Evaluation of benign salivary gland disorders comparative study of MR sialography and digital subtraction sialography

To evaluate the accuracy of magnetic resonance [MR] sialography in detecting salivary glandular calculi and ductal stenosis. MR sialography has become an alternative imaging technique for ductal salivary gland diseases. We compared the diagnostic accuracy of MR sialography and digital subtraction sialography in patients with benign salivary gland disorders. In our study, we attempted to examine salivary glands in 65 patients with clinically suspected diagnoses of sialadenitis and/or sialolithiasis. Each patient underwent digital subtraction sialography and MR sialography. MR sialography was obtained with a T2-weighted single-shot turbo spin-echo sequence [TR/TE 2800/1100 msec, acquisition time 7 seconds], with use of a quadrature head coil. Final diagnoses were confirmed by clinical follow-up and results of biopsy [n = 9] or surgery [n = 19]. Eighty-one salivary glands [48 parotid, 33 submandibular] in 65 patients were successfully visualized with both modalities. MR sialography depicted the main ductal system and first- and second-order branches, whereas digital subtraction sialography was able to depict third-order branches. Sensitivity and specificity to diagnose chronic sialadenitis were 70% and 98% with MR and 96% and 100% with digital subtraction sialography. MR sialography enabled diagnosis of sialolithiasis with a sensitivity of 80% and a specificity of 98% versus 90% and 98% for each with digital subtraction sialography. MR sialography with a heavily T2-weighted sequence is highly successful in the noninvasive visualization of the ductal system of major salivary glands. It is useful for diagnosing sialolithiasis and sialadenitis. Digital subtraction sialography, an invasive technique, had a substantial procedural failure rate, particularly for the submandibular duct. However, because of its higher spatial resolution, successfully completed digital subtraction sialography achieved superior diagnostic information compared with that of MR sialography

Evaluation the upper urinary tract with MR virtual endoscopy

We investigated the feasibility of applying surface-rendered virtual endoscopy to the visualization of the upper urinary tract by processing unenhanced MR urography data sets. Twenty-six patients, having neoplastic lesions [n = 9], calculi [n = 8], pelviureteric junction stenoses [n = 4], postoperative fibrotic strictures [n = 3], and extrinsic compressions of the ureter [n = 2], underwent unenhanced MR urography. Virtual endoscopy of the upper urinary tract was obtained using a thresholding technique and surface-rendering MR urography data sets. Virtual endoscopy of the renal pelvis and calices was feasible in all cases on the side of the urinary obstruction. Virtual endoscopy of the ureter was obtained for a diameter of at least larger than 5 mm. The nondilated side could be partially explored in 11 cases [43%]. The mean virtual endoscopy threshold required for the visualization of the urinary tract was 157.36-159.94. The mean time for virtual endoscopy was 13.8 min. Endoluminal masses were found in three [12%] of 26 cases on the renal pelvis [corresponding to neoplastic lesions], and occlusions, in 23 [88%] of 26 on the pelviureteric junction and ureter [neoplastic lesions and other abnormalities]. Virtual endoscopy of MR urography data sets is feasible in patients with urinary tract dilatation. Virtual endoscopy displays the renal pelvis, calices, and ureter and, moreover, can show endoluminal changes caused by abnormalities

Comparison of MR enteroclysis images and conventional enteroclysis in small-bowel disease

To investigate if magnetic resonance [MR] enteroclysis can be performed routinely and to compare MR enteroclysis findings with those of conventional enteroclysis. MR enteroclysis was performed in 30 patients with symptoms of inflammatory bowel disease or small-bowel obstruction [SBO]. A methylcellulose-water solution was used to distend the small bowel. To monitor dynamic changes in the small bowel, a single-shot fast spin-echo T2-weighted sequence was applied. For morphologic assessment, breath-hold T2-weighted fast spin-echo and coronal T1-weighted gradient-recalled-echo MR images were obtained without and with gadolinium enhancement. Image quality and degree of small-bowel distention were graded. MR imaging findings and degree of SBO were compared with findings at conventional enteroclysis [n = 25]. MR enteroclysis was well tolerated and provided adequate image quality and sufficient small-bowel distention. SBO grade based on MR enteroclysis images [n = 10] was identical to that based on conventional enteroclysis images [n = 6]. MR findings were identical to those at enteroclysis in 23 patients, superior in six patients, and inferior in one patient. MR enteroclysis can be performed routinely with adequate image quality and sufficient small-bowel distention. The functional information provided by MR enteroclysis is identical to that provided at conventional enteroclysis

Imaging findings in intrahepatic portal venous shunts

The purpose of this study was to discover and describe the imagining findings of intrahepatic portal venous shunts. In our study, we attempted to discover and describe the imagining findings of intrahepatic portal venous shunts in 22 patients [9 men and 13 women]. The average age of the patients was 71.2 years [range, 43-90 years]. Each patient underwent CT, MRI, and sonography. Images were reviewed and intrahepatic portal venous shunts were identified. This yielded 25 intrahepatic portal venous shunts in 22 patients. Twenty-four [96%] of 25 intrahepatic portal venous shunts were located between a portal vein branch and a hepatic vein .One of 25 communicated with the inferior vena cava. Nineteen patients had a solitary intrahepatic portal venous shunt, 15 in the left lobe and 4 in the right lobe. Three patients had two intrahepatic portal venous shunts [3/22, 13.6%]: Two had one in each lobe and one had two in the left lobe. Intrahepatic portal venous shunts are common,. They may appear in patients with healthy livers and in patients with portal hypertension. Most shunts in our series were in the left lobe and had aneurysmal communication between the portal and hepatic veins. CT, MRI and Color Doppler ultrasonography are capable of showing and differentiating different types of hepatic portal venous shunts

Blood-flow volume quantification in internal carotid and vertebral arteries: using of 3 different ultrasound techniques - comparison with phase-contrast MR imaging

Optimal estimation 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. 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. 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. Flow volumes obtained with BFI showed the highest correlation with MR phase-contrast imaging among 3 different sonographic techniques. B-flow sonography may be a very effective and cost-efficient alternative for MR phase-contrast studies for the calculation of cerebral BFV

Role of helical computed tomography and duplex sonography in evaluation of the lower extremity veins in patients with suspected pulmonary embolism

The purpose of this study was to evaluate the role of gray scale and color Doppler appearances and applications of Helical CT in evaluation of patients with suspected venous thromboembolic disease. In patients undergoing a combined CT angiography and venography, the accuracy of helical CT venography for the detection of deep venous thrombosis was compared with that of lower extremity Duplex sonography. Seventy consecutive patients with clinically suspected pulmonary embolism underwent both combined CT angiography and venography and bilateral leg sonography within 24 hr. The final reports were evaluated for the presence or absence of deep venous thrombosis and the final assessment based on multiple subjective and objective clinical and imaging criteria was recorded in three categories: 1, CT venography better than sonography; 2, CT venography equivalent to sonography; and 3, sonography better than CT venography. Sixty-eight patients [97%] had a satisfactory or good quality CT venography examination. Two CT venography studies had false-positive findings due to flow artifacts. Both CT venography and sonography had positive findings for deep venous thrombosis in five patients, and both had negative findings in 63 patients. CT venography was better and more efficacious than sonography [category 1] in 25 patients [36%]. CT venography was equivalent to sonography [category 2] in 26 patients [37%], and sonography was better than CT venography [category 3] in 19 patients [27%]. Compared with sonography, CT venography is a relatively accurate method for evaluation of deep venous thrombosis. Combined CT pulmonary angiography and CT venography may be more efficacious than, sonography and CT