Use of ultrasonography in the patient with acute abdominal trauma

The purpose of this study was to assess the use of ultrasonography in patients with acute abdominal trauma. Five hundred prospective patients, who came to the Emergency Department with acute trauma, were evaluated with ultrasonography and included in this study. The ultrasonographic examination focused on detection of free fluid but included evaluation of parenchymal organs for injury. The physical examination was not used in the statistical analysis of the sonographic findings. In comparing ultrasonography to computed tomography, diagnostic peritoneal lavage, or operative findings, we obtained 24 true positive, 79 true negative, four false positive, and 14 false negative results. Sensitivity of ultrasonography in detecting free fluid in comparison to computed tomography, diagnostic peritoneal lavage, and surgery was 63%, specificity was 95%, accuracy was 85%, positive predictive value was 86%, and negative predictive value was 85%. The most common reason for false negative sonographic results was identification of free fluid in the pelvis on computed tomograms but not on ultrasonograms owing to lack of a full bladder. In none of these instances were the sonographic false negative results of clinical significance. Ultrasonography allowed detection of solid organ injury of the liver in one of seven cases, of the kidney in one of four cases, and in the bowel in zero of three cases. In the three instances of bowel injury, free fluid was noted on ultrasonograms. Ultrasonography fared better in cases of splenic laceration, permitting detection in nine of 14 cases. The emergent ultrasonogram may be used to detect free fluid in the abdomen of the acutely traumatized patient. However, sonography is limited in detecting free fluid in the pelvis using the present technique and does not allow visualization of organ injury. Limitations of this examination should be recognized for appropriate triage of the acutely traumatized patient.

Axial ultrasonographic imaging of the fetal maxilla for accurate characterization of facial clefts

The purpose of this study was to determine whether scanning of the fetal midface in the axial plane allows accurate characterization of facial clefts. During fetal anatomic survey, facial clefts were identified in six fetuses. The midface anatomy was evaluated with ultrasonography in the coronal and axial planes, and the clefts were characterized prospectively as unilateral or bilateral and as involving the lip alone or both the lip and the palate. The integrity of the upper lip was assessed in the coronal and axial planes. The continuity of the normal C-shaped curve of the tooth-bearing alveolar ridge and the anterior six tooth sockets was assessed in the axial plane. The prospective prenatal diagnosis was correlated with postnatal findings in all cases. The clefts where characterized prospectively as unilateral cleft lip (one case), unilateral cleft lip and cleft palate (four cases), and bilateral cleft lip and cleft palate (one case). The prenatal characterization was confirmed to be correct postnatally in all cases. Prenatal sonographic evaluation of the axial view of the tooth-bearing alveolar ridge of the maxilla allows accurate determination of whether a cleft is confined to the lip or involves both the lip and the palate.

Color Doppler ultrasonographic detection of a vibrating needle system

The purpose of this study was to compare needle detection using a commercially available vibrating needle system that is used with color Doppler sonography and conventional real-time needle guidance during ultrasonographically guided intervention. Twenty-four paired (48 total) sonographically guided needle placements were performed in 22 patients for fine needle biopsy. Two patients underwent two additional needle placements at later times and, therefore, underwent a total of four needle passes each. Twenty-four of the needles were placed utilizing conventional real-time ultrasonographic guidance, and 24 were guided using a commercially available vibrating needle system. The Color Mark System was compared with standard technique for needle visualization and graded according to ease of needle visualization (improved, no change, or more difficult visualization). This was done for both needle tip and needle shaft visualization. Visualization was graded in both superficial (less than 3 cm deep) and deep structures. Overall needle tip and shaft visualization improved in 14 of 24 cases in superficial tissues and in three of 24 cases in superficial and deep tissues with the Color Mark System. The vibrating needle system also was judged to be somewhat cumbersome when used with a 22 gauge needle, as its weight tended to bend the needle shaft. The needle vibrating system may enhance needle visualization in superficial structures, but with the present design it is of limited use in deep tissues.

Evaluation of fetal midface anatomy related to facial clefts: use of US

PURPOSE

To identify the sonographic appearance of normal fetal midface anatomy of in vitro fetal specimens and to correlate the appearance with that of in utero fetuses to determine which aspects of this anatomy can be evaluated clinically.

MATERIALS AND METHODS

The midface structures of 12 normal fetal specimens were examined in the axial, sagittal, and coronal planes with ultrasound. The results were correlated with those of other modalities. One hundred consecutive, normal in utero fetuses were scanned in the same planes in an attempt to identify the same anatomic landmarks identified in the fetal specimens.

RESULTS

In the fetal specimens, the upper lip (coronal plane), alveolar ridge, tooth sockets, point of fusion of primary and secondary palates (axial plane), and fusion line of the secondary palate (sagittal plane) were consistently observed. In the 100 in utero fetuses, the same anatomy was visualized in the coronal plane in 95 (95%), in the axial plane in 97 (97%), and in the sagittal plane in 26 (26%). The mean scanning time was 2.8 minutes.

CONCLUSION

Important aspects of fetal midface anatomy that relate to facial clefts can be observed in utero at prenatal sonography in the coronal and axial planes.

Pelvic abscesses: transvaginal US-guided drainage with the trocar method

The effectiveness of the trocar technique of catheter placement for transvaginal sonographically guided drainage of pelvic abscess was assessed in seven women who presented with pelvic pain, fever, and presumed pelvic abscess. Endovaginal ultrasound was performed to document fluid collection before drainage. All procedures were performed in less than 1 hour, without complications. Catheters were left in place for 1-3 days. Catheter placement was curative in six of seven patients (86%).

Hepatic ablation using bipolar radiofrequency electrocautery

RATIONALE AND OBJECTIVES

Percutaneous methods have been used to treat primary and secondary hepatic neoplasms. In the current study, we evaluated the potential of bipolar radiofrequency (RF) electrocautery to increase in vitro liver tissue destruction when compared with monopolar RF electrocautery.

METHODS

Two needles (electrodes) were placed into fresh bovine liver tissue for use with bipolar electrocautery. Needle tip exposure was kept constant at 3 cm while other parameters, including treatment time, power (wattage), interneedle distance, and needle tip temperature, were changed. Pathologic and histologic correlation was performed, and tissue necrosis was weighed in grams for individual parameters.

RESULTS

There was a minimal threshold of approximately 45 degrees C where tissue coagulation occurred. Tissue coagulation increased the longer treatment went on. Increasing temperature, wattage, or both increased tissue coagulation such that necrosis was too rapid and char formation occurred, which prevented further coagulation. For all wattages and temperatures, there was increasing tissue necrosis with increasing needle separation, until a point at which further needle separation produced less tissue necrosis. Optimizing parameters allowed tissue coagulation of greater than 30 g.

CONCLUSION

Bipolar RF electrocautery shows promise for increasing the tissue coagulation in fresh bovine liver compared with the previously described monopolar technique.

Skeletal coccidioidomycosis: imaging findings in 19 patients

OBJECTIVE

The objective of this study was to describe the distribution and radiologic appearance of skeletal coccidioidomycosis in 19 documented cases.

DESIGN AND PATIENTS

Medical records of 19 patients (17 men, 2 women; age range 17-62 years, mean age 34 years) with clinically confirmed skeletal coccidioidomycosis were retrospectively reviewed. The patients were studied with plain radiography (n = 19), skeletal scintigraphy (n = 6), computed tomography (CT) (n = 5), and magnetic resonance imaging (MRI) (n = 1).

RESULTS

Multiple lesions were seen in 11 of 19 patients (58%). Of a total of 46 lesions, 27 (59%) were described as punched-out lytic, 10 (22%) as permeative/destructive, and 9 (17%) as involving a joint and/or disk space. Lesions were identified in almost every bone (with the exception of the facial bones, ulna, carpus, and fibula) and were most commonly found in the axial skeleton (20 of 46; 43%).

CONCLUSION

Skeletal coccidioidomycosis is frequently multicentric and may involve almost any bone. The axial skeleton is the most common site of involvement. Lesions are usually well demarcated but may present with an ill-defined border and permeative type of bone destruction, especially in the spine. Joint involvement is not uncommon. Plain radiographs are effective in the initial evaluation of bones and joints, scintigraphic studies can identify disseminated disease, and CT and MRI are effective in determining soft tissue involvement and spinal abnormalities.

Complications of laparoscopic cholecystectomy: imaging and intervention

Cholecystectomy is the most common abdominal operation done in the United States, with more than half a million cholecystectomies performed annually. Recently, there has been a trend to perform laparoscopic, rather than open, cholecystectomy. The introduction of any new technique involves a learning curve for surgeons, and several complications may occur with this procedure. Radiologists may be called on to help diagnose and manage injuries occurring after laparoscopic cholecystectomy. This article will review the complications of laparoscopic cholecystectomy, emphasizing the role of imaging in both diagnosis and nonsurgical management of these injuries.

Indirect computed tomography lymphography of subdiaphragmatic lymph nodes using iodinated nanoparticles in normal dogs

RATIONALE AND OBJECTIVES

We evaluated the imaging characteristics of an iodinated particulate contrast agent for indirect computed tomography (CT) lymphography of normal subdiaphragmatic lymph nodes in dogs.

METHODS

Four milliliters of a 15% (wt/vol) iodinated nanoparticle suspension was injected into the gastric, colonic, rectal, or cervical submucosa, loose paraprostatic fascia, or metatarsal subcutaneous tissues in 10 healthy beagles. Endoscopic, CT, or ultrasound guidance was used when necessary to facilitate contrast agent delivery. CT and radiographic images were obtained prior to contrast administration and at 4 hr, 24 hr, and 7 days postcontrast injection. Postmortem examinations were then conducted.

RESULTS

CT images showed enhancement of regional lymph nodes draining the various injection sites. The mean attenuation of opacified nodes was 678 +/- 463 Hounsfield units 24 hr after injection and remained elevated 7 days later. Lymph node opacification on CT images correlated well with the node location observed on postmortem examinations.

CONCLUSION

Subdiaphragmatic lymph nodes can be effectively opacified using an iodinated nanoparticle contrast agent for indirect CT lymphography.

Cephalocele detection in utero: sonographic and clinical features

Sonographic and clinical features of 26 fetal cephaloceles were reviewed retrospectively. The most frequent reason for referral was elevated maternal serum alpha-fetoprotein levels. The smallest lesion identified was 0.4 x 0.5 cm (frontal, at 20 weeks); the largest was 9.0 x 10.0 cm (frontal, at 27 weeks). Twenty-four of 26 cephaloceles were detected on prenatal ultrasound examination; in 13 of these, more than 50% of the intracranial contents were exteriorized. Fifteen of 24 cephaloceles detected prenatally had a sulcal pattern (identified between 16 and 36 weeks' gestation); five were solid without a sulcal pattern (identified between 13 and 21 weeks' gestation), three were cystic, and one underwent a change in appearance from solid at 21 weeks to cystic at 26 weeks. Other cranial features were evaluated and included visible skull defect, seen in 23/24 (96%), ventriculomegaly, in 6/26 (23%); microcephaly, in 12/24 (50%); beaked tectal plate, in 6/16 (38%); and flattened basiocciput, in 9/24 (38%). Of the 26 cases, 14 had normal amniotic fluid volume, five had oligohydramnios and seven had polyhydramnios. Fetuses with oligohydramnios had the highest incidence of concurrent fetal abnormalities; four of five fetuses (80%) with oligohydramnios had additional structural abnormalities. In the overall population, a very high incidence of other abnormalities was found; 17/26 (65%) cases showed additional abnormalities, some of which were not detected by ultrasound. Five fetuses had Meckel-Gruber syndrome and three had amniotic band syndrome. Only one of the 18 karyotypes obtained was abnormal (trisomy 18). Survival was very poor; only two of the eight who survived until birth are currently living.

Percutaneous ultrasound-guided radiofrequency electrocautery ablation of prostate tissue in dogs

RATIONALE AND OBJECTIVES

We investigated the feasibility of percutaneous radiofrequency (RF) electrocautery in ablation of prostate tissue in dogs.

METHODS

We used six dogs in whom a specially designed needle was placed percutaneously into the prostate. RF electrocautery was applied to the needle and treatment was monitored with ultrasound. Animals were sacrificed and gross examination of the prostate and surrounding tissues was performed. Histopathologic examinations of the prostate were also performed.

RESULTS

The treatment zone appeared as an elliptical echogenic focus on ultrasound that increased in size with the application of current. Gross and histopathologic correlation demonstrated that the treatment area included a central area of char with a surrounding area of coagulation. There were no deleterious effects to surrounding tissues.

CONCLUSION

Our results demonstrate the feasibility of percutaneous ultrasound-guided RF electrocautery ablation of canine prostate tissue.

Significance of orbital measurements in the fetus

Orbital imaging is not performed routinely during obstetrical sonography, but the discovery of abnormal orbital diameters provides evidence of fetal dysgenesis. This study was designed to establish the validity of a previously developed orbital nomogram for a high-risk population and to determine whether proved cases of hypotelorism and hypertelorism fell outside the normal ranges. Inner and outer orbital measurements of 422 fetuses were obtained prospectively during routine obstetrical sonography in a high-risk patient population. Comparison of these measurements to the previously established nomogram demonstrated that the nomogram is still accurate with current equipment and in a population at high risk for anomalies. In addition, sonograms and autopsy and clinical data from six cases of hypotelorism, two of cyclopia, and three of hypertelorism were reviewed retrospectively. Both inner and outer orbital measurements fell clearly below two standard deviations of the mean in all six cases of hypotelorism. The three cases of hypertelorism had inner orbital measurements above the 95th percentile and outer orbital distances within normal limits but near the 95th percentile. All cases with abnormal orbital distances had associated intra- or extracranial abnormalities, including holoprosencephaly, encephalocele, cleft palate, cardiac anomalies, imperforate anus, diaphragmatic hernia, and digit anomalies.

Distal lateral ventricular atrium: reevaluation of normal range

PURPOSE

To reassess the mean size of the lateral cerebral ventricular atrium in the fetus.

MATERIALS AND METHODS

Measurements were obtained from axial ultrasound (US) images of 500 fetuses by using the standard criteria, and they were reviewed for consistency. Eleven fetuses had ventricular atrial measurements of 10 mm or more, and they were also followed up. Postnatal evaluation consisted of US examinations of the head in three patients and clinical examination of all 11 patients.

RESULTS

The mean size of the ventricular atrium was 6.6 mm with a standard deviation (SD) of 1.4 mm. However, the mean plus 2.5 SD would yield an upper normal limit of 10.1 mm. Findings at the postnatal examinations of the 11 fetuses with isolated lateral ventriculomegaly (three with measurements of 13 mm or less and eight with measurements at 10 mm) were normal.

CONCLUSION

Use of 10 mm (mean from this study plus 2.5 SD) as the upper limit of normal for the ventricular atrial measurement should be continued. Measurements of 10 mm or above should prompt a careful search for associated fetal abnormalities and consideration of amniocentesis.

Proximal fetal cerebral ventricle: description of US technique and initial results

PURPOSE

To establish adequacy and ease of visualization of the proximal ventricle, normal range of measurements of the proximal ventricle, and distance of the proximal choroid plexus from the lateral ventricular wall.

MATERIALS AND METHODS

With use of an angled technique, ultrasound (US) evaluation of the proximal fetal ventricle was attempted in 439 fetuses during routine obstetric US examination. Ease of examination, additional time required, mean measurements, and standard deviation (SD) were calculated.

RESULTS

Visualization and measurement of the proximal ventricle were performed without difficulty in 77% of cases and with difficulty in 19%, and were impossible in 4%. Average additional time required was 4.2 minutes. The upper limit of normal for the midportion of the proximal ventricle was 8 mm (mean + 2.5 SD). In no normal pregnancy was the proximal ventricle separated from the choroid plexus by greater than 3 mm.

CONCLUSION

Visualization and measurement of the proximal fetal cerebral ventricle can be performed during routine obstetric US examination in little additional time and can be used to detect abnormalities that might otherwise be overlooked because of fetal position.

Ultrasonography: not useful in detecting susceptibility to malignant hyperthermia

MH is a rare, potentially fatal complication of general anesthesia. Halothane-caffeine contracture testing of a muscle biopsy is the only accepted diagnostic test for MH. A previous report indicated that ultrasonography may aid in diagnosis of MH. Using sonographic examination of the thigh and calf, we evaluated eight patients with proved susceptibility to MH and eight control patients. Two radiologists independently evaluated the sonograms for echogenicity and definition of fascial planes. We detected no consistent and reliable differences between control and MH patients. We conclude that, in our hands, ultrasonography is not useful in differentiating patients with MH from normal persons.

Refinement of a technique for thermocholecystectomy in an animal model

RATIONALE AND OBJECTIVES

A modification of a thermal ablation system was tested for improved cystic duct occlusion and gallbladder mucosa ablation in an animal model.

METHODS

Fourteen domestic swine were included in group 1 with thermal treatment of the cystic duct to 75 degrees C for 15 minutes, followed by heating of the gallbladder lumen with a catheter/heating device to 54 degrees C for 30 minutes. One swine served as a control (group 2). A ligature was placed around the cystic duct without thermal treatment of the cystic duct and with the catheter/heating device placed into the gallbladder for 30 minutes without thermal treatment. All animals were killed after 3 weeks with histologic examination of the gallbladder, cystic duct, and surrounding organs.

RESULTS

In group 1, technical failure due to catheter clogging occurred in the first three animals, which were killed immediately. Eleven animals were treated with a redesigned catheter system. Three weeks after treatment, 10 of the 11 animals had complete cystic duct occlusion and complete obliteration of the cystic duct mucosa. One of the 11 animals experienced partial cystic duct ablation. Nine of the 11 treated animals experienced complete mucosal ablation of the gallbladder. Five of the 11 animals had no residual lumen, whereas 6 of the 11 had a luminal volume that averaged 4 mL compared to 35 mL before treatment. In group 2, the control subject had a gallbladder volume of 50 mL and normal gallbladder and cystic duct mucosa.

CONCLUSIONS

This study demonstrates improvement in both cystic duct occlusion and gallbladder mucosa ablation with standardization of the technique for thermocholecystectomy in an animal model. However, a better system is required to promote complete obliteration of the gallbladder lumen.

Three-dimensional sonographic evaluation of developmental dysplasia of the hip: preliminary findings

PURPOSE

To determine the value of three-dimensional (3D) sonography in the evaluation of developmental dysplasia of the hip.

MATERIALS AND METHODS

3D reconstruction and section analysis were performed on 38 data acquisitions obtained in nine patients with a clinical diagnosis of developmental dysplasia of the hip. Data were obtained mostly in the coronal plane, and section-analysis and 3D volume reconstruction images were generated.

RESULTS

Of the 32 image sets obtained in the coronal plane, the technical quality of 27 (84%) section-analysis images and 25 (78%) spatial-revolving images was judged to be satisfactory.

CONCLUSION

In addition to permitting global visualization of the hip, 3D sonography offers imaging in the sagittal and craniocaudal projections, something no other modality can offer. 3D sonography can also demonstrate the relationship of the femoral head to the acetabulum and femoral head containment more thoroughly than does conventional sonography.

Color flow sonographic mapping of intravascular extension of malignant renal tumors

The purpose of this study was to evaluate the possible role of CDFI in identifying malignant renal tumor thrombus in the renal vein or the IVC. This study involved 24 tumors in 23 patients, including 19 renal cell carcinomas, four Wilms' tumors, and one rhabdoid tumor. CDFI had an overall sensitivity of 95% in predicting combined renal vein and IVC tumor involvement but was more sensitive in the renal vein alone (100%) than in the IVC alone (89%). Specificity of CDFI was nearly equal for both renal vein and IVC thrombus at 85%. The main limitation of CDFI was its inability to predict venous tumor extension in large or bulky tumors. We would recommend CDFI as a method of detecting renal vein or IVC thrombus at the time of initial real-time sonographic detection of tumor. When CT or MR imaging is equivocal, CDFI may be used to predict tumor thrombus in the renal vein or IVC.