Indirect MR arthrography of the knee: effects of low-intensity ultrasound on the diffusion rate of intravenously administered Gd-DTPA in healthy volunteers.

RATIONALE AND OBJECTIVES: To evaluate whether application of low-intensity ultrasound may increase the diffusion rate of intravenously administered gadopentetate dimeglumine (Gd-DTPA) and increase the amount of joint fluid on indirect magnetic resonance (MR) arthrography. METHODS: Conventional MR imaging, indirect MR arthrography, and power Doppler ultrasonography were performed before and after application of therapeutic, pulsed low-intensity ultrasound in 12 asymptomatic knees of 12 volunteers. Intra-articular diffusion of intravenously administered Gd-DTPA as measured by signal intensity differences of the intra-articular joint fluid before and after ultrasound treatment was assessed. In addition, the amount of joint fluid was rated, and differences in synovial blood flow as evidenced by power Doppler ultrasonography were noted. RESULTS: All volunteers tolerated well the application of therapeutic low-intensity ultrasound. A significant increase in intra-articular diffusion of intravenously administered Gd-DTPA was noted in all knees, and an increase in joint fluid was noted in 8 of 12 knees (66.6%). Detection of power Doppler flow signal in the synovium of the suprapatellar recess was possible in one instance at posttreatment exam. CONCLUSIONS: Use of pulsed, therapeutic low-intensity ultrasound may increase the diffusion rate of intravenously administered Gd-DTPA and may induce joint effusion.

Comparison of unenhanced and contrast-enhanced spiral CT for assessing interval change in patients with colorectal liver metastases.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine whether the interval change in hepatic colorectal metastases as assessed with serial computed tomographic (CT) scans without contrast material enhancement differs from that as assessed using serial, portal dominant phase, contrast-enhanced CT scans. MATERIALS AND METHODS: Unenhanced and contrast-enhanced abdominal CT scans were obtained in 28 patients. Three radiologists separately reviewed serial unenhanced and contrast-enhanced studies to assess the interval change in liver metastases. These radiologists recorded total number of lesions, bidimensional measurements of the largest lesions (as many as three), and overall impressions regarding the interval change (none, worse, or better). RESULTS: Among the 84 judgments (28 patients x 3 radiologists), comparisons of unenhanced and contrast-enhanced CT studies were concordant in 60 assessments (71%). Nineteen (23%) showed mild disagreement. Of these, contrast-enhanced CT studies demonstrated disease stability when unenhanced CT studies demonstrated otherwise in 11 judgments, whereas unenhanced CT studies demonstrated stability when contrast-enhanced CT studies demonstrated otherwise in eight assessments. Furthermore, of the five marked disagreements, two resulted from a conclusion of interval improvement on unenhanced CT studies and a conclusion of interval worsening on contrast-enhanced CT studies, whereas three demonstrated the opposite. Neither set of serial CT studies systematically resulted in under- or overestimation of disease progression (McNemar Q test, P < .25). CONCLUSION: The authors found no consistent pattern to demonstrate that serial unenhanced or contrast-enhanced CT studies resulted in over- or underestimation of disease progression.

US, CT, and MR evaluation of accessory renal arteries and proximal renal arterial branches.

RATIONALE AND OBJECTIVES: The purpose of this study was to compare color Doppler ultrasound (US), computed tomographic (CT) angiography, and magnetic resonance (MR) angiography for the evaluation of accessory renal arteries and proximal branches of the main renal artery. MATERIALS AND METHODS: Fifty-six subjects who had undergone conventional arteriography of the renal arteries participated in a prospective comparison of Doppler US (45 patients), CT angiography (52 patients), and nonenhanced MR angiography (28 patients). Conventional arteriography depicted 28 accessory renal arteries and 21 proximal branches of the main renal artery within 2 cm of the aorta. RESULTS: US depicted five of 24 accessory renal arteries seen at arteriography but no proximal arterial branches. CT angiography depicted 24 of 26 accessory renal arteries and 13 of 17 proximal arterial branches, as well as 15 additional accessory renal arteries not seen at conventional arteriography. MR demonstrated 11 of 15 accessory arteries, as well as four additional accessory arteries not seen at conventional arteriography. MR did not depict any of nine proximal arterial branches seen at conventional arteriography. CONCLUSION: When compared with US or nonenhanced MR angiography, CT is the preferred method for evaluation of accessory renal arteries and proximal branches of the renal artery.

Comparison of Doppler US and CT angiography for evaluation of renal artery stenosis.

RATIONALE AND OBJECTIVES: The authors compared Doppler ultrasound (US) with computed tomographic (CT) angiography in the evaluation of stenosis of the main renal artery. MATERIALS AND METHODS: Fifty-six patients who had undergone conventional angiography of the renal arteries participated in a prospective comparison of Doppler US (45 patients) and CT angiography (52 patients). US evaluation included both the main renal artery and segmental renal arteries. RESULTS: There were 27 main renal arteries with at least 50% stenosis in 20 patients. In 36 patients, there was no significant stenosis. All cases of main renal artery stenosis detected with Doppler US of the segmental arteries were also identified with Doppler US of the main renal artery. The by-artery sensitivity (63%) of US of the main renal artery was greater than that (33%) of US of the segmental arteries. CT angiography was more sensitive (96%) than Doppler US (63%) in the detection of stenosis, but the specificity of CT (88%) was similar to that of US (89%). The difference in the area under the receiver operating characteristic curve (AUC) between CT (AUC = 0.94) and US (AUC = 0.82) was statistically significant (P = .038). CONCLUSION: Doppler US of the main renal artery is more sensitive than Doppler US of segmental arteries in the detection of stenosis. CT angiography is more accurate than Doppler US in the evaluation of renal artery stenosis.

Ultrasound of the ankle and foot.

Ultrasound is an excellent tool for evaluating common ankle problems. it is more economical than MRI and its real-time nature helps in correlating the study with the symptomatic area. US can be used in ankle to evaluate tendons (including tears, tendinitis and tenosynovitis), joints, plantar fascia, ligaments, soft tissue masses, ganglion cysts, Morton's neuroma, and to look for foreign bodies. Power Doppler can be used to evaluate blood flow in acute inflammatory process and in reflex sympathetic dystrophy.

Hepatic vascular diseases: CT and MRI.

Continued development of CT and MRI techniques has allowed these modalities to detect most hepatic vascular diseases, often obviating more invasive tests. In this article, the techniques for hepatic vascular diagnosis are reviewed, with emphasis on spiral CT and two-dimensional MRI techniques, and then the major vascular diseases on which these two modalities have a significant diagnosing impact are considered.

Routine ultrasound surveillance of the pregnant uterus.

The routine ultrasound examination of the pregnant uterus is presented in this article. The approach is based on published guidelines, dividing the examination into studies of the first trimester and studies of the second and third trimesters. The discussion emphasizes the standard anatomical views and describes the normal sonographic appearances. The methods of obtaining important measurements are described, and tables are provided to analyze these measurements. A systematic approach to obstetric ultrasound is important in ensuring completeness and in maximizing the detection of fetal abnormality.

Multiple actinomycotic liver abscesses: MRI appearances with etiology suggested by abdominal radiography. Case report.

The magnetic resonance imaging appearances of multiple actinomycotic liver abscesses are described. The abscesses appeared hypointense to liver parenchyma on T1-weighted sequences and hyperintense on T2-weighted sequences with some surrounding edema. Following intravenous gadolinium diethylenetriamine-pentaacetic acid, the masses showed a thick enhancing rim but no central enhancement. Although no etiology was discovered in the initial clinical history, antecedent dental surgery was evident on abdominal radiography that depicted dental amalgam in the ascending colon.

Foreign body granuloma simulating solid neoplasm on MR.

We report a postoperative foreign body granuloma occurring in the thyroid bed after anterior cervical fusion. The magnetic resonance (MR) imaging finding of increased signal on T2-weighted images is atypical for this type of granuloma and is thought to be due to the large proportion of cellularity in the mass histologically. In the differential diagnosis of solid postoperative masses it is important to consider foreign body granuloma, as it can mimic neoplastic disease both clinically and radiographically.

Assessment of angiogenesis: implications for ultrasound imaging.

In this paper, the fundamentals of tumor angiogenesis and the implications for ultrasound imaging will be described. Twenty-eight athymic nude mice were implanted with the human melanoma cell lines DB-1 or MW-9 (14 mice/group). Ultrasound contrast agents were injected in the tail veins. Power Doppler and pulse inversion harmonic imaging (PI-HI) was performed (in real time and intermittently). Ultrasound results were compared to immunohistochemical stains for endothelial cells (CD31), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2). Linear regression analysis indicated statistically significant correlations between percent area stained with COX-2 and with VEGF relative to power Doppler (p<0.05) and intermittent PI-HI (p<0.05) measures of tumor neovascularity in the MW-9 and the DB-1 mice, respectively. Preliminary results from a human trial of the anti-angiogenic drug Angiostatin (Entremed, Rockville, MD) showed tumor volumes increased in two patients, while the vascularity remained virtually unchanged. Conversely, in three patients with diminished tumor volumes vascularity increased by 38%. In conclusion, contrast enhanced ultrasound imaging of tumor neovascularity may provide noninvasive markers of angiogenesis and may become a useful tool for monitoring anti-angiogenic therapies in vivo.

Clinical impact of sonographically guided biopsy of salivary gland masses and surrounding lymph nodes.

Although fine-needle aspiration biopsy of salivary gland masses has been reported in the otolaryngology literature, the use of sonography to guide the biopsy of nonpalpable masses and masses seen on other cross-sectional imaging studies has not been described. Our goal was to evaluate sonographically guided biopsy of masses and lymph nodes related to the salivary glands. We analyzed the records of 18 patients who had undergone fine-needle aspiration biopsy of a salivary gland mass or lymph node with a 25-, 22-, or 20-gauge needle. A definitive cytologic diagnosis was made for 13 of the 18 patients (72%); cytology was suggestive but not definitive in three patients (17%) and insufficient in two (11%). Definitive diagnoses were made in three cases of reactive lymph node, in two cases each of lymph node metastasis and Warthin's tumor, and in one case each of pleomorphic adenoma, adenoid-cystic carcinoma, schwannoma-neurofibroma, parotid metastasis, parotid lymphoma, and Sjögren's-related lymphoid-epithelial lesion. Sonographically guided biopsy allows for confident needle placement in masses seen on computed tomography and magnetic resonance imaging. Sonography can usually distinguish a perisalivary lymph node from true intrasalivary masses, and it can help the surgeon avoid the pitfall of a nondiagnostic aspiration of the cystic component of masses. We conclude that sonographically guided biopsy of salivary gland masses can provide a tissue diagnosis that can have a direct impact on clinical decision making.

Monitoring angiogenesis in human melanoma xenograft model using contrast-enhanced ultrasound imaging.

The potential for noninvasive monitoring and quantification of tumor angiogenesis with contrast-enhanced ultrasound imaging has been investigated in a murine cancer model. Seventy athymic nude mice were implanted with the human melanoma cell line DB-1 but only 30 of these were available for the final study. The 30 mice were divided into three groups (10 mice/group), which were studied with contrast-enhanced ultrasound imaging 4, 5 or 6 weeks post-implantation. Power Doppler and pulse inversion harmonic imaging (PIHI) were performed (in real time and intermittently) with a Sonoline Elegra scanner (Siemens Medical Solutions, Issaquah, WA) following injection of Optison (dose: 0.4-0.6 ml/kg; GE Healthcare, Princeton, NJ). Ultrasound results were compared to immunohistochemical stains for endothelial cells (CD31), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2). Linear regression analysis indicated statistically significant correlations between the percent area stained with VEGF and ultrasound measures of tumor neovascularity obtained with all three techniques (p < 0.01). Contrast-enhanced ultrasound imaging of tumor neovascularity appears to provide a noninvasive marker of angiogenesis corresponding to the expression of VEGF in the DB-1 model and may become a useful tool for monitoring clinical anti-angiogenic therapies.

Superficial soft-tissue masses suggestive of recurrent malignancy: sonographic localization and biopsy.

OBJECTIVE: We investigated the usefulness of high-resolution sonography to localize superficial soft-tissue masses and to guide needle sampling for recurrent malignancy. MATERIALS AND METHODS: High-resolution sonography (10-MHz) was used to locate and guide needle sampling of 16 palpable and eight impalpable superficial masses suggestive of recurrent malignancy in 23 patient (12 men, 11 women; 34-85 years old). After detection, 22 (92%) of the masses were immediately sampled by fine-needle aspiration with 18- to 25-gauge needles and two (8%) were sampled by a 20-gauge core gun. RESULTS: Diagnostic material was obtained without complication from all 24 masses and proved positive for recurrent disease in 13 (54%). Ten (63%) of 16 palpable and three (38%) of eight impalpable masses proved positive for recurrent malignancies. One third of superficial soft-tissue masses were detected by imaging only, and of the masses not revealed on imaging, three (23%) of 13 were the site of first recurrence. Most nonnodal superficial masses (8/13) were benign, unlike the lymph nodes, of which three (27%) of 11 were benign. CONCLUSION: Not all early recurrent malignancies within the skin and subcutaneous tissues are detected by clinical examination. High-resolution sonography provided us with a rapid, safe, and accurate means of localizing and then guiding needle biopsies of superficial soft-tissue masses suggestive of recurrent malignancy.

CT of disseminated plasmacytoma in an AIDS patient.

It is well known that acquired immunodeficiency syndrome (AIDS) is associated with increased risk of neoplasms, particularly Kaposi sarcoma and non-Hodgkin lymphoma. There have been several recent reports in the literature describing plasma cell tumors in AIDS patients. We report the imaging findings in a case of widely disseminated plasmacytoma in a patient with known AIDS.

The frequency, appearance, and significance of splenic perfusion defects in CT arterial portography.

BACKGROUND: The purpose of this study was to determine the frequency, appearance, and significance of splenic perfusion defects on computed tomographic arterial portography (CTAP). METHODS: CTAP was performed with dynamic scanning at 1-cm increments on 46 consecutive patients prior to laparotomy. Two readers retrospectively reviewed these studies in consensus and recorded the number, size, and shape of focal splenic perfusion defects. These defects were later correlated with surgical findings and at least one of the following imaging modalities: delayed CT 4-6 h after CTAP, intravenously enhanced CT, sonography, or magnetic resonance imaging (MRI). RESULTS: Splenic perfusion defects were present in 14 of 46 CTAP studies (30%), and in seven patients these defects were multiple. Most defects were wedge-shaped and peripherally located, although several round defects simulating metastases were also present. The spleen was normal at surgery in all patients, and comparison imaging revealed only a small splenic infarct in one patient on MRI. CONCLUSIONS: Splenic perfusion defects occur in about one-third of patients referred for CTAP, are usually wedge-shaped but may be round, and should not be interpreted as metastases without other evidence of a space-occupying mass.

Sonographic evaluation of fetal growth: growth rate variability as a function of the interval between examinations.

OBJECTIVE: Fetal growth rates determined on the basis of findings at two separate sonographic examinations can be used to detect growth abnormalities. This article determines the relationship between the length of the interval between examinations and the associated variability in measured fetal growth rates. MATERIALS AND METHODS: We analyzed 1479 fetal measurements of the biparietal diameter, average abdominal diameter, and femur length from 539 normal pregnancies. Mean growth rates were computed as functions of gestational age. The standard deviation of the growth rate was computed as a function of the interval between examinations. RESULTS: The standard deviation of fetal growth rates is relatively constant when the interval between examinations is 8-10 weeks or more, but increases substantially when the interval is fewer than 6 weeks. CONCLUSION: From a purely statistical point of view, the optimal interval for assessment of fetal growth rates is 8-10 weeks or more. Shorter intervals, however, usually are mandated by the clinical situation. Correction factors can be used to determine the standard deviations and associated confidence intervals for fetal growth measured over a period of fewer than 10 weeks.

Transrectal sonographically guided drainage of deep pelvic abscesses.

OBJECTIVE: As an alternative to traditional surgical transrectal and transgluteal drainage, we have examined the efficacy of transrectal sonographically guided drainage for deep pelvic abscesses not accessible by percutaneous transabdominal or transvaginal routes. SUBJECTS AND METHODS: In nine patients (five males and four females) 5-51 years old, sonography or CT showed pelvic abscesses that were deemed unapproachable by percutaneous transabdominal or transvaginal routes because of interposed bowel (five patients), presacral location (two patients), or inability of the pediatric vagina to accommodate a transvaginal probe (one patient). One patient refused both transvaginal and transgluteal routes in preference to transrectal drainage. IV sedation (adults) or general anesthesia (children) was used for all drainages. A 7.5-MHz end-fire transrectal sonographic probe fitted with a biopsy guide was inserted into the rectum, and the collection was localized. With sonographic guidance, an 18-gauge needle and then a guidewire were advanced into the collection. Then with fluoroscopic guidance, a self-retaining drainage catheter was placed by using the Seldinger technique. RESULTS: All nine collections were successfully accessed and effectively drained without complication. Catheters were removed after 1-24 days (mean, 7 days; median, 5 days) without recurrent abscesses. CONCLUSION: Transrectal sonographically guided drainage of deep pelvic abscesses is a safe, well-tolerated, effective alternative to the more traditional surgical transrectal drainage or transgluteal approach, especially in pelvic abscesses that cannot be safely drained via a percutaneous transabdominal or transvaginal route.

Synovial fluid in the hindfoot and ankle: detection of amount and distribution with US.

PURPOSE: To determine the amount and distribution of synovial fluid detectable with ultrasonography (US) of the hindfoot and ankle in asymptomatic volunteers. MATERIALS AND METHODS: US was performed with a 7.5- or 10-MHz linear transducer of 60 hindfeet and ankles in 30 volunteers. Presence and amount of fluid were assessed in the ankle joint recesses, adjacent bursae, and tendon sheaths. Symmetry of bilateral fluid was evaluated. RESULTS: Fluid was detected in the anterior recess in 20 ankles (bilaterally in eight volunteers), retrocalcaneal bursa in 30 ankles (bilaterally in 12 volunteers), posterior tibial tendon sheath in 46 ankles (bilaterally in 19 volunteers), and common peroneal tendon sheath in seven ankles (bilaterally in three volunteers). No fluid was seen in the posterior recess. On average, symmetry was present for only the retrocalcaneal bursal and peroneal tendon sheath fluid. CONCLUSION: US of the hindfoot and ankle commonly depicts articular, bursal, and tendon sheath fluid in asymptomatic volunteers. The presence of fluid in these locations, even when unilateral or asymmetric, does not necessarily imply underlying abnormality.

The association of paracardial adenopathy with hepatic metastasis found on CT arterial portography.

BACKGROUND: The association of paracardial lymphadenopathy with hepatic metastases in patients undergoing computed tomographic arterial portography (CTAP) prior to possible resection of hepatic metastases is documented. METHODS: CTAP was performed on 45 patients with hepatic metastasis, including 30 with colorectal carcinoma, using 1 cm increments from the dome of the diaphragm through the liver. Two radiologists, blinded to the diagnosis and surgical results, reviewed all portograms and identified all paracardial lymph nodes larger than 8 cm. RESULTS: Enlarged paracardial lymph nodes were found in three of the 30 colorectal carcinoma patients and two of the remaining 15 patients. All three colorectal patients with paracardial lymphadenopathy demonstrated massive metastatic involvement of the anterior segment of the right hepatic lobe (segment 8: Couinaud nomenclature). Additional metastasis in the superior aspect of the liver was seen in two of these patients as well. Both patients without colorectal carcinoma with paracardial lymphadenopathy had metastasis involving the superior aspect of the liver. Paracardial lymphadenopathy was right-sided in all five patients and bilateral in one. By contrast, 48% (19 of 40) of patients without enlarged paracardial lymph nodes had metastasis in the anterior segment of the right lobe. CONCLUSIONS: This study suggests that paracardial lymphadenopathy is associated with metastatic disease to specific areas within the liver. This nodal involvement can be attributed to lymphatic drainage from the diaphragmatic surface of the liver.