Xerotomographic diagnosis of central bronchogenic carcinoma.

Xerotomography was used to examine 14 patients with substantial pulmonary opacities, in whom the diagnosis of bronchogenic carcinoma had been suspected. Xerotomography was valuable because it provided excellent delineation of the tracheobronchial tree, which assisted in differentiation of benign from malignant lesions. Malignancy was suggested by: 1) amputation, 2) eccentric narrowing of the bronchus, 3)irregularity of the bronchial wall, 4)presence of an intraluminal mass. Mediastinal and hilar node enlargement could also be assessed. The use of these criteria allowed a correct preoperative diagnosis in 12 of 14 patients. Due to the high radiation dosage, this method is not suitable for use as a screening procedure.

Incidence of deep vein thrombosis after laparoscopic vs minilaparotomy cholecystectomy.

OBJECTIVES: To determine the frequency of deep vein thrombosis (DVT) associated with minimally invasive cholecystectomy and to determine, using minilaparotomy cholecystectomy as a control operation, the influence of the laparoscopic pneumoperitoneum on DVT formation. DESIGN: Prospective nonrandomized control trial. SETTING: Tertiary care university hospital. PATIENTS: One hundred consecutive patients intended to undergo either laparoscopic cholecystectomy (59 patients) or minilaparotomy cholecystectomy (41 patients) with either of 2 surgeons were prospectively enrolled between April 1996 and April 1997. The minilaparotomy cholecystectomy group served as controls to isolate the effect of the pneumoperitoneum. Patient details, operative details, and any thromboembolic or bleeding complications were recorded. The same thromboprophylaxis regimen was prescribed for each group; namely, preoperative and postoperative subcutaneous low-molecular-weight heparin (LMWH), graduated compression stockings, and intraoperative intermittent calf compression. INTERVENTION: Minimally invasive cholecystectomy. MAIN OUTCOME MEASURE: Frequency of DVT. Bilateral lower limb venous color duplex scanning was used to detect DVT. Scans were performed on 3 occasions: (1) preoperatively on admission to hospital, (2) on the first postoperative day, and (3) between 2 and 4 weeks postoperatively. RESULTS: Three patients in the laparoscopic group and 2 patients in the minilaparotomy group underwent conversion to conventional open cholecystectomy. There were no significant differences between patients in the 2 groups for age, sex, body mass index, preoperative white blood cell count, platelet count, prothrombin time, or activated partial thromboplastin time. There were no significant differences between the 2 groups for elective vs emergency operations, public hospital vs private hospital admissions, or consultant vs resident surgeon. Macroscopic gallbladder pathology grades for both groups were not significantly different, and there was no significant difference in the duration of postoperative hospital stay. Operative cholangiography was performed in a significantly larger proportion of laparoscopic cases (86% vs 66% in the minilaparotomy group; chi(2) test, P=.002), and the duration of anesthesia was significantly longer for the laparoscopic operation (118 minutes vs 98 minutes; t test, P=.05). Ninety-seven patients received preoperative LMWH and all patients received graduated compression stockings, intraoperative intermittent calf compression, and postoperative LMWH. Two of the 100 patients had postoperative DVT, 1 after laparoscopic cholecystectomy and 1 after minilaparotomy cholecystectomy. Both DVTs were detected by duplex examination on the first postoperative day. The DVT found after laparoscopic cholecystectomy was in 1 of the 3 patients who did not receive preoperative LMWH. There were no DVTs in any of the 40 patients who had an additional duplex scan between 2 and 4 weeks after operation. CONCLUSIONS: Despite the theoretical risk of thromboembolic disease due to use of the laparoscopic pneumoperitoneum, the frequency of DVT after either laparoscopic cholecystectomy or minilaparotomy cholecystectomy is low if adequate thromboprophylaxis is provided.

Ultrasonic examination of the pancreas.

Gray scale scanners allow the demonstration of much more anatomical detail than was possible with the older type scanners. The initial step in the ultrasonic examination of the pancreas is display of the anatomical detail of the portal vasculature which provides a guidepost to the pancreas. Pancreatitis is characterized by a diffusely enlarged echo-free pancreas. Pancreatic pseudocyst is almost always an echo-free unilocular fluid collection. The size of a pancreatic pseudocyst can be measured so that progress can be assessed. Pseudocysts located in the region of the tail of the pancreas may be best demonstrated by scanning from the back over the left kidney. Pancreatic pseudocysts may be partly solid. Pancreatic carcinoma appears as a localized relatively echo-free, poorly defined solid mass which attenuates the ultrasound beam. Pancreatic carcinoma smaller than 2 cm in diameter are particularly difficult to diagnose by ultrasonic examination. Pancreatic carcinoma may be difficult to distinguish from chronic pancreatitis. Dilated bile ducts can be demonstrated and point to extrahepatic biliary obstruction. Serial ultrasonic scans have been suggested as a means of monitoring the response of pancreatic tumors to therapy. The relative diagnostic value of endoscopic retrograde cannulation of the pancreatic ducts and ultrasound has not as yet been established. Ultrasonic examination is easier to perform and less expensive than any other pancreatic imaging procedure other than the upper gastrointestinal barium examination.

The cerebellopontine angle: does the translabyrinthine approach give adequate access?

A long-standing but unfounded criticism of the translabyrinthine approach is the misperception that this approach does not give adequate access to the cerebellopontine angle. Because of what is perceived as limited visualization and operating space within the cerebellopontine angle, some surgeons still believe that the translabyrinthine approach is inappropriate for large acoustic tumors. In this study, the surgical access to the cerebellopontine angle by virtue of the translabyrinthine approach is measured and analyzed. The parameters are compared with those measured for the retrosigmoid approach. This series objectively confirms that the translabyrinthine approach offers the neurotologic surgeon a shorter operative depth to the tumor, via a similar-sized craniotomy. This permits superior visualization by virtue of a wider angle of surgical access. Such access is achieved with the merit of minimal cerebellar retraction.

Knowledge-based method for segmentation and analysis of lung boundaries in chest X-ray images.

We present a knowledge-based approach to segmentation and analysis of the lung boundaries in chest X-rays. Image edges are matched to an anatomical model of the lung boundary using parametric features. A modular system architecture was developed which incorporates the model, image processing routines, an inference engine and a blackboard. Edges associated with the lung boundary are automatically identified and abnormal features are reported. In preliminary testing on 14 images for a set of 18 detectable abnormalities, the system showed a sensitivity of 88% and a specificity of 95% when compared with assessment by an experienced radiologist.

Isolated congenital round window absence.

An adult with unilateral round window atresia is presented. With care, CT scanning may be used to demonstrate round window occlusion. Cochlear fenestration resulted in only a modest hearing improvement. Previously reported cases are reviewed.

The use of ultrasound in the diagnosis of gastroenterological disease.

Ultrasound is high frequency mechanical vibration. As far as is presently known, there are no harmful effects of ultrasound at the energy levels used in currently available commercial ultrasonic scanners. Ultrasonic studies are independent of organ function, are painless, and require nor special preparation. Ultrasonic scanning is useful in the diagnosis of pancreatic disease, especially in the detection of complications of pancreatitis such as pancreatic abscess or pseudocyst, and in diagnosing pancreatic carcinoma. Gallstones and dilation of the biliary tree can be detected ultrasonically even when the patient is jaundiced. Primary liver tumors and hepatic metastases can often be demonstrated. Intraabdominal abscesses are better investigated by ultrasound than by any other means currently available. Ultrasonic scanning also provides a sensitive means of detecting ascites. Ultrasonic control of needle placement has been suggested for pancreatic and liver biopsy, for aspiration of intraabdominal fluid collections, and for percutaneous transhepatic cholangiography. Ultrasonic B-mode scans provide undistorted images of cross sections through the abdomen which can be used in radiotherapy planning to localize tumor masses and to place kidney shields accurately. Organ volumes can be estimated from a set of ultrasonic B-mode scans without any assumptions being made as to the shape of the organ.

Cine display of numerous static ultrasound images: a step toward automation of ultrasound studies.

Ultrasound images were assembled and viewed in a motion picture format to facilitate the laborious task of reviewing numerous sonograms. Sequential, closely spaced images from an automated water bath ultrasound scanner were recorded both on a video disc recorder capable of high speed playback and on a film strip using a 35-mm half frame camera. A conventional 35-mm cine viewer was used to evaluate the film strip. Advantages of the motion picture format are (a) many images can be reviewed easily and rapidly, (b) objects that extend through several images are easily perceived and an impression of the third dimension is obtained, (c) the chances of diagnostic errors due to wide spacing or selective recording of images are lessened, and (d) fuller advantage can be taken of the scanner's capacity for automatic operation. Disadvantages of the technique are (a) respiratory motion must be minimized, and (b) the method is useful only in conjunction with water bath scanners.

Confusing appearance of a dilated jejunal loop.

A case report is presented concerning a patient with a dilated loop of bowel that was misinterpreted on ultrasound examination. Attention is called to this entity as part of the differential diagnosis of an intra-abdominal fluid collection demonstrated by ultrasound.

Ultrasonography of abdominal fluid collections.

Ultrasonic examination of abdominal fluid collections sometimes allows identification of the nature of the contained fluid. Abscesses, hematomas, and lymphoceles tend to be ellipsoidal unless confined by particularly resistant structures. Abscesses often contain fine debris. Hematomas develop coarse clumps of strongly echoing material as they age. Lymphoceles have sharp walls and are echo-free. Ascites has an irregular outline, a sharply defined wall, and is echo-free. There may be bowel loops floating in it. Pseudocysts have a widely variable appearance. Bowel loopes that are distended with fluid often show peristalsis. Ultrasonically directed fine needle puncture allows confirmation of the nature of the fluid.

Gray-scale ultrasonic properties of the normal and inflamed pancreas.

Eighty-seven examinations of the pancreas in 52 patients with acute or chronic pancreatitis and 31 examinations in 31 normal subjects were reviewed. Demonstration of the portal and splenic veins served as a guidepost to the pancreas. The normal pancreas was indistinguishable from the surrounding tissues in a substantial minority of examinations, and the ultrasonic characteristics of the normal pancreas were quite variable. Acute pancreatitis was found to be characterized by swelling, loss of internal echoes, and loss of distinction between the pancreas and splenic vein. In 50% of patients with chronic inactive pancreatitis, the pancreas could not be identified. Ultrasound should precede endoscopic retrograde cholangiopancreatography whenever a pseudocyst might be present.

Frequency domain processing for ultrasonic attenuation measurement in liver.

A frequency domain signal processing scheme is developed for measuring attenuation and attenuation slope in vivo, using equally spaced depth samples and linear regression techniques. The algorithm may be expressed in terms of linear, commuting operators acting on an array of log power spectra. By interchanging operators, a computationally efficient scheme may be developed, and the accuracy of the result assessed in terms of tissue uniformity and frequency linearity. Corresponding algorithms are demonstrated for measurement of attenuation at particular frequencies and attenuation in focal lesions. Measurements have been made using an Octoson water-delay echoscope on both normal and pathological livers. Variation of attenuation with a number of disease states has been found.

Acute hemorrhage into the gallbladder diagnosed by computed tomography and ultrasonography.

Hemorrhage into the gallbladder occurs rarely and may result from gangrenous cholecystitis, cystic artery aneurysm, or varicose veins in the gallbladder wall. A definitive diagnosis of intraluminal gallbladder hemorrhage is possible with computed tomography.

Ultrasonic distinction of abscesses from other intra-abdominal fluid collections.

The nature of 103 intra-abdominal fluid collections examined by ultrasound was determined by autopsy, needle aspiration, spontaneous drainage or surgical exploration. Abscesses, chronic hematomas, lymphoceles, urinomas, cysts and fluid-filled bowel loops are all approximately elliptical or circular in cross section. Collections of ascites have a very irregular outline. Bowel loops appear as multiple circles, all of similar size. Chronic hematomas contain strongly echoing material, while lymphoceles, urinomas, renal and hepatic cysts and collections of ascites are echo-free. Ovarian cysts into which there has been bleeding may contain echoes. The walls of abscesses, chronic hematomas, and bowel loops are less sharp than the walls of other collections. Intrahepatic abscesses may have more ragged walls than abscesses elsewhere. Ultrasonic characteristics of abscesses and hematomas overlap. It is sometimes possible to distinguish the nature of the fluid by its ultrasonic properties, but atypical appearances are not rare.

CT scanning of the breast using a conventional CT scanner.

Using a conventional body CT scanner, computed tomography of the breast was performed on 32 patients known to have or suspected of having breast masses. Xeromammograms were available for comparison in all cases. All mass lesions were histologically proved. Seven patients were examined prone, 25 supine. The prone position yielded pictures that resembled craniocaudal mammograms. Breast asymmetry, skin thickening, stranding from a mass to the chest wall, calcification, and axillary lymphadenopathy could be demonstrated by means of CT. The portion of the breast adjacent to the chest wall was more readily examined by means of CT than by conventional mammography. Internal mammary nodes could not be demonstrated.

Jejunojejunal intussusception secondary to leiomyoma.

A case of jejunojejunal intussusception in a 59 year old male secondary to a leiomyoma is reported. The patient presented with abdominal pain and vomiting. He was admitted with a diagnosis of gastroenteritis. Antegrade barium study showed a jejunojejunal intussusception with a soft tissue mass as the lead point. Computed tomography scan demonstrated the soft tissue mass to have properties suggestive of a leiomyoma. The diagnosis was confirmed on examination of the excised specimen.