Sonographic evaluation of the anterior liver surface in chronic liver diseases using a 7.5-MHz annular-array transducer: correlation with laparoscopic and histopathologic findings

PURPOSE: We studied the sonographic appearance of the anterior liver surface using an ultrasound scanner equipped with a 7.5-MHz annular-array transducer to determine the accuracy of this imaging modality in monitoring the course of chronic liver diseases. METHODS: We prospectively evaluated patterns of the liver surface in the sonograms of 77 consecutive patients with chronic liver diseases who had undergone sonographic examination with a 7.5-MHz annular-array transducer and a 3.75-MHz convex-array transducer over a 2-year period and compared these findings with those of laparoscopy (using previously described categories) and histopathology. RESULTS: Histopathologically confirmed disease prevalences for inactive chronic hepatitis, active chronic hepatitis, liver cirrhosis, and others were 10% (8/77), 56% (43/77), 29% (22/77), and 5% (4/77), respectively. The sonographic appearance of the liver surface with the 3.75-MHz transducer was classified as either a regular or an irregular pattern. The regular pattern corresponded to 69% (34/50) of the cases in laparoscopic category 200 or 300 and the irregular pattern with 85% (23/27) of the cases in category 400 or 500. The sonographic appearance of the liver surface with the 7.5-MHz transducer was classified as regular, unevenly irregular, diffusely irregular, or nodular. These 4 patterns detected 75% (24/32), 78% (14/18), 52% (12/23), and 75% (3/4) of the cases of laparoscopic categories 200, 300, 400, and 500, respectively. In a comparison of the sonographic patterns of the liver surface with the differential histopathologic findings, the regular sonographic pattern corresponded to 88% (7/8) of the cases of inactive chronic hepatitis, the unevenly irregular pattern with 35% (15/43) of the cases of active chronic hepatitis, and the diffusely irregular and nodular patterns (considered as 1 group) with 68% (15/22) of the cases of liver cirrhosis. CONCLUSIONS: Our results suggest that sonographic evaluation of the liver surface with a 7.5-MHz annular-array transducer using this classification provides detailed information on the evolution of chronic liver diseases that correlates with the laparoscopic and histopathologic findings and thus is a useful noninvasive method for monitoring the disease course to cirrhosis.     

Sonography in Budd-Chiari syndrome.

OBJECTIVE: The objective of this presentation is to provide an overview of sonographic manifestations of Budd-Chiari syndrome (BCS). METHODS: Patients were scanned with ultrasound systems using mainly a 2- to 5-MHz curvilinear transducer and in some patients a 5- to 12-MHz linear transducer. The patients were asked to fast from the previous night or for at least 6 hours. Color and spectral Doppler sonography was performed in all patients. RESULTS: Commonly seen findings in BCS include inferior vena cava (IVC) webs and thrombi, IVC narrowing, hepatic venous thrombosis, enlarged caudate lobes, ascites, intrahepatic or extrahepatic collaterals, monophasic to absent flow in the hepatic veins, and high flow velocities in areas of stenosis in the IVC or hepatic veins. Inferior vena cava stents used in the treatment of BCS could also be seen. CONCLUSIONS: Budd-Chiari syndrome is an uncommon disorder; outcome is poor in many cases; and the condition is often misdiagnosed or underdiagnosed. Sonography is a noninvasive and effective modality for diagnosis of BCS.     

Accuracy and outcome of sonographically guided intra-articular sodium hyaluronate injections in patients with osteoarthritis of the hip.

OBJECTIVE: The aim of this study was to evaluate the accuracy and outcome of sonographically guided intra-articular sodium hyaluronate injections in patients with osteoarthritis of the hip. METHODS: The prospective study involved 10 patients who had the diagnosis of unilateral hip osteoarthritis. The mean age of the patients was 63.2 years (range, 27-80 years). Depending on patient body weight, either a 3.5- to 5-MHz convex transducer or a 5- to 12-MHz linear transducer was used to examine each affected joint. Every subject received 3 injections of sodium hyaluronate, 1 per week for 3 consecutive weeks. With real-time sonographic monitoring, each joint was penetrated with a 20-gauge Chiba needle. Contrast medium was injected initially, and proper intra-articular placement was verified with computed tomography before the hyaluronate injection. Each patient's outcome was assessed on the basis of visual analog scale results and Western Ontario and McMaster Universities osteoarthritis index findings that were recorded before the set of injections and 2, 4, and 6 months after the third injection. RESULTS: Computed tomography confirmed accurate placement in all 30 injections in the study. The visual analog scale and the Western Ontario and McMaster Universities osteoarthritis index scores showed that 80% of the patients had less pain in the joint at 6 months after the last injection. CONCLUSIONS: Sonographically guided intra-articular injection of sodium hyaluronate for patients with hip osteoarthritis is easy to perform and is a safe, economical, and well-tolerated form of treatment. In contrast to fluoroscopic or computed tomographic guidance, the sonographic technique exposes neither the patient nor the physician to radiation.     

Dynamic sonography of external snapping hip syndrome.

OBJECTIVE: To evaluate the dynamic sonographic findings of external snapping hip syndrome. METHODS: Five patients with 7 cases of painful external snapping hip (3 male and 2 female; age range, 14-32 years; mean, 19 years) were examined with sonography. Two patients had bilateral snapping. Dynamic sonographic examinations of hips were performed with a linear 5- to 12-MHz transducer during hip motion. RESULTS: Dynamic sonographic studies of the affected hip revealed causes of the external snapping hip in all cases. It was elicited by an abnormal jerky movement of the iliotibial band overlying the greater trochanter in 5 of 7 cases and of the gluteus maximus muscle in 2 cases. The iliotibial band over the greater trochanter was hypoechoic in 3 of the 5 cases and thickened in 1 case. Dynamic sonography showed good correlations between the jerky movements of the iliotibial band and the gluteus maximus muscle and the painful snapping reported by the patients. CONCLUSIONS: Dynamic sonography was helpful in the diagnosis of external snapping hip syndrome; it showed real-time images of sudden abnormal displacement of the iliotibial band or the gluteus maximus muscle overlying the greater trochanter as a painful snap during hip motion.     

The fetal esophagus: anatomical and physiological ultrasonographic characterization using a high-resolution linear transducer.

OBJECTIVE: To study the sonographic anatomy and physiology of the human fetal esophagus during the mid-trimester of pregnancy using a high-resolution linear transducer. METHODS: This was a prospective observational study of the fetal esophagus between 19 and 25 weeks' gestation. The study was performed in 60 consecutive fetuses, after a normal anatomy scan, using a 5-13-MHz matrix array wide-band transducer. During the examination the collapsed esophagus was first visualized, and followed by a 5-min video recording in order to demonstrate luminal patency and peristaltic waves. RESULTS: Complete anatomical visualization of the esophagus was possible in 52 (86.7%) patients and at least partial visualization in 58 (96.7%) patients. Three different patterns of esophageal motility were observed: a simultaneous and short opening of the whole esophagus was found in 35 (58.3%) fetuses; a segmental, peristalsis-like movement from the pharynx, through the mediastinum, and into the stomach was found in 18 (30%) fetuses; and in one fetus reflux-like passage of solid contents from the stomach was observed. The mean time required for demonstration of esophageal patency was 96.1 (range, 10-300) s. CONCLUSIONS: Demonstration of normal anatomy and physiological activity of the fetal esophagus is feasible using appropriate transducers. The most commonly observed pattern of esophageal motility in the mid-trimester of pregnancy is the simultaneous relaxation of the upper and lower esophageal sphincters with concurrent opening of the esophageal lumen from the upper thorax to the stomach. Demonstration of a patent esophagus may be helpful in fetuses with suspected esophageal atresia.     

Three-dimensional sonography of muscle hernias.

OBJECTIVE: Muscle hernias through a defect in the fascia can be subtle and difficult to see on 2-dimensional (2D) scans. We describe the appearance of muscle hernias on 3-dimensional (3D) sonographic multiplanar scans and 3D rendering. METHODS: Two patients were examined with a 2D linear 5- to 12-MHz probe. The questionable area was scanned with a 5- to 12-MHz linear 3D transducer. Multiplanar reconstruction and 3D rendering were performed to show the hernia. RESULTS: In both cases, the muscle hernia was small and subtle on 2D scans but became slightly more prominent on examination after the muscle was exercised. In both patients, the hernias were very obvious on 3D scans. CONCLUSIONS: Symptomatic muscle hernias may sometimes be very small and difficult to see on 2D scans. Three-dimensional rendering shows the hernia very well.     

Intracervical sonographic-pathologic correlation: preliminary results.

OBJECTIVE: To determine whether current-generation endoluminal ultrasonic transducer technology could visualize dysplastic and malignant cervical lesions. METHODS: Inclusion criteria for patients enlisted in the study were abnormal Papanicolaou test results, an abnormality seen at colposcopy, and consent for a cone biopsy. In addition, we included 4 women who were undergoing hysterectomy but had no evidence of cervical abnormalities at the time of surgery, for a total of 28 women. We used a 20-MHz annular array intravascular transducer. We correlated all sonographic and pathologic results with regard to being normal or abnormal using the Pearson product moment correlation coefficient, and we evaluated interobserver variation by having 5 blinded sonologists interpret each examination and calculating kappa statistics. RESULTS: We performed intracervical sonography on 24 women with abnormal Papanicolaou test results and on 4 women without abnormalities. Nineteen of the 24 women with proven disease had abnormal sonographic images. Five women with pathologically proven cervical intraepithelial neoplasia I had normal sonographic images. Lesions ranged in size from 0.3 to 7 mm. Two carcinomas (5 and 7 mm diameter), multiple nabothian cysts, cervicitis, and 2 giant cell foreign body reactions were visible on sonography. The correlation coefficient for abnormal sonographic and pathologic findings was 0.87 (P < .005). We obtained a kappa value of 0.75 for interobserver variation. CONCLUSIONS: Intracervical sonography was able to visualize dysplastic lesions and carcinomas as hypoechoic defects with surrounding echogenic areas of glandular cervical mucosa. Lesions were shown with sufficient resolution and interobserver variation to suggest that the technique may be clinically applicable, particularly for planning surgical therapy. However, design of a transducer that can be easily sterilized between examinations, similar to current endovaginal probes, would be necessary to make intracervical sonography a clinically feasible examination.     

Does the 10-MHz transvaginal transducer improve the diagnostic certainty that an intrauterine fluid collection is a true gestational sac?

PURPOSE: We studied whether a 10-MHz transvaginal transducer improves the diagnostic certainty that a small intrauterine fluid collection is a true gestational sac. METHODS: Over a 6-week period, women who presented with a positive pregnancy test and a fluid collection (devoid of any characteristics such as yolk sac or fetal pole) in the uterus seen with a standard 6-7-MHz transvaginal transducer were entered in the study. The patients were immediately rescanned with a 10-MHz transvaginal probe, and characteristics of the fluid collection using this probe were noted. Specifically, the visualization of a yolk sac or the intradecidual or double decidual sign was considered an objective improvement in the certainty that the fluid collection was a gestational sac. RESULTS: Twelve patients presented with a positive pregnancy test and a fluid collection in the uterus seen with a 6-7-MHz probe. Eight of these fluid collections were smaller than 1 cm in mean diameter, and all 8 of these patients had an objective improvement in the diagnosis of an intrauterine pregnancy using the 10-MHz probe. The other 4 patients had fluid collection 1-2 cm in mean diameter seen at 6-7 MHz. The 10-MHz probe improved the diagnostic confidence in 2 of these 4 patients. CONCLUSIONS: In patients with early pregnancies who have questionable gestational sacs on sonography with standard 6-7-MHz transducers, the 10-MHz probe improves the diagnostic confidence of the presence of an intrauterine gestational sac.     

Quantitative assessment of fetal bowel echogenicity: comparison of harmonic,compound, and fundamental sonographic images

PURPOSE: The aims of this study were to assess normal fetal bowel echogenicity quantitatively and to compare the levels of bowel echogenicity observed with the use of 3 different sonographic image-processing techniques-harmonic plus compound imaging, harmonic imaging alone, and fundamental imaging-and 2 different broadband transducers. METHODS: Women with normal singleton second-trimester fetuses underwent sonographic scanning with both a 2-5-MHz and a 4-7-MHz transducer. The use of the 3 imaging techniques and the 2 transducers resulted in 6 types of images: 2-5-HC (harmonic plus compound images), 2-5-H (harmonic images), and 2-5-F (fundamental images), and 4-7-HC, 4-7-H, and 4-7-F images. The relative echogenicities (brightness) of the fetal bowel and iliac bone were measured, and bowel echogenicity ratios (bowel echogenicity/iliac bone echogenicity x 100) were calculated using graphics software. The resulting data were analyzed to evaluate differences in echogenicity ratios between the 6 types of images. RESULTS: We examined 37 fetuses during the study period. The bowel echogenicity ratios were highest on the images obtained with harmonic and compound-imaging techniques (2-5-HC, 84.7 +/- 23.4%; 4-7-HC, 98.5 +/- 36.4%). The bowel echogenicity ratio for the 2-5-HC images was significantly higher than those for the 2-5-H and the 2-5-F images (p < 0.01 and p < 0.001, respectively), and those for the 4-7-HC and 4-7-H images were higher than that for the 4-7-F images (p < 0.01 for both comparisons). CONCLUSIONS: A sonographic finding of echogenic fetal bowel should be interpreted cautiously because the use of special image-processing techniques can artificially enhance the apparent level of echogenicity of the bowel. We recommend rescanning without the use of those techniques if the fetal bowel appears to have an increased level of echogenicity.     

Sonography of various cystic masses of the female groin.

OBJECTIVE: The purpose of this presentation is to review the pathologic spectrum of cystic masses that may involve the female groin region, with a correlation of the lesions with their sonographic appearance. METHODS: We reviewed the sonographic findings of palpable groin masses showing a cystic pattern in female patients. The groin region is best depicted with a high-frequency (7.5- to 12-MHz) linear array transducer. Color Doppler sonography and an extended field of view are helpful in the differential diagnosis of variable groin masses. RESULTS: There are various cystic masses involving the female groin, such as round ligament cysts, varicosities of the round ligament, inguinal herniation of the ovary, cystic lymphangiomas, epidermal inclusion cysts, abscesses, and pseudoaneurysms. CONCLUSIONS: Sonography with color Doppler imaging is helpful for the differential diagnosis of the pathologic spectrum of cystic masses involving the female groin.     

Findings of extrathyroid lesions encountered with thyroid sonography.

OBJECTIVE: The purpose of this presentation is to illustrate the normal sonographic anatomy of the anterior neck region and the sonographic findings of various kinds of extrathyroid lesions. METHODS: Cases of extrathyroid lesions were collected and reviewed retrospectively from our archives. All of the sonographic examinations were performed with high-frequency (5- to 15-MHz) linear array transducers. RESULTS: The normal sonographic anatomy of the anterior neck region and various pathologic conditions of patients with extrathyroid lesions are discussed. CONCLUSIONS: Sonography is a useful imaging method for evaluating anterior neck anatomy and various pathologic conditions in patients with extrathyroid lesions.     

Doppler sonographic assessment of posttraumatic reflex sympathetic dystrophy.

OBJECTIVE: To reveal the arterial Doppler sonographic findings in cases of posttraumatic reflex sympathetic dystrophy METHODS: Eleven patients had hand reflex sympathetic dystrophy, and 9 had foot reflex sympathetic dystrophy. The duration of symptoms ranged from 1 to 28 weeks, and the history of fracture ranged from 6 to 48 weeks. Bilateral brachial or popliteal arteries proximal to injuries were evaluated by Doppler sonography with a 7.5-MHz linear transducer. All patients also had triphasic bone scintigraphy and extremity thermography RESULTS: Two patients had monophasic waveforms and 4 had low-pulsatility triphasic waveforms on the affected limbs when compared with the asymptomatic limbs. All opposite asymptomatic limbs had normal triphasic waveforms in these 6 cases. Spectral analysis revealed a loss or decrease of a normal reversed flow component with a reduced pulsatility index on the affected limb. Fourteen other patients had symmetric triphasic waveforms. We observed that the patients who had stage 1 reflex sympathetic dystrophy and warm limbs with durations of symptoms of more than 2 weeks had positive Doppler sonographic findings, whereas all patients with stage 2 reflex sympathetic dystrophy and all with normal skin temperature, regardless of stage, had normal waveforms. CONCLUSIONS: Doppler sonography revealed loss of normal triphasic arterial waveforms in some of the cases of stage 1 disease, whereas many cases of stage 1 disease and all cases of stage 2 disease had normal findings. Therefore, we think that Doppler sonography cannot be used for the diagnosis of reflex sympathetic dystrophy but may help in assessing hemodynamic stages of the disease.     

Ultrasonographic examination on patients with chronic wrist pain: a retrospective study

OBJECTIVE: To describe the results of ultrasonographic examination in a series of patients with chronic wrist pain and to define the proportion of occult carpal ganglion in these patients. DESIGN: A retrospective study including 57 patients with wrist pain consecutively referred for sonographic examination. The inclusion criteria for this study were a history of wrist pain longer than 3 mos with no wrist trauma, and no palpable mass at the wrist. Ultrasound examination with a 10-MHz linear transducer was used to detect wrist pathology. A well-demarcated anechoic mass with posterior enhancement and without vascularity within the mass on sonography was defined as a ganglion cyst. RESULTS: Thirty-three of the 57 patients (58%) were diagnosed by sonographic examination as having a ganglion in the wrist joint. The size of the ganglion demonstrated on sonographic imaging ranged from 2 x 5 mm to 10 x 9 mm on a longitudinal scan of the wrist (with a mean of 4 x 7 mm.). Surgical excision was carried out in 12 patients who had ganglions diagnosed by sonographic examination; in all cases, the mucin content of the specimen was demonstrated. Eight patients underwent local aspiration followed by steroid injection under the guidance of ultrasound. The aspirated content was a jelly-like substance. In these 20 treated patients, symptoms of wrist pain improved after intervention. CONCLUSIONS: The prevalence of occult carpal ganglion is common in chronic wrist pain patients. High-resolution sonographic examination facilitates early detection of occult carpal ganglion.     

肛周感染性疾病的超声分型和声像图特征

目的 探讨高频超声对肛周感染性疾病超声诊断分型、声像图特征及临床意义。方法 通过对56例肛周感染性疾病患者选用6～10MHz普通线阵探头或5～10MHz腔内端式探头，进行肛管及周围超声扫查，然后依据声像图特征进行简略分型。结果 发现单纯型肛周脓肿24例，肛瘘20例，复合型肛周脓肿12例；其中有2例复合型肛周脓肿因瘘管短小、位于肛管后方近6点钟处，未能发现瘘管而诊断为单纯型肛周脓肿。上述病例均经手术证实。结论 肛周感染性疾病超声诊断及分型是一种简便、适用、易行的方法，有助于临床选择治疗方案。     

Sonographic characterization of the lumbar intervertebral disk with anatomic correlation and histopathologic findings.

OBJECTIVE: The purpose of this study was to describe the normal anatomy and abnormalities of the lumbar intervertebral disk with sonography in cadaveric specimens and to correlate the sonographic findings with pathologic findings. METHODS: Sonographic imaging with both 4.5- and 10-MHz linear array transducers was performed on 35 lumbar intervertebral disks in 13 human cadaveric spines. The cadaveric specimens were sectioned for anatomic and histopathologic evaluation. Findings on anatomic sections were correlated with the findings on corresponding sonographic images with respect to the sonographic appearance of disk components in 30 intervertebral disks. RESULTS: High-resolution sonography with a 10-MHz frequency transducer enabled distinction of the nucleus pulposus from the annulus fibrosus and assessment of the echogenic characteristics of these structures. Sonography showed numerous fine linear echoes in the outer portion of the intervertebral disk in 26 (87%) of 30 specimens, which corresponded to the normal concentric arrangement of the fibers in the periphery of the annulus fibrosus. Amorphous areas of low echogenicity in the inner portion of the annulus fibrosus (n = 14, 47%) correlated with degenerative changes of the disk on corresponding microscopic sections. The nucleus pulposus appeared relatively isoechoic (n = 5, 17%) or hyperechoic (n = 4, 13%) to the annulus fibrosus. In degenerative disks (n = 21, 70%), the nucleus pulposus showed decreased echogenicity, and differentiation between the nucleus pulposus and annulus fibrosus was difficult. CONCLUSIONS: High-resolution sonography is a simple imaging method that can show the normal lumbar intervertebral disk and degenerative changes in appropriate subjects. High-resolution sonography proves superior to conventional sonography for evaluation of the lumbar intervertebral disk.     

Intrathoracic postesophagectomy stomach: the role of chest sonography in pediatric patients.

OBJECTIVE: Sonography is a reliable imaging tool, complementary to plain radiography in certain pediatric chest disorders. It can assist in localizing and characterizing mediastinal, pleural, and pulmonary opacities. We have found that sonography is also valuable in elucidating postoperative chest radiography. In this series, our objective was to assess the value of sonography for understanding the radiologic changes in the child after esophagectomy and to highlight its ability to show the intrathoracic stomach. METHODS: Sonography was performed with a 5- to 12-MHz linear array transducer via anterior, lateral, and posterior intercostal approaches of the abnormal hemithorax in supine, prone, and, when necessary, upright positions. RESULTS: The distended fluid- or food-filled stomach was identified on sonography as the source of the undefined thoracic opacity on plain radiography in 2 patients. CONCLUSIONS: The postoperative pediatric chest radiograph is often difficult to understand. Sonography can differentiate between lung consolidation or pleural fluid and a food- or fluid-filled stomach. Simple maneuvers such as postural changes can confirm in the diagnosis.     

Sonography of the normal ulnar nerve at Guyon's canal and of the common peroneal nerve dorsal to the fibular head

PURPOSE: This study was conducted to evaluate the ability of sonography to visualize the ulnar nerve at Guyon's canal and the common peroneal nerve dorsal to the fibular head and to test for correlations between nerve measurements and subject characteristics. METHODS: We used a 5-12-MHz linear-array transducer in sonographic evaluation of 15 healthy adult volunteers. We evaluated the correlations between nerve diameters and surface areas and subject body mass index and height. We also tested for differences between nerve measurements in women and men and between nerve measurements from the left and right sides of the body. RESULTS: Both nerves were visualized in all subjects. Subject height correlated significantly with the anteroposterior diameter of the right ulnar nerve. Body mass index correlated significantly with the surface area of both ulnar nerves, with the anteroposterior diameter of both ulnar nerves, with the transverse diameter of the left ulnar nerve, and with the transverse diameter of the right common peroneal nerve. There was a statistically significant difference in anteroposterior diameter of the left ulnar and left common peroneal nerves between women and men. There were no significant differences between left- and right-side measurements for the combined data from the entire group of subjects. CONCLUSIONS: A 5-12-MHz linear-array transducer readily allows for visualization of the ulnar nerve at Guyon's canal and the common peroneal nerve dorsal to the fibular head.     

Simple ultrasound evaluation of the anal sphincter in female patients using a transvaginal transducer.

OBJECTIVE: Fecal incontinence affects 0.2% of women aged 15-64 years and about 1.3% of women over 64 years. Most cases are related to instrumental deliveries affecting the anal sphincter complex. We propose a simple technique using the generally available transvaginal transducer to evaluate the anal sphincter complex. METHODS: Ninety-two patients underwent ultrasound examination. Group I consisted of 53 nulliparous patients. In Group II there were six patients with normal spontaneous vaginal deliveries without episiotomies. In Group III there were 14 patients with vaginal deliveries and one to three episiotomies but no lacerations. In Group IV there were nine postpartum patients with recently repaired (48 h to 3 weeks) third- and fourth-degree lacerations. All women in Groups I-IV were asymptomatic. Group V consisted of 10 patients symptomatic for fecal incontinence. We used a vaginal probe (5-9-MHz) with the footprint placed in the fourchette pointing towards the anus in a transverse and then in a median (sagittal) plane. If seen, the combined internal and external anal sphincter thickness at the 12 o'clock location was measured. We visualized normal star-shaped mucosal folds on the transverse section and described the sonographic anatomy in both planes. RESULTS: The mean sphincter thickness measured at 12 o'clock in Group I was 2.3 (range, 1.0-4.7) mm, in Group II it was 2.9 (range, 2.4-3.4) mm, and in Group III it was 2.3 (range, 1.0-3.7) mm. The differences between these three groups were not significant. Patients from Group IV showed thinning or discontinuous sphincter anatomy at the 12 o'clock position. All symptomatic patients from Group V showed abnormal sphincter anatomy, and the normal star-like appearance of the anal mucosa on the transverse section was deformed, radiating from the point of the sphincter damage. Four of the 10 patients in this group underwent surgical repair. In these patients the sonographic findings were confirmed. CONCLUSIONS: The images obtained using this imaging modality show the sphincter muscle anatomy as well as the possible pathology. Due to its simplicity the technique can be applied in any place where a vaginal transducer is available.     

Sonographic elasticity imaging of acute and chronic deep venous thrombosis in humans.

OBJECTIVE: The purpose of this study was to assess the ability of sonographic elasticity imaging to distinguish acute from chronic deep venous thrombosis (DVT). METHODS: Fifty-four patients, 26 with acute DVT and 28 with chronic DVT, were studied, and we analyzed the data in 46 patients, 23 with acute (mean age, 5.7 days) and 23 with chronic (>8 months) DVT. Scanning was performed with a 5-MHz linear array transducer during continuous freehand external deformation of each thrombus using the ultrasound scan head. The strains in the thrombi were normalized to the average strain between the skin surface and the back wall of the vein. Relative thrombus echogenicity was measured by comparing the echogenicity of the thrombus with that of the adjacent arterial lumen. Statistical analyses were performed with the Mann-Whitney U test and receiver operating characteristic analysis. RESULTS: The median normalized strain magnitude for the acute cases was 2.75, with an interquartile range of 2.4 to 3.71, whereas the median normalized strain magnitude for the chronic cases was 0.94, with interquartile range of 0.48 to 1.36. The difference was highly significant (P < 10(-7)). The area under the receiver operating characteristic curve (A(z)) was 0.97 +/- 0.02 (SE). The echogenicity difference between the populations was highly significant (P < 10(-5)), with A(z) of 0.92 +/- 0.04. The difference between the A(z) values was not significant (P > .05). CONCLUSIONS: In this population, sonographic elasticity imaging performs at least as well as thrombus echogenicity. Thrombus aging using elasticity imaging would be particularly helpful in evaluating symptoms in patients with post-thrombotic syndrome.     

Ultrasound-Triggered Release of Recombinant Tissue-Type Plasminogen Activator from Echogenic Liposomes

Echogenic liposomes (ELIP) were developed as ultrasound-triggered targeted drug or gene delivery vehicles (Lanza et al. 1997; Huang et al. 2001). Recombinant tissue-type plasminogen activator (rt-PA), a thrombolytic, has been loaded into ELIP (Tiukinhoy-Laing et al. 2007). These vesicles have the potential to be used for ultrasound-enhanced thrombolysis in the treatment of acute ischemic stroke, myocardial infarction, deep vein thrombosis or pulmonary embolus. A clinical diagnostic ultrasound scanner (Philips HDI 5000; Philips Medical Systems, Bothell, WA, USA) equipped with a linear array transducer (L12-5) was employed for in vitro studies using rt-PA-loaded ELIP (T-ELIP). The goal of this study was to quantify ultrasound-triggered drug release from rt-PA-loaded echogenic liposomes. T-ELIP samples were exposed to 6.9-MHz B-mode pulses at a low pressure amplitude (600 kPa) to track the echogenicity over time under four experimental conditions: (1) flow alone to monitor gas diffusion from the T-ELIP, (2) pulsed 6.0-MHz color Doppler exposure above the acoustically driven threshold (0.8 MPa) to force gas out of the liposome gently, (3) pulsed 6.0-MHz color Doppler above the rapid fragmentation threshold (2.6 MPa) or (4) Triton X-100 to rupture the T-ELIP chemically as a positive control. Release of rt-PA for each ultrasound exposure protocol was assayed spectrophotometrically. T-ELIP were echogenic in the flow model (5 mL/min) for 30 min. The thrombolytic drug remained associated with the liposome when exposed to low-amplitude B-mode pulses over 60 min and was released when exposed to color Doppler pulses or Triton X-100. The rt-PA released from the liposomes had similar enzymatic activity as the free drug. These T-ELIP are robust and echogenic during continuous fundamental 6.9-MHz B-mode imaging at a low exposure output level (600 kPa). Furthermore, a therapeutic concentration of rt-PA can be released by fragmenting the T-ELIP with pulsed 6.0-MHz color Doppler ultrasound above the rapid fragmentation threshold (1.59 MPa). (E-mail: denise.smith@uc.edu)