Thromboembolic disease: variability of interobserver agreement in the interpretation of CT venography with CT pulmonary angiography.

OBJECTIVE: The objective of this study was to determine interobserver agreement in the diagnosis of acute deep venous thrombosis on CT venography performed in addition to CT pulmonary angiography. SUBJECTS AND METHODS: One hundred forty-six CT venograms of 144 patients (mean age, 61.74 years) clinically suspected of having pulmonary embolism were analyzed prospectively and independently by two experienced thoracic and body imaging radiologists and later by consensus of the two radiologists. The CT venography protocol consisted of 5-mm-thick axial images at 20-mm intervals from the popliteal fossa to the renal veins. Images were acquired 3-4 min after the start of 100-150 mL of undiluted contrast medium administration at 4 mL/sec. Thirteen venous segments were analyzed in each patient. There were 1586 analyzable venous segments. RESULTS: Interobserver agreement, with the patient as the unit of analysis, was moderately good (kappa, 0.59; 95% confidence interval [CI], 0.39-0.78). Kappa values were similar for CT venography studies performed with 150 mL of contrast medium and 4-min delay (kappa, 0.62; 95% CI, 0.30-0.88) and with 3-min delay and 100 mL of contrast medium (kappa, 0.56; 95% CI, 0.32-0.80). Interobserver disagreement occurred in 17 (12%) of 146 CT venography studies. Findings of 11 CT venography studies were interpreted as negative, and six were interpreted as positive after consensus interpretation. CONCLUSION: Interobserver agreement for deep venous thrombosis with CT venography is moderately good.

Correlation of high-resolution breast MR imaging with histopathology; validation of a technique.

A high-resolution three-dimensional surface gradient coil set was used to obtain magnetic resonance (MR) images of breast specimens, using a gradient-echo pulse sequence (TR/TE 1000/8 msec, flip angle 75 degrees), with 117 micrometer in-plane resolution and 1 mm slice thickness. Breast tissues were obtained from one autopsy and three surgical specimens. High-resolution breast MR images and histopathology sections (7 micrometer thickness) were acquired in the same anatomical plane. Radiographs were acquired of the sliced specimens (approximately 5 mm thick) so that images from all three methods could be correlated. It was found that in vitro high-resolution breast MRI correlated well with low-resolution microscopic histology, demonstrating normal anatomy (lobules, ducts, connective tissue strands, blood vessels) and pathology (tumor content, margins, and presence of microcalcifications) of the breast more clearly than conventional pre-gadolinium breast MRI. High-resolution breast MRI may improve specificity, when added to a conventional breast MRI protocol.

Thoracic aortic injury: how predictive is mechanism and is chest computed tomography a reliable screening tool? A prospective study of 1,561 patients.

BACKGROUND: Thoracic aortic injury (TAI) is a devastating condition in which prompt recognition can obviate morbidity and mortality. It is a long-held belief that TAI is more likely when there is a "major mechanism of injury." The purposes of this prospective study were to determine mechanism characteristics that are predictive of TAI and to evaluate chest computed tomography (CT) as a screening tool for TAI. METHODS: Over a 5 1/2 year period, blunt chest trauma patients at two Level I trauma centers were evaluated for potential TAI. Patients were assigned mechanism and radiograph scores from 1 (low suspicion for TAI) to 5 (very high suspicion for TAI). Immediate aortography was obtained when suspicion for TAI was very high. The remaining patients were evaluated with contrast-enhanced chest CT. Confirmatory aortography was obtained on all positive chest CT scans and on all patients with mechanism scores of 4 or 5 even if the CT was negative. Mechanism and radiographic data were correlated with the results of aortic imaging. RESULTS: Of the 1,561 patients evaluated for TAI, 30 aortic injuries were found. The assessment of mechanism was imperfect with a reliance on often incomplete and subjective data. The subjective mechanism score proved to be the most useful predictor of TAI. Radiographic scores were useful but insensitive for intimal injuries. Computed tomography was found to have 100% and 100% NPV for TAI. CONCLUSION: Considering the inherent difficulties in identifying patients at risk for TAI and the effectiveness of chest CT as a screening tool for aortic injury, we recommend liberal use of chest CT in blunt chest trauma. Guidelines for determining the need for aortic imaging are outlined.

Can chest CT be used to exclude aortic injury?

PURPOSE: To determine whether chest computed tomography (CT) can be used to exclude aortic injury. MATERIALS AND METHODS: Patients in whom there was very high suspicion of traumatic aortic injury were examined with aortography only. Other patients were examined with contrast material-enhanced CT. Follow-up aortography was performed in all patients with moderate to high suspicion of traumatic aortic injury and in all patients with CT scans that were positive for traumatic aortic injury. CT scans were regarded as positive when they showed mediastinal hematoma or direct findings of aortic injury. During a 4 1/2-year period, 1,009 patients (263 female, 746 male; age range, 3-90 years) were evaluated for possible traumatic aortic injury. RESULTS: Of the 207 patients who underwent aortography directly without CT, 10 had traumatic aortic injury. Of the 802 patients who were examined with CT, 382 underwent follow-up aortography. In this group, there were 10 true-positive and no false-negative CT scans. CT had 100% sensitivity and a 100% negative predictive value for the detection of traumatic aortic injury.

Clinical validity of helical CT being interpreted as negative for pulmonary embolism: implications for patient treatment.

OBJECTIVE: The purpose of our study was to assess the clinical usefulness of helical CT findings that are interpreted as negative for pulmonary embolism. MATERIALS AND METHODS: One hundred twenty-six patients underwent 132 helical CT examinations and 352 patients underwent ventilation-perfusion scanning for suspected acute pulmonary embolism over a 17-month period at a single institution. Findings from clinical follow-up at a minimum of 6 months were assessed, with a special focus on the presence of recurrent thromboembolism and mortality in 78 consecutive patients in whom helical CT findings were interpreted as negative for pulmonary embolism and anticoagulant therapy was not administered (group I). During the same 17-month period, 46 patients underwent ventilation-perfusion scanning that was interpreted as normal (group II), and 132 patients underwent ventilation-perfusion scanning that was interpreted as showing a very low to low probability for pulmonary embolism (group III). Patients in groups II and III did not undergo helical CT or pulmonary angiography and did not receive anticoagulant therapy. However, clinical follow-up was solicited. Patients from groups II and III were used as control subjects. RESULTS: Nine patients in group I died, one of whom was found to have a microscopic pulmonary embolism at autopsy. In group II, four patients died, none of whom were shown to have a missed or recurrent pulmonary embolism. Of the 18 patients in group III who died, three had a recurrent or missed pulmonary embolism (mean interval, 9 days), and two were found to have deep vein thrombosis on sonography of the leg (mean interval, 12 weeks). Negative predictive values for helical CT, normal lung scanning, and low-probability ventilation-perfusion scanning were 99%, 100%, and 96%, respectively (p = .299). CT provided either additional findings or an alternate diagnosis in 42 (53.8%) of the 78 patients in whom helical CT findings had been interpreted as negative for pulmonary embolism. CONCLUSION: A helical CT scan can be effectively used to rule out clinically significant pulmonary emboli and may prevent further investigation or unnecessary treatment of most patients.

Pulmonary embolism: diagnosis with spiral CT and ventilation-perfusion scanning--correlation with pulmonary angiographic results or clinical outcome.

PURPOSE: To compare the accuracy of spiral computed tomography (CT) with that of ventilation-perfusion (V-P) scintigraphy in the diagnosis of pulmonary embolism (PE). MATERIALS AND METHODS: Fifty-four patients in whom indeterminate V-P scans or discordant clinical and scintigraphic results were obtained underwent both V-P scanning and contrast material-enhanced spiral CT. The reference standard was pulmonary angiographic results in 26 patients (group I) or clinical outcome in 28 (group II). RESULTS: Six (25%) of 24 group I patients had proved PE. The prospective sensitivity and specificity for segmental or subsegmental PE were 67% and 100%, respectively, and the positive and negative predictive values were 100% and 90%, respectively. In two group II patients, V-P scans had high probability for acute embolism, but spiral CT scans showed only chronic PE; in one patients, the V-P scan had low probability and the CT scan was positive for acute PE. An alternative CT diagnosis was established in four (31%) of 13 patients in whom a normal or low-probability V-P scan was obtained. Clinical outcome was consistent with spiral CT results in all cases. CONCLUSION: Spiral CT has greater accuracy and specificity than V-P scanning in patients with an unresolved diagnosis and may be useful as the primary screening technique for PE.

Mayer-Rokitansky-Kuster-Hauser syndrome diagnosed by magnetic resonance imaging in a 15-year-old girl.

STUDY OBJECTIVE: Mayer-Rokitansky-Kuster-Hauser syndrome diagnosed by magnetic resonance imaging (MRI) in a 15-year-old girl with primary amenorrhea is reported. DESIGN: The presentation, MRI, and the subsequent evaluation and treatment of an adolescent female patient with Rokitansky syndrome are described. Correlation is made with previous clinical, pathologic, and imaging reports in the literature. SETTING: An adolescent girl with primary amenorrhea was referred to our institution for completion of her diagnostic work-up. Previous limited evaluations suggested the presence of anomalies of the genitourinary tract. Further delineation of the suspected congenital defects was necessary. PARTICIPANT: The 15-year-old female patient was evaluated by the gynecology service. Diagnostic radiology and pediatric urology were consulted. INTERVENTIONS: MRI, physical examination under anesthesia, and cystoscopy were performed. After initial nonoperative treatment, the patient underwent hysterectomy and sigmoid vaginoplasty. MAIN OUTCOME MEASURES: The patient's primary amenorrhea was explained. Mayer-Rokitansky-Kuster-Hauser syndrome was diagnosed. Vaginal agenesis and widely separated rudimentary uterine horns were well shown by the MRI. Associated skeletal anomalies were noted. A treatment plan was initiated based on a good understanding of the anatomic defects. RESULTS: The MRI and physical examination firmly established the diagnosis. The patient was counseled and managed conservatively at first. Hysterectomy and vaginoplasty were subsequently performed. CONCLUSIONS: Mayer-Rokitansky-Kuster-Hauser syndrome is an unusual müllerian-duct anomaly that is a cause of primary amenorrhea. It can be confidently and noninvasively diagnosed with MRI. The MRI demonstration of vaginal, cervical, and uterine morphology contributes significantly to treatment planning and patient management.

Scrotal cystocele detected by sonography.

We report two cases of scrotal cystocele. In patients suspected of having a scrotal cystocele, we believe that ultrasonography is the initial examination of choice. Emptying of a scrotal cystocele with voiding is an important diagnostic feature. Failure to show a direct communication between the bladder and scrotal cystocele with ultrasonography should not exclude the diagnosis. Scrotal cystocele should be considered in the differential diagnosis of the fluidfilled scrotum. The preoperative detection of massive inguinoscrotal bladder herniation is important to avoid bladder injury during herniorrhaphy.

Demonstration of CT hyperdensity in patients with acute renal failure associated with rhabdomyolysis.

Abnormal hyperdensity consistent with skeletal muscle calcification was shown by CT in four of eight (50%) patients with rhabdomyolysis. This finding correlated significantly with antecedent hypocalcemia (p = 0.01) and renal insufficiency (p = 0.03). In patients with rhabdomyolysis, CT can show abnormal skeletal muscle hyperdensity consistent with calcification. A work-up for hypocalcemia and renal insufficiency should be initiated when this finding is demonstrated. Noncontrast CT could be useful in cases of acute renal failure of unknown etiology to help diagnose occult rhabdomyolysis.

Diagnosis of synthetic vascular graft infection: comparison of CT and gallium scans.

Sixteen patients were examined with both abdominal CT and 67Ga scintigraphy for suspected synthetic vascular graft infection. Two patients were studied twice, yielding a total of 18 paired tests. A total of 25 grafts were analyzed. The results of CT and 67Ga scintigraphy were compared for grafts in specific anatomic locations including the retroperitoneum, groin, and abdominal wall, and for combined sites. When all locations were considered as a group, CT had a sensitivity of 100% and specificity of 72%; 67Ga scintigraphy had a sensitivity of 78% and specificity of 94%. 67Ga scintigraphy proved to be more specific than CT (p less than .05) for combined sites, but no significant difference in sensitivities was demonstrated, possibly because of the small number of infected grafts in our study. No differences in sensitivities or specificities were statistically significant when grafts in individual anatomic sites were analyzed. Since no significant difference between the sensitivities of CT and 67Ga scanning was demonstrated in our study, although the number of infected grafts was small, CT is recommended as the initial examination when graft infection is suspected because it can be performed immediately. 67Ga scintigraphy remains an important complementary test, adding specificity to the diagnostic workup.

Dandy-Walker syndrome: a review of fifteen cases evaluated by prenatal sonography.

Fifteen cases of the Dandy-Walker syndrome evaluated by prenatal sonography were reviewed retrospectively. A posterior fossa cyst communicating with the fourth ventricle was a feature in each case. Hydrocephalus was present in 53% of fetuses. Extracranial congenital malformations were documented in 60% of cases. Cardiac, genitourinary, gastrointestinal, and skeletal anomalies were noted. Of 12 available karyotypes, 4 (33%) were abnormal, including two cases of trisomy 18. Excluding terminated pregnancies, there was an overall mortality of 55%. Associated congenital defects contributed to 83% of the postnatal deaths. The Dandy-Walker syndrome can be accurately diagnosed in utero by sonographic demonstration of characteristic morphologic changes in the fetal posterior fossa. The prenatal examination should include an evaluation of associated supratentorial and extracranial defects. Coexisting structural and chromosomal anomalies occur frequently and adversely affect survival.