Blunt hepatic trauma: evaluation with contrast-enhanced sonography: sonographic findings and clinical application.

OBJECTIVE: The purpose of this study was to report our initial experience in the assessment of liver trauma with real-time contrast-enhanced sonography (CES). METHODS: From January 2000 to December 2003, there were 431 hemodynamically stable patients evaluated with sonography for blunt abdominal trauma. Among these patients, 87 were selected to undergo second-level imaging, consisting of CES and computed tomographic (CT) evaluation. Indications for further assessment were baseline sonographic findings positive for liver injury, baseline sonographic findings positive for injury to other abdominal parenchyma, baseline sonographic findings positive for free fluid only, baseline sonographic findings indeterminate, and baseline sonographic findings negative with persistent clinical or laboratory suspicion. RESULTS: There were 23 hepatic lesions shown by CT in 21 patients. Peritoneal or retroperitoneal fluid was identified in 19 of 21 positive cases by all 3 imaging modalities. Liver injury was found in 15 patients on sonography and in 19 on CES. Contrast-enhanced sonography compared better than unenhanced sonography with the criterion standard for related injury conspicuity, injury size, completeness of injury extension, and involvement of the liver capsule. Both CES and CT showed intrahepatic contrast material pooling in 2 cases. All patients with false-negative sonographic or CES findings recovered uneventfully. CONCLUSIONS: Contrast-enhanced sonography is an effective tool in the evaluation of blunt hepatic trauma, being more sensitive than baseline sonography and correlating better than baseline sonography with CT findings. In institutions where sonography is regarded as the initial procedure to screen patients with trauma, this technique may increase its effectiveness. In addition, CES may be valuable in the follow-up of patients with conservatively treated liver trauma.     

Assessment of the therapeutic response of hepatocellular carcinoma treated with transcatheter arterial chemoembolization: comparison of contrast-enhanced sonography and 3-phase computed tomography.

OBJECTIVE: The purpose of this study was to compare contrast-enhanced sonography with 3-phase computed tomography (CT) in assessing the therapeutic response of hepatocellular carcinomas (HCCs) treated with transcatheter arterial chemoembolization (TACE). METHODS: Twenty-nine nodular HCCs treated with TACE were examined with contrast-enhanced sonography, 3-phase helical CT, and conventional angiography. Contrast-enhanced sonographic and CT findings were interpreted separately and prospectively for the presence or absence of contrast enhancement in the treated HCCs. Conventional angiography served as the reference standard. RESULTS: Intratumoral enhancement was seen in 19 HCCs (61%) on contrast-enhanced sonography and 12 HCCs (39%) on CT. Enhancement patterns on sonography were blush in 8 (42%), branching in 2 (11%), nodular in 4 (21%), and stippled in 5 (26%). Of the 19 HCCs with intratumoral enhancement on contrast-enhanced sonography, 13 (68%) showed tumor staining on angiography. Of the 12 HCCs without intratumoral enhancement on sonography, 1 (8%) showed tumor staining on angiography. The sensitivity and specificity of contrast-enhanced sonography in depicting flow in HCCs treated with TACE were 93% and 65%, respectively. The sensitivity and specificity of 3-phase CT were 64% and 100%. CONCLUSIONS: Contrast-enhanced sonography is a more sensitive imaging method than 3-phase CT in depicting vascularity in HCCs treated with TACE.     

Contrast-enhanced two- and three-dimensional sonography for evaluation of intra-abdominal hemorrhage.

OBJECTIVE: To determine whether a contrast agent enhances sonographic detection of bleeding sites in the abdomen and whether contrast-enhanced three-dimensional sonography provides additional information compared with contrast-enhanced two-dimensional sonography. METHODS: Bleeding sites were created within the livers (n = 3), spleens (n = 5), and kidneys (n = 3) of 3 dogs. A sonographic contrast agent with vascular and parenchymal enhancement capabilities was administered intravenously at a dose of 0.02 mL/kg. Before and after each contrast agent injection, the bleeding sites were imaged with two- and three-dimensional sonography in gray scale harmonic imaging and color flow modes. Sonographic findings were compared with gross pathologic findings. RESULTS: Noncontrast-enhanced sonography was not able to show the specific location of the active bleeding in any of the organs evaluated. The contrast agent enhanced the sonographic detection of blood flow in normal vessels and extravasated blood from damaged vessels or organs in all cases. Intrasplenic and intrahepatic hematomas were better identified on delayed imaging sequences because there was marked enhancement of the normal parenchyma, whereas the hematomas remained unenhanced. Reconstructed three-dimensional sonography showed spatial relationships of the bleeding sites and surrounding structures. Gross pathologic findings were consistent with the contrast-enhanced sonographic results. CONCLUSIONS: Contrast-enhanced sonography improves the detection and evaluation of abdominal bleeding sites. Contrast-enhanced three-dimensional sonography appears to provide additional information when compared with two-dimensional sonography.     

Sonographic patterns of intraperitoneal hemorrhage associated with blunt splenic injury.

OBJECTIVE: To determine the correlation between sonographic detection of free fluid in the left upper quadrant and blunt splenic injury. METHODS: A retrospective review was conducted of all consecutive emergency blunt trauma sonograms obtained at a level I trauma center from January 1995 to January 2001. Data were collected on demographics, free fluid location, and patient outcome. Injuries were determined from computed tomography, diagnostic peritoneal lavage, laparotomy, or a combination thereof. RESULTS: A total of 4320 blunt trauma sonograms were obtained, and 596 patients (14%) had intra-abdominal injuries. The mean age was 33.7 +/- 19.1 years (range, 1-95 years), with 294 (49%) male and 302 (51%) female. There was no statistical difference between age, sex, or mechanism for all subgroups. There were 409 true-positive, 187 false-negative, 88 false-positive, and 3636 true-negative findings. Sensitivity of sonography for detecting all intra-abdominal injuries was 68%, and specificity was 97.6%; sensitivity for detecting isolated splenic injuries was 73.8%. Locations of free fluid in patients with nonsplenic injuries were compared with those in patients with splenic injuries. Isolated left upper quadrant free fluid was significantly associated with splenic injury (odds ratio = 3.0; P = .002), followed by diffuse free fluid (odds ratio = 2.1; P = .005). A subanalysis of isolated splenic injuries also revealed a significant association with left upper quadrant free fluid (odds ratio = 3.1; P = .007) and diffuse free fluid (odds ratio = 2.7; P = .0007). CONCLUSIONS: Free fluid in the left upper quadrant is significantly associated with splenic injury. This finding should triage patients more rapidly to computed tomography, angiography, embolization, and laparotomy.     

Evaluation using contrast-enhanced harmonic gray scale sonography after radio frequency ablation of small hepatocellular carcinoma: sonographic-histopathologic correlation.

OBJECTIVE: To evaluate the usefulness of contrast-enhanced harmonic wideband gray scale sonographic images obtained after radio frequency-induced coagulation necrosis, we compared the morphologic and histopathologic characteristics of the ablated tumors with sonographic images of the tumors. METHODS: Forty-eight patients with 72 hepatocellular carcinomas with a maximal diameter of 3 cm or less were treated percutaneously using radio frequency ablation. Six treated tumors in 4 patients were resected 1 month after ablation; the remaining 66 treated tumors were evaluated by a biopsy procedure performed with an 18-gauge fine needle 1 month after ablation. The excised tumors and biopsy specimens were then examined by histopathologic methods, and the findings were compared with those obtained on contrast-enhanced harmonic wideband gray scale sonography. Hematoxylin-eosin-stained specimens were inconclusive as to whether cellular viability remained; therefore, cell viability was determined by a positive result after histochemical (lactate dehydrogenase and nicotinamide adenine dinucleotide phosphate-diaphorase) staining. RESULTS: Contrast-enhanced harmonic wideband gray scale sonography after radio frequency ablation showed residual tumor enhancement in 5 (6.9%) of the 72 tumors; the histopathologic results for these 5 tumors were also positive for tumor residue. The remaining 67 tumors (93.1%) did not show any residual tumor enhancement when examined by sonography; however, only 66 tumors did not reveal tumor residue when examined histopathologically. Contrast-enhanced harmonic wideband sonographic imaging provided results that were comparable with histopathologic findings, the criterion standard for diagnosis; the sensitivity and specificity of the sonographic images for the detection of residual tumor tissue in ablated tumors were 83.3% (5 of 6) and 100% (66 of 66), respectively. CONCLUSIONS: Contrast-enhanced harmonic wideband gray scale sonography is a potentially useful technique for evaluating the therapeutic effects of radio frequency ablation on hepatocellular carcinoma.     

Screening sonography in pregnant patients with blunt abdominal trauma.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of screening sonography for the detection of clinically significant abdominal injury in pregnant patients with blunt trauma. METHODS: We retrospectively reviewed the records of 5173 patients with blunt abdominal trauma who underwent screening sonography. Pregnant patients were identified, and the prospective sonographic interpretations were compared with surgical findings, computed tomography (CT), subsequent sonography, cystography, and the clinical course. RESULTS: Of 1567 female patients with trauma, 947 were of reproductive age and, 102 (11%) of these 947 were pregnant. One patient was excluded because a truth standard was not available. Five (5%) of these 101 patients were found to have injuries at surgery. These injuries involved the placenta (2 injuries), spleen (2 injuries), liver (1 injury), and kidney (1 injury); all required surgery. Initial sonographic findings were positive in 4 of 5 patients with injuries. The missed injury was a placental injury detected 15 hours after screening sonography because of fetal bradycardia. After screening sonography, 6 patients underwent additional abdominal imaging: CT (3 patients), cystography (1 patient), and additional sonography (2 patients). Of 101 patients, 95 (94%) required no additional tests, and 97 (96%) required no test involving ionizing radiation. No pregnant patient underwent diagnostic peritoneal lavage. Sensitivity was 80% (95% confidence interval, 28%-100%), and specificity was 100% (96 of 96; 95% confidence interval, 96%-100%) for detecting major abdominal injury. CONCLUSIONS: Sonography is an effective screening examination that can obviate more hazardous tests such as CT, cystography, and peritoneal lavage in most pregnant patients with trauma requiring objective evaluation of the abdomen.     

Ablation therapy guided by contrast-enhanced sonography with Sonazoid for hepatocellular carcinoma lesions not detected by conventional sonography.

OBJECTIVE: We evaluated the usefulness of contrast-enhanced harmonic gray scale sonography with a newly developed sonographic contrast medium as a means of guidance for percutaneous ablation therapy of hepatocellular carcinoma lesions not detected by conventional sonography. METHODS: We examined 85 patients with 108 hepatocellular carcinoma lesions that were identified as hypervascular by multidetector-row computed tomography by using contrast-enhanced harmonic gray scale sonography after injection of Sonazoid (GE Healthcare, Oslo, Norway), a lipid-stabilized suspension of a perfluorobutane gas microbubble contrast agent. We scanned the whole liver by this modality at a low mechanical index in the late phase to detect lesions not detected by conventional sonography and then scanned the lesions again by this modality at a high mechanical index to visualize tumor vessels and enhancement. We also performed percutaneous ablation therapy guided by this modality to treat viable hepatocellular carcinoma lesions that could not be detected by conventional sonography. RESULTS: Conventional sonography identified 90 (83%) of 108 hepatocellular carcinoma lesions; 15 (14%) additional viable lesions not detected by conventional sonography were detected in the late phase of contrast-enhanced harmonic gray scale sonography at a low mechanical index, and tumor vessels and enhancement were observed in the late phase at a high mechanical index. Contrast-enhanced harmonic gray scale sonography diagnosed 105 (97%) of the 108 viable hepatocellular carcinoma lesions, and 14 (93%) of the 15 lesions not detected by conventional sonography were successfully treated by percutaneous ablation therapy guided by this modality. CONCLUSIONS: Contrast-enhanced harmonic gray scale sonography is useful for guidance of percutaneous ablation therapy of hepatocellular carcinoma lesions not detected by conventional sonography.     

Contrast-enhanced power Doppler sonography in breast lesions: effect on differential diagnosis after mammography and gray scale sonography.

OBJECTIVE: To evaluate the efficacy of contrast-enhanced power Doppler sonography in the differential diagnosis of breast lesions after a mammography-gray scale sonography combination. METHODS: Sixty-eight patients with 69 breast masses underwent power Doppler sonography before and after intravenous injection of a contrast agent. The lesions were diagnosed as "highly suggestive of malignancy" (category 5; n = 32), "suspicious" (category 4; n = 21), and "probably benign" (category 3; n = 16) by mammography and gray scale sonography, modeled on the American College of Radiology Breast Imaging Reporting and Data System classification. Power Doppler findings did not affect patient treatment. The authors subjectively evaluated the estimated area of vascularity, degree of enhancement following contrast agent administration, morphologic features, and distribution of vessels within the lesions. RESULTS: The final diagnoses were malignant in 28 lesions and benign in 41. Significant enhancement after contrast agent injection was detected in both the malignant and benign groups. Only 2 criteria, estimated area of vascularity and degree of enhancement following contrast agent administration, proved to be significant diagnostic determinants for contrast-enhanced power Doppler sonography (P < .001; interobserver agreements, 74.4 and 77.8, respectively). Contrast-enhanced power Doppler sonography provided a higher specificity, positive predictive value, and negative predictive value than power Doppler sonography but a lower sensitivity and negative predictive value than mammography-gray scale sonography. Only in the category 4 lesions could the combination of mammography-gray scale sonography and contrast-enhanced power Doppler sonography accomplish a higher specificity (71%) and positive predictive value (70%) than mammography-gray scale sonography (39% and 53%, respectively). CONCLUSIONS: Power Doppler and contrast-enhanced power Doppler sonography cannot be recommended as confirmatory tests in Breast Imaging Reporting and Data System category 3 and category 5 lesions. Although contrast-enhanced power Doppler sonography may help reduce unnecessary biopsies in Breast Imaging Reporting and Data System category 4 lesions, recommendation of its use has many drawbacks, such as imperfectly established criteria, lack of absolute certainty, and high cost.     

Contrast-enhanced sonography of autoimmune pancreatitis: comparison with pathologic findings.

OBJECTIVE: We evaluated the vascularity of autoimmune pancreatitis lesions on contrast-enhanced harmonic gray scale sonographic images in comparison with the pathologic findings. METHODS: Six patients with autoimmune pancreatitis were examined. All patients held their breath from 20 to 50 seconds after the injection of a contrast agent while the vascularity of the lesion was examined by contrast-enhanced harmonic gray scale sonography (early phase), and lesion enhancement was monitored at about 90 seconds after the injection while the patients held their breath for a few seconds (delayed phase). We then compared the vascularity on the contrast-enhanced harmonic gray scale sonographic images with the pathologic findings (fibrosis and inflammation) in all lesions. The vascularity of 3 of the 6 lesions was also evaluated by contrast-enhanced harmonic gray scale sonography before and after treatment with corticosteroids. RESULTS: The autoimmune pancreatitis lesions exhibited mild (n = 1), moderate (n = 3), or marked (n = 2) enhancement throughout almost the entire lesions in both the early and delayed phases. The grade of lesion vascularity on the contrast-enhanced harmonic gray scale sonographic images correlated with the pathologic grade of inflammation and inversely correlated with the grade of fibrosis associated with autoimmune pancreatitis. The vascularity of all 3 lesions had decreased on the contrast-enhanced harmonic gray scale sonographic images after steroid therapy. CONCLUSIONS: Contrast-enhanced harmonic gray scale sonography may be useful for evaluating the vascularity of autoimmune pancreatitis lesions and the therapeutic efficacy of steroid therapy.     

Imaging of peripheral cholangiocarcinoma with low-mechanical index contrast-enhanced sonography and SonoVue: initial experience.

OBJECTIVE: The purpose of this study was to investigate the imaging findings of peripheral cholangiocarcinoma with low-mechanical index (MI) contrast-enhanced sonography. METHODS: Eighteen nodules of peripheral cholangiocarcinoma proved by pathologic examination in 18 patients were evaluated with contrast-enhanced sonography. A low-MI real-time contrast-enhanced sonographic mode (ie, contrast pulse sequencing) and a sulfur hexafluoride-filled microbubble contrast agent (SonoVue [BR1]; Bracco SpA, Milan, Italy) were used. RESULTS: On contrast-enhanced sonographic images, all 18 nodules (100%) of peripheral cholangiocarcinoma showed inhomogeneous enhancement during the arterial phase, and the emergence of nodule enhancement was earlier in 3 nodules (16.7%), simultaneous in 13 (72.2%), and later in 2 (11.1%), respectively, when compared with the adjacent liver tissue. During the arterial phase, 8 nodules (44.4%) showed irregular peripheral rimlike hyperenhancement, 2 (11.1%) showed inhomogeneous hyperenhancement, and 8 (44.4%) showed inhomogeneous hypoenhancement. In portal and late phases, all 18 nodules (100%) showed hypoenhancement. When contrast-enhanced sonography was added for analysis, the confidence levels of the investigators were improved in 15 (83.3%) of 18 nodules, and 17 (94.4%) of 18 peripheral cholangiocarcinomas were correctly characterized. CONCLUSIONS: The imaging findings of peripheral cholangiocarcinoma had some characteristics on low-MI contrast-enhanced sonography. Knowledge of these characteristics might be beneficial for improving the diagnostic performance of sonography in evaluating this entity.     

Acoustic radiation force impulse elastography and contrast-enhanced sonography of sinusoidal obstructive syndrome (Veno-occlusive Disease): preliminary results

We report quantitative liver acoustic radiation force impulse (ARFI) elastographic findings in 2 cases of sinusoidal obstructive syndrome and liver contrast-enhanced sonographic features in one of these cases. To our knowledge, findings in this condition from these techniques have not been reported previously. Acoustic radiation force impulse elastography showed median high shear wave velocities (case 1, 2.75 m/s; case 2, 2.58 m/s) that normalized after specific treatment for sinusoidal obstructive syndrome; therefore, ARFI elastography provided quantitative information that helped diagnose this condition as well as monitor the response to treatment. Contrast-enhanced sonographic findings in one of the cases showed patchy liver enhancement that correlated with the high-velocity patchy distribution on ARFI elastography in that case and enhanced multidetector row computed tomographic findings in the other case. This contrast-enhanced sonographic pattern progressively normalized during follow-up after specific treatment. The elastographic features in both cases and contrast-enhanced sonographic features in one of them contributed to early diagnosis and follow-up of sinusoidal obstructive syndrome in both patients. Further prospective studies are necessary to define the role of ARFI elastography and contrast-enhanced sonography in the early diagnosis and clinical follow-up of this condition.     

Hepatic angiomyolipoma: identification of an efferent vessel as a hepatic vein by contrast-enhanced harmonic sonography

Two cases of hepatic angiomyolipoma were studied by contrast-enhanced harmonic sonography. The special tumor hemodynamics, namely the efferent blood flow of the hepatic angiomyolipoma draining into the hepatic vein, were clearly shown on harmonic imaging, and they corresponded well with those seen on angiography and computed tomography during angiography. Benign hepatic tumors were diagnosed preoperatively in both cases according to the hemodynamic findings. Hepatic angiomyolipoma was finally identified histologically. The special tumor hemodynamics might be one of the important characteristics of hepatic angiomyolipoma. Contrast-enhanced harmonic sonography is useful for the detection of special tumor hemodynamics and may facilitate the differential diagnosis from other hepatic tumors, especially malignant liver tumors.     

Percutaneous injection therapy for blunt splenic trauma guided by contrast-enhanced ultrasonography.

OBJECTIVE: The purpose of this study was to investigate the application of contrast-enhanced ultrasonography (CEUS) in managing blunt splenic trauma and the effectiveness of CEUS-guided percutaneous injection therapy. METHODS: Six patients with grade 3 or 4 splenic injuries as determined by CEUS and contrast-enhanced computed tomography were given hemocoagulase atrox and absorbable cyanoacrylate percutaneously, which were injected into the injury region and active bleeding site, respectively, under CEUS guidance. Immediately after the procedure and 1 and 3 days, 1 and 2 weeks, and 1 and 6 months after the procedure, follow-up CEUS up was performed in all patients. RESULTS: Among the 6 patients, 4 cases of CEUS-guided hemostatic injection were successful without complications. Rehemorrhage occurred in 1 patient, and a traumatic arteriovenous fistula occurred in another; repeated injection therapy in these 2 patients was effective. During the follow-up, there were no complications, and spleen perfusion recovered gradually. CONCLUSIONS: Contrast-enhanced ultrasonography can be used to guide percutaneous injection therapy and therefore achieve the goal of using interventional ultrasonography in managing splenic trauma.     

Evaluation of hepatic focal nodular hyperplasia with contrast-enhanced gray scale harmonic sonography: initial experience.

OBJECTIVE: To assess the potential of contrast-enhanced gray scale harmonic sonography in the evaluation of the typical vascular and enhancement patterns of hepatic focal nodular hyperplasia. METHODS: Thirteen patients with 13 lesions of hepatic focal nodular hyperplasia underwent contrast-enhanced gray scale harmonic sonography. After the injection of a microbubble contrast agent (SH U 508A), gray scale harmonic sonographic studies using a Coded Harmonic Angio technique were performed with a combination of a period of continuous scanning to assess the vascular pattern (vascular imaging) and interval delay scanning to determine the sequential enhancement pattern (acoustic emission imaging). Each imaging pattern was categorized and analyzed by consensus of 2 experienced radiologists. RESULTS: In 12 (92%) of 13 lesions, vascular imaging during the arterial phase showed central arteries of a spoked wheel pattern, whereas the remaining lesion had stippled vascularity. On acoustic emission imaging, 11 (85%) of 13 lesions were hyperechoic during the early phase, and the remaining 2 (15%) were isoechoic compared with surrounding parenchyma. Ten (77%) of 13 lesions remained either hyperechoic (5 of 13) or isoechoic (5 of 13) during the delay phase, whereas the remaining 3 lesions (23%) were hypoechoic. CONCLUSIONS: Contrast-enhanced gray scale harmonic sonography showed the typical vascularity of a spoked wheel pattern during the vascular phase and persistent enhancement on serial acoustic emission imaging in most cases of hepatic focal nodular hyperplasia, and thereby it can be a promising technique in noninvasive diagnosis of this entity.     

Giant mucocele of the appendix: clinical and imaging findings in 3 cases.

OBJECTIVE: Clinical and imaging (sonographic and computed tomographic [CT]) findings in 3 cases of giant mucocele of the appendix are described. METHODS: Clinical records of 3 cases of giant mucocele of the appendix were reviewed. All patients had a basal B-mode sonographic examination and a contrast-enhanced sonographic examination using a second-generation low-mechanical index contrast medium. In all cases, a dual-phase spiral CT examination was carried out. RESULTS: In 2 cases, the abdominal masses were discovered in asymptomatic patients; 1 patient had vague abdominal discomfort. A pathologic diagnosis of benign cystoadenoma was found at pathologic examination in all cases, and malignant pseudomyxoma peritonei was disclosed in 1 patient 1 year later. Common sonographic findings were as follows: (1) a huge abdominal mass with a maximum diameter ranging between 20 and 25 cm; (2) a thin hyperechoic border without either solid vegetations or signs of infiltration of surrounding tissues; (3) a complex internal echo structure with anechoic lacunae interspersed between curvilinear, wavy bands of echogenic material (the so-called sonographic onion skin sign); and (4) avascularity of the masses shown on contrast-enhanced sonography with a low-mechanical index medium. At CT, a well-circumscribed cysticlike mass of low attenuation was displayed in all cases. There was lack of enhancement during a dual-phase examination in 2 cases; in the other, a small peripheral area of faint enhancement was appreciated. Only in the latter case could CT reliably assess the origin of the mass. CONCLUSIONS: It is suggested that a combination of sonographic (namely the onion skin sign) and CT findings may aid in the correct preoperative diagnosis of giant mucocele of the appendix.     

Sonographic assessment of blunt abdominal trauma: a 4-year prospective study

PURPOSE: Emergency abdominal sonography has become a common modality worldwide in the evaluation of injuries caused by blunt trauma. The sensitivity of sonography in the detection of hemoperitoneum varies, and little is known about the accuracy of sonography in the detection of injuries to specific organs. The purpose of this study was to determine the overall accuracy of sonography in the detection of hemoperitoneum and solid-organ injury caused by blunt trauma. METHODS: From January 1995 to October 1998, 3,264 patients underwent emergency sonography at our institution to evaluate for free fluid and parenchymal abnormalities of specific organs caused by blunt trauma. All patients with intra-abdominal injuries (IAIs) were identified, and their sonographic findings were compared with their CT and operative findings, as well as their clinical outcomes. RESULTS: Three hundred ninety-six (12%) of the 3,264 patients had IAIs. Sonography detected free fluid presumed to represent hemoperitoneum in 288 patients (9%). The sonographic detection of free fluid alone had a 60% sensitivity, 98% specificity, 82% positive predictive value, and 95% negative predictive value for diagnosing IAI. The accuracy was 94%. Seventy patients (2%) had parenchymal abnormalities identified with sonography that corresponded to actual organ injuries. The sensitivity of the sonographic detection of free fluid and/or parenchymal abnormalities in diagnosing IAI was 67%. CONCLUSIONS: Emergency sonography to evaluate patients for injury caused by blunt trauma is highly accurate and specific. The sonographic detection of free fluid is only moderately sensitive for diagnosing IAI, but the combination of free fluid and/or a parenchymal abnormality is more sensitive.     

Sonography in the Evaluation of Acute Appendicitis

Objective. The purpose of this study was to evaluate the negative predictive value (NPV) of sonography in the diagnosis of acute appendicitis. Methods. Right lower quadrant sonograms of 193 patients (158 female and 35 male; age range, 3–20 years) with suspected acute appendicitis over a 1‐year period were retrospectively reviewed. Sonographic findings were graded on a 5‐point scale, ranging from a normal appendix identified (grade 1) to frankly acute appendicitis (grade 5). Sonographic findings were compared with subsequent computed tomographic (CT), surgical, and pathologic findings. The diagnostic accuracy of sonography was assessed considering surgical findings and clinical follow‐up as reference standards. Results. Forty‐nine patients (25.4%) had appendicitis on sonography, and 144 (74.6%) had negative sonographic findings. Computed tomographic scans were obtained in 51 patients (26.4%) within 4 days after sonography. These included 39 patients with negative and 12 with positive sonographic findings. Computed tomography changed the sonographic diagnosis in 10 patients: from negative to positive in 3 cases and positive to negative in 7. Forty‐three patients (22.2%) underwent surgery. The surgical findings were positive for appendicitis in 37 (86%) of the 43 patients who had surgery. Patients with negative sonographic findings who, to our knowledge, did not have subsequent CT scans or surgery were considered to have negative findings for appendicitis. Seven patients with negative sonographic findings underwent surgery and had appendicitis; therefore, 137 of 144 patients with negative sonographic findings did not have appendicitis. On the basis of these numbers, the NPV was 95.1%. Conclusions. Sonography has a high NPV and should be considered as a reasonable screening tool in the evaluation of acute appendicitis. Further imaging could be performed if clinical signs and symptoms worsen.     

Detection of bleeding in injured femoral arteries with contrast-enhanced sonography.

OBJECTIVE: The purpose of this study was to investigate the feasibility of detecting acute arterial bleeding by means of contrast-enhanced sonography. METHODS: Puncture injury was produced transcutaneously with an 18-gauge needle in 26 femoral arteries (13 in the control group and 13 in the contrast-enhanced group) of rabbits. A sonographic contrast agent (Optison; Mallinckrodt Inc, St Louis, MO) was administered intravenously at a dose of 0.06 to 0.07 mL/kg. Sonography of the femoral arteries was performed before and after injury, both before and after injection of Optison, with B-mode imaging, color Doppler imaging, and pulse inversion harmonic imaging (PIHI). RESULTS: The specific location of active bleeding could not be visualized in B-mode and PIHI scans in the control group (no Optison injection). After administration of Optison, the bleeding site was visualized because of the increased echogenicity of the extravasated blood at the puncture site in both B-mode imaging and PIHI. In color Doppler images, bleeding sites were localized successfully in 84.6% of the cases in the presence of Optison and in 30.8% of the cases without Optison. Histologic examination (light microscopy) of the hematoma confirmed the presence of contrast agent microbubbles in the extravascular space surrounding the artery. CONCLUSIONS: Contrast-enhanced sonography may provide an effective method for detecting arterial bleeding.     

Significant predictors for determination of testicular rupture on sonography: a prospective study.

OBJECTIVE: The purpose of this study was to evaluate prospectively useful sonographic diagnostic criteria for testicular rupture in patients with blunt scrotal trauma and to determine significant predictors among the criteria. METHODS: From July 2004 to February 2007, 29 consecutive patients (mean age, 22.8 years; range, 20-43 years) with blunt scrotal trauma who underwent scrotal sonography were enrolled. Ten ruptured testes and 6 intact testes were confirmed by surgery, and an additional 13 intact testes were confirmed by a physical examination. The sonographic findings were recorded with respect to contour irregularity, the presence of intratesticular and extratesticular heterogeneous echoes, loss of blood flow on color Doppler sonography, and engorgement of the pampiniform plexus by consensus between 2 radiologists. The sonographic findings used to diagnose testicular rupture were analyzed by the Fisher exact test, and significant predictors were determined by multiple regression analysis. RESULTS: The ruptured testes showed contour irregularity (P=.0002), a heterogeneous intratesticular echo pattern (P=.0077), and loss of blood flow on color Doppler sonography (P=.0093). Engorgement of the pampiniform plexus was seen in most nonruptured testes (P=.0178). Contour irregularity was the only significant predictor for the diagnosis of testicular rupture (P=.0002). On the basis of this single predictor, diagnostic predictive values for sonography were calculated; the accuracy, sensitivity, and specificity were all 90%. The positive predictive value and negative predictive value were 82% and 94%, respectively. CONCLUSIONS: Among the useful sonographic criteria, contour irregularity is the only significant predictor for the diagnosis of testicular rupture in patients with blunt scrotal trauma.     

Value of contrast-enhanced power Doppler sonography using a microbubble echo-enhancing agent in evaluation of small breast lesions

PURPOSE: The purpose of this study was to prospectively evaluate the usefulness of contrast-enhanced power Doppler sonography (PDUS) using a microbubble echo-enhancing agent in differentiating between malignant and benign small breast lesions. PATIENTS AND METHODS: Between July 1, 2000, and September 30, 2001, we performed gray-scale sonographic examination of patients in whom diagnostic sonography or screening mammography had revealed solid breast lesions measuring less than 2 cm in the largest dimension. The patients were then examined on PDUS before and after injection of a microbubble contrast agent. The sonographic findings for all 3 techniques, as well as the morphologic features of the Doppler signals for each patient before and after injection of the contrast agent on PDUS, were independently assessed. Each lesion was classified as "benign" or "malignant" on the basis of specific criteria for sonographic interpretation. A hemodynamic study was performed in which time-transit profiles of the Doppler signals on contrast-enhanced PDUS were generated using a computer-assisted program, and the results for each patient were compared with the findings of a histopathologic examination of surgical specimens. RESULTS: Thirty-six patients (35 women and 1 man) with a mean age of 43.5 years (range, 18-69 years) were evaluated. The tumors ranged from 4 to 19 mm in the largest dimension. Histopathologic examination revealed that 19 tumors were benign and 17 were malignant. For morphologic diagnosis of the malignant lesions, the sensitivity of gray-scale sonography was 100%, compared with 29% for PDUS without contrast enhancement. The specificity of gray-scale sonography was 47%, compared with 74% for PDUS without contrast enhancement. Contrast-enhanced PDUS had a sensitivity of 71% and a specificity of 58%. The diagnostic accuracy was 72% for gray-scale sonography, 53% for PDUS without contrast enhancement, and 64% for contrast-enhanced PDUS. The time-transit profiles of the hemodynamic study did not reveal a statistically significant difference in the accuracy rates of contrast-enhanced PDUS between benign and malignant breast lesions. CONCLUSIONS: Compared with PDUS without contrast enhancement, contrast-enhanced PDUS provides better visualization of the morphology of vascular Doppler signals that is characteristic of malignancy and therefore has a higher sensitivity and diagnostic accuracy, albeit a lower specificity. In differentiating between benign and malignant small breast lesions, contrast-enhanced PDUS can be helpful when used with gray-scale sonography and PDUS without contrast enhancement.