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Ultrasound in Medicine and Biology

US has been reported to range from 78% to 90% for benign lesions and lower for malignant tumors (57% to 67%). Estimating the histologic type of a parotid tumor has been reported to have an accuracy of 60%. Fine needle aspiration (FNA) has a limited role in the evaluation of salivary tumors. However, FNA and core needle biopsy are of great aid in the evaluation of inflammatory or tumor-like conditions of salivary glands. CDU-guided biopsy with sampling in different locations of the enlarged salivary gland can provide sufficient diagnostic information from the histologic study to prevent sampling errors of the cytologic study. CDU shows promise as an adjunct to gray-scale US in the differential diagnosis of salivary pathologies.

INTRAOPERATIVE ULTRASOUND 1153 Intraoperative ultrasonography as guidance for resective liver surgery Torzilli G, University of Milan-Istituto Clinico Humanitas. IRCCS, Italy Imaging-guided therapeutic procedures have modified the approach to liver tumors, both introducing new treatment modalities and also changing the policy of hepatectomies. Indeed with intraoperative ultrasonography (IOUS) it is possible to achieve better knowledge about tumor diagnosis, location and staging. Nowadays, new techniques such as contrast-enhanced IOUS (CEIOUS) using second generation contrast agents has further expanded and optimised these applications. Indeed, CEIOUS has allowed better detectability of tiny nodules in surgery for colorectal cancer liver metastases, and better differentiation of those new lesions detected at IOUS during surgery for hepatocellular carcinoma (HCC) in liver cirrhosis. However, IOUS may act as an instrument useful for resection, allowing the accomplishment of procedures otherwise not possible. Careful definition of relations between the tumor and portal branches allows liver resections for primary and metastatic neoplasms both conservative and radical. Furthermore, precise definition of hepatic vein anatomy, with the aid also of color Doppler, enables hepatectomies otherwise not possible, and makes the need for major hepatectomies once more less frequent. For all these possibilities, the main impact of IOUS in liver surgery is optimizing the balance between the oncological radicality and the sparing of the highest amount of functioning liver parenchyma. In our experience, in spite the high rate of tumor presenting with contact or infiltration of major intrahepatic vessels (44%), major resections (more than two segments) were accomplished in 20%, and only 9% had more than three segments removed. More conservative resections mean safer operations: indeed we had low mortality (0.7%) and no major morbidity. Furthermore, more limited resections are not related to less radical procedure, once IOUS guidance is properly and extensively accomplished. In this sense, we did not observe any local recurrence. In conclusion, IOUS is able to modify the quality of surgical treatment and consequently the patient’s prognosis. Therefore, resectable surgery of the liver, to be considered even today as the treatment of choice for primary and metastatic liver tumors, must be accomplished under IOUS guidance. 1154 Laparoscopic ultrasonography for abdominal tumors Santambrogio R, Barabino M, Opocher E, Ospedale San Paolo— Bilio-pancreatic Surgical Unit, Italy Accurate preoperative staging of gastrointestinal malignancies is of major importance in the decision for adequate stage-related therapy. There is evidence that laparoscopy in combination with laparoscopic

Volume 32, Number 5S, 2006 ultrasound (L-LUS) is more accurate in the detection of intraabdominal tumors than conventional preoperative imaging. Staging L-LUS is a minimally invasive technique that reveals local tumor extent and intraabdominal disseminated tumor spread. Therefore, laparoscopic ultrasound is an ideal adjunct to laparoscopy because this technique may compensate for the lack of tactile feedback with laparoscopic instruments. The concept of using ultrasound through a laparoscopic access for liver tumors was first described by Yamakawa et al. in 1958, but it was only since the end of the 1980s that laparoscopic ultrasound probes were introduced in the clinical practice. Currently available data indicate that L-LUS provides information similar to that obtained by intraoperative ultrasound and can identify lesions that are too small to be visible by preoperative imaging techniques. Furthermore, L-LUS also allows performance of US-guided biopsy or interstitial therapies as ethanol injection, cryoablation or radiofrequency thermal ablation in the same session. Laparoscopic radiofrequency represents a safe and effective treatment for patients with hepatocellular carcinoma not amenable to surgical resection, especially when the percutaneous approach to the lesion is deemed very difficult or impossible. Better protection of vital structures and a more accurate staging are major advantages of this approach. In the future, these advantages and the possibility to perform a more aggressive approach (in association with local vascular exclusion) could favor a more extensive use of the laparoscopic radiofrequency. More recently, some series of laparoscopic segmentectomy were reported; the authors showed that laparoscopic resections are feasible and safe in selected patients with left-sided and right-peripheral lesions requiring limited resections. Staging L-LUS can also provide a significant effect in the multimodal approach to a population of patients undergoing regional treatment of hepatic colorectal metastases. Staging L-LUS also acts as a bridge to a potential laparoscopic approach of both primary colon tumor and liver metastases. Patients with hilar cholangiocarcinoma and gallbladder cancer frequently have unresectable disease that is not apparent on preoperative imaging studies. L-LUS can correctly identify unresectable disease and prevents unnecessary laparotomy in about one third of patients. Color-coded Doppler imaging can be very valuable for the assessment of resectability in patients with pancreatic cancer. Current data confirm that laparoscopic ultrasound is capable of enhancing the accuracy of staging laparoscopy. Compared to standard laparoscopy, a combination of both techniques markedly increases the sensitivity of staging laparoscopy in the determination of unresectable disease. This is of major importance in the assessment of occult liver metastases and lymph node involvement. Laparoscopic ultrasonography improves the diagnostic accuracy compared to conventional imaging techniques and should be considered as integral part of staging laparoscopy. It may help in choosing the most suitable treatment for the patient. However, a steep learning curve for L-LUS has been reported, and a training workshop experience with LUS will be needed to improve both accuracy rates and LUS technique. 1155 Ultrasonography in emergency surgery Barozzi L, Valentino M, Pavlica P, S.orsola—Malpighi University Hospital, Bologna, Italy Ultrasound provides critical information to emergency physicians in the acute setting, by rapidly and accurately defining anatomic structures and function, providing guidance for urgent procedures and identifying pathologic conditions as well as localizing sources of pains. The ultrasound examination performed by emergency radiologists or physicians differs from the routine exam. It is usually performed at the bedside simultaneously with clinical examination, resuscitation or other procedures. It attempts to answer a single clinical question within minutes. Primary applications of emergency ultrasound are traumatic injuries, ectopic pregnancy, evaluation of cardiac arrest, research for

Abstracts abdominal aortic aneurism, acute abdominal pain and assistance in surgery procedures. Emergency ultrasound has different roles in different clinical settings. It communicates to other physicians only the specific information of the primary problem and describes possible adjacent pathologies (e.g., gallstones in a traumatized patient). Although it is generally a limited focus examination, any incidental findings should be noted in the medical report and the patients informed of them. Emergency ultrasound for trauma is a reliable tool for screening of patients with sustained abdominal trauma for the presence of hemoperitoneum. Along with conventional radiographs of the chest, pelvis and lateral cervical spine, it is part of the basic diagnostic imaging procedures routinely performed in the emergency room of many trauma centers. Focused assessment with sonography for trauma (FAST) is a rapid examination of the abdomen, including the pleural and pericardial cavity, to detect the presence of free fluid and to determine the need for immediate laparotomy. Due to its poor ability to detect parenchyma lesions, there is general agreement that computed tomography should remain the gold standard for the demonstration of blunt injury to solid organs. The advent of ultrasound contrast agents has also provided a new tool for investigating abdominal trauma. Contrast-enhanced ultrasound (CEUS) operates at low mechanical index, and is able to analyze resonance signals originating from second generation contrast agents. These consist of a stabilized aqueous suspension of sulphur hexafluoride microbubbles with a phospholipids shell, of a diameter allowing for both transpulmonary and trans-sinusoidal passage. They have high resistance to the mechanical effects of the ultrasound beam thus permitting a long duration. CEUS provides continuous real-time imaging in grey scale, producing a high amplitude signal in well perfused parenchyma. Its important role in the detection of traumatic abdominal solid organ lesions has been demonstrated, correlating with CT images. The main advantage of CEUS in trauma is to increase the accuracy of solid organ injuries revealing parenchyma lesions that were only visible with CT. Moreover, CEUS is so rapid (4 to 6 min) that it does not unduly prolong the assessment of the patient. While it cannot completely replace CT, it permits more confidence in the trauma setting, improving the limits of the sonography. While not precluding any of the multitudes of other indications for procedural emergency ultrasound, the above mentioned procedures are felt to have important clinical application by an increasing number of emergency radiologists and physicians. 1156 Intraoperative ultrasonography as guidance for living donor liver transplantation Kokudo N, Sano K, Makuuchi M, University of Tokyo, Japan Intraoperative ultrasound (IOUS) is an indispensable tool in living donor liver transplantation both for safety of the donor and for quality of the partial liver graft. We present two important techniques, ultrasonically assisted retrohepatic dissection for a liver hanging maneuver and evaluation of hepatic venous congestion in the graft or the remnant liver. A micro-convex 7.5MHz IOUS probe (SSD6500 or Prosound alpha 10, ALOKA Co. Ltd.) was used in B-mode, color Doppler mode, or eFLOW mode. [IOUS guided retrohepatic dissection.] After the cranial dissection of the supra-hepatic inferior vena cava between the middle and right hepatic veins (MHV and RHV), a long light curved Kelly clamp is inserted from the caudal edge behind the caudate lobe and passed cranially along the anterior midline of the vena cava. A safe dissection path is confirmed by IOUS, identifying the position of the clamp tip, the proper hepatic vein draining the caudate lobe and the caudal end of the cranial dissection. Out of 101 most recent donors, this method was successful in 84 (83.2%). [Evaluation of hepatic venous congestion.] During liver transection along the main portal fissure, several sizable venous tributaries of MHV are divided. IOUS visualizes

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reversed portal flow in the congested area because portal branch functions as a drainage route when venous branches are occluded. A temporary arterial clamping test discolors the congested area, which is easily identified. IOUS, can also visualize venous communications between MHV and RHV, when present. If the venocongestive area is demonstrated to be so large that the graft volume excluding this area is thought to be insufficient for postoperative metabolic demand in the recipient, venous reconstruction is recommended.

ULTRASOUND OF JOINTS 1157 Respective roles for ultrasound and MRI of shoulder van Holsbeeck MT, Henry Ford Health System, United States of America Ultrasound, with its unique real-time imaging features, can diagnose and differentiate the different types of impingement in the shoulder. MRI, as an established static imaging technique, maps soft tissue injury in great detail in patients who suffer from chronic glenohumeral instability. SUBACROMIAL IMPINGEMENT: through abduction and forward elevation, one can gain insights in the movement of the supraspinatus in the supraspinatus outlet. Neer was the first to popularize the principle of subacromial impingement. Many attempts have been made to classify impingement. Some use terminology referring to primary and secondary impingement. The primary form follows subacromial narrowing, posterior capsular tightness and excessive superior humeral head migration due to a depressor weakness. In the secondary form, pain results from glenohumeral and scapulothoracic instability (Matsen, 1992). ULTRASOUND shows thickening of the subacromial subdeltoid bursa, supraspinatus tendinosis as hypoechoic areas in the tendon, biceps tendinosis with loss of fibrillar structure, increased tendon girth and focal hypoechogenicity and a spectrum of tears ranging from intratendinous, partial thickness bursal or articular to full-thickness tears. The bone surface invariably shows small surface pits alternating with irregular enthesophyte-like projections. In the dynamics one can often observe catching of the bursa and cephalad migration of the head relative to the acromion with obvious loss of the function of the humeral head depressors. INTERNAL IMPINGEMENT: the rotator cuff lesions that accompany glenohumeral instability classified under the extrinsic or secondary impingement often present with posterior articular sided partial-thickness tear of the supraspinatus and/or injury of the infraspinatus at arthroscopy. These findings suggest a different mechanism of impingement (Walch, 1992). In the early 1990s, arthroscopists hypothesized an internal impingement or glenohumeral impingement in which the posterior supraspinatus and infraspinatus could get “caught” in the posterosuperior joint space. The close approximation of the posterior greater tuberosity and the posterosuperior glenoid in extreme external rotation during abduction (ABER) may result in wear of articular tendon fibers and sometimes end up with a crush movement or pealing of the labrum. Humeral retroversion, capsular tightness and increased anterior capsular laxity would all contribute to this phenomenon, which is particularly common in throwing athletes. The pain in these throwers presents most intensely during the late cocking phase. ULTRASOUND shows excessive capsular laxity with a shift of the humerus in a posteroanterior direction. Also, posterior labral tears, ganglia and capsular tears, partial articularside tears of posterior supra and infraspinatus are often observed. Greater tuberosity erosion occurs frequently in this entity. The changes on the bone surface resemble those observed in subacromial impingement. The erosions are often more shallow and they are located several centimeters more posterior on ultrasound. These bone changes resemble intraosseous ganglia on MR (Giaroli, 2004).