Incidental Findings of Gallbladder and Bile Ducts-Management Strategies: General Aspects, Gallbladder Polyps and Gallbladder Wall Thickening-A World Federation of Ultrasound in Medicine and Biology (WFUMB) Position Paper

The World Federation of Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings with a series of position papers to give advice on characterization and management. The biliary system (gallbladder and biliary tree) is the third most frequent site for incidental findings. This first part of the position paper on incidental findings of the biliary system is related to general aspects, gallbladder polyps and other incidental findings of the gallbladder wall. Available evidence on prevalence, diagnostic work-up, malignancy risk, follow-up and treatment is summarized with a special focus on ultrasound techniques. Multiparametric ultrasound features of gallbladder polyps and other incidentally detected gallbladder wall pathologies are described, and their inclusion in assessment of malignancy risk and decision- making on further management is suggested.

Using Immersive Virtual Reality Simulation to Ensure Competence in Contrast-Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) is used in various medical specialties as a diagnostic imaging tool and for procedural guidance. Experience in the procedure is currently attained via supervised clinical practice that is challenged by patient availability and risks. Prior simulation-based training and subsequent assessment could improve and ensure competence before performance on patients, but no simulator currently exists. Immersive virtual reality (IVR) is a new promising simulation tool that can replicate complex interactions and environments that are unfeasible to achieve by traditional simulators. This study was aimed at developing an IVR simulation-based test for core CEUS competencies and gathering validity evidence for the test in accordance with Messick's framework. The test was developed by IVR software specialists and clinical experts in CEUS and medical education and imitated a CEUS examination of a patient with a focal liver lesion with emphasis on the pre-contrast preparations. Twenty-five medical doctors with varying CEUS experience were recruited as test participants, and their results were used to analyze test quality and to establish a pass/fail standard. The final test of 23 test items had good internal reliability (Cronbach's α = 0.85) and discriminatory abilities. The risks of false positives and negatives (9.1% and 23.6%, respectively) were acceptable for the test to be used as a certification tool prior to supervised clinical training in CEUS.

Development of and Gathering Validity Evidence for a Theoretical Test in Contrast-Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) is an imaging modality applied in a broad field of medical specialties for diagnostic uses, guidance during biopsy procedures and ablation therapies and sonoporation therapy. Appropriate training and assessment of theoretical and practical competencies are recommended before practicing CEUS, but no validated assessment tools exist. This study was aimed at developing a theoretical multiple-choice question-based test for core CEUS competencies and gathering validity evidence for the test. An expert team developed the test via a Delphi process. The test was administered to medical doctors with varying CEUS experience, and the results were used to evaluate test items, internal-consistency reliability, ability to distinguish between different proficiency levels and to establish a pass/fail score. Validity evidence was gathered according to Messick's framework. The final test with 47 test items could distinguish between operators with and without CEUS experience with acceptable reliability. The pass/fail score led to considerable risk of false positives and negatives. The test may be used as an entry test before learning practical CEUS competencies but is not recommended for certification purposes because of the risk of false positives and negatives.

Contrast-Enhanced Ultrasound: Development of Syllabus for Core Theoretical and Practical Competencies

Contrast-enhanced ultrasound (CEUS) is dependent on the observer's competencies, and thus, appropriate education and testing of individual competency is essential. The current international curriculum in CEUS is methodologically weak and lacks validated competency assessment tests. In this study, we aimed to develop a syllabus for core competencies in CEUS using the Delphi process and an international panel of experts. A core writing group constructed an initial draft of the syllabus based on the existing literature. Eight international experts in CEUS or medical education were recruited as Delphi panelists. The draft underwent iterative and anonymous Delphi rounds until a pre-defined level of consensus was reached. The final syllabus consisted of 16 items, which were indexed in two main domains and in procedural order. An expert-generated proposal for a syllabus of core CEUS competencies has been constructed via the Delphi process and may serve as framework for future development of a CEUS curriculum, including competency assessment tests.

Prognostic factors after ultrasound-guided percutaneous ablation of colorectal liver metastases: A systematic review

Introduction

Liver metastases from colorectal cancer are common and ablation therapy is a favourable treatment option for selected patients not suited for surgical resection. This study aimed to systematically review the literature and present prognostic factors associated with survival and local recurrence after percutaneous ultrasound-guided ablation treatment.

Materials and methods

This review is reported according to the PRISMA. PubMed, Embase and Scopus were searched and records were independently screened by two authors, initially on title and abstract and subsequently on full-text basis. The quality of the studies was assessed using the Newcastle-Ottawa quality assessment scale.

Results

Of 2.882 records screened, 18 studies were included. The median survival was 23 months. One-year survival was median 95% and 3-year survival was median 58%. Complete ablation response and adjuvant chemotherapy produce considerably improved survival and low local recurrence rate outcomes.

Conclusion

Percutaneous ultrasound-guided ablation technique for colorectal liver metastases provides impressive survival rates for patients not suited for surgical resection. However, there are some factors related to poorer prognosis, which may be considered when selecting patients.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part V - EUS-Guided Therapeutic Interventions (short version)

The fifth section of the Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for all the categories of endoscopic ultrasound-guided treatment reported to date. Celiac plexus neurolysis and block, vascular intervention, drainage of fluid collections, drainage of biliary and pancreatic ducts, and experimental tumor ablation techniques are discussed. For each topic, all current evidence has been extensively analyzed and summarized into major recommendations for reader consultation (short version; the long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part V

The fifth section of the Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for all the categories of endoscopic ultrasound-guided treatment reported to date. Celiac plexus neurolysis and block, vascular intervention, drainage of fluid collections, drainage of biliary and pancreatic ducts, and experimental tumor ablation techniques are discussed. For each topic, all current evidence has been extensively analyzed and summarized into major recommendations for reader consultation in clinical practice (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part IV - EUS-guided Interventions: General aspects and EUS-guided sampling (Long Version)

The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part IV - EUS-guided interventions: General Aspects and EUS-guided Sampling (Short Version)

The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle-based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (short version; the long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part III - Abdominal Treatment Procedures (Long Version)

The third part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound (INVUS) assesses the evidence for ultrasound-guided and assisted interventions in abdominal treatment procedures. Recommendations for clinical practice are presented covering indications, contraindications, and safe and effective performance of the broad variety of these techniques. In particular, drainage of abscesses and fluid collections, interventional tumor ablation techniques, interventional treatment of symptomatic cysts and echinococcosis, percutaneous transhepatic cholangiography and drainage, percutaneous gastrostomy, urinary bladder drainage, and nephrostomy are addressed (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part III - Abdominal Treatment Procedures (Short Version)

The third part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound assesses the evidence for ultrasound-guided and assisted interventions in abdominal treatment procedures. Recommendations for clinical practice are presented covering indications, contraindications, safety and efficacy of the broad variety of these techniques. In particular, drainage of abscesses and fluid collections, interventional tumor ablation techniques, interventional treatment of symptomatic cysts and echinococcosis, percutaneous transhepatic cholangiography and drainage, percutaneous gastrostomy, urinary bladder drainage, and nephrostomy are addressed (short version; a long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part II. Diagnostic Ultrasound-Guided Interventional Procedures (Long Version)

This is the second part of the series on interventional ultrasound guidelines of the Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). It deals with the diagnostic interventional procedure. General points are discussed which are pertinent to all patients, followed by organ-specific imaging that will allow the correct pathway and planning for the interventional procedure. This will allow for the appropriate imaging workup for each individual interventional procedure (Long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part II. Diagnostic Ultrasound-Guided Interventional Procedures (Short Version)

This is the second part of the series on interventional ultrasound guidelines of the Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). It deals with the diagnostic interventional procedure. General points are discussed which are pertinent to all patients, followed by organ-specific imaging that will allow the correct pathway and planning for the interventional procedure. This will allow for the appropriate imaging workup for each individual interventional procedure (Long version/ short version; the long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I. General Aspects (long Version)

This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I. General Aspects (Short Version)

This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (short version; the long version is published online).

Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in the liver - update 2012: A WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Contrast kinetics of the malignant breast tumour—Border versus centre enhancement on dynamic midfield MRI

PURPOSE

To quantify the border versus centre enhancement of malignant breast tumours on dynamic magnetic resonance mammography.

MATERIALS AND METHODS

Fifty-two women diagnosed with primary breast cancer underwent dynamic magnetic resonance mammography (Omniscan 0.2 mmol/kg bodyweight) on a midfield scanner (0.6 T), prior to surgery. The following five variables were recorded from the border and centre regions of the tumours: Early Enhancement, Time to Peak, Wash-in rate, Wash-out rate and Area under Curve. Information on histology type, oestrogen and progesterone receptor status was collected. Statistical analysis was performed in SAS 9.1 as paired samples t-tests.

RESULTS

Fifty of 52 malignant tumours displayed a faster Early Enhancement in the border region compared to the centre (p<0.0001). Significant differences between the border and centre values were found for Time to Peak, Wash-in rate, Wash-out rate and Area under Curve. Hormone receptor positive tumours displayed an over-all highly significant difference between border and centre enhancement, whereas no significant differences for any of the five variables were recorded in neither oestrogen nor progesterone hormone receptor negative tumours.

CONCLUSION

The border/centre enhancement difference in malignant breast tumours is easily visualized on midfield dynamic magnetic resonance mammography. The dynamic behaviour is significantly correlated to histological features and receptor status of the tumours.

Signal intensity of normal breast tissue at MR mammography on midfield: applying a random coefficient model evaluating the effect of doubling the contrast dose

PURPOSE

To prospectively investigate the effect on signal intensity (SI) of healthy breast parenchyma on magnetic resonance mammography (MRM) when doubling the contrast dose from 0.1 to 0.2 mmol/kg bodyweight.

MATERIALS AND METHODS

Informed consent and institutional review board approval were obtained. Twenty-five healthy female volunteers (median age: 24 years (range: 21-37 years) and median bodyweight: 65 kg (51-80 kg)) completed two dynamic MRM examinations on a 0.6T open scanner. The inter-examination time was 24 h (23.5-25 h). The following sequences were applied: axial T2W TSE and an axial dynamic T1W FFED, with a total of seven frames. At day 1, an i.v. gadolinium (Gd) bolus injection of 0.1 mmol/kg bodyweight (Omniscan) (low) was administered. On day 2, the contrast dose was increased to 0.2 mmol/kg (high). Injection rate was 2 mL/s (day 1) and 4 mL/s (day 2). Any use of estrogen containing oral contraceptives (ECOC) was recorded. Post-processing with automated subtraction, manually traced ROI (region of interest) and recording of the SI was performed. A random coefficient model was applied.

RESULTS

We found an SI increase of 24.2% and 40% following the low and high dose, respectively (P<0.0001); corresponding to a 65% (95% CI: 37-99%) SI increase, indicating a moderate saturation. Although not statistically significant (P=0.06), the results indicated a tendency, towards lower maximal SI in the breast parenchyma of ECOC users compared to non-ECOC users.

CONCLUSION

We conclude that the contrast dose can be increased from 0.1 to 0.2 mmol/kg bodyweight, if a better contrast/noise relation is desired but increasing the contrast dose above 0.2 mmol/kg bodyweight is not likely to improve the enhancement substantially due to the moderate saturation observed. Further research is needed to determine the impact of ECOC on the relative enhancement ratio, and further studies are needed to determine if a possible use of ECOC should be considered a compromising factor, if an MRM is indicated in a young woman.

Percutaneous radiologic gastrostomy with a simplified gastropexy technique under ultrasonographic and fluoroscopic guidance: experience in 154 patients

PURPOSE

To evaluate the effectiveness and safety of percutaneous radiologic gastrostomy (PRG) under ultrasonographic (US) and fluoroscopic guidance using a simplified gastropexy technique.

MATERIAL AND METHODS

One hundred and fifty-four (154) patients (mean age 73, range 22-93 years) were referred for PRG. Indication for PRG was neurologic disease, head/neck cancer, and other disease in 73%, 15%, and 12%, respectively. Initially, the stomach was filled with 300-500 cm3 of tap water via a nasogastric tube. The fluid-filled stomach was punctured under US guidance. A guidewire and a single T-fastener were introduced. Under fluoroscopic guidance, the tract was dilated over the guidewire until a 16F dilator with a peel-away sheath could be introduced. During dilatation, the external suture string to the T-fastener was held tight to fixate the gastric wall. A 14F balloon-retained gastrostomy tube was introduced and inflated. The T-fastener was then released, and the gastrostomy tube was retracted gently to affix the gastric wall to the abdominal wall (tube gastropexy). Technical success was assured by aspiration of gastric fluid and fluoroscopically by injection of a water-soluble contrast medium.

RESULTS

The primary technical success rate was 98%. At 30-day follow-up, 3.2% had major complications and 14% minor complications. Three patients (1.9%) died of complications related to the procedure. Thirteen cases (8%) of simple tube displacement without other complications occurred.

CONCLUSION

PRG guided by US and fluoroscopy is a relatively safe technique with a high success rate, provided the stomach can be properly distended with fluid. However, tube gastropexy alone does not seem to protect against early dislodgement.

Ultrasonically guided insertion of a peritoneo-gastric shunt in patients with malignant ascites

PURPOSE

A new method for internal drainage of malignant ascites is presented in 5 patients with symptomatic malignant ascites.

MATERIAL AND METHODS

US-guided percutaneous gastrostomy and paracentesis were performed using the Seldinger technique. A 2.5-mm Cope-loop catheter was inserted in the fluid-filled stomach. In the lower abdomen the proximal part of a Denver peritoneo-venous shunt was introduced after dilation up to 4.8 mm. The pump chamber was sutured to the skin. The distal part of the Denver shunt was cut a few cm from the pump chamber and connected to the gastrostomy catheter. When pumping, ascites is shunted to the stomach lumen.

RESULTS

The insertion presented no complications, and all shunt systems initially functioned well. However, the shunts had to be removed within the first 2 weeks because of mechanical problems such as clotting, leakage, and peritoneal septum formation. No infections were reported.

CONCLUSION

The peritoneo-gastric shunt may present a therapeutic alternative in selected patients, but the mechanical problems have first to be solved.

[Laparoscopic ultrasonography of liver, biliary tract and pancreas with flexible tip transducers]

The scanning procedure and the ultrasound-anatomy of the liver, gall-bladder, bile ducts and pancreas are presented. Ten consecutive patients referred for laparoscopic cholecystectomy were scanned through a 10/11 mm trocar inserted periumbilically. In two cases concrements in the bile ducts were found peroperatively. The flexible-tip enables operator steering of the transducer which ensures an optimal acoustic contact. Colour and spectral Doppler were frequently used to identify vascular structures. We conclude that a flexible-tip laparoscopic ultrasound-scanner provides valuable assistance in abdominal laparoscopic procedures, and may substitute the palpation of the abdominal organs in laparoscopic abdominal surgery.

Gastric and duodenal wall thickening on abdominal ultrasonography. Positive predictive value

In a retrospective study, 79 patients with gastric (n = 59) or duodenal (n = 20) wall thickening on conventional abdominal ultrasonograms were included. To reduce bias, patients with a microscopic diagnosis of upper GI neoplasia present at the time of scanning were excluded. The final diagnosis was based upon endoscopy, operation, upper GI series, or autopsy. Among the 59 cases of gastric wall thickening, 33 (56%) proved to be gastric cancer, one (2%) was benign neoplasia, and 17 (29%) showed nonneoplastic pathology (ulcer, gastritis, fibrosis). In eight cases (13%) no gastric pathology was present in the final diagnosis, thus producing false-positive sonographic diagnoses. Among the 20 cases of duodenal wall thickening, five (25%) proved to be duodenal cancer and seven (35%) showed nonneoplastic duodenal pathology. We concluded that gastric or duodenal wall thickening shown on abdominal sonography is a significant finding indicating upper GI pathology (malignant or nonmalignant) in a high percentage of the gastric (86%) and duodenal (60%) cases.

Acute puerperal breast abscesses: US-guided drainage

Breast abscesses typically develop in lactating women. The recommended treatment is surgical incision and drainage with the patient under general anesthesia. Ultrasonically guided percutaneous drainage with local anesthesia was performed in 19 consecutive patients referred for treatment because of clinical signs of acute puerperal breast abscess. Eighteen of the 19 patients (95%) were successfully treated. Long-term follow-up (median, 12 months) did not show any recurrences, and the cosmetic results were excellent. Eight of the 19 patients (42%) continued nursing during and after treatment. Ten of the 19 (53%) were treated on an outpatient basis. On the basis of these results, the authors recommend ultrasonically guided percutaneous treatment for use in patients with acute puerperal breast abscesses.

Interstitial hyperthermia of colorectal liver metastases with a US-guided Nd-YAG laser with a diffuser tip: a pilot clinical study

Ultrasound (US)-guided interstitial hyperthermia performed with the neodymium yttrium aluminum garnet laser with a diffuser tip involves placement of a laser fiber in solid tissue followed by irradiation from within the center of the tumor to be treated. The authors previously described the development of a US-guided technique that permits simultaneous interstitial laser irradiation and temperature measurements, with real-time US monitoring. With the use of a dedicated diffuser tip modification of the bare laser fiber, it has proved possible to produce spherical coagulations with a diameter comparable to that of liver metastases of clinical relevance. This technique was used in 11 patients with 16 colorectal liver metastases, 12 of which were radically ablated. Real-time US and interstitial temperature monitoring during treatment had a positive predictive value of 86% and negative predictive value of 100% in judging the final result. The technique is feasible, effective, and safe, but the effect on patient survival must be tested in future randomized clinical studies.

[Ultrasonically guided pericardiocentesis]

Ultrasonically guided pericardiocentesis was performed on 25 occasions in 23 consecutive patients. Incipient cardiac tamponade was present in 22 patients and the procedure was performed for diagnostic purposes in one patient. In 21 cases, 5.7 French pig-tail catheters were employed and 1.2 mm lumbar puncture needles in four cases. In 19 out of 22 patients (86%) with incipient cardiac tamponade the ultrasonically guided pericardiocentesis was considered successful. In one patient, the catheter was misplaced in the right atrium, one patient developed pyopericardium and one patient developed transient tachycardia. In two cases, no material could be obtained. Ultrasonically guided pericardiocentesis is preferable to "blind" puncture and the procedure should be carried out by physicians with experience in interventional ultrasound.

[Color Doppler ultrasound. Principles, technique and clinical use possibilities]

The medical ultrasound, the Doppler frequency shift is the difference between the frequency of the transmitted and reflected ultrasound. This is due a relative movement between the reflector (most frequently the red blood cells) and the ultrasound transducer. The ultrasound apparatus registers this difference in frequency and calculates the linear rate of flow employing the Doppler equation. The Doppler analysis is presented acoustically, graphically or by means of a colour code. In pulsed Doppler technique, conventional ultrasound scanning can be combined with Doppler analysis. Important indications are: differentiation between vascular and non-vascular structure, documentation of flow and determination of the direction of flow, diagnosis and quantitation of arterial stenoses and assessment of transplants.

The aortic wall: an in vitro study of the double-line pattern in high-resolution US

An in vitro study of macroscopically normal aortas from human cadavers was performed with high-resolution ultrasound (US). Rectangular pieces of 10 fresh aortas were submerged in saline solution and scanned from the intimal side. On US images a characteristic double-line pattern, consisting of an inner and an outer echogenic line separated by a relatively hypoechoic line, was seen. This configuration was initially interpreted as tunica intima, tunica media, and tunica adventitia. The thickness of each layer on the US images was measured by means of a computer-assisted procedure and on histologic specimens was measured by means of stereomicroscopy. The correlation between the two measurements was poor. Experiments in which intima and part of the media were removed did not change the US appearance. Plexiglas, metal plates, and plastic foil showed a similar double-line pattern. A needle experiment disclosed that the inner echogenic and the hypoechoic lines were displayed in front of the true water-tissue interface, which was represented by the outer echogenic line. The authors conclude that the double-line pattern is thus an artifact.

Nine pheochromocytomas in the same patient. Final mapping with ultrasound and angiography

A 37-year-old man presented with hypertension and elevated urine catecholamine. Ultrasound scanning revealed a solid tumour of the right adrenal gland and two solid tumours in the retroperitoneum. The findings were confirmed with computed tomography and abdominal angiography. At surgery only the tumour of the right adrenal gland was removed. The histopathologic diagnosis was pheochromocytoma. Postoperatively the symptoms and biochemistry were unchanged and the patient was referred for further treatment. At ultrasonography and abdominal aortography 6 remaining tumours were demonstrated. Surgery was performed and 8 pheochromocytomas were extirpated (3 were closely spaced small tumours in a conglomerate corresponding to one of the visualized tumour sites). On histopathologic examination no signs of invasive growth were found. The patient recovered completely. The blood pressure was still normal 2 1/2 years later. Angiography and non-invasive examination of the entire abdomen and pelvis should be routine when pheochromocytomas are searched for.