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Sanjay Saini

Publications and source records attributed to Sanjay Saini.

At least 55 records · Page 3Linked to original sources
PubMed2002

The role of magnetic resonance cholangiopancreatography in patients with suspected biliary obstruction.

Endoscopic retrograde cholangiopancreatography (ERCP) is an accepted and accurate procedure that combines the advantage of diagnosis of biliary obstruction with possible therapeutic endobiliary intervention. However, it is an operator-dependent and invasive procedure that is associated with complications and limitations. Magnetic resonance cholangiopancreatography (MRCP) is a unique noninvasive technique for the diagnosis of biliary obstruction. It is well suited to provide the information required to plan the optimal therapeutic approach for these patients. MRCP has the potential to replace or at least precede ERCP as the first-line imaging effort in the evaluation of suspected biliary obstruction. Significant advantages and some notable limitations inherent to the modality dictate its judicious use in appropriate circumstances. The present article reviews the utility of MRCP in evaluation of biliary obstruction, with brief reference to its principles and techniques.

Adenocarcinoma↗
PubMed2002

Cystic pancreatic neoplasms evaluation by CT and magnetic resonance cholangiopancreatography.

CT provides limited assistance in the differentiation between serous and mucinous neoplasms. Because of the variability in the radiographic appearance of serous cystadenomas and overlap in CT characteristics with mucinous neoplasms, most serous neoplasms still require ancillary testing such as biopsy to reach a definitive diagnosis. MRCP is useful in differentiating benign and malignant mucinous tumors including IPMT of the pancreas. The presence of mural nodules is suggestive of malignancy; however, the absence of mural nodules does not indicate that the tumor is benign. A maximum main pancreatic duct diameter of greater than 15 mm and diffuse dilatation of the main pancreatic duct are suggestive of malignancy in main duct-type tumors. Among branch duct-type tumors, malignant tumors tend to be larger than benign tumors; however, this finding is variable. The presence of main pancreatic duct dilatation may be helpful in determining malignancy of branch duct-type tumors.

Biopsy↗
PubMed2002

Multimodality diagnosis of liver tumors: feature analysis with CT, liver-specific and contrast-enhanced MR, and a computer model.

RATIONALE AND OBJECTIVES: The purpose of this study was to measure and to clarify the diagnostic contributions of image-based features in differentiating benign from malignant and hepatocyte-containing from non-hepatocyte-containing liver lesions. MATERIALS AND METHODS: Six experienced abdominal radiologists each read images from 146 cases (including a contrast material-enhanced computed tomographic [CT] scan and contrast-enhanced and unenhanced magnetic resonance [MR] images) following a checklist-questionnaire requiring them to rate quantitatively each of as many as 131 image features and then reported on each of the two differentiations. The diagnostic value of each feature was assessed, and linear discriminant analysis was used to develop statistical prediction rules (SPRs) for merging feature data into computerized "second opinions." For the two differentiations, accuracy (area under the receiver operating characteristic curve [Az]) was then determined for the radiologists' readings by themselves and for each of three SPRs. RESULTS: Thirty-seven candidate features had diagnostic value for each of the two differentiations (a slightly different feature set for each). Radiologists' performance at both differentiations was excellent (Az = 0.929 [benign vs malignant] and 0.926 [hepatocyte-containing vs non-hepatocyte-containing]). Performance of the SPR that operated on the features from all modalities together was better than that of radiologists (Az = 0.936 [benign vs malignant] and 0.951 [hepatocyte-containing vs non-hepatocyte-containing]), but this difference was of marginal statistical significance (P = .11). Contrast-enhanced MR imaging and contrast-enhanced CT each made significant adjunctive contributions to accuracy compared with unenhanced MR imaging alone. CONCLUSION: Many CT- and MR imaging-based features have diagnostic value in differentiating benign from malignant and hepatocyte-containing from non-hepatocyte-containing liver lesions. Radiologists could also benefit from the fully informed SPR's "second opinions."

Adult↗
PubMed2002

CT tumor measurement for therapeutic response assessment: comparison of unidimensional, bidimensional, and volumetric techniques initial observations.

PURPOSE: To compare unidimensional, bidimensional, and volumetric techniques for evaluation of treatment response in patients with liver metastases from breast cancer in a phase III clinical trial. MATERIALS AND METHODS: Helical computed tomographic (CT) studies in 38 patients with liver metastases from breast cancer who were enrolled in a phase III clinical trial were evaluated before treatment and at 6 months after treatment. Two subspecialty radiologists measured all lesions on transverse CT scans with use of electronic calipers according to both unidimensional and bidimensional criteria. Volumetric measurements were made by tracing individual lesions. Measurements of individual lesions were summed to obtain patient response, which was categorized as complete response, disappearance of lesions; partial response, greater than 30% decrease in tumor diameter (unidimensional), greater than 50% reduction in tumor area (bidimensional), or greater than 65% reduction in tumor volume (volumetric); disease progression, greater than 20% increase in tumor diameter, greater than 25% increase in tumor area, or greater than 73% increase in tumor volume: or stable disease (size response other than that of complete response, partial response, or disease progression). RESULTS: In 37 patients, there was concordant treatment response with use of unidimensional and bidimensional techniques. Volumetric measurement produced results different from those of the unidimensional and bidimensional techniques in 12 and 13 patients, respectively. In six patients with partial response per unidimensional and bidimensional criteria, the response based on the volumetric technique was stable disease. In two patients with stable disease per bidimensional and unidimensional criteria, the response was partial response by volumetric measurement. In four patients with disease progression per bidimensional and unidimensional criteria, the response was stable disease per volumetric criteria. CONCLUSION: Volumetric measurement of tumor burden gives different results for treatment response compared with that of the unidimensional or bidimensional technique in a considerable proportion of patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Using multidetector CT for preoperative vascular evaluation of liver neoplasms: technique and results.

OBJECTIVE: The purpose of our study was to evaluate the performance of CT angiography using multidetector CT (MDCT) for preoperative vascular evaluation in candidates who were scheduled for liver neoplasm resection. SUBJECTS AND METHODS: Forty-two consecutive subjects with malignant liver tumors scheduled for resection were studied with multiphase MDCT. The first 22 subjects underwent both multiphase MDCT angiography and catheter angiography before surgery. The subsequent 20 subjects underwent only preoperative CT angiography. Postprocessing was performed, and the images were analyzed for the depiction of arterial, portal vein, and hepatic vein anatomy and for the identification of important vascular variants. The postprocessing findings were compared and correlated with the findings from catheter angiography (22/42) or intraoperative sonography (42/42) and surgery (42/42). RESULTS: Arterial anomalies were detected on the images of 17 of 42 patients, including a replaced right hepatic artery in five, replaced left hepatic artery in six, accessory right and left hepatic arteries in two, common trunk for the celiac and superior mesenteric arteries in one, and early bifurcation of the celiac artery in one. In 22 patients in whom catheter angiography confirmation was available, the number of arteries and almost all the significant anomalies were correctly identified on CT angiography (accuracy, 97%; sensitivity, 94%; specificity, 100%). In the subset of 20 patients who underwent MDCT angiography without catheter angiography confirmation, all clinically relevant information was provided by CT angiography. The portal and hepatic vein anatomy and the relationships of the liver tumors to the neighboring venous structures were shown on CT. CONCLUSION: Multidetector CT provides valuable preoperative information about hepatic vascular architecture and can be used as a noninvasive alternative to catheter angiography before oncologic liver surgery.

Adult↗
PubMed2002

Clinical comparison of standard-dose and 50% reduced-dose abdominal CT: effect on image quality.

OBJECTIVE: We hypothesized that radiation doses for abdominal CT could be reduced by adjusting the dose for a patient's weight and cross-sectional abdominal dimensions, with the resultant scans still being of diagnostic quality. SUBJECTS AND METHODS: Using a multidetector CT scanner, we prospectively studied 39 patients who were 65 years and older who had a known history of cancer. After performing a diagnostic contrast-enhanced CT examination, we obtained four slices each (centered at the top of the right kidney) at a standard radiation dose (240-300 mA) and at a 50% reduced dose (120-150 mA) at a constant kilovoltage of 140. Scans were obtained during a single breath-hold, with a 2.5-mm detector configuration and a slice pitch of 6:1. Reconstructed slice thickness was 5 mm. In a blinded review, two radiologists rated the randomized CT scans for overall image quality and anatomic details of liver, spleen, adrenal glands, kidneys, pancreas, and abdominal wall, using a 5-point scale (1 = unacceptable, 2 = substandard, 3 = acceptable, 4 = above average, and 5 = superior). Patients' weight and abdominal circumference, area, and anteroposterior and transverse diameters were correlated with image quality of scans obtained at standard-dose and 50% reduced-dose CT. Statistical analysis of the data was performed using Wilcoxon's signed rank test. RESULTS: Overall, the image quality score was significantly higher (p < 0.005) on the scans obtained with standard-dose CT. No statistically significant difference in image quality was noted in the 50% reduced- and standard-dose CT scans in patients who weighed less than 180 lb, or 81 kg, (p > 0.05) and who had a transverse abdominal diameter of less than 34.5 cm (p > 0.05), an anteroposterior diameter of less than 28 cm (p > 0.05), a cross-sectional circumference of less than 105 cm (p > 0.05), and a cross-sectional area of less than 800 cm(2) (p > 0.05). Good interobserver agreement (p > 0.5) was found between the two reviewing radiologists. CONCLUSION: Abdominal CT scan quality appears to be acceptable even with a 50% reduction in radiation dose except in patients with large anthropometric measurements. A reduction in CT radiation dose is possible if the tube current is optimized for the patient's weight and abdominal dimensions.

Abdomen↗
PubMed2002

Pseudoenhancement of simulated renal cysts in a phantom using different multidetector CT scanners.

OBJECTIVE: We undertook this study to determine whether pseudoenhancement of renal cysts occurs on scans obtained with multidetector CT (MDCT) scanners and whether the effect is influenced by scanning parameters. MATERIALS AND METHODS: A kidney phantom with varying attenuation was created to simulate different levels of renal parenchymal enhancement (150 and 250 H). Two water-filled cylinders simulating renal cysts-one with a 5-mm diameter and one with a 15-mm diameter-were suspended in the "kidney." After validating the pseudoenhancement effect produced in our phantom model with a single-detector helical CT scanner, we investigated the effect with matrix array and adaptive array MDCT scanners using detector configurations of 1.25 and 2.5 mm and beam pitches of 0.75:1.0 and 1.5:1.0 at an effective reconstructed slice thickness of approximately 3 mm. Three sets of experiments were performed at each setting, and mean cyst density was measured. Data were statistically analyzed using the Student's t test and multiple logistic regression analysis when appropriate. RESULTS: Although pseudoenhancement was observed with MDCT scanners, the effect was statistically significant only for scans depicting the smaller cyst at a background renal density of 250 H on the matrix array MDCT. Modulation of scanning parameters did not alter these findings. Pseudoenhancement was significantly higher with the matrix array MDCT scanner than with the adaptive array MDCT scanner (p < 0.05). CONCLUSION: In our phantom model, high levels of renal enhancement produced pseudoenhancement in small renal cysts with different models of MDCT scanners, irrespective of pitch or detector configuration.

Humans↗
PubMedDate not supplied

Right-sided colonic diverticulitis: CT findings.

Right-sided colonic diverticulitis is an uncommon but clinically significant condition as it closely mimics other common acute right-sided abdominal conditions like acute appendicitis and cholecystitis. CT can provide a rapid and accurate diagnosis of this condition and thereby prevent unnecessary laparotomy and surgical procedures since it is essentially a benign self-limiting condition requiring medical treatment. It is the aim of this pictorial essay to describe the CT findings and increase awareness among radiologists of this condition.

Acute Disease↗
PubMedDate not supplied

Functioning acinar cell pancreatic carcinoma: diagnosis on mangafodipir trisodium (Mn-DPDP)-enhanced MRI.

We describe the imaging findings of a functional pancreatic acinar cell carcinoma in a patient who presented with weight loss, hyperlipasemia, and multiple foci of subcutaneous fat necrosis. The tumor invaded the adjacent splenic and portal vein, causing isolated left-sided portal hypertension. At MRI, the tumor showed marked enhancement following administration of the hepatobiliary-specific contrast agent mangafodipir trisodium (Mn-DPDP), thereby demonstrating the functional nature of the tumor. Avid uptake of Mn-DPDP by a functioning pancreatic tumor has not been reported in the radiology literature.

Aged↗
PubMedDate not supplied

Contrast-enhanced MRI of the liver with mangafodipir trisodium: imaging technique and results.

Magnetic resonance (MR) contrast agents are now routinely used for detecting and characterizing focal liver lesions. Liver specific, hepatobiliary, MRI contrast agent mangafodipir trisodium (Mn-DPDP) is taken up by the functioning hepatocytes and excreted by the biliary system. Contrast uptake leads to persistent elevation of T1-weighted signal of normal liver parenchyma within 10 minutes of injection. Most tumors of non-hepatocellular origin typically are hypointense relative to enhanced liver parenchyma on T1 weighted images and are more conspicuous than on unenhanced images. Whereas, tumors of hepatocellular origin such as focal nodular hyperplasia (FNH), adenoma, and well-differentiated hepatocellular carcinomas (HCC) have been shown to accumulate Mn-DPDP, providing characterization information to discriminate hepatocellular from non-hepatocellular tumors. The purpose of this pictorial essay is to illustrate the appearance of various liver tumors on mangafodipir enhanced liver MR imaging.

Adult↗
PubMedDate not supplied

Current status of imaging in pancreatic diseases.

Recent technological developments in multidetector CT allow pancreatic imaging in a single breath-hold, which is especially valuable in obtaining isotropic three-dimensional reformations that improve our ability to provide accurate preoperative vascular mapping. Advanced MR technology allows faster imaging of pancreas, thus facilitating MR cholangiopancreatography. Use of tissue-specific MR contrast agents, endoscopic ultrasound, and positron emission tomography (PET) in pancreatic imaging has evolved considerably. This review article discusses the roles of CT, MR, endoscopic ultrasound, and PET imaging in the pancreas.

Acute Disease↗
PubMedDate not supplied

CT characterization of "indeterminate" renal masses: targeted or comprehensive scanning?

PURPOSE: A comprehensive renal mass evaluation CT protocol is usually performed for simultaneous characterization and staging of incidentally discovered renal masses considered indeterminate on ultrasound (US). The purpose of the study was to determine if a comprehensive examination is appropriate in these patients. MATERIALS AND METHODS: The authors performed a retrospective review of 100 patients (mean age, 61 years) with 102 sonographically indeterminate renal masses and who were referred to undergo CT for lesion characterization. Lesions were classified according to surgical histology or imaging follow-up evaluation. Statistical analysis was performed. RESULTS: Thirteen lesions (12.7%) in 11 (11%) patients (mean age, 59 years) were malignant. Eighty-seven lesions (85.3%) in 87 patients (87%; mean age, 62 years) were benign. Two lesions (1.96%) in two patients (2%) remained indeterminate. CONCLUSION: Although comprehensive renal mass evaluation protocol provides a more thorough patient evaluation, only a small fraction of indeterminate renal masses seen on US are malignant. The authors' results suggest a targeted renal CT imaging protocol for evaluation of indeterminate renal masses incidentally discovered on US.

Adult↗
PubMedDate not supplied

Comparison between low (3:1) and high (6:1) pitch for routine abdominal/pelvic imaging with multislice computed tomography.

PURPOSE: The purpose of this study was to compare the performance of low helical pitch acquisition (3:1) and high helical pitch acquisition (6:1) for routine abdominal/pelvic imaging with multislice computed tomography (CT). METHOD: Three hundred eighty-four patients referred for abdominal/pelvic CT were examined in a breath-hold on a multislice CT scanner (LightSpeed QX/I; General Electric Medical Systems, Milwaukee, WI). Patients were randomized and scanned with pitch of 3:1 or 6:1 using a constant 140 peak kV and 280-300 mA. Images were reconstructed at a 3.75-mm slice thickness. Direct comparison between the two pitches was possible in a subset of 40 patients who had a follow-up scan performed with the second pitch used in each patient. A comparison was also performed between standard dose CT using a pitch of 6:1 and 20% reduced radiation dose CT using a pitch of 3:1. Two readers performed a blind evaluation using a three-point scale for image quality, anatomic details, and motion artifacts. Statistical analysis was performed using a rank sum test and the Wilcoxon signed rank test. RESULTS: Overall image quality mean scores were 2.5 and 2.3 for a pitch of 3:1 and a pitch of 6:1, respectively (P = 0.134). Likewise, mean anatomic detail and motion artifact scores were 2.5 and 2.6 for a 3:1 pitch and 2.3 and 2.5 for a 6:1 pitch, respectively (P > 0.05). In patients with a direct comparison of the two pitches (with the standard radiation dose as well as with a 20% reduction in milliamperes), no statistically significant difference in the performance of the two pitches was observed (P > 0.05). CONCLUSION: Image quality with a high pitch (6:1) is acceptable for routine abdominal/pelvic CT.

Adult↗