ABSTRACT
AIM: To evaluate prospectively the improvement in the signal:noise ratio (SNR), with the use of parallel technique in single breath-hold diffusion-weighted imaging (DWI) of the liver and its affect on apparent diffusion coefficient (ADC) measurements. MATERIALS AND METHODS: This study was approved by our institutional review board. Written informed consent was obtained from all participants. Fifteen patients underwent single breath-hold DWI of the liver with and without parallel imaging technique. SNR and ADC values were measured over a lesion-free right hepatic lobe by two radiologists in both series. When a focal hepatic lesion was present the contrast:noise ratio (CNR) and ADC were also measured. Paired Student's t-tests were used for statistical analysis. RESULTS: Mean SNR values of the liver were 20.82+/-7.54 and 15.83+/-5.95 for DWI with and without parallel imaging, respectively. SNR values measured in DWI using parallel imaging were found to be significantly higher (p<0.01). Mean ADC of the liver were 1.61+/-0.45 x 10(-3)mm(2)/s and 1.56+/-0.28 x 10(-3)mm(2)/s for DWI with and without parallel imaging, respectively. No significant difference was found between the two sequences for hepatic ADC measurement (p>0.05). Overall lesion CNR was found to be higher in DWI with parallel imaging. CONCLUSION: Parallel imaging is useful in improving SNR of single breath-hold DWI of the liver without compromising ADC measurements.
Subject(s)
Liver Diseases/diagnosis , Liver/pathology , Magnetic Resonance Imaging/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Adult , Carcinoma/diagnosis , Carcinoma/secondary , Carcinoma, Hepatocellular/diagnosis , Colonic Neoplasms/pathology , Female , Hemangioma/diagnosis , Humans , Liver Neoplasms/diagnosis , Male , Middle Aged , Prospective Studies , Retrospective Studies , Sensitivity and SpecificityABSTRACT
BACKGROUND AND PURPOSE: Optimal estimation of cerebral blood-flow volume (BFV) may be an important indicator for better evaluation of the patients with cerebrovascular disorders. In this study, we compared the BFV values at bilateral internal carotid and vertebral arteries of healthy volunteers obtained with color Doppler, power Doppler, and B-flow ultrasound (US) studies and tried to determine which examination is more correlated with MR phase-contrast quantification. METHODS: BFVs of the internal carotid and vertebral arteries of 40 healthy volunteers (19 men and 21 women; age range, 20-47 years) were measured by using color Doppler, power Doppler, B-flow US and MR phase-contrast imaging. The flow measurements obtained with the sonographic techniques were compared with MR phase contrast, which is accepted as the most reliable method for the estimation of cerebral BFV. RESULTS: Quantification with power Doppler imaging showed the highest values among sonography techniques, followed by color Doppler imaging, B-flow imaging (BFI), and MR phase-contrast flow quantification. There was a statistically significant difference between the flow-volume values obtained with these 4 different techniques (P < .05). BFI yielded the closest values (internal carotid arteries, 238.84 mL/min; vertebral arteries, 51.16 mL/min) to MR phase-contrast flow quantification study with higher correlation rates. CONCLUSION: Flow volumes obtained with BFI showed the highest correlation with MR phase-contrast imaging among 3 different sonography techniques. B-flow sonography may be a very effective and cost-efficient alternative for MR phase-contrast studies for the calculation of cerebral BFV.
Subject(s)
Blood Flow Velocity/physiology , Blood Volume/physiology , Carotid Artery, Internal/physiology , Echoencephalography/methods , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Magnetic Resonance Angiography/methods , Vertebral Artery/physiology , Adult , Female , Humans , Male , Mathematical Computing , Middle Aged , Reference Values , Sensitivity and SpecificityABSTRACT
Intestinal pneumatosis is a relatively rare condition that has been associated with a wide variety of abnormalities. Traditionally, this entity has been diagnosed by radiographic films, contrast series, or more accurately by computed tomography. However, reports describing findings of intestinal pneumatosis on sonographic examination, which is an important initial diagnostic tool for abdominal diseases, are limited. We suggest that twinkling artifact may be of value in the sonographic diagnosis of this condition. We report two cases of intestinal pneumatosis that were diagnosed initially by sonography with the aid of twinkling artifact.
Subject(s)
Artifacts , Pneumatosis Cystoides Intestinalis/diagnostic imaging , Aged , Aged, 80 and over , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Tomography, X-Ray Computed , Ultrasonography, Doppler, ColorABSTRACT
The presence of portal and systemic venous gas is traditionally regarded as an ominous radiological sign indicating a grave prognosis. With advances in imaging technology, the incidence of its detection has increased along with its association with clinically benign disorders. We present a young patient with systemic and portal venous gas after traumatic lumbar puncture.
