Isolated calf vein thrombosis: comparison of MR venography and conventional venography after initial sonography in symptomatic patients

RATIONALE AND OBJECTIVES

The authors performed this study to compare magnetic resonance (MR) venography and conventional venography in the diagnosis of deep venous thrombosis (DVT) in the calf after sonography.

MATERIALS AND METHODS

Sonography was performed in 595 patients who were suspected of having lower-extremity DVT. Patients with positive above-knee duplex sonograms, allergy to iodinated contrast material, renal insufficiency, or cardiac pacemakers and patients who were obese were excluded. The remaining 73 patients were asked to undergo MR venography and conventional venography. All studies were to be performed within 48 hours of the clinical diagnosis and according to standard clinical practice. Images were interpreted by radiologists who were blinded to the results of other modalities. Two separate analyses were performed: one in which conventional venography was used as the standard of reference, and one in which the presence of at least two positive studies for thrombus was considered diagnostic.

RESULTS

Although 36 patients agreed to participate in the study, only 14 underwent MR venography and conventional venography within 48 hours of the clinical diagnosis. With use of any two positive studies for confirmation, acute DVT was diagnosed in three patients. Conventional venography depicted two of the three cases, whereas sonography and MR venography each depicted all three. The findings were concordant in only five of the 14 patients.

CONCLUSION

Moderate discrepancy among modalities was demonstrated. This suggests radiologists should undertake comparisons among these three modalities for the detection of calf DVT. In patients with a high clinical suspicion, a second modality may be useful if the initial study is negative.

Does mortality occur early or late in acute pancreatitis?

Several prior studies have suggested that 80% of deaths in acute pancreatitis occur late as a result of pan-creatic infection. Others have suggested that approx half of deaths occur early as a result of multisystem organ failure. The aim of the present study was to determine the timing of mortality of acute pancreatitis at a large tertiary-care hospital in the United States.

METHODS

Patients with a diagnosis of acute pancreatitis (ICD-9 code 577.0) admitted to Brigham and Women's Hospital from October 1, 1982 to June 30, 1995 were retrospectively studied to determine total mortality, frequency of early vs late deaths, and clinical features of patients with early (< or = 14 d after admission) or late deaths (> 14 d after admission).

RESULTS

The overall mortality of acute pancreatitis was 2.1% (17 deaths among 805 patients). Eight deaths (47%) occurred within the first 14 d of hospitalization (median d 8, range 1-11 d), whereas 9 occurred after 14 d (median d 56, range 19-81). Early deaths resulted primarily from organ failure. Late deaths occurred postoperatively in 8 patients with infected or sterile necrosis and 1 patient with infected necrosis treated medically.

CONCLUSION

Approximately half of deaths in acute pancreatitis occur within the first 14 d owing to organ failure and the remainder of deaths occur later because of complications associated with necrotizing pancreatitis. Improvement in mortality in the future will require innovative approaches to counteract early organ failure and late complications of necrotizing pancreatitis.

Comparison of endoscopic retrograde cholangiopancreatography with MR cholangiopancreatography in patients with pancreatitis

PURPOSE

To assess the usefulness of magnetic resonance (MR) cholangiopancreatography (MRCP) in the evaluation of disease in patients with acute or chronic pancreatitis.

MATERIALS AND METHODS

MR imaging was performed at 1.5 T in 39 patients with chronic (n = 30) or acute (n = 9) pancreatitis. The patients underwent a pancreas MR imaging protocol that included an MRCP sequence. Comparison was made with findings at endoscopic retrograde cholangiopancreatography (ERCP), performed within 30 days. Three blinded readers used a scoring system to evaluate nine segments of the pancreatic and biliary ducts as depicted on the ERCP and MRCP images. MRCP image quality was also evaluated.

RESULTS

Of 196 segments analyzed, 17 were not seen at MRCP (sensitivity, 91%). Of the segments visualized at MRCP, 14 were incorrectly characterized (accuracy, 92%). At MRCP, segments not detected or mischaracterized were either normal, slightly dilated, or narrowed. At ERCP, 42 segments in 19 patients were not visualized. MRCP findings were considered useful in all those cases. MRCP image quality was not interpretable in two cases due to artifacts.

CONCLUSION

Very good correlation between ERCP and MRCP findings was demonstrated. Both modalities failed to depict pathologic conditions depicted by the alternative method. MRCP may obviate ERCP, particularly in patients who cannot undergo ERCP or in whom ERCP has been unsuccessful.

Computerized realistic simulation: a teaching module for crisis management in radiology

OBJECTIVE

Computerized realistic simulation technology has been used as a training tool in fields such as aviation and military training and in the nuclear power industry. More recently, it has been adapted for use in anesthesia crisis resource management. We describe the effectiveness of a simulation program like that used by anesthesiology departments that we developed to teach radiologists the principles of crisis management.

MATERIALS AND METHODS

A mock CT scanner and patient simulator were used to simulate the environment in which radiologists encounter crises. Twenty-four residents attended the training program, four at each half-day session. Two responded to and two observed an initial crisis, after which they attended a lecture and watched a videotape review. The second pair then participated in a different crisis scenario. The scenario order was randomized. All scenarios were videotaped and randomly reviewed by two physicians not involved with the course. The following behavioral qualities of the participating residents were evaluated using a five-point scale, ranging from poor (1) to excellent (5): global assessment, communication skills, use of support personnel, use of resources, and role clarity. Residents then rated the course on a five-point scale using the following criteria: overall course usefulness, attainment of course goals, realism of scenarios, quality of lecture, and quality of videotape review.

RESULTS

The trainees who had attended the lecture and watched the videotape review before participating in a scenario consistently scored higher than those who had not in the following areas (score after training/score before training): global assessment, 4.08/2.50; communication skills, 4.09/2.67; use of support personnel, 4.17/3.00; use of resources, 4.00/2.92; and role clarity, 4.17/2.67. Moreover, the participants gave the course the following average ratings: overall usefulness, 4.93; attainment of course goals, 4.78; realism of scenarios, 4.63; quality of lecture, 4.63; and quality of videotape review, 4.85.

CONCLUSION

Although the critical assessment of a teaching method is difficult and subjective by nature, the improvement in behavioral performance scores suggests that simulation technology effectively conveyed the principles of crisis management. The course ratings show that the program was well accepted by participants.

Multidisciplinary gastrointestinal cancer clinic: abdominal radiologist as active participant

RATIONALE AND OBJECTIVES

Abdominal radiologists actively participated and provided subspecialty radiologic expertise in a multidisciplinary gastrointestinal cancer clinic that served a tertiary referral center. The purpose of this study was to evaluate the feasibility and nonradiologists' opinions of this new approach to radiologic consultation.

MATERIALS AND METHODS

One of four subspecialty-trained abdominal radiologists joined physicians from four other subspecialties in staffing weekly 4-hour clinic sessions. Images were reviewed, opinions on test selection and interventional options rendered, and patients met with when interventional options were considered. Radiologists were compensated a fixed sum for each session. A survey of nonradiologists' opinions about the radiologists' active participation was conducted after 15 months (61 clinic sessions).

RESULTS

Abdominal radiologists' active participation was feasible and highly regarded by nonradiologist physicians. Specific benefits cited in the survey included improved interpretation, more efficient use of nonradiologist physician time, and improved rapport between radiologists and nonradiologists. Nonradiologist physicians believed that patient care was improved and that the radiologists' participation should continue.

CONCLUSION

The active participation of abdominal radiologists in a multidisciplinary gastrointestinal cancer clinic is feasible and highly regarded by nonradiologists.

Differentiation of liver hemangiomas from metastases and hepatocellular carcinoma at MR imaging enhanced with blood-pool contrast agent Code-7227

PURPOSE

To evaluate differentiation of liver lesions at magnetic resonance (MR) imaging enhanced with Code-7227.

MATERIALS AND METHODS

Thirty-five patients with 38 proved liver lesions (15 hemangiomas, 17 metastases, six hepatocellular carcinomas [HCCs]) underwent T1-weighted gradient-echo and T2-weighted fast-spin-echo MR imaging at 1.5 T before and after intravenous administration of Code-7227 (1.1 mg iron per kilogram of body weight).

RESULTS

In hemangiomas, the mean contrast-to-noise ratio on precontrast and postcontrast images, respectively, increased from -4.51 +/- 4.7 (standard deviation) to 5.19 +/- 6.3 on T1-weighted images and decreased from 14.73 +/- 7.4 to 0.64 +/- 5.1 on T2-weighted images. In comparison, metastases remained hypointense to liver on T1-weighted images (from -5.77 +/- 5.9 to -7.8 +/- 6.8) and hyperintense on T2-weighted images (from 8.73 +/- 5.4 to 12.61 +/- 6.1). Although HCC enhanced more than metastases, they also remained hypointense to liver on T1-weighted images (from -4.87 +/- 6.1 to -1.79 +/- 5.7) and hyperintense on T2-weighted images (from 10.12 +/- 7.9 to 8.7 +/- 6.4). The degree of enhancement on T1-weighted images and of signal intensity drop on T2-weighted images were significantly lower in malignant liver masses than in hemangiomas (P < .001).

CONCLUSION

Distinctly different enhancement patterns with Code-7227 helped accurate differentiation of liver lesions.

MR imaging evaluation of renal cell carcinoma

BACKGROUND

This study examines the minimally required imaging protocol needed for detection and staging of renal cell carcinoma (RCC).

METHODS

In 81 patients (21 women, 60 men; mean age = 62 years) with 85 RCCs, T1-weighted (T1WI), contrast-enhanced T1-weighted (Gd-T1WI), T2-weighted (T2WI), and gradient recalled echo-fast low flip angle shot (GRE/FLASH) images were evaluated alone and in combination. Surgical-pathological findings were available in all patients and were considered the standard of reference.

RESULTS

Tumor detection for lesions smaller than 3 cm was better on Gd-T1WI than on any other sequence, but only the comparison with noncontrast T1WI and GRE/FLASH was statistically significant (detection: T1WI = 33%, Gd-TIWI = 80%, T2WI = 60%, GRE = 47%). The respective accuracies of T1WI, Gd-T1WI, T2WI, and GRE/FLASH images were 81%, 78%, 71%, and 62% for evaluating local tumor extension; 90%, 88%, 89%, and 85% for lymphadenopathy; and 89%, 81%, 91%, and 95% for renal vein thrombus. The combination of T1WI and GRE sequences rendered the highest overall staging accuracy.

CONCLUSION

For tumor detection, contrast-enhanced T1WI is necessary for lesions smaller than 3 cm. For tumor staging, although the addition of GRE results in significant improvement in the evaluation of venous thrombus, any combination of two sequences will result in similar accuracy, and the use of multiple sequences is not necessary.

MR imaging of bladder diseases

The multiplanar and soft-tissue characterization capabilities of MR imaging make it a valuable diagnostic tool for imaging the urinary bladder. This article reviews the techniques used for MR imaging of the bladder, bladder anatomy, and the various MR features of many bladder pathologies.

MR imaging of scrotal, testicular, and penile diseases

MR imaging has been successfully applied to a variety of diseases involving the scrotum, testes and penis. It offers superior contrast resolution and multiplanar imaging capability. This article discusses MR imaging features of normal and pathologic conditions.

CT-guided aspiration of suspected pancreatic infection: bacteriology and clinical outcome

We have performed CT-guided percutaneous needle aspiration in 104 patients with severe pancreatitis strongly suspected of harboring pancreatic infection on the basis of systemic toxicity and CT findings (Balthazar CT grade D or E). Of these 104 patients, 51 (49%) were documented with pancreatic infection. Gram stain was positive in 54 of 58 infected aspirates, and culture was positive in all 58. Klebsiella, Escherichia coli, and Staphylococcus aureus were the most frequent organisms. Eighty-six percent of infected processes contained only one organism. Overall, pancreatic infection was documented by GPA within the first 2 wk in approx one-half of patients. There were no complications. The overall rate of infection decreased from 60 (1980-1987) to 34% (1988-1995) (p = 0.011). This change was caused by a reduction in the rate of infected necrosis from 67 to 32% (p = 0.015). The overall mortality rate remained at 20%. The mortality of sterile pancreatitis was not different from infected pancreatitis (p = 0.14). We conclude that GPA is a safe, accurate method of diagnosis of pancreatic infection. The rate of pancreatic infection appears to be decreasing. The overall mortality of severe pancreatitis among patients suspected of harboring pancreatic infection has remained unchanged because of the high mortality associated with both infected necrosis and severe sterile necrosis.

Thrombophlebitic retroperitoneal collateral veins mimicking lymphadenopathy: MR and CT appearance

The authors report the magnetic resonance (MR) and computed tomography (CT) features of what is believed to be thrombophlebitis of the left cava of a duplicated IVC, which mimicked lymphadenopathy, and prompted both a CT-guided needle aspiration biopsy and surgical exploration. Knowledge that retroperitoneal vascular anomalies can mimick lymphadenopathy, both clinically and radiographically, may help obviate further testing and intervention.

Intracranial human immunodeficiency virus infection in an infant: sonographic findings

Multiple hyperechoic foci were noted on a head sonogram in the basal ganglia and periventricular white matter of an eleven month old, human immunodeficiency virus (HIV) seropositive male infant. The infant presented with failure to thrive, recurrent viral and bacterial infections, and progressive neurologic impairment. Toxoplasmosis, Cytomegalo-inclusion virus and other "TORCH" infections were excluded. A computed tomography (CT) scan of the brain demonstrated multiple punctate calcifications in the above areas. The literature indicates that these changes might be the result of direct HIV infection of the brain. To our knowledge this is the first reported case of the sonographic findings.