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Biomedical subjects

J T Ferrucci

Publications and source records attributed to J T Ferrucci.

At least 37 records · Page 2Linked to original sources
PubMed1997

CT colonoscopy of colorectal neoplasms: two-dimensional and three-dimensional virtual-reality techniques with colonoscopic correlation.

OBJECTIVE: The aim of this study was to compare the diagnostic accuracy of two-dimensional (2D) CT colonography and three-dimensional (3D) virtual colonoscopy with conventional colonoscopy in patients who have suspected colorectal neoplasms. SUBJECTS AND METHODS: Twenty patients were studied (eight women and 12 men; mean age, 53 years; range, 42-85 years). All patients had findings on conventional colonoscopy suggestive of colorectal carcinoma and underwent colonic CT within 3 hr of endoscopy. Two-dimensional CT colonography and 3D virtual colonoscopy images were generated from the same data set that was obtained from thin-section helical CT of the abdomen and pelvis after rectal insufflation of room air. Three-dimensional virtual colonoscopy images were obtained by downloading CT data to a workstation equipped with commercially available software. Volume- and perspective-rendering techniques were used to achieve interactive, 3D virtual "fly-through" examinations of the colonic mucosa. The results of 2D CT colonography and 3D virtual colonoscopy were compared with the findings of conventional colonoscopy and correlated with surgical and pathologic outcome where possible. RESULTS: Twenty masses (defined as intraluminal projections 2 cm or larger in diameter) and 15 polyps (defined as projections smaller than 2 cm in diameter) were identified in our study group. All masses and 14 of 15 polyps were successfully shown on 2D colonography. Three findings of polyps on 2D colonography were false-positive, and one was false-negative. Three-dimensional virtual colonoscopy revealed 19 of 20 masses and 13 of 15 polyps. On conventional colonoscopy, all 20 masses and 13 of 15 polyps were identified, with one false-positive finding of a malignant stricture in a normal colon. Complete examination of the colon was possible in 18 of 20 patients using the 2D technique and in 17 of 20 patients using 3D virtual colonoscopy, whereas conventional colonoscopy showed the entire colon in only 12 of 20 patients. CONCLUSION: Two-dimensional CT colonography and 3D virtual colonoscopy are complementary and effective techniques for examining the colon in patients with suspected colorectal carcinoma. CT techniques offer several advantages over conventional colonoscopy including the ability to detect abnormalities proximal to obstructing carcinomas, accurate localization of abnormalities within the colon, and good patient tolerance. These CT techniques may play an important role in future diagnosis of colorectal cancer and for screening patients at risk.

Colonic Polyps↗
PubMed1996

Magnetic resonance cholangiography: comparison with endoscopic retrograde cholangiopancreatography.

BACKGROUND & AIMS: Magnetic resonance cholangiography (MRC) is a noninvasive diagnostic modality capable of producing high-quality images of the biliary tree. The purpose of this study was to determine in a prospective, blinded fashion the sensitivity and specificity of three-dimensional fast spin-echo (3D FSE) MRC for the evaluation of biliary tract abnormalities. METHODS: Forty-six patients referred for elective direct cholangiography (45 endoscopic retrograde cholangiopancreatography and 1 percutaneous transhepatic cholangiography) were studied prospectively with 3D FSE MRC during a 1-year period. All images were interpreted blindly by two radiologists. The presence of dilatation, strictures, and intraductal abnormalities was recorded. Sensitivity and specificity of 3D FSE MRC were determined using findings on direct cholangiography as the gold standard. RESULTS: MRC images of diagnostic quality were obtained in 44 (95.7%) of the patients. Sensitivity for the detection of bile duct dilatation (n = 27), biliary strictures (n = 10), and intraductal abnormalities (n = 7) was 96.3%, 90%, and 100%, respectively. In addition, the MRC showed 16 of 17 patients with normal bile ducts (specificity, 94.1%). CONCLUSIONS: MRC has a very high sensitivity and specificity in the evaluation of the biliary tract. Based on these data, we believe that the efficacy of MRC using 3D FSE is sufficient to warrant its use in the routine diagnosis of biliary tract disease.

Adolescent↗
PubMed1996

MR cholangiopancreatography after unsuccessful or incomplete ERCP.

PURPOSE: To assess the value of magnetic resonance (MR) cholangiopancreatography in patients in whom endoscopic retrograde cholangiopancreatography (ERCP) was unsuccessful or did not completely delineate ductal abnormalities. MATERIALS AND METHODS: MR cholangiopancreatography was performed in 37 consecutive patients because ERCP was unsuccessful (n = 20), postsurgical biliary-enteric anatomy was present (n = 10), or evidence of complete pancreatic duct obstruction was found ar ERCP (n = 7). RESULTS: MR cholangiopancreatography was successful in all patients. Eleven patients had normal MR findings and required no further intervention. Eight patients has abnormalities that were detected with MR but were followed up clinically. Eleven patients subsequently underwent laparotomy, three underwent therapeutic percutaneous transhepatic cholangiography (PTC), two underwent diagnostic (PTC), and one underwent ultrasound-guided biopsy. CONCLUSIONS: MR cholangiopancreatography plays an important role in the care of patients in whom ERCP is unsuccessful or incomplete and when technical difficulties can be anticipated.

Bile Duct Diseases↗
PubMed1995

Cellular uptake and trafficking of a prototypical magnetic iron oxide label in vitro.

RATIONALE AND OBJECTIVES: Target-specific magnetic resonance (MR) contrast agents are being developed to improve the accuracy of MR imaging. The purpose of this study was to determine the mechanism of cell uptake, and modes of intracellular trafficking of a prototypical iron oxide label (RMA) used in the synthesis of some target-specific MR contrast agents. METHODS: The prototypical agent (RMA) consisted of a dextran-coated monocrystalline iron oxide that was modified with rhodamine (fluorescent label) and opsonized with albumin. Fluorescence microscopy was performed in a phagocytic C6 cell line and in murine bone marrow macrophages. Immunohistochemistry against lysosomal markers was used to confirm the intracellular location of the label. RESULTS: RMA was identified inside cells after incubation at concentrations as low as 4.0 x 10(-10) M Fe, typically observed with receptor mediated endocytosis and several orders of magnitude lower than that expected with fluid phase pinocytosis. Cell uptake could be inhibited by excess protein but not by dextran. RMA localized initially to tubular and to round intracellular organelles and co-localized with an antibody against a murine lysosomal glycoprotein antibodies (LGP-A) in macrophages. Three days after incubation, RMA was concentrated in perinuclear vesicles, which most likely represent terminal lysosomes where final breakdown appears to occur. CONCLUSIONS: The mechanism of cellular uptake of a prototypical opsonized iron oxide label is consistent with receptor-mediated endocytosis. Immediately after cell contact, RMA localizes to the lysosomal compartment and at long time points reside in vesicles that by morphology and distribution appear to be terminal lysosomes. Iron oxides therefore demonstrate metabolism via the lysosomal pathway.

Albumins↗
PubMed1995

Pancreatic duct: MR cholangiopancreatography with a three-dimensional fast spin-echo technique.

PURPOSE: To determine the role of three-dimensional fast spin-echo magnetic resonance (MR) cholangiopancreatography in the evaluation of the normal and abnormal pancreatic duct. MATERIALS AND METHODS: A non-breath-hold MR cholangiopancreatographic technique with use of a body coil was compared with direct pancreatography performed with endoscopic retrograde cholangiopancreatography in 37 patients. RESULTS: MR cholangiopancreatograms of satisfactory quality were obtained in 92% of patients. Sensitivity for detection of pancreatic duct dilatation (n = 15) was 100% and 87% (observers 1 and 2, respectively). Among patients with pancreatic duct strictures (n = 8), 75% of the strictures were detected; there was a single false-positive finding. Specificity for both observers was 69% for the maximum intensity projection reconstructions and increased to 81% with review of the source images. Four of six cases of pancreas divisum (67%) and two cases of pancreatic duct stones were demonstrated. Interobserver agreement was moderate to substantial, as assessed with kappa-analysis. CONCLUSION: MR cholangiopancreatography can accurately demonstrate the normal pancreatic duct as well as various pancreatic duct abnormalities.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1995

Treatment of pelvic abscesses: value of one-step sonographically guided transrectal needle aspiration and lavage.

OBJECTIVE: The percutaneous treatment of pelvic abscesses has traditionally involved the placement of drainage catheters via a transgluteal, transrectal, or transvaginal route. These procedures are painful and prolonged. The goal of this study was to demonstrate the effectiveness of a one-step, single-puncture method for draining pelvic abscesses by use of a transrectal sonographically guided needle for aspiration and lavage instead of a two-step Seldinger technique for catheter placement. SUBJECTS AND METHODS: Thirty-three pelvic abscesses in 24 patients were drained by use of transrectal ultrasound guidance. All abscesses were initially seen on transrectal sonograms or CT scans and ranged from 2 to 11 cm in diameter. Abscesses were located in the prostate (n = five), seminal vesicles (n = five), pouch of Douglas (n = 21), and interloop (between bowel loops) (n = two). Causes of pouch of Douglas (cul-de-sac) abscesses included appendicitis (n = two), Crohn's disease (n = two), diverticulitis (n = three), trauma (n = six), HIV infection (n = two), complications of sigmoidectomy (n = one), complications of colectomy (n = one), pelvic inflammatory disease (n = two), and severe prostatitis (n = two). Interloop abscesses were attributable to HIV infection (n = one) and lymphoma (n = one). The procedure was performed without a cleansing enema or local anesthesia and required less than 30 min. An 18-gauge needle was inserted transrectally into the abscess cavity under transrectally guided sonography. The fluid collection was completely aspirated, and the cavity was lavaged with saline. Administration of antibiotics for 7-21 days, rather than prolonged catheter drainage, was used to treat residual infection. Resolution was documented after 7 days by sonography or CT examination. RESULTS: Transrectal aspiration was successful in treating 28 (85%) of the 33 pelvic abscesses in 21 (88%) of the 24 patients. Failure occurred in three patients, two with multiple abscesses and one with an enteric fistula for whom surgical drainage was subsequently required. The volume of aspirates ranged from 5 to 220 ml. There were no complications. CONCLUSION: Transrectal sonographically guided needle aspiration-lavage offers a one-step method for treating pelvic abscesses that does not require catheter placement or prolonged drainage. The procedure produces minimal discomfort and essentially no complications. Our results show that transrectal sonographically guided needle aspiration combined with antibiotic therapy is an effective treatment for pelvic abscesses.

Abscess↗
PubMed1995

MR cholangiopancreatography: efficacy of three-dimensional turbo spin-echo technique.

OBJECTIVE: The purpose of this study was to correlate a new three-dimensional turbo spin-echo MR cholangiopancreatography technique with endoscopic cholangiopancreatography or percutaneous cholangiography to determine the efficacy of the new technique for visualizing and diagnosing diseases of the pancreatic and biliary ducts. It was hypothesized that the new technique would provide diagnostic images without prolonged breath holding or a surface coil as required by previous MR techniques. SUBJECTS AND METHODS: We describe a respiratory-triggered, heavily T2-weighted, three-dimensional, multislab turbo spin-echo sequence for MR cholangiopancreatography. Thirty patients with suspected biliary or pancreatic disease were randomly selected from referrals for endoscopic retrograde cholangiopancreatography. All patients were imaged with the optimized MR technique prior to attempted endoscopic or percutaneous cholangiopancreatography. The MR images were evaluated without additional clinical or radiographic information by consensus opinion of two of the authors for visualization and caliber of the ducts. When the ducts were abnormal, the level and probable cause were categorized as follows: normal, periampullary stricture, localized duct stenosis, multifocal strictures, calculous disease, duct anomalies, and cystic disease. The images obtained by conventional percutaneous or endoscopic cholangiopancreatography were evaluated in the same manner with the exception that additional clinical and radiologic information was provided. The diagnostic categories determined by MR and direct cholangiopancreatography were compared. Patients were included in the analysis only if endoscopic or percutaneous opacification of the biliary or pancreatic ducts was successful. RESULTS: Diagnostic MR images were obtained in 29 (97%) of 30 patients. Endoscopic or percutaneous cholangiopancreatography was successful in 21 of the 29 patients for the common bile duct and in 17 of the 29 patients for the pancreatic duct. The diagnosis for the common bile duct by the MR technique agreed with the diagnosis by endoscopic or percutaneous cholangiopancreatography in 19 (90%) of 21 patients. For diagnosis of diseases of the pancreatic duct, there was agreement in 15 (88%) of 17 patients. CONCLUSION: Respiratory-triggered, multislab, three-dimensional turbo spin-echo MR cholangiopancreatography is a noninvasive technique for visualization of the pancreatic and biliary ductal systems. It is capable of providing diagnostic information equivalent to invasive techniques in a large percentage of patients and should be the technique of choice when invasive techniques are incomplete, unsuccessful, or technically difficult.

Adolescent↗
PubMed1994

Dissolution of calcified gallstones. Part I. Correlation of in vitro dissolution kinetics in methyl tert-butyl ether with patterns of calcification by computed tomography.

RATIONALE AND OBJECTIVES: The authors evaluated the relationship between stone computed tomography (CT) attenuation patterns and the kinetics of dissolution with methyl tertbutyl ether (MTBE). METHODS: Single moderately and heavily calcified gallstones from 40 patients were selected from a gallstone library and classified for pattern of calcification by in vitro CT scan (dense, rim, core, and laminated). Each stone was placed in a 10-mL aliquot of MTBE for 24 hours. Stone residue was blotted dry and weighted at 8, 16, and 24 hours. Results were normalized with respect to stone size. RESULTS: Only 1 of 40 (4%) specimens dissolved to particulate matter that was smaller than 2 mm. All (6 of 6) stones that were densely calcified showed virtually no dissolution. The rate of gallstone dissolution varied temporally within the rim, core, and laminated stone categories and was related to the composition of the layer exposed to the solvent at any given time. CONCLUSION: The success and rate of dissolution may be predicted by the pattern of calcification as determined by computed tomography (CT).

Cholelithiasis↗
PubMed1994

Dissolution of calcified gallstones. Part II. Evaluation of edetic acid preparations for dissolution of residue after in vitro methyl tert-butyl ether treatment.

RATIONALE AND OBJECTIVES: The authors assessed the potential of edetic acid (EDTA) preparations to dissolve the residue of calcified gallstones partially treated with methyl tert-butyl ether (MTBE). METHODS: Nineteen triplets (57 gallstones) were submitted to dissolution in EDTA, urea-EDTA, and an MTBE control for 48 hours after initial partial dissolution in MTBE for 24 hours. Results were compared with findings at specimen computed tomography and crystallographic analysis. All data were corrected for differences in stone size. RESULTS: In all three treatment groups (EDTA, urea-EDTA, MTBE), almost identical dissolution outcomes were observed within each triplet. Most triplets that dissolved displayed a laminated or a core-calcification pattern and consisted primarily of cholesterol. Specimens that dissolved poorly in all three groups displayed dense calcifications or thick calcified rims and were classified as pigment stones. CONCLUSION: Because no statistically significant differences in dissolution were found among the EDTA, urea-EDTA, and MTBE treatments, we conclude that EDTA preparations are not superior to the continued use of MTBE for dissolution of residue after initial MTBE treatment.

Chelating Agents↗
PubMed1994

Prediction of gallstone composition: synthesis of CT and radiographic features in vitro.

PURPOSE: To test a morphoradiographic algorithm designed to predict the composition of gallstones with use of computed tomography (CT) to define calcification patterns. MATERIALS AND METHODS: Two reviewers retrospectively evaluated the radiographic features of 120 separate in vitro specimens (59 radiopaque and 61 radiolucent), then classified the stones into several categories of composition with the algorithm. RESULTS: The most useful features for prediction of cholesterol composition were, in order of decreasing importance, stone shape, absence of dense calcification on plain radiographs, overall CT attenuation not higher than that of water, presence of a second generation of smaller stones, and a peripheral cover of calcification detected on CT scans of aging cholesterol stones. The greatest error occurred in distinction between stones with mixed composition (50%-79% cholesterol) and older stones with higher cholesterol content (80%-95% cholesterol). CONCLUSION: The range of qualitative CT appearances advances the possibility of predicting gallstone composition and potential outcome of nonsurgical treatment.

Bile Pigments↗
PubMed1994

Liver tumor imaging. Current concepts.

With the increasing availability of curative surgical techniques for primary and secondary hepatic neoplasms, the tasks for clinical imaging of patients suspected of having liver cancer have become more exacting. Detection of tumor, differential diagnosis of individual nodules, and mapping the anatomic extensions of malignant disease are now required routinely. The most sensitive imaging techniques are computed tomography and arterial portography and intraoperative sonography, but because of their invasiveness, there are reserved exclusively for cancer staging. For primary screening, magnetic resonance imaging is increasingly preferred over computed tomography because of its superiority in discriminating hemangiomas and cysts from metastases without the need for iodinated contrast material.

Carcinoma, Hepatocellular↗
PubMed1993

Screening for colon cancer: controversies and recommendations.

Colorectal cancer is the second most common cause of overall cancer mortality in the United States. This article review pertinent clinical and policy issues, details current colorectal cancer screening concepts, summarizes American College of Radiology achievements to date, and outlines projects in the next phase of the effort.

Barium Sulfate↗