Patient satisfaction after MRCP and ERCP.

OBJECTIVE: Magnetic resonance cholangiopancreatography (MRCP) is an accurate diagnostic test for detecting abnormalities of the pancreaticobiliary system. Because it is noninvasive, MRCP appears to be more tolerable than ERCP, although this has not been studied. The purpose of this study is to compare patient satisfaction after MRCP and ERCP performed sequentially. METHODS: We prospectively recruited 34 patients undergoing ERCP, for whom an MRCP was able to be performed before ERCP. Patient satisfaction was assessed by validated questionnaires using seven-point Likhert scales (individual ratings and direct comparisons). The following dimensions were explored: anxiety, pain, discomfort, tolerability (relative to expectations), willingness to repeat the procedure, and overall preference. Chi2 and Student's t tests (paired and unpaired) were performed, and 95% CIs were provided. RESULTS: Two patients (5.9%) were unable to undergo MRCP because of claustrophobia. The remaining 32 completed both tests (94% same day) and all questionnaires. Average age was 56+/-18 yr, and 66% were women. In 23 patients, some degree of biliary obstruction was suspected; nine patients had pancreatitis. Patients reported a lower degree of pain (p < 0.001) and discomfort (p = 0.047) with MRCP, but MRCP was more difficult than they expected (p = 0.0 12). Patients were marginally more willing to repeat MRCP (ns, p = 0.09). On direct comparisons, patients were more satisfied with MRCP regarding anxiety (p = 0.04) and pain (p = 0.001). Patients displayed a higher overall preference for MRCP compared with ERCP (p = 0.01); however, only 59% clearly preferred MRCP over ERCP. The most common problem with MRCP was claustrophobia or noise (n = 15), and the differences were more striking in the subgroup without this problem. The subgroup undergoing purely diagnostic ERCPs showed clear preferences for MRCP. CONCLUSIONS: In many respects, MRCP is well tolerated, and certain subgroups, especially those undergoing diagnostic ERCPs, prefer MRCP over ERCP. As an endoscopist, one needs to be aware of the limitations of MRCP and relay these to the patient, as it seems that patients find MRCP more difficult than anticipated, and a significant number still prefer ERCP over MRCP. Patient satisfaction may be further improved by reducing noise and claustrophobia with selective premedication, earplugs, and the use of the new quieter fenestrated magnetic resonance imaging scanners.

Expectant treatment of ectopic pregnancies: clinical and sonographic predictors.

OBJECTIVE: We identified the potential clinical and sonographic predictors of the spontaneous resolution of ectopic pregnancies. SUBJECTS AND METHODS: We performed a prospective study of 78 consecutive patients with a transvaginal sonographic diagnosis of ectopic pregnancy who had either two consecutive quantitative measurements of their beta subunit of human chorionic gonadotropin (beta-hCG) more than 24 hrs apart or an embryo with a heart beat. We evaluated the patient's age, time from the last menstrual period, beta-hCG level, size of ectopic pregnancy, presence of a gestational sac or embryonic elements, vascularity on color Doppler sonography, peak systolic velocity, and resistive index of ectopic pregnancy at the time of presentation as potential independent predictors of the final outcome. Logistic regression was performed to identify the independent predictors. RESULTS: Forty-six patients had declining beta-hCG levels, and 32 ectopic pregnancies showed an embryo with a heart beat or had steady or rising beta-hCG levels. Univariate analysis indicated that a longer time from the last menstrual period (older ectopic pregnancies), lower beta-hCG levels, and the absence of gestational sac are statistically more significantly seen in ectopic pregnancies with declining beta-hCG levels (p < 0.05). Resistive index of ectopic pregnancy reached borderline significance (p = 0.05). In a multiple logistic model, the same variables were independent predictors of outcome (p < 0.05). Resistive index was also a predictor (p = 0.09). CONCLUSION: Longer times from the last menstrual period, lower beta-hCG levels, absence of gestational sacs, and higher resistive indexes of ectopic pregnancy at the time of presentation appear to be independent predictors of the spontaneous resolution of ectopic pregnancy.

Adenomyosis: US features with histologic correlation in an in-vitro study.

PURPOSE: To evaluate the accuracy of ultrasonographic (US) features of adenomyosis by correlating them with histologic findings and to assess inter- and intraobserver agreement. MATERIALS AND METHODS: US was performed and videotaped in 102 consecutive hysterectomy specimens in a water bath. Videotapes were reviewed initially by two independent radiologists blinded to the clinical and histologic findings and after 1 month by one of the two; US and histologic findings were correlated. Features evaluated included diffuse abnormal echotexture of myometrium, subendometrial myometrial cysts, subendometrial echogenic nodules, subendometrial echogenic linear striations, nodular endometrial-myometrial junction, poor definition of the endometrial-myometrial junction, asymmetric thickness of the anteroposterior wall of the myometrium, and globular configuration. RESULTS: The prevalence of adenomyosis in this cohort was 29.4% (30 of 102 specimens). The mean sensitivity, specificity, negative predictive value, positive predictive value (PPV), and accuracy for the diagnosis of adenomyosis for the three reviews were 81%, 71%, 90%, 54%, and 74%, respectively. All findings evaluated, except for nodular endometrial-myometrial junction, were significantly more common in uteri with adenomyosis (P <.05). Heterogeneous myometrium reached borderline significance (P =.05). The specificities and PPVs of subendometrial striations, subendometrial echogenic nodules, and asymmetric myometrial thickness were significantly higher than those of other features (P <.05). The interobserver agreement was moderate (kappa = 0.48), and the intraobserver agreement was good (kappa = 0. 67) for the three reviews. CONCLUSION: The presence of subendometrial linear striations, subendometrial echogenic nodules, or asymmetric myometrial thickness improves the specificity and PPV of US in diagnosing adenomyosis.

Dynamic enhancement of upper abdominal organs in normal volunteers with MRI and effects of contrast dose reduction.

BACKGROUND: To quantify enhancement parameters of the upper abdominal organs over time during magnetic resonance (MR) examinations and to evaluate the effect of a dose reduction of contrast medium on these parameters. METHODS: Ten volunteers underwent two separate dynamic enhanced MR examinations with 0.1 and 0.075 mmol/kg of contrast medium, respectively. Breath-hold gradient-echo T1-weighted images were acquired every second for 118 s followed by delayed images. The percentages of enhancement, the time to maximum enhancement, and the area under the time-versus-enhancement curve were calculated for each organ. RESULTS: The mean times to maximum percentage of enhancement were less than 25 s for the pancreas, kidneys, and spleen and 50 s for the liver. The mean values of maximum percentage of enhancement for the standard/reduced doses were 72%/62% (pancreas), 165%/155% (kidneys), 114%/87% (spleen), and 67%/53% (liver). This difference was significant when liver enhancement was considered (p = 0.02). In addition, when the areas under the time-versus-enhancement curves were compared, the difference between the standard dose and reduced dose was significant for all organs tested (p < 0.05). CONCLUSIONS: Dynamic scanning of the upper abdomen should start early after contrast injection. Injection parameters should be standardized to capture arterial and venous enhancements in liver examinations. A 25% dose reduction did not significantly affect peak enhancement (except for the liver) but did significantly reduce overall enhancement.

Hepatic CT enhancement: effect of the rate and volume of contrast medium injection in an animal model.

BACKGROUND: To evaluate the relative effect of rate of injection and volume of contrast medium on aortic, portal, and hepatic enhancement during computed tomography (CT). METHODS: Thirty-eight nonincremental CT examinations were performed in three mini-pigs by using a combination of three different volumes (1.5, 2, and 3 mL/kg) and five different rates (1.5, 3, 4.5, 6, and 7.5 mL/s) of contrast material injection. Time-density enhancement curves of the aorta, portal vein, and liver were plotted over time for each rate of injection, each volume of contrast, and each volume-rate combination. In addition, aortic, portal, and liver peak enhancements, time-to-peak enhancements, optimal scanning intervals, and contrast enhancement indices were calculated for each volume-rate combination. RESULTS: Higher rates of injection increased peak aortic enhancement but had no effect on peak portal or hepatic enhancement. This result may be explained by the dilution of the bolus of contrast medium in the splanchnic circulation. When the results of a 6-mL/s injection of 1.5 mL/kg of contrast material were compared with a 3-mL/s injection of 2 mL/kg, maximum aortic enhancement increased by 32%, whereas maximum liver enhancement decreased by 35%. CONCLUSION: An increase in the rate of contrast injection results in an increase of peak aortic enhancement even when the total iodine load is decreased. However, an increase of the rate of contrast injection does not increase maximum liver enhancement, which is related to the total iodine dose injected. Therefore, one cannot compensate a decrease in the iodine load by an increase in injection rate in contrast-enhanced CT of the liver.

Acute pancreatitis: interobserver agreement and correlation of CT and MR cholangiopancreatography with outcome.

PURPOSE: To assess the correlation between and the interobserver agreement of contrast medium-enhanced computed tomography (CT) and nonenhanced and contrast-enhanced magnetic resonance (MR) imaging findings in patients with acute pancreatitis and to correlate these findings with outcome. MATERIALS AND METHODS: Two blinded reviewers separately assessed contrast-enhanced CT and nonenhanced and contrast-enhanced MR images in 30 patients with acute pancreatitis and established a severity index based on the presence of peripancreatic fluid collections and pancreatic necrosis. The Spearman rank correlation coefficient and weighted kappa statistic were used to assess the correlation between each imaging technique and the interobserver agreement, respectively. Correlation between hospitalization days, morbidity, and severity indexes were assessed by using linear correlation. RESULTS: A strong correlation existed for both reviewers when comparing contrast-enhanced CT with nonenhanced (r = 0.82, 0.79) or contrast-enhanced (r = 0.82, 0.79) MR cholangiopancreatography or when comparing nonenhanced and contrast-enhanced MR cholangiopancreatography (r = 0.99, 1.00). The interobserver agreement in staging was stronger with nonenhanced (kappa = 0.76) and contrast-enhanced (kappa = 0.78) MR cholangiopancreatography than with contrast-enhanced CT (kappa = 0.70). There was no linear correlation between the severity index for contrast-enhanced CT and outcome, while there was a linear correlation between nonenhanced or contrast-enhanced MR cholangiopancreatographic staging and the patient morbidity rate. CONCLUSION: MR cholangiopancreatography could be an alternative to contrast-enhanced CT for the initial staging of acute pancreatitis.

Evolution of a filmless digital imaging and communications in medicine-conformant picture archiving and communications system: design issues and lessons learned over the last 3 years.

This presentation describes our experience and lessons learned over the first 3 years of developing and operating a filmless picture archiving and communications system (PACS) for all computed tomography (CT), magnetic resonance (MR), ultrasound, and nuclear medicine studies in our hospital. The PACS conforms to the Digital Imaging and Communications in Medicine (DICOM) standard and includes a sophisticated Worldwide Web (WWW)-based interface to complement the regular DICOM services. The PACS has undergone many design modifications from its inception, which have addressed performance, functionality, support, and maintenance issues. The lessons we have learned through making these modifications are described here and may prove to be helpful to anyone planning to deploy a PACS of their own.

Liver metastasis: comparison of 2 methods for reporting of disease in patients receiving chemotherapy.

OBJECTIVE: To compare bidimensional measurements with direct volumetry in the reporting of disease in patients with liver metastases who are receiving chemotherapy. PATIENTS AND METHODS: Ten patients (6 men and 4 women) receiving chemotherapy were included. A total of 37 contrast-enhanced abdominal computed tomographic (CT) scans, forming 26 pairs of studies, were evaluated retrospectively by 2 independent reviewers. One reviewer recorded bidimensional measurements from hard-copy films, and the other recorded volumetric measurements at the CT console. All measurements were analysed before and after application of a 5% variation interval. RESULTS: Reporting of disease was initially discordant in 5 (19%) of the 26 paired examinations. After application of a 5% variation interval, 9 cases (35%) were discordant. When borderline results (type of response modified by 5% variation) were excluded, 4 discordant cases (20%) remained. All but 1 case showed progressive disease with bidimensional measurements and no change at volumetry. The presence of a new lesion affected reporting in only 1 case. CONCLUSION: The 2 methods of reporting disease are not interchangeable. We believe that volumetric measurements are more representative of tumour burden than bidimensional measurements. However, acquisition of nonhelical data may be a pitfall in volumetric measurements. The increasing availability of helical CT technology should resolve this issue.

Choledocholithiasis: evaluation of MR cholangiography for diagnosis.

PURPOSE: To evaluate the test performance of magnetic resonance (MR) cholangiography for help in diagnosing choledocholithiasis. MATERIALS AND METHODS: Fast spin-echo MR cholangiography was performed by using a torso multicoil array in 110 patients suspected of having bile duct obstruction. Axial and coronal images were reviewed by two observers who were blinded to results of direct cholangiography and final diagnoses. The final diagnosis was established by using direct cholangiographic (n = 103) or surgical (n = 7) findings. RESULTS: Of the 110 patients, 30 (27%) had choledocholithiasis, and 80 (73%) did not. Reviewer 1 used MR cholangiograms to achieve a sensitivity of 90%, specificity of 100%, positive predictive value of 100%, negative predictive value of 96%, and overall accuracy of 97%. Reviewer 2 achieved a sensitivity of 90%, specificity of 93%, positive predictive value of 82%, negative predictive value of 96%, and overall accuracy of 92%. Interobserver agreement for MR cholangiograms was 93% (kappa = 0.82). CONCLUSION: MR cholangiography exhibited excellent test performance and resulted in excellent interobserver agreement for the diagnosis of choledocholithiasis.

Enhancement patterns of renal masses during multiphase helical CT acquisitions.

BACKGROUND: To describe the appearance of renal masses during multiphase helical computed tomography (CT) acquisition and evaluate the impact of a cortical nephrographic phase on diagnosis. METHODS: The CT examinations of 33 patients with 37 lesions [18 renal cell carcinomas (RCC), nine solid tumors, 10 cystic lesions] were reviewed to characterize renal masses during four phases of CT scanning: plain, cortical nephrographic, tubular nephrographic, and pyelographic. Two reviewers analyzed all lesions on the complete data set, and a third reviewer analyzed three combinations of images separately: (1) plain and tubular nephrographic phases, (2) plain and cortical nephrographic phases, and (3) three phases combined. Receiver operating characteristics (ROC) curves were generated to determine the respective value of each combination in lesion characterization. RESULTS: During the cortical nephrographic phase, hyperdensity of solid renal masses was 100% specific and 22% sensitive for RCC, whereas combining hyperdense and isoattenuating heterogeneous masses was 91% specific and 56% sensitive. ROC curves demonstrated a sensitivity of 85%, 90%, 100% for the three combinations, respectively, with a constant specificity of 88% for diagnosing RCC. CONCLUSION: The cortical nephrographic phase is useful to characterize renal masses and should be included in the routine helical CT protocol.

Sonographic appearance of benign and malignant conditions of the colon.

OBJECTIVE: The objective of this study was to compare the sonographic appearance of different abnormalities of the colon to evaluate the role of sonography in their differential diagnosis. MATERIALS AND METHODS: We retrospectively reviewed videotaped sonographic examinations of 99 patients with proven diagnoses that included diverticulitis (n = 35), malignancy (n = 20), Crohn's disease (n = 16), pseudomembranous colitis (n = 14), ischemic colitis (n = 9), and ulcerative colitis (n = 5). Data were collected with regard to gut features, including the site of colonic involvement, associated small-bowel involvement, length of diseased segment, stratification, luminal contents, pneumatosis, and diverticula. Perigut features evaluated included abnormal fat, abscess, fistula, and ascites. RESULTS: On sonography, the following features were statistically significant (p < .05). Involvement of the small bowel was more common in patients with Crohn's disease than in the remainder of the study population (44% versus 1%). Left-sided colonic disease (91% versus 38%), diverticula (91% versus 3%), and perigut findings (91% versus 57%), including abnormal fat (83% versus 39%) and abscess (34% versus 8%), were features that indicated diverticulitis. Malignant conditions were more common in patients with a greater wall thickness (mean, 26.2 mm versus 10.2 mm), asymmetric involvement (85% versus 39%), loss of stratification (85% versus 20%), absence of perigut findings (65% versus 22%), and involvement of a short diseased segment (70% versus 16%). Involvement of the entire colon (50% versus 2%), luminal contents (64% versus 28%), and ascites (64% versus 26%) were features suggesting pseudomembranous colitis. CONCLUSION: Although the sonographic appearances of abnormalities of the colon overlap, some sonographic features are helpful in the differential diagnosis of colonic abnormalities.

Helical CT of the pancreas: a comparison of cine display and film-based viewing.

OBJECTIVE: Radiologists must manage a tremendous number of helical CT images daily. Hence, the use of cine display review is increasing. Our aim was to compare cine display of helical CT examinations of the pancreas with conventional film-based viewing. SUBJECTS AND METHODS: Forty-eight consecutive patients undergoing helical CT of the pancreas were prospectively included in the study. Five-millimeter-thick contrast-enhanced helical CT sections of the pancreas were reconstructed in 1-mm increments for cine display review and in 5-mm-thick increments for film-based review. Two radiologists reviewed the two sets of data independently. Review of the cine display images was followed by review of the film-based images 2 months later. For both the cine display and the film-based images, reviewers used a four-point scale to grade vascular anatomy (splenic vein and artery, superior mesenteric vein and artery, portal confluence, dorsal pancreatic artery, and gastroduodenal artery); ductal anatomy (common bile duct in its hilar, suprapancreatic, and intrapancreatic portions and pancreatic duct in its caudal, corporeal, and cephalic portions); sharpness of the pancreatic and lesion contours; and overall image quality. RESULTS: The conspicuity of pancreatic contours was graded better on cine display (p = .0035). All venous and arterial landmarks were graded significantly better on cine display. Likewise, visibility of the common bile ducts and pancreatic ducts was scored significantly better with cine display. In three patients, cine display images revealed the pancreatic duct, and the film-based images did not. Although 21 lesions were shown on both sets of images, the lesions were better seen on cine display (p < .005). CONCLUSION: Vascular and ductal anatomy is better delineated on cine images generated from overlapped sections than on conventional film-based images. Lesions are also more sharply delineated on cine display images.

Spontaneously resolving acute appendicitis: clinical and sonographic documentation.

PURPOSE: To document findings in a subgroup of patients with acute appendicitis that spontaneously resolved. MATERIALS AND METHODS: From February 1989 through December 1995, nine patients were seen with a diagnosis of acute appendicitis that did not necessitate immediate surgery. Clinical, ultrasound (US), and pathologic findings were retrospectively reviewed. RESULTS: Four of the nine patients underwent elective appendectomy 15-84 days (mean, 52 days) after initial presentation, and five did not undergo surgery. Seven patients experienced spontaneous pain relief before admission to the hospital, and two improved within a few hours of being admitted. No patient had an indication of peritoneal irritation at physical examination. Four patients had a normal white blood cell count, and five had leukocytosis. Maximum appendiceal diameter was 9-12 mm. Five patients had inflamed periappendiceal fat. No patient had abscess or appendicolithiasis shown at US. A normal appendix was identified at follow-up (mean, 40 months; range, 1-60 months) in four of five patients who did not undergo elective appendectomy. Two patients experienced recurrent bouts of pain, and one of these patients underwent appendectomy before the planned elective procedure. CONCLUSION: On the basis of clinical, US, and pathologic findings, mild acute appendicitis spontaneously resolved in a subgroup of patients.

Magnetic resonance cholangiopancreatography.

Magnetic resonance (MR) cholangiopancreatography is a new, noninvasive method of assessing the biliary tract and pancreatic duct. MRCP sequences are based on heavily T2-weighted pulse sequences, resulting in the bile ducts and pancreatic duct having very high signal intensity. Preliminary results indicate that the results of MRCP in most biliary tract diseases are similar to those of more invasive techniques of direct cholangiography, such as, endoscopic retrograde cholangiopancreatography.

Design and implementation of World Wide Web-based tools for image management in computed tomography, magnetic resonance imaging, and ultrasonography.

This article describes our experience in developing and using several web-based tools to facilitate access to and management of images from inside and outside of our department. Having recently eliminated film in ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), a simple method was required to access imaging from computers already existing throughout the hospital. The success of the World Wide Web (WWW), the familiarity of endusers with web browsers, and the relative ease of developing user interfaces virtually dictated that such an approach be pursued in our case. The resulting web-based tools allow validated users to search our Digital Imaging and Communications in Medicine (DICOM)-compliant archive servers for specific exams; to download image data from a remote site; to request the retrieval of data from long-term storage; to view images, and to perform certain DICOM routing operations. The existing infrastructure of the internet has allowed us to develop a low-cost system capable of being used for teleradiology. Since low-level, machine-specific interface programming was avoided, these tools were developed rapidly and are easily adapted. The familiarity of browser-based interfaces has facilitated user acceptance, and the benefit of platform independence minimizes software portability concerns.

Implementation of a filmless mini picture archiving and communication system in ultrasonography: experience after one year of use.

This article details our experience in developing and operating an ultrasound mini-picture archiving and communication system (PACS). Using software developed in-house, low-end Macintosh computers (Apple Computer Co. Cupertino, CA) equipped with framegrabbers coordinate the entry of patient demographic information, image acquisition, and viewing on each ultrasound scanner. After each exam, the data are transmitted to a central archive server where they can be accessed from anywhere on the network. The archive server also provides web-based access to the data and manages pre-fetch and other requests for data that may no longer be on-line. Archival is fully automatic and is performed on recordable compact disk (CD) without compression. The system has been filmless now for over 18 months. In the meantime, one film processor has been eliminated and the position of one film clerk has been reallocated. Previously, nine ultrasound machines produced approximately 150 sheets of laser film per day (at 14 images per sheet). The same quantity of data are now archived without compression onto a single CD. Start-up costs were recovered within six months, and the project has been extended to include computed tomography (CT) and magnetic resonance imaging (MRI).

CD-based image archival and management on a hybrid radiology intranet.

This article describes the design and implementation of a low-cost image archival and management solution on a radiology network consisting of UNIX, IBM personal computer-compatible (IBM, Purchase, NY) and Macintosh (Apple Computer, Cupertino, CA) workstations. The picture archiving and communications system (PACS) is modular, scaleable and conforms to the Digital Imaging and Communications in Medicine (DICOM) 3.0 standard for image transfer, storage and retrieval. Image data is made available on soft-copy reporting workstations by a work-flow management scheme and on desktop computers through a World Wide Web (WWW) interface. Data archival is based on recordable compact disc (CD) technology and is automated. The project has allowed the radiology department to eliminate the use of film in magnetic resonance (MR) imaging, computed tomography (CT) and ultrasonography.

Effect of portal venous flow augmentation on liver enhancement with CT.

BACKGROUND: The purpose of this study was to evaluate the effect of portal flow augmentation on hepatic computed tomographic (CT) enhancement. METHODS: Thirteen patients undergoing follow-up CT of the liver within 6 months of initial study ingested 470 mL of Ensure 30 min before the second examination. Contrast medium injection and scanning parameters were identical for both studies. RESULTS: The time to peak and the maximum and mean liver enhancements were 68 s, 56 HU, and 46 HU, respectively, for the examinations without Ensure and 68 s, 53 HU, and 44 HU for the examinations with Ensure. No significant difference was found between the two groups when mean liver enhancement was calculated over 3-s time intervals. CONCLUSION: Portal venous flow augmentation induced by a meal had no effect on liver enhancement.