CT enterography and fistulizing Crohn's disease: clinical benefit and radiographic findings.

BACKGROUND: To estimate the clinical benefit of CT enterography (CTE) in patients with fistulizing Crohn's disease and describe the appearance of fistulas at CTE. METHODS: Crohn's patients who had undergone CTE, which diagnosed an abscess or fistula, were identified. A gastroenterologist reviewed clinical notes prior to and following CTE to assess the pre-CTE clinical suspicion for fistula/abscess, and post-CTE alteration in patient management. A radiologist reassessed all fistula-positive cases, which were confirmed by a non-CT reference standard, to describe their radiologic appearance. RESULTS: Fifty-six patients had CT exams identifying 19 abscesses and 56 fistulas. There was no or remote suspicion of fistula or abscess at pre-imaging clinical assessment in 50% of patients. Thirty-four patients (61%) required a change in or initiation of medical therapy and another 10 (18%) underwent an interventional procedure based on CT enterography findings. Among 37 fistulas with reference standard confirmation, 30 (81%) were extraenteric tracts, and 32 (86%) were hyperenhancing compared to adjacent bowel loops. Most fistulas (68%) contained no internal air or fluid. CONCLUSION: CTE detects clinically occult fistulas and abscesses, resulting in changes in medical management and radiologic or surgical intervention. Most fistulas appear as hyperenhancing, extraenteric tracts, usually without internal air or fluid.

Head-to-head comparison of oral contrast agents for cross-sectional enterography: small bowel distention, timing, and side effects.

OBJECTIVE: To determine small bowel distention, scanning time, and side effects of commercially available oral contrast agents used in cross-sectional enterography. METHODS: Ten healthy volunteers ingested 2000 mL of water, methylcellulose, polyethylene glycol (PEG), or 1350 mL of low-concentration barium (LCB) followed by 500 mL water on different days. Magnetic resonance imaging occurred every 10 minutes from 30 to 90 minutes after ingestion. Small bowel distention was compared between time points and agents. Volunteers ranked side effects, drinking difficulty, and preference. RESULTS: By quantitative assessment, PEG and LCB distended small bowel loops better than water and methylcellulose (P < 0.0001). Time to optimal distention of the terminal ileum was from 51 to 72 minutes. Water and methylcellulose had the fewest side effects. Water was the most preferred contrast and PEG the least. CONCLUSIONS: Polyethylene glycol and LCB distend small bowel better than water and methylcellulose. Polyethylene glycol was the most difficult to drink and least preferred agent.

Comparative performance of two polyp detection systems on CT colonography.

OBJECTIVE: The purpose of our study was to evaluate two current automatic polyp detection systems to determine their sensitivity and false-positive rate in patients who have undergone CT colonography and subsequent endoscopy. MATERIALS AND METHODS: We evaluated two polyp detection systems--Polyp Enhanced Viewing (PEV) and the Summers computer-aided detection (CAD) system (National Institutes of Health [NIH]) using a unique cohort of CT colonography examinations: 31 examinations with true-positive lesions identified by radiologists and 34 examinations with false-positive lesions incorrectly identified by radiologists. All patients had reference-standard colonoscopy within 7 days of CT. Candidate lesions were compared with the endoscopic reference standard and prospective radiologist interpretation. The sensitivity and false-positive rates were calculated for each system. RESULTS: The NIH system had a higher sensitivity than the PEV tool for polyps > or = 1 cm (22/23, 96%; 78-99%, 95% CI vs 14/23, 61%; 38-81%, 95% CI; p = 0.008, respectively). There was no significant difference in the detection of medium-sized polyps 6-9 mm in size (8/13 vs 6/13, p = 0.68, respectively). The PEV tool had an average of 1.18 false-positive detections per patient, whereas the NIH tool had an average of 5.20 false-positive detections per patient, with the PEV tool having significantly fewer false-positive detections in both patient groups (p < 0.001). CONCLUSION: One polyp detection system tended to operate with a higher sensitivity, whereas the other tended to operate with a lower false-positive rate. Prospective trials using polyp detection systems as a primary or secondary means of CT colonography interpretation appear warranted.

Automated polyp measurement with CT colonography: preliminary observations in a phantom colon model.

OBJECTIVE: The purpose of this study was to evaluate the accuracy and precision of polyp measurements obtained with an automated tool in a colon phantom containing polyps of multiple sizes, morphologic types, and locations. MATERIALS AND METHODS: A colon phantom was scanned at 12, 25, 50, and 100 mA with standard CT colonographic acquisition parameters. Four reviewers using manual 2D methods and an automated polyp measurement tool measured 24 polyps of varying sizes and morphologic types, some at a haustral fold tip and some not at a fold tip. The accuracy (difference from true value) of manual and automated methods was compared across polyp sizes, morphologic types, locations, and doses. Precision (closeness of different measures) was compared for intraobserver and interobserver measurements. RESULTS: The accuracy of automated polyp measurement was dependent on morphologic type (p < or = 0.02), size (for three of four reviewers, p < or = 0.05), and location of polyps with respect to haustral folds (two of four reviewers, p < or = 0.01). For two of four reviewers, automated measures were less accurate for 5-mm polyps, flat polyps, and polyps at the tips of folds (p < or = 0.04). Intraobserver precision was high, two automated measurements being within 0.1 mm of each other 82-93% of the time. Interobserver precision values for automated measures were more similar 85% of the time (82/96; p < 0.001). CONCLUSION: Accuracy of automated polyp measurements depends on polyp size, morphologic type, and location. When using an automated tool, radiologists should visually inspect automated polyp measurements, particularly for small and flat polyps and those located on folds, because manual measurements may be more accurate in this setting. Automated polyp measurements are more precise than manual measurements.

Polyp measurement with CT colonography: multiple-reader, multiple-workstation comparison.

OBJECTIVE: The risk of invasive colorectal cancer in colorectal polyps correlates with lesion size. Our purpose was to define the most accurate methods for measuring polyp size at CT colonography (CTC) using three models of workstations and multiple observers. MATERIALS AND METHODS: Six reviewers measured 24 unique polyps of known size (5, 7, 10, and 12 mm), shape (sessile, flat, and pedunculated), and location (straight or curved bowel segment) using CTC data sets obtained at two doses (5 mAs and 65 mAs) and a previously described colonic phantom model. Reviewers measured the largest diameter of polyps on three proprietary workstations. Each polyp was measured with lung and soft-tissue windows on axial, 2D multiplanar reconstruction (MPR), and 3D images. RESULTS: There were significant differences among measurements obtained at various settings within each workstation (p < 0.0001). Measurements on 2D images were more accurate with lung window than with soft-tissue window settings (p < 0.0001). For the 65-mAs data set, the most accurate measurements were obtained in analysis of axial images with lung window, 2D MPR images with lung window, and 3D tissue cube images for Wizard, Advantage, and Vitrea workstations, respectively, without significant differences in accuracy among techniques (0.11 < p < 0.59). The mean absolute error values for these optimal settings were 0.48 mm, 0.61 mm, and 0.76 mm, respectively, for the three workstations. Within the ultralow-dose 5-mAs data set the best methods for Wizard, Advantage, and Vitrea were axial with lung window, 2D MPR with lung window, and 2D MPR with lung window, respectively. Use of nearly all measurement methods, except for the Vitrea 3D tissue cube and the Wizard 2D MPR with lung window, resulted in undermeasurement of the true size of the polyps. CONCLUSION: Use of CTC computer workstations facilitates accurate polyp measurement. For routine CTC examinations, polyps should be measured with lung window settings on 2D axial or MPR images (Wizard and Advantage) or 3D images (Vitrea). When these optimal methods are used, these three commercial workstations do not differ significantly in acquisition of accurate polyp measurements at routine dose settings.

Active Crohn disease: CT findings and interobserver agreement for enteric phase CT enterography.

PURPOSE: To retrospectively evaluate small-bowel enhancement characteristics and the sensitivity, specificity, and interobserver agreement of computed tomographic (CT) findings by using histologic and endoscopic results as a reference standard in patients undergoing enteric phase CT enterography. MATERIALS AND METHODS: The institutional review board approved this retrospective HIPAA-compliant study, which included patients who consented to having their medical records used for research purposes. Enteric phase CT enterographic and ileoscopic findings with or without ileal histologic results were examined in 42 patients (24 women, 18 men). Enteric phase CT enterography was performed after 150 mL of intravenous contrast material was administered at 4 mL/sec, with a 45-second delay. Mural attenuation was measured in the distended and collapsed jejunal and ileal loops and in the terminal ileum. Two radiologists examined CT images for findings of Crohn disease. Mural attenuation for different bowel loops was compared by using a Student t test, with kappa statistics used to measure interobserver agreement and Pearson correleation coefficients used to compare visual and quantitative measures. RESULTS: Distended jejunal loops had significantly greater attenuation than distended ileal loops (113 HU vs 72 HU; P < .001). Attenuation of collapsed jejunal (134 HU) and ileal (108 HU) loops was greater than that of distended jejunal and ileal loops (P < .001). Terminal ileal enhancement was the most sensitive visual CT finding of Crohn disease for both radiologists. Mural thickening demonstrated the greatest interobserver agreement (kappa = 0.83). Visual enhancement and quantitative mural attenuation were significantly correlated (P < .003). CONCLUSION: At enteric phase CT enterography, jejunal attenuation is greater than ileal attenuation and collapsed bowel loops demonstrate greater attenuation than distended bowel loops. Mural hyperenhancement and increased mural thickness are the most sensitive CT findings of active Crohn disease.

Spectrum of malignant somatostatin-producing neuroendocrine tumors.

OBJECTIVE: To evaluate the clinical manifestations and outcome of patients with somatostatinomas--rare neuroendocrine tumors of pancreaticoduodenal origin. METHODS: We searched the medical archives and tumor registry of our institution for somatostatinomas or somatostatin-staining tumors for the 12-year period from January 1990 to February 2002. In addition, we reviewed laboratory databases for patients who had an elevated serum somatostatin level. Patients with a neuroendocrine tumor and an elevated serum somatostatin level or somatostatin-positive tumor immunostaining were included in this study. RESULTS: Eleven patients qualified (9 men and 2 women; median age at diagnosis, 45 years; age range, 22 to 73). The diagnosis of a somatostatinoma was made by immunostaining of the tumor in 9 patients and by finding elevated serum somatostatin levels in 2. Five primary tumors were of duodenal and 6 of pancreatic origin. Psammoma body formation and association with neurofibromatosis were seen only in the duodenal tumors. The known primary tumor sizes varied from 2 to 6 cm. Liver metastatic lesions were present in 6 patients, abdominal lymph node involvement was found in 10 patients, and lung, spleen, and ovarian metastatic involvement was noted in 1 patient each. Diabetes was present in 4 patients (36%) and cholelithiasis in 7 (64%). The presence of a mass led to the diagnosis in most patients with primary duodenal tumors, whereas patients with pancreatic tumors were more likely to have endocrine manifestations. A Whipple procedure was performed in 6 patients, distal pancreatectomy in 3, hepatic artery embolization or ligation in 3, and partial hepatectomy in 1. Cancer-related death occurred in 4 patients, 1 to 8 years after diagnosis (median, 4.5 years). At last follow-up, 2 patients were alive without evidence of disease (8 and 10 years after diagnosis), and 3 were alive with liver metastatic lesions. The status of 2 patients was unclear. CONCLUSION: Somatostatinomas occurred with approximately equal frequency in the duodenum and the pancreas. The duodenal tumors were more likely to be pure somatostatinomas and have psammoma bodies. Pancreatic tumors were more likely to be multihormonal. Cholelithiasis and diabetes were seen in 64% and 36%, respectively, of the patients. Mass effect of the tumor was the usual manifestation leading to diagnosis. These tumors are slow growing, and long-term survival is possible.

CT enterography as a diagnostic tool in evaluating small bowel disorders: review of clinical experience with over 700 cases.

Computed tomographic (CT) enterography combines the improved spatial and temporal resolution of multi-detector row CT with large volumes of ingested neutral enteric contrast material to permit visualization of the small bowel wall and lumen. Adequate luminal distention can usually be achieved with oral hyperhydration, thereby obviating nasoenteric intubation and making CT enterography a useful, well-tolerated study for the evaluation of diseases affecting the mucosa and bowel wall. Unlike routine CT, which has been used to detect the extraenteric complications of Crohn disease such as fistula and abscess, CT enterography clearly depicts the small bowel inflammation associated with Crohn disease by displaying mural hyperenhancement, stratification, and thickening; engorged vasa recta; and perienteric inflammatory changes. As a result, CT enterography is becoming the first-line modality for the evaluation of suspected inflammatory bowel disease. CT enterography has also become an important alternative to traditional fluoroscopy in the assessment of other small bowel disorders such as celiac sprue and small bowel neoplasms.

Primary squamous cell carcinoma of the thyroid: report of ten cases.

OBJECTIVES: To define the clinical and pathologic characteristics of primary squamous cell carcinoma of the thyroid (PSCCT), a rare tumor, and compare it to the more common secondary squamous cell carcinoma of the thyroid (SSCCT). MATERIALS AND METHODS: A search of tumor registry and medical archives of our institution identified 24 cases of squamous cell carcinoma involving the thyroid in a 25-year period (1978-2003). Medical records and pathology specimens were reviewed. This investigation did not reveal other primary sites in 10 (PSCCT). Other primary sites were identified in 14 patients (SSCCT). Immunostaining was done for thyroglobulin, cytokeratin (7 and 19), thyroid transcription factor (TTF), calcitonin, p21, MIB-I, and p53. RESULTS: All 10 PSCCTs presented with a rapidly enlarging neck mass. Excision was possible in 8. PSCCT had the following features on immunostaining: keratin (8/8, 100%), thyroglobulin (5/8, 62.5%), TTF positive (3/8, 37.5%), and calcitonin negative. Cytokeratins 7 and 19 were diffusely and strongly positive in the PSCCT. Expression of putative biomarkers p21, MIB-I, and p53 was elevated with PSCCT cells showing mean expression of 36%, 48%, and 39%, respectively, compared to less than 5% in non-neoplastic tissues. The mean survival from diagnosis was 8.6 months. All patients died of disease. Airway compromise was the cause of death in the majority. In SSCCT, positivity for thyroglobulin and TTF was not seen. The locations of the primary sites were: larynx (7; 50%), trachea (4; 29%), esophagus (2; 14%), and oral cavity (1; 7%). At last follow-up, 4 were alive with mean survival of 5.5 years. Six had cancer-related mortality with mean survival of 46 months. CONCLUSION: PSCCT is an aggressive cancer with death occurring within the first year in most patients. The prognosis for patients with PSCCT is worse than SSCCT. p21, MIB-I, and p53 are overexpressed in PSCCT. Thyroglobulin and TTF can show focal positivity in PSCCT distinguishing it from SSCCT.

Potential risk factors for diabetic neuropathy: a case control study.

BACKGROUND: Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. METHODS: In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS) was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography). The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI), blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. RESULTS: Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, < 0.001 and 0.005). No correlation was found with any atherosclerosis risk factor (high BP, hyperlipidemia, cigarette smoking). CONCLUSION: In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

Comparison of positron emission tomography, computed tomography, and endoscopic ultrasound in the initial staging of patients with esophageal cancer.

INTRODUCTION: Improvement in esophageal cancer staging is needed. Positron emission tomography (PET), computed tomography (CT), and endoscopic ultrasound (EUS) in the staging of esophageal carcinoma were compared. METHODS: PET, CT, and EUS were performed and interpreted prospectively in 75 patients with newly diagnosed esophageal cancer. Either tissue confirmation or fine needle aspiration (FNA) was used as the gold standard of disease. Sensitivity and specificity for tumor, nodal, and metastatic (TNM) disease for each test were determined. TNM categorizations from each test were used to assign patients to subgroups corresponding to the three treatment plans that patients could theoretically receive, and these were then compared. RESULTS: Local tumor staging (T) was done correctly by CT and PET in 42% and by EUS in 71% of patients (P value > 0.14). The sensitivity and specificity for nodal involvement (N) by modality were 84% and 67% for CT, 86% and 67% for EUS, and 82% and 60% for PET (P value > 0.38). The sensitivity and specificity for distant metastasis were 81% and 82% for CT, 73% and 86% for EUS, and 81% and 91% for PET (P value > 0.25). Treatment assignment was done correctly by CT in 65%, by EUS in 75%, and by PET in 70% of patients (P value > 0.34). CONCLUSIONS: EUS had superior T staging ability over PET and CT in our study group. The tests showed similar performance in nodal staging and there was a trend toward improved distant disease staging with CT or PET over EUS. Assignment to treatment groups in relation to TNM staging tended to be better by EUS. Each test contributed unique patient staging information on an individual basis.

CT colonography: unraveling the twists and turns.

PURPOSE OF REVIEW: The performance of CT colonography has varied widely among published studies to date. This paper reviews differences in indications, populations, technique, and radiologist visualization, to elucidate the key factors that may give rise to disparate results. RECENT FINDINGS: The role of CT colonography in screening asymptomatic patients is controversial. Studies employing subjects with known neoplasms generally report higher accuracy, while studies employing surveillance subjects report lower accuracy. Technical factors that appear to be associated with higher accuracy include meticulous bowel preparation and inflation, multidetector CT, combined two- and three-dimensional visualization, and radiologist experience and proclivity. Interobserver variability and practice guidelines remain significant issues for this developing technique. Interobserver variability may be reduced in the future by computer-aided detection algorithms or the routine use of skilled second readers. CT colonography is performed routinely for some indications, as it has demonstrated superior performance to noncolonoscopic screening alternatives. SUMMARY: The disparity in results of reported large-scale CT colonography studies in asymptomatic subjects may be explained in part by differences in patient population characteristics, CT technique, and interobserver variability. CT colonography exceeds the performance of nonendoscopic approaches to colorectal cancer screening. Continuing innovation will seek to improve endoluminal visualization, reduce interobserver variability, and improve patient acceptance.

Vitamin D deficiency and causative factors in the population of Tehran.

BACKGROUND: There are multiple studies in different countries regarding the prevalence of vitamin D deficiency. These studies showed high prevalence of vitamin D deficiency in Asian countries. This study tries to elucidate the prevalence of vitamin D deficiency and its influencing factors in population of Tehran. METHODS: 1210 subjects 20-64 years old were randomly selected. 25 (OH) D serum levels were measured. Duration of exposure to sunlight, the type of clothing and level of calcium intake and BMI were quantified based on a questionnaire. RESULTS: A high percentage of vitamin D deficiency was defined in the study population. Prevalence of severe, moderate and mild Vitamin D deficiency was 9.5%, 57.6% and 14.2% respectively. Vitamin D serum levels had no significant statistical relation with the duration of exposure to sunlight, kind of clothing and BMI. Calcium intake in the normal vitamin D group was significantly higher than the other groups (714.67 +/- 330.8 mg/day vs 503.39 +/- 303.1, 577.93 +/- 304.9,595.84 +/- 313.6). Vitamin D serum levels in young and middle aged females were significantly lower than the older group. CONCLUSIONS: Vitamin D deficiency has a high prevalence in Tehran. In order to avoid complications of vitamin D deficiency, supplemental dietary intake seems essential.