate ...

BACKGROUND: Plain radiographic assessment of posterolateral fusion has been reported as accurate in only two thirds of patients who were found to be healed at surgical exploration. Plain radiographic techniques for fusion assessment of interbody fusion with radiolucent cages are reported to be accurate. A helical computed tomography (CT) scan ...

BACKGROUND AND PURPOSE: In patients with a percutaneous nephrostomy tube (PCN) inserted for symptomatic stone disease, antegrade pyelography is an accepted modality to assess the collecting system and residual stone status prior to PCN removal. Recently, unenhanced multidetector CT (UMDCT) has shown its superiority for the assessment of urinary-tract stones. ...

This article discusses the radiologic management of the patient who has acute flank pain. It describes the evolution of radiologic imaging in patients who present with acute symptoms caused by suspected urolithiasis, the advantages of unenhanced helical CT and the limitations of abdominal radiography, intravenous urography, and ultrasonography in this ...

To evaluate the sensitivity and specificity of noncontrast helical computerized tomography (CT) in ureteric colic with comparative evaluation of KUB and ultrasonography (USG). Tertiary care university hospital. One hundred patients aged between 20 and 75 years referred from the emergency department as acute ureteric colic were evaluated with KUB and ...

PURPOSE: To determine the applicability of cone-beam computed tomography (CBCT) in otological imaging, and to compare its accuracy with the routinely used multislice helical CT (MSCT) for imaging of the middle- and inner-ear areas. MATERIAL AND METHODS: Thirteen unoperated human cadaver temporal bones were imaged with CBCT and MSCT. Sixteen ...

PURPOSE OF REVIEW: Congenital abnormities in urology are very common. These abnormalities include calyceal diverticula, which are frequently diagnosed as an incidental finding. Once symptomatic, calyceal diverticula have to be located by accurate imaging and then treated in an appropriate manner. RECENT FINDINGS: Possible methods of treatment in calyceal diverticula ...

To evaluate our initial experience with Helical Computed Tomography (CT) Myelogram in the investigation of spinal abnormalities. As late as 1980, CT was still regarded as unreliable compared with myelography however, the advent of slip-ring technology in the 1990s, in association with the use of more powerful computers and higher ...

PURPOSE: To use CT attenuation numbers as a means of determining the susceptibility of an artificial stone to in-vivo fragmentation with extracorporeal shockwave lithotripsy (SWL). MATERIALS AND METHODS: Four types of artificial kidney stones having different CT attenuation values were used. One randomly selected stone was implanted in the renal ...

BACKGROUND AND PURPOSE: Routine CT of the brain is traditionally performed with sequential CT. We assessed whether sequential CT can be replaced with thinly collimated multisection spiral CT without loss of image quality. MATERIALS AND METHODS: An observer study was conducted using data from 23 patients who were scanned with ...

PURPOSE: To report results from two clinical trials evaluating helical tomotherapy (HT). METHODS AND MATERIALS: Patients were enrolled in one of two prospective trials of HT (one for palliative and one for radical treatment). Both an HT plan and a companion three-dimensional conformal radiotherapy (3D-CRT) plan were generated. Pretreatment megavoltage ...

OBJECTIVE: In urolithiasis with indwelling ureteral stent, an adequate visualization of retained stone is often obscured by the stent. In functional solitary kidney, it is essential to detect retained fragments before stent removal. We examined the capability of non-contrast helical computed tomography (NCHCT) in discriminating stone from stent. PATIENTS AND ...

Accurate imaging is a prerequisite for adaptive radiation therapy of mobile tumours. We present an evaluation of the performance of slow computed tomography (CT) for mapping and delineating the excursion boundary of a moving object using a tumour phantom scanned with the helical MVCT scanner of a tomotherapy unit. A ...

Helical tomotherapy is a volumetric image-guided, fully dynamic, intensity-modulated radiation therapy (IMRT) delivery system. The daily use of its pretreatment megavoltage (MV) CT imaging for patient setup verification allows one to correct for interfraction setup error. This is a primary requirement for the accurate delivery of complex IMRT treatment plans, ...

PURPOSE: The purpose of this study was to analyze the morphologic changes of the airway in obstructive sleep apnea (OSA) patients by helical computed tomography (CT) scanning following maxillomandibular advancement (MMA) surgery. MATERIALS AND METHODS: Twenty consecutive OSA patients treated with MMA from 2000 to 2003 at the University of ...

OBJECTIVES: The purpose of this study was to evaluate and to compare the validity of the different CT image protocols (single- and multislice CT) in the analysis of simulated mandibular condyle lesions. METHODS: Simulated lesions were created in 15 dry mandibles using a dental round burr. The mandibles were then ...

The efficacy of Extracorporeal Shock Wave Lithotripsy (ESWL) depends greatly on the capability to focus shock waves on renal stone. To achieve automatic focusing on moving target, the target must be under tracking. A mesh-based block matching algorithm is proposed for renal stone tracking using ultrasound image sequence. Since multiple ...

OBJECTIVE: The objective of this study was to evaluate the performance of routine helical liver CT in the detection and grading of esophageal varices in cirrhotic patients. MATERIALS AND METHODS: A total of 67 consecutive cirrhotic patients who underwent both upper endoscopy and helical liver CT within a 4-week interval ...

BACKGROUND/AIM: The level of agreement concerning the diagnosis of nephrocalcinosis (NC) based on ultrasonography (US), computed tomography (CT) or kidney/ureter/bladder (KUB) X-ray was assessed. METHODS: Sequences of KUB+US+CT from 62 patients, 48 with at least one exam suggesting NC and 14 with pelvicalyceal calcifications (nephrolithiasis) were reviewed twice by 3 ...

BACKGROUND AND PURPOSE: Noncontrast spiral CT (NCCT) has emerged as the investigation of choice in patients presenting with renal-tract calculi. As management guidelines are based on stone size measured on plain radiography of the kidneys, ureters, and bladder (KUB), it is important to assess the accuracy of stone size measured ...

BACKGROUND AND PURPOSE: To compare helical, MIP and AI 4D CT imaging, for the purpose of determining the best CT-based volume definition method for encompassing the mobile gross tumor volume (mGTV) within the planning target volume (PTV) for stereotactic body radiation therapy (SBRT) in stage I lung cancer. MATERIALS AND ...

This study was a retrospective single-institutional study approved by the Committee on Human Research and was HIPAA compliant. A waiver for informed consent was granted. The purpose of the study was to evaluate the effect of four peak voltage settings on the in vitro conspicuity of gallstones in an anthropomorphic ...

OBJECTIVE: The aim of this prospective study is to determine the diagnostic accuracy of multidetector-row computed tomography (CT) compared to histopathologic findings in tumor staging of renal cell carcinoma, with the focus on tumor stage, vein and artery infiltration, and infiltration of the renal pelvis. MATERIALS AND METHODS: In a ...

Knowledge of the chemical composition and structure of urinary stones is of great value in the choice of treatment and prevention of recurrence. This is a brief review and a comparative study of the principles and practical application of various chemical and physical techniques used for urinary stone analysis. The ...

OBJECTIVE: This prospective blinded comparison of helical CT and helical CT arterial portography aimed to detect liver metastasis from colorectal carcinoma. METHODS AND MATERIALS: 50 patients with colorectal carcinoma were evaluated comparing helical CT with helical CT arterial portography. Each imaging study was evaluated on a 5-point ROC scale by ...

OBJECTIVE: The purpose of this study was to investigate the efficacy of late-phase pulse inversion harmonic imaging (PIHI) in detecting occult metastases and to compare the results with helical computed tomography (CT) in a group of patients whose fundamental liver sonographic results were normal. METHODS: Thirty-two patients (21 women and ...

OBJECTIVE: The purpose of this study was to assess the value of adding a T1-weighted image to MR cholangiopancreatography (MRCP) to detect bile duct stones. MATERIALS AND METHODS: During a 30-month period, 148 patients suspected of having biliary stones and who underwent MRI including MRCP, a fat-suppressed T1-weighted fast low-angle ...

Subjective and objective image quality (IQ) criteria, radiation doses, and acquisition times were compared using incremental monoslice, incremental multislice, and helical multislice acquisition techniques for routine unenhanced brain computed tomography (CT). Twenty-four patients were examined by two techniques in the same imaging session using a 16-row CT system equipped with ...

Percutaneous renal stone surgery requires detailed imaging to define stone burden and delineate the anatomy of the kidney and nearby organs. It is also essential to carry out safe percutaneous access and to assess postoperative outcomes. The emergence of CT as the imaging modality of choice for detecting renal calculi ...

BACKGROUND: Dynamic three-dimensional computed tomography (D-3DCT: high-speed helical scanning during defecation) was used for morphological evaluation of intrapelvic structures in patients with rectal prolapse and rectocele. METHODS: Twenty-five patients with rectal prolapse or rectocele diagnosed by conventional defecography (CD) or clinical findings were additionally investigated with D-3DCT. D-3DCT images were ...

OBJECTIVE: The purpose of this study was to compare conventional high-resolution CT (HRCT) with helical 16-MDCT in the detection of bronchiectasis. MATERIALS AND METHODS: We retrospectively evaluated 80 patients including 61 with bronchiectasis (mean age, 64 years; range, 22-87 years) and a control group of 19 patients with normal MDCT ...

BACKGROUND: We determined the accuracy of combined unenhanced and contrast-enhanced helical computed tomography (CT) for diagnosis of bile duct stones. METHODS: During a 12-month period, 1090 patients who underwent combined CT and endoscopic retrograde cholangiography (ERC) or percutaneous transhepatic cholangioscopy (PTC) were enrolled in this study. The results of prospective ...

BACKGROUND: The purpose of this study was to evaluate the benefit of additional prone CT scanning to helical CT screening to detect early interstitial lung disease (ILD). METHODS: Helical CT screening was performed as an optional test in 1098 subjects during their annual health examination. Subjects with parenchymal abnormalities in ...

OBJECTIVE: High reproducibility on coronary artery calcium (CAC) scoring is a key requirement in monitoring the progression of coronary atherosclerosis. Retrospective ECG-gated helical CT has been shown to be superior to prospective gating helical CT in the reproducibility of CAC measurements. However, it brings with it a high level of ...

OBJECTIVES: To test, for the first time, the predictive capability of the total stone volume (TSV) and the attenuation value histogram. Recently, the mean attenuation value (MAV) of urinary stones has been recognized as a predictor of fragility by extracorporeal shock wave lithotripsy. However, properties other than MAV, including the ...

BACKGROUND: Tracheal agenesis is a rare and usually lethal anomaly. In the past, opaque contrast medium was injected via the esophagus to demonstrate the anatomy. OBJECTIVE: To demonstrate the utility of helical and multidetector CT in delineating the aberrant anatomy in newborns with tracheal agenesis. MATERIALS AND METHODS: Four newborns ...

Tomotherapy is the delivery of intensity modulated radiation therapy using rotational delivery of a fan beam in the manner of a CT scanner. In helical tomotherapy the couch and gantry are in continuous motion akin to a helical CT scanner. Helical tomotherapy is inherently capable of acquiring CT images of ...