PubMed Health⌕ Search

Biomedical subjects

Claude B Sirlin

Publications and source records attributed to Claude B Sirlin.

At least 19 recordsLinked to original sources
PubMed2024

Value of HCC surveillance in a landscape of emerging surveillance options: Perspectives of a multi-stakeholder modified Delphi panel.

HCC surveillance is recommended by liver professional societies but lacks broad acceptance by several primary care and cancer societies due to limitations in the existing data. We convened a diverse multidisciplinary group of cancer screening experts to evaluate current and future paradigms of HCC prevention and early detection using a rigorous Delphi panel approach. The experts had high agreement on 21 statements about primary prevention, HCC surveillance benefits, HCC surveillance harms, and the evaluation of emerging surveillance modalities. The experts agreed that current data have methodologic limitations as well as unclear generalizability to Western populations. Although a randomized clinical trial of surveillance versus no surveillance is unlikely feasible, they concurred that alternative designs, such as a comparison of 2 surveillance modalities, could provide indirect evidence of surveillance efficacy. The panel acknowledged the presence of surveillance harms, but concurred the overall value of surveillance appears high, particularly given a greater emphasis on benefits over harms by both patients and clinicians. The experts underscored the importance of a framework for measuring both benefits and harms when evaluating emerging surveillance strategies. The panel acknowledged performance metrics of emerging methods may differ from other cancer screening programs given differences in populations, including higher risk of cancer development and competing risk of morality, and differences in diagnostic workflow in patients at risk of HCC. These data provide insights into the perceived value of HCC surveillance in an era of emerging blood- and imaging-based surveillance strategies.

Humans↗
PubMed2006

Liver fibrosis: noninvasive diagnosis with double contrast material-enhanced MR imaging.

PURPOSE: To retrospectively evaluate the accuracy of double contrast material-enhanced (hereafter double-enhanced) magnetic resonance (MR) imaging depiction of hepatic fibrosis, with histopathologic analysis findings as the reference standard. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study and waived the requirement for informed consent. One hundred one patients (58 men, 43 women; mean age +/- standard deviation, 52 years +/- 10) who underwent double-enhanced MR imaging with superparamagnetic iron oxide (SPIO)-enhanced and double-enhanced spoiled gradient-echo (SPGR) sequences between 2001 and 2004 and had a reliable reference standard for the diagnosis of liver fibrosis were included. Two blinded MR radiologists retrospectively scored qualitative (reticulation, nodularity, and total scores) and quantitative (contrast-to-noise ratio between hyperintense and hypointense liver regions, coefficient of variation, and noise-corrected coefficient of variation) liver texture features on MR images in consensus. The image scores for patients with advanced (METAVIR fibrosis score >/= 3) versus those for patients with mild (METAVIR score </= 2) fibrosis were compared, and receiver operating characteristic curves were determined. Diagnostic performance values were calculated at the optimal operating point. Mann-Whitney U and unpaired Student t tests were performed. RESULTS: Qualitative and quantitative image scores were significantly higher for patients with METAVIR fibrosis scores of 3 or higher than for those with scores of 2 or lower (P < .001); on SPIO-enhanced SPGR images, differences increased with increasing echo time. Diagnostic performance for detection of grade 3 or more severe fibrosis was better with the double-enhanced sequence than with the SPIO-enhanced sequences, and qualitative scores had higher diagnostic performance than quantitative scores. The sensitivity, specificity, and accuracy of qualitative scores on double-enhanced SPGR images were higher than 90%. CONCLUSION: Advanced hepatic fibrosis can be detected by using double-enhanced MR imaging. Although diagnostic performance depended on the sequence and scoring system used, sensitivity, specificity, and accuracy values higher than 90% were achievable.

Contrast Media↗
PubMed2005

Chest radiography with a flat-panel detector: image quality with dose reduction after copper filtration.

PURPOSE: To compare image quality and estimated dose for chest radiographs obtained by using a cesium iodide-amorphous silicon flat-panel detector at fixed tube voltage and detector entrance dose with and without additional 0.3-mm copper filtration. MATERIALS AND METHODS: The study was approved by the institutional ethics committee. All prospectively enrolled patients signed the written consent form. Chest radiographs in two projections were acquired at 125-kVp tube voltage and 2.5-microGy detector entrance dose. The experimental group (38 patients) was imaged with 0.3-mm copper filtration; the control group (38 patients) was imaged without copper filtration. An additional 12 patients were imaged with and without copper filtration and served as paired subject-controls. Three readers blinded to group and clinical data independently evaluated the radiographs for image quality on a digital display system. Twelve variables (six for each radiographic projection) were assigned scores on a seven-point ordinal scale. Scores between experimental and control groups were compared: Logistic regression analysis and Mann-Whitney U test were used for unpaired patients; and Wilcoxon and McNemar test, for paired patients. In all, 72 comparisons were determined (36 [12 variables x three readers] for unpaired patients and 36 for paired patients). In a phantom study, radiation burden of experimental protocol was compared with that of control protocol by using Monte Carlo calculations. RESULTS: For 70 of 72 comparisons, digital radiographs obtained with copper filtration were of similar image quality as radiographs obtained without copper filtration (P = .123 to P > .99). For two of 72 comparisons, one observer judged the experimental protocol superior to the control protocol (P = .043, P = .046). Patient dose reduction estimated with Monte Carlo calculations was 31%. Use of copper filtration increased exposure times by 48% for posteroanterior views and by 34% for lateral views. CONCLUSION: Subjectively equivalent chest radiographic image quality was found with estimated 30% dose reduction after addition of 0.3-mm copper filtration with flat-panel cesium iodide-amorphous silicon technology.

Cesium↗
PubMed2005

Whole-body CT screening: spectrum of findings and recommendations in 1192 patients.

PURPOSE: To retrospectively determine the frequency and spectrum of findings and recommendations reported with whole-body computed tomographic (CT) screening at a community screening center. MATERIALS AND METHODS: This HIPAA-compliant study received institutional review board approval, with waiver of informed consent. The radiologic reports of 1192 consecutive patients who underwent whole-body CT screening of the chest, abdomen, and pelvis at an outpatient imaging center from January to June 2000 were reviewed. Scans were obtained with electron-beam CT without oral or intravenous contrast material. Reported imaging findings and recommendations were retrospectively tabulated and assigned scores. Descriptive statistics were used (means, standard deviations, and percentages); comparisons between subgroups were performed with univariate analysis of variance and chi(2) or Fisher exact tests. RESULTS: Screening was performed in 1192 patients (mean age, 54 years). Sixty-five percent (774 of 1192) were men and 35% (418 of 1192) were women. Nine hundred three (76%) of 1192 patients were self referred, and 1030 (86%) of 1192 subjects had at least one abnormal finding described in the whole-body CT screening report. There were a total of 3361 findings, with a mean of 2.8 per patient. Findings were described most frequently in the spine (1065 [32%] of 3361), abdominal blood vessels (561 [17%] of 3361), lungs (461 [14%] of 3361), kidneys (353 [11%] of 3361), and liver (183 [5%] of 3361). Four hundred forty-five (37%) patients received at least one recommendation for further evaluation. The most common recommendations were for additional imaging of the lungs or the kidneys. CONCLUSION: With whole-body CT screening, findings were detected in a large number of subjects, and most findings were benign by description and required no further evaluation. Thirty-seven percent of patients had findings that elicited recommendations for additional evaluation, but further research is required to determine the clinical importance of these findings and the effect on patient care.

Adult↗
PubMed2005

Imaging features of perivascular fatty infiltration of the liver: initial observations.

PURPOSE: To retrospectively identify and describe the imaging features that represent perivascular fatty infiltration of the liver. MATERIALS AND METHODS: The institutional review board approved the study and waived informed consent. The study complied with the Health Insurance Portability and Accountability Act. Ten patients (seven women, three men; mean age, 78 years; range, 31-78 years) with fatty infiltration surrounding hepatic veins and/or portal tracts were retrospectively identified by searching the abdominal imaging teaching file of an academic hospital. The patients' medical records were reviewed by one author. Computed tomographic (CT), magnetic resonance (MR), and ultrasonographic (US) imaging studies were reviewed by three radiologists in consensus. Fatty infiltration of the liver on CT images was defined as absolute attenuation less than 40 HU without mass effect and, if unenhanced images were available, as relative attenuation at least 10 HU less than that of the spleen; on gradient-echo MR images, it was defined as signal loss on opposed-phase images compared with in-phase images; and on US images, it was defined as hyperechogenicity of liver relative to kidney, ultrasound beam attenuation, and poor visualization of intrahepatic structures. Perivascular fatty infiltration of the liver was defined as a clear predisposition to fat accumulation around hepatic veins and/or portal tracts. For multiphase CT images, the contrast-to-noise ratio was calculated for comparison of spared liver with fatty liver in each imaging phase. RESULTS: Fatty infiltration surrounded hepatic veins in three, portal tracts in five, and both hepatic veins and portal tracts in two patients. Six of the 10 patients had alcoholic cirrhosis, two reported regular alcohol consumption (one of whom had acquired immunodeficiency syndrome and hepatitis B), one was positive for human immunodeficiency virus, and one had no risk factors for fatty infiltration of the liver. In three of the 10 patients, fatty infiltration was misdiagnosed as vascular or neoplastic disease on initial CT images but was correctly diagnosed on MR images. CONCLUSION: Perivascular fatty infiltration of the liver has imaging features that allow its recognition.

Adipose Tissue↗
PubMed2005

CT appearance of the normal appendix in adults.

The aims of this study were to identify (1) the normal range of the appendix on computed tomography (CT), (2) the correlation of patient age and sex with the visibility and appearance of the appendix on CT, and (3) the normal variations in wall thickness, intraluminal content, and location of the appendix. Three hundred seventy-two outpatients underwent abdominopelvic CT. The scans were reviewed on the picture archiving and communication system and appendiceal outer-to-outer wall diameter, wall thickness, location, content and its correlation with appendix diameter were analyzed. The appendix was visualized in 305/372 patients. Its location relative to the cecum was highly variable. The diameter range was 3-10 mm; in 42% of cases the diameter was greater than 6 mm. When the intraluminal content (185/305) was visualized, the diameter was slightly superior to the mean (p=0.0156). In 329 CT scans in which oral contrast material was given, the appendix was filled by contrast material in 74/329 patients. The appendix wall thickness was measurable in 22/305 patients (average 0.15 cm). There is significant overlap between the normal and abnormal CT appearance of the appendix. Consequently the diagnosis of acute appendicitis should be based not only on the appearance of the appendix but also on the presence of secondary signs.

Administration, Oral↗
PubMed2005

Hypotensive patients with blunt abdominal trauma: performance of screening US.

PURPOSE: To determine retrospectively the accuracy of screening ultrasonography (US) in patients with hypotension (systolic blood pressure or =2) (consensus by three readers) and were assigned to a low- or high-risk group according to the presence of hematuria and/or axial fracture on radiographs. Screening US results were compared with findings with the best available reference standard (computed tomography [CT]), repeat US, other diagnostic test, laparotomy, autopsy, clinical course). Data were compared by using chi(2) or Fisher exact test, depending on expected frequencies, with Bonferroni correction for multiple comparisons. Continuous variables were compared by using unpaired Student t test or Mann-Whitney U test, depending on data distribution. RESULTS: The study included 77 male and 51 female patients (mean age, 42 years). Sensitivity was 85% (44 of 52) for detection of any injuries, 97% (30 of 31) for surgical injuries (ie, injuries requiring surgery), and 100% (10 of 10) for fatal injuries. Specificity was 96% (73 of 76), 82% (80 of 97), and 69% (81 of 118), and accuracy was 91% (117 of 128), 86% (110 of 128), and 71% (91 of 128), for respective injury categories. One nonfatal surgical injury was missed in a high-risk patient. For each injury category, frequency of injury in patients with a fluid score of 2 or more was nine times that in patients with a score of 0 (P < .001 for all comparisons). Frequency of false-negative US findings in high-risk patients was eight times that in low-risk patients (P < .01). CONCLUSION: In patients who are hypotensive after blunt abdominal trauma and not hemodynamically stable enough to undergo diagnostic CT, negative US findings virtually exclude surgical injury, while positive US findings indicate surgical injury in 64% of cases.

Abdominal Injuries↗
PubMed2005

Ovarian imaging by magnetic resonance in obese adolescent girls with polycystic ovary syndrome: a pilot study.

OBJECTIVE: To determine whether magnetic resonance (MR) imaging can serve as a useful investigational tool in the assessment of the polycystic ovary as compared with transabdominal ultrasound (US) for obese adolescents with polycystic ovary syndrome (PCOS). DESIGN: Prospective observational study. SETTING: Tertiary university hospital. PATIENT(S): Eleven obese adolescents with PCOS. INTERVENTION(S): Pelvic MR and US imaging and blood sampling. MAIN OUTCOME MEASURE(S): Total ovarian volume and follicle count; mean follicle count per longitudinal cross-section; stromal area; biochemical correlations with measured ovarian parameters. RESULT(S): With MR, the mean (+/-SE) total follicle count (21.9 +/- 1.3) was significantly greater than that observed with US (5.5 +/- 1.7) and significantly correlated with total ovarian volume. Two-dimensional cross-sectional analysis of the ovary by MR revealed a significantly greater mean follicle count (12.1 +/- 0.8) compared with the results obtained by US (3.0 +/- 0.5). The stromal area (173.3 +/- 25.1 mm2) was approximately 35% of the total ovarian surface area. No correlations were observed between biochemical indices and measured ovarian parameters. CONCLUSION(S): In contrast to US, MR provides vastly greater delineation of the structural components of the ovary in obese girls with PCOS and thus can serve as an excellent investigational technique to assess the morphological transformation of the adolescent ovary.

Adolescent↗
PubMed2005

Female pelvis.

MR is the diagnostic imaging modality of choice for many disorders of the female pelvis. Benign uterine disease is well-demonstrated using rapid sequences and minimal examination time,whereas evaluation of malignancy is best performed with high-resolution techniques. Wide-spread availability of ultrafast sequences has expanded MR imaging applications to include evaluation of pelvic floor relaxation and fetal anomalies. Promising developments, such as new contrast agents, MR-guided focused ultrasound,and 3 tesla imaging, suggest continued advancement of MR imaging in the care of patients who have gynecologic disease.

Contrast Media↗
PubMed2005

MRI of the female pelvis using vaginal gel.

OBJECTIVE: Vaginal distention with aqueous gel optimizes MRI evaluation of the vaginal walls and outer contours of the cervix. The objective of this pictorial essay is to illustrate the use of vaginal gel for MRI of the female pelvis. CONCLUSION: Distention of the vagina with gel is an inexpensive, well-tolerated procedure that may improve MRI evaluation of a variety of gynecologic conditions.

Adult↗
PubMed2005

Screening sonography in pregnant patients with blunt abdominal trauma.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of screening sonography for the detection of clinically significant abdominal injury in pregnant patients with blunt trauma. METHODS: We retrospectively reviewed the records of 5173 patients with blunt abdominal trauma who underwent screening sonography. Pregnant patients were identified, and the prospective sonographic interpretations were compared with surgical findings, computed tomography (CT), subsequent sonography, cystography, and the clinical course. RESULTS: Of 1567 female patients with trauma, 947 were of reproductive age and, 102 (11%) of these 947 were pregnant. One patient was excluded because a truth standard was not available. Five (5%) of these 101 patients were found to have injuries at surgery. These injuries involved the placenta (2 injuries), spleen (2 injuries), liver (1 injury), and kidney (1 injury); all required surgery. Initial sonographic findings were positive in 4 of 5 patients with injuries. The missed injury was a placental injury detected 15 hours after screening sonography because of fetal bradycardia. After screening sonography, 6 patients underwent additional abdominal imaging: CT (3 patients), cystography (1 patient), and additional sonography (2 patients). Of 101 patients, 95 (94%) required no additional tests, and 97 (96%) required no test involving ionizing radiation. No pregnant patient underwent diagnostic peritoneal lavage. Sensitivity was 80% (95% confidence interval, 28%-100%), and specificity was 100% (96 of 96; 95% confidence interval, 96%-100%) for detecting major abdominal injury. CONCLUSIONS: Sonography is an effective screening examination that can obviate more hazardous tests such as CT, cystography, and peritoneal lavage in most pregnant patients with trauma requiring objective evaluation of the abdomen.

Abdominal Injuries↗
PubMed2004

Gadolinium-DTPA-dextran: a macromolecular MR blood pool contrast agent.

RATIONALE AND OBJECTIVES: Magnetic resonance (MR) imaging blood pool agents offer numerous advantages for vascular and tumor imaging. The purpose of this study was to test gadolinium-diethylenetriaminepentaacetate-dextran ([Gd]DTPA-dextran) as a new water soluble macromolecular blood pool agent for MR imaging. MATERIALS AND METHODS: [Gd]DTPA-dextran (187 gadolinium atoms per dextran, molecular weight 165 kD, diameter 17.6 nm) was synthesized. Fifteen anesthetized New Zealand White rabbits with thigh VX2 tumors were scanned in a knee coil at 1.5T. Coronal 3D MR angiographic sequences were obtained before and at several time points up to 72 hours after the intravenous bolus injection of [Gd]DTPA-dextran providing gadolinium at either 0.05 (n = 4) or 0.1 mmol/kg (n = 8) or [Gd]DTPA-bismethylamide (BMA) providing gadolinium at 0.1 mmol/kg (n = 3). Time enhancement curves for aorta, cava, and tumor rim were compared by univariate General Linear Model. RESULTS: Contrast enhancement of cava and aorta relative to a water phantom were significantly greater at all time points after either dose of [Gd]DTPA-dextran than after [Gd]DTPA-BMA (P < 0.01). Tumor rim enhancement was less intense for either dose of [Gd]DTPA-dextran at peak than for [Gd]DTPA-BMA (P < 0.05). Tumor rim enhancement with both doses of [Gd]DTPA-dextran became equivalent to that of [Gd]DTPA-BMA at one hour and was greater at 24 hours (P < 0.05). CONCLUSION: [Gd]DTPA-dextran is a new macromolecular MR contrast agent that can be synthesized to carry a high density of gadolinium atoms without intra-molecular cross-linking. It provides significantly greater vascular residence time than a conventional gadolinium chelate and shows promise for MR blood pool imaging.

Animals↗
PubMed2004

Blunt abdominal trauma: clinical value of negative screening US scans.

PURPOSE: To assess clinical and surgical outcomes in patients with blunt abdominal trauma and negative screening ultrasonographic (US) scans. MATERIALS AND METHODS: From a database of 4,000 patients who underwent screening US for suspected blunt abdominal trauma at a level 1 trauma center, the authors retrospectively identified 3,679 patients with negative US findings. In these patients, outcome was determined by means of retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. In patients with false-negative findings at screening US, all imaging studies and medical charts were also reviewed. Proportions were statistically compared by means of the Pearson chi(2) and Fisher exact tests. Monte Carlo estimation was applied when expected frequencies were low. RESULTS: Among the 3,679 patients with negative findings at screening US, 99.9% (n = 3,641) had no injuries (true-negative findings). Differences in true-negative rates as a function of year (P >.5) or time of day (P >.3) were not significant. Among the 3,641 patients with true-negative findings, 93.6% (n = 3,407) required no additional tests and 6.4% (n = 234) underwent computed tomography or other tests. The percentage of patients who underwent additional tests was significantly higher in the 1st year of the study (19.2%) than in subsequent years (all comparisons, P <.001). Thirty-eight patients had false-negative US findings for abdominal injury. The injuries that were missed in 24 patients were nonsurgical (those that were treated successfully without intervention or were considered minor at autopsy) and those in 14 patients were surgical (required surgical intervention). Cumulatively, 65 injuries were missed. The six most common injuries included retroperitoneal hematoma (n = 13) and injuries in the spleen (n = 10), liver (n = 9), kidney (n = 8), adrenal gland (n = 8), and small bowel (n = 7). Twenty-five of the 38 patients had no or trace hemoperitoneum. Mean diagnostic delay until recognition of missed injury was 16.8 hours +/- 4.3 (standard error of the mean). The missed injury was identified within 12 hours in 19 of the 38 patients and within 24 hours in 34. CONCLUSION: The combination of negative US findings and negative clinical observation virtually excludes abdominal injury in patients who are admitted and observed for at least 12-24 hours.

Abdomen↗
PubMed2003

Carotid arteries: contrast-enhanced US angiography--preliminary clinical experience.

B-mode ultrasonographic (US) angiography enhanced with a microbubble-based US contrast agent (FS069) was evaluated in human subjects with carotid artery disease. Results at contrast material-enhanced US angiography and duplex US were compared with those at conventional angiography. Both US angiography and duplex US accurately depicted stenoses of 70% or more compared with those depicted at conventional angiography. The percentage diameter stenosis of the internal carotid artery measured at US angiography strongly correlated with that measured at conventional angiography (r = 0.988). The percentage area stenosis measured at US angiography strongly correlated with ex vivo measurements of the resected carotid plaque at magnetic resonance imaging (r = 0.979). US angiography depicted unsuspected wall irregularities, ulceration, and dissection.

Aged↗
PubMed2003

Screening US for blunt abdominal trauma: objective predictors of false-negative findings and missed injuries.

PURPOSE: To determine the risk for missed injury in patients with blunt abdominal trauma and negative findings at screening ultrasonography (US) and with coexistent hematuria or fracture of the sixth through 12th ribs, lumbar spine, or pelvis. MATERIALS AND METHODS: From a database of 4,000 patients screened with US for blunt abdominal trauma at a level 1 trauma center, the 3,679 patients with negative US findings were retrospectively classified by consensus of two authors into high-risk (n = 494) and low-risk (n = 3,185) groups based on the presence of hypothetical predictors of missed injury: hematuria (n = 96) or fracture of the sixth through 12th ribs (n = 216), lumbar spine (n = 105), or pelvis (n = 174). Outcome in each patient was determined by the same two authors consensually after retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. The risk for missed abdominal injury was determined for each patient risk group and for each hypothetical predictor. Risks were statistically compared by using the Pearson chi2, Fisher exact, or Fisher-Freeman-Halton exact test, depending on expected frequencies. RESULTS: High-risk patients were 24 times more likely to have abdominal injuries after negative US findings (30 [6.1%] of 494) than were low-risk patients (eight [0.25%] of 3,185) (P <.001). Among high-risk patients, the absolute risks for missed abdominal injury associated with specific predictors were 15.6% (15 of 96 patients) for hematuria, 6.0% (13 of 216) for lower rib fractures, 7.6% (eight of 105) for lumbar spine fractures, and 5.2% (nine of 174) for pelvic fractures. Each of these risks was significantly higher for patients in the high-risk group than for those in the low-risk group (P <.001). CONCLUSION: Hematuria and fracture of the lower ribs, lumbar spine, or pelvis are objective predictors of missed abdominal injury in patients with blunt abdominal trauma and negative US findings, and such patients may benefit from additional screening with computed tomography.

Abdominal Injuries↗
PubMedDate not supplied

Disproportionate fat stranding: a helpful CT sign in patients with acute abdominal pain.

Fat stranding adjacent to thickened bowel wall seen at computed tomography (CT) in patients with acute abdominal pain suggests an acute process of the gastrointestinal tract, but the differential diagnosis is wide. The authors observed "disproportionate" fat stranding (ie, stranding more severe than expected for the degree of bowel wall thickening present) and explored how this finding suggests a narrower differential diagnosis, one that is centered in the mesentery: diverticulitis, epiploic appendagitis, omental infarction, and appendicitis. The characteristic CT findings (in addition to fat stranding) of each of these entities often lead to a final diagnosis. Diverticulitis manifests with mild, smooth bowel wall thickening and no lymphadenopathy. Epiploic appendagitis manifests with central areas of high attenuation and a hyperattenuated rim, in addition to its characteristic location adjacent to the colon. In contrast, omental infarction is always centered in the omentum. The most specific finding of appendicitis is a dilated, fluid-filled appendix. Correct noninvasive diagnosis is important because treatment approaches for these conditions range from monitoring to surgery.

Abdomen, Acute↗
PubMedDate not supplied

Cisterna chyli at routine abdominal MR imaging: a normal anatomic structure in the retrocrural space.

The cisterna chyli, a dilated lymphatic sac in the retrocrural space, represents the origin of the thoracic duct. It is seen in approximately half of lymphangiographic studies and 20% of autopsies. Highly fluid-sensitive magnetic resonance (MR) imaging sequences such as single-shot rapid acquisition with refocused echoes, which are currently used in many abdominal MR imaging protocols, frequently result in the depiction of this structure. The cisterna chyli was evident on abdominal MR images acquired in 30 (15%) of 200 consecutive patients who underwent MR imaging at the authors' institution between February and June 2002. Its appearance varied from that of a thick tube to that of a thin tube, parallel or converging tubes, tortuous tubes, a sausage-shaped fluid collection, a focal collection, or a focal plexus. Radiologists who perform MR imaging should be familiar with the various possible appearances of this normal anatomic structure so as not to mistake it for a pathologic entity.

Diagnosis, Differential↗