Longitudinal volume analysis from computed tomography: Reproducibility using adrenal glands as surrogate tumors.

This study aims to determine the precision (reproducibility) of volume assessment in routine clinical computed tomography (CT) using adrenal glands as surrogate tumors. Seven patients at our institution were identified retrospectively as having received numerous abdominal CT scans (average 13.1, range 5 to 20). The adrenal glands were used as surrogate tumors, assuming no actual volume change. Left and right adrenal gland volumes were assessed by hand segmentation for each patient scan. Over 1240 regions of interest were outlined in total. The reproducibility, expressed as the coefficient of variation (COV), was used to characterize measurement precision. The average volumes were 5.9 and 4.5 cm(3) for the left and right adrenal gland, respectively, with COVs of 17.8% and 18.9%, respectively. Using one patient's data (20 scans) as an example surrogate for a spherical tumor, it was calculated that a 13% change in volume (4.2% change in diameter) could be determined with statistical significance at P=0.05. For this case, cursor positioning error in linear measurement of object size, by even 1 pixel on the CT image, corresponded to a significant change in volume (P=0.05). The precision of volume determination was dependent on total volume. Precision improved with increasing object size (r(2) =0.367). Given the small dimensions of the adrenal glands, the ~18% COV is likely to be a high estimate compared to larger tumors. Modern CT scanners working with thinner sections (i.e. <1 mm) are likely to produce better measurement precision. The use of volume measurement to quantify changing tumor size is supported as a more precise metric than linear measurement.

Comparison of two-dimensional and three-dimensional iterative watershed segmentation methods in hepatic tumor volumetrics.

In this work the authors compare the accuracy of two-dimensional (2D) and three-dimensional (3D) implementations of a computer-aided image segmentation method to that of physician observers (using manual outlining) for volume measurements of liver tumors visualized with diagnostic contrast-enhanced and PET/CT-based non-contrast-enhanced (PET-CT) CT scans. The method assessed is a hybridization of the watershed method using observer-set markers with a gradient vector flow approach. This method is known as the iterative watershed segmentation (IWS) method. Initial assessments are performed using software phantoms that model a range of tumor shapes, noise levels, and noise qualities. IWS is then applied to CT image sets of patients with identified hepatic tumors and compared to the physicians' manual outlines on the same tumors. The repeatability of the physicians' measurements is also assessed. IWS utilizes multiple levels of segmentation performed with the use of "fuzzy regions" that could be considered part of a selected tumor. In phantom studies, the outermost volume outline for level 1 (called level 1_1 consisting of inner region plus fuzzy region) was generally the most accurate. For in vivo studies, the level 1_1 and the second outermost outline for level 2 (called level 2_2 consisting of inner region plus two fuzzy regions) typically had the smallest percent error values when compared to physician observer volume estimates. Our data indicate that allowing the operator to choose the "best result" level iteration outline from all generated outlines would likely give the more accurate volume for a given tumor rather than automatically choosing a particular level iteration outline. The preliminary in vivo results indicate that 2D-IWS is likely to be more accurate than 3D-IWS in relation to the observer volume estimates.

Appearance of solid organ injury with contrast-enhanced sonography in blunt abdominal trauma: preliminary experience.

OBJECTIVE: The purpose of this study was to compare the detection rate of injury and characterize imaging findings of contrast-enhanced sonography and non-contrast-enhanced sonography in the setting of confirmed solid organ injury. SUBJECTS AND METHODS: This prospective study involved identifying hepatic, splenic, and renal injuries on contrast-enhanced CT. After injury identification, both non-contrast-enhanced sonography and contrast-enhanced sonography were performed to identify the possible injury and to analyze the appearance of the injury. The sonographic appearance of hepatic, splenic, and renal injuries was then analyzed, and the conspicuity of the injuries was graded on a scale from 0 (nonvisualization) to 3 (high visualization). RESULTS: Non-contrast-enhanced sonography revealed 11 (50%) of 22 injuries, whereas contrast-enhanced sonography depicted 20 (91%) of 22 injuries. The average grade for conspicuity of injuries was increased from 0.67 to 2.33 for spleen injuries and from 1.0 to 2.2 for liver injuries comparing non-contrast-enhanced with contrast-enhanced sonography, respectively, on a scale from 0, being nonvisualization, to 3, being high visualization. The splenic injuries appeared hypoechoic with occasional areas of normal enhancing splenic tissue within the laceration with contrast-enhanced sonography. Different patterns were observed in liver injuries including a central hypoechoic region. In some liver injuries there was a surrounding hyperechoic region. CONCLUSION: Contrast-enhanced sonography greatly enhances visualization of liver and spleen injuries compared with non-contrast-enhanced sonography. Solid organ injuries usually appeared hypoechoic on contrast-enhanced sonography, but often a hyperechoic region surrounding the injury also was identified with liver injuries.

Endometrial and endocervical micro echogenic foci: sonographic appearance with clinical and histologic correlation.

OBJECTIVE: The purpose of this research was to determine the clinical and histologic importance of small echogenic foci seen in the endometrium/endocervix on pelvic sonography. METHODS: A retrospective study was performed on 62 women, aged 28 to 81 years, who had echogenic foci of the endometrium and endocervix. Patients' medical records were accessed to review pertinent obstetric and gynecologic information. Additionally, histopathologic slides from patients who underwent diagnostic procedures (endometrial biopsy or dilation and curettage) or hysterectomy were reviewed. RESULTS: The clinical information for the 62 women included the following: mean age, 49 years; history of exogenous hormonal use, 84%; prior abortion (therapeutic or spontaneous), 57%; prior dilation and curettage, 56%; prior cesarean delivery, 28%; and sexually transmitted disease, 36%. The initial finding of echogenic foci was followed by ultrasound examinations in 18 patients for a mean interval of 16 months. Of the 18 patients, the foci remained unchanged in 13 women and disappeared or became less prominent in the other 5. Histopathologic results were available in 28 women, and microcalcifications were found in 15 of them. The etiology most common was microcalcification but also included crystals, debris from laminaria, and ossified tissues. Clinical follow-up in 62 patients showed that this condition was mostly benign (endometrioid carcinoma developed in 1 patient). CONCLUSIONS: Histopathologic studies showed microcalcifications, which are the most common cause of echogenic foci. The foci were stable with time and seemed to be an incidental finding associated mostly with benign conditions. The etiologic factors for echogenic foci may be numerous.

Blunt abdominal injury in the pregnant patient: detection with US.

PURPOSE: To determine the accuracy of ultrasonography (US) for the detection of blunt intraabdominal injury in pregnant patients and to compare differences between pregnant and nonpregnant patients of childbearing age. MATERIALS AND METHODS: A retrospective review of results of all consecutive emergency blunt trauma US examinations performed at a level I trauma center from January 1995 to June 2002 was conducted. Data on demographics, free fluid location, and patient outcome were collected. Injuries were determined on the basis of results of computed tomography and/or laparotomy. The Student t test was used to detect differences between continuous variables, and chi(2) analysis was used to evaluate differences between proportions. RESULTS: A total of 2319 US examinations for blunt trauma were performed in girls and women between the ages of 10 and 50 years. There were 328 pregnant patients, 23 of whom had intraabdominal injury. The mean age of the pregnant patients was 24.7 years +/- 6.1 (standard deviation) (age range, 14-42 years). In pregnant patients, the sensitivity of US was 61% (14 of 23 patients), the specificity was 94.4% (288 of 305 patients), and the accuracy was 92.1% (302 of 328 patients). Pregnant patients were significantly more likely to have sustained injuries from assault (odds ratio: 2.6, P < .001). The most common pattern of free fluid accumulation detected at US in pregnant patients was that of fluid in the left and right upper quadrants and pelvis (n = 4, 29%); the second most common pattern was one of isolated pelvic fluid (n = 3, 21%). CONCLUSION: For detection of intraabdominal injury, US was less sensitive in pregnant patients than in nonpregnant patients but was highly specific in both subgroups. The sensitivity of US was highest in pregnant patients during the first trimester.

Sonographic duplication artifact of the spinal cord in infants and children.

OBJECTIVE: To describe the features of sonographic duplication artifacts that we have occasionally seen when imaging the spinal cord of infants and children, mostly with postrepair myelomeningocele. METHODS: Sonography of the spine was performed for the evaluation of neonates with suspected spinal cord abnormalities and of older children in the follow-up of postrepair open-spine defects. RESULTS: Each of our patients had a single spinal cord, but the duplication artifact was seen with 2 brands of scanners and with both linear array and vector array transducers. CONCLUSIONS: The finding of duplication artifacts when imaging the spinal cord of infants and children should be recognized as such and should not be misinterpreted as representing diastematomyelia or diplomyelia.

Caput succedaneum mimicking a cephalocele.

Caput succedaneum is relatively common at birth but infrequently diagnosed in utero. It has a benign prognosis, but it is very important not to misdiagnose it as a cephalocele, which carries a guarded prognosis. We present the case of a patient who experienced preterm labor and premature rupture of the membranes at 28 weeks' menstrual age. Our initial diagnosis was cephalocele, but after the male infant was delivered by cesarean section, examination revealed no bone defect, and our final diagnosis was caput succedaneum. We also discuss the sonographic findings and diagnostic differences between caput succedaneum, cephalocele, and other fetal head masses.

The focused abdominal sonography for trauma scan: pearls and pitfalls.

OBJECTIVE: To review the state-of-the-art use of sonography in evaluating the patient with trauma. METHODS: We reviewed our experience in performing more than 5000 sonographic examinations in the patient with trauma. The recent experience of other publications advocating newer applications of sonography in the patient with trauma are discussed and presented in a pictorial fashion. RESULTS: The main focus of sonography in the patient with trauma has been in performance of the focused abdominal sonography for trauma scan. The focused abdominal sonography for trauma scan is usually performed in the patient with blunt abdominal trauma and is used to check for free fluid in the abdomen or pelvis. There are certain pitfalls that need to be avoided and certain limitations of the focused abdominal sonography for trauma scan that need to be recognized. These pitfalls and limitations are reviewed. More recently, sonography has been used to detect certain solid-organ injuries that have a variety of appearances. Thus, sonography may be used to localize the specific site of injury in these patients. More recently, sonography has been used to evaluate thoracic abnormalities in patients with trauma, including pleural effusions, pneumothoraces, and pericardial effusions. CONCLUSIONS: The use of sonography in evaluating the patient with trauma has rapidly expanded in the past decade. Those using sonography in this group of patients should be aware of its many uses but also its potential pitfalls and limitations.