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209
Meeting ..,.
.
S.
S
,
.
The Society of Gastrointestinal Meeting, February 1992 Elizabeth
Radiologists:
21st Annual
Whalen1
The 21 st annual meeting of The Society of Gastrointestinal Radiologists (SGA) was held February i 6-21 , 1 992, at the Hyatt Regency Grand Cypress, Orlando, FL. Among the activities offered were the annual Walter B. Cannon lecture, presentations of 34 scientific papers, 36 workshops, six parallel focus sessions, a categorical course on frontiers in gastrointestinal radiology, a radiology-pathology mini-course, 24 poster presentations, and an “unknown” film panel. Regrettably, AJR space limitations do not allow complete coyerage of the entire prognam, but we have tried to include here a wide range of topics and types of presentations. Among the awards presented, Joseph T. Ferrucci (Boston, MA) received the annual Walter B. Cannon Medal, and John H. C. Ransom (New York, NY) presented the Cannon Lecture. Three prizes were given for excellence in scientific presentations. The Aoscoe E. Miller Award for the best scientific paper was presented to Lars G. Crabo and coauthors (P. C. Freeney, D. 0. Graney, D. M. Conley; Seattle, WA) for “Venous Drainage of the Pancreatic Head: Contrast-Enhanced CT Appearance” (described later: see the section on scientific presentations, pancreas and liven subsection). Gerald D. Dodd (Pittsburgh, PA) was the winner of the Memorial Award, which recognizes the best presentation by a first-time presenter at an SGA meeting. Dr. Dodd’s paper by himself and three coauthors (W. J. Miller, A. L. Baron, S. R. Confer) concerned sonographic screening of cirrhotic livers (described later: see the section on scientific presentations, pancreas and liver subsection). Dana Premer and colleagues (D. L. Day, J. Crowe, B. Carpenter; Minneapolis, MN) won an awand for 1
News
Contributing
editor,
American
Journal
of Roentgeno!ogy,
Ste. 103, 2223
their poster presentation, tions of Cystic Fibrosis.”
Scientific
“Imaging
of Abdominal
Presentations
Esophagus Malpositioned nasal enter/c feeding tubes.-Shayle Patzik (Chicago, IL) presented a study performed by himself and C. Smith concerning the prevalence of malpositioned nasal enteric feeding tubes at their institution, clinicians’ awareness of the problem, and the guidelines in place concerning use of feeding tubes. These flexible, small-bore, polyurethane tubes, often inserted at bedside, carry potential complications due to misplacement. Cane must be taken in the placement of these tubes and in follow-up studies to ensure against such complications. In a review of chest/abdominal radiographs of 1 00 consecutive patients with nasal entenic feeding tubes, these researchers found 1 9% were not in the optimal location-this figure is more than 1 00% higher than previously reported; moreover, approximately 8 hr after tube insertion, 21 % of the clinicians involved in the cases were unaware that tests had shown the tubes had been malpositioned. The problem appears to be unrecognized at teaching institutions; of the eight institutions contacted for this study, none had developed guidelines for either tube placement or follow-up. To avoid complications from tube malpositioning, these researchers recommend imaging-guided tube placement whenever possible, limiting “blind tube” placement to trained and
Avenida
de Ia Playa,
La Jolla,
CA 92037.
Editor’s note.-”Meeting News” articles report the highlights of important national radiology meetings. The articles will not undergo the peer required of AJR publications, nor will they offer a critique of the information provided. The sole purpose of the series is to provide Journal readers substantive, and accurate reviews of topics of current interest, written in a readable fashion and published promptly after the meeting. AJR 159:209-216,
July 1992 0361-803X/92/1591-0209
© American
Roentgen
Manifesta-
Ray Society
review usually with succinct,
MEETING
Downloaded from www.ajronline.org by 118.163.44.31 on 11/11/15 from IP address 118.163.44.31. Copyright ARRS. For personal use only; all rights reserved
2i 0
qualified personnel, and obtaining a radiograph immediately after the procedure to check tube placement. Gastroesophageal reflux.-The role of barium studies in detecting gastroesophageal reflux was discussed by J. Keith Thompson (Birmingham, AL). He and his coauthors (A. E. Koehher, J. E. Richter) had observed that, although barium studies are generally held in low regand because of presumed how sensitivity in detecting gastroesophageal reflux, radiology departments receive many referrals to assess this diagnosis. Moreover, the water siphon test is also held in low regard because of its presumed oversensitivity. In this study, all patients were referred for either barium swallow or upper gastrointestinal studies, and reflux as seen on images was graded on a scale of 0 to 5 (clearance time also was recorded). All 83 patients had both barium studies and 24-hr pH monitoning within a period of 14 days; elicitation maneuvers were used in all patients. The 24-hr pH testing (despite its admitted problem with reproducibility values between 80% and 85%) was used as the gold standard to determine reflux. According to this standard, 55% of the patients did have gastroesophageal reflux. When results of barium studies were considered without the water siphon results, the success of barium studies in detecting reflux was as follows: sensitivity, 44%; specificity, 89%; positive predictive value, 84%; and negative predictive value, 53%. When the water siphon results were considered along with the barium study results, the success in detecting gastroesophageal reflux was as follows: sensitivity, 65%; specificity, 80%; positive predictive value, 82%; and negative predictive value, 62%. These results suggest that barium studies are reasonable screening tests for gastroesophageal reflux; they yield fain sensitivity and high positive predictive value when elicitation maneuvers are used, and addition of the water siphon test increases sensitivity significantly with only minimal effects on positive predictive values. Michael Y. M. Chen (Winston-Salem, NC) presented an investigation of the correlation of esophageal pH testing and radiographic findings in gastroesophageah reflux (coauthors: D. J. Ott, W. C. Wu, J. W. Sinclair, D. W. Gelfand). They studied 1 i 2 consecutive patients who had undergone both pH monitoring and multiphasic esophagography. For pH studies, the investigators recorded the percentage of time during which pH was less than 4, the number of reflux episodes, the duration of reflux episodes, and the symptoms. Cases of gastroesophageal reflux were categorized as mild, moderate, or severe on the basis of total acid exposure. In 62 patients, pH monitoring results showed no reflux; in six (1 0%) of these, however, reflux was diagnosed radiographically. Of the 50 patients with abnormal results on pH tests, reflux was diagnosed radiographically in 1 5 (30%). Detection rates of gastroesophageal reflux by radiography increased with severity of the disease: mild, 25%; moderate, 27%; and severe, 57%. On the basis of these findings, radiographic findings do not correlate with gastrointestinal reflux found by pH monitoring, particularly in patients with mild or moderate disease. Pancreas
and Liver
Contrast-enhanced CT appearance of venous drainage of the pancreatic head.-Lars G. Crabo (Seattle, WA) was
NEWS
AJR:159,
July 1992
awarded the Roscoe E. Miller Award for his and his coworkens’ (P. C. Fneeney, D. 0. Graney, D. M. Conley) study on CT of the pancreatic head. They wanted to investigate the clinical significance of anatomic findings on CT of the small pancreatic veins because CT is currently the most widely used diagnostic test for pancreatic adenocarcinoma. However, when this imaging method is used, the number of resectable pancreatic tumors is overestimated by 36-62%. CT of these pancreatic veins may improve results because these veins are abnormal in pancreatic cancer. Studying CT scans from 1 00 consecutive patients without evidence of pancreatic disease, these investigators found ranges in size as follows: anterior pancreaticoduodenal veins (APDV5), 1 -4 mm; posterior pancreaticoduodenal veins (PPDV5), 1 -4 mm; and gastrocohic venous trunk (Gd), 3-7 mm. In their dynamic CT study of venous anatomy, they found that the APDVs and PPDVs lie just within the parenchyma on the anterior and posterior surfaces of the head of the pancreas, and the GCT joins the superior mesenteric vein anterior to the uncinate process. The frequencies of visualization of small pancreatic veins on contrastenhanced CT were as follows: APDV, 98%; PPDV, 88%; and GCT, 89%. Dynamic CT can show the APDVs, the PPDVs, and the GCT; CT can help reassess patients with pancreatic head carcinoma; and CT evaluation of pancreaticoduodenal vein involvement may be useful in staging pancreatic cancer. Sonographic screening for hepatic malignancies in cirrhotic livers.-ln a presentation that won him the Memorial Award, Gerald D. Dodd (Pittsburgh, PA) presented the preliminary results of a prospective study by himself and his coauthors (W. J. Miller, A. L. Baron, S. R. Confer). They investigated sonographic detection of malignant tumors in 200 consecutive liver transplant recipients. Although several previous studies have investigated associated applications of hepatic imaging, these studies have been limited by three factors: their retrospective nature, limited pathologic correlation, and nonscreening protocol. In this study, sonognams were obtained in all 200 patients before liven transplantation to check for number, size, and location of tumors; state-of-the-art equipment was used; and staff radiologists interpreted all the images. About 86% of the sonographic examinations were performed within 1 20 days before the transplantation, and the sonographic criteria for tumor included heterogeneity and focal mass. The preoperative sonograms yielded low sensitivity but very high specificity for malignant tumor; most of the tumors missed were small (i cm), and the largest tumor missed was a diffusely infiltrating lesion that could not be seen even retrospectively. Previous studies have shown higher detection rates for sonognaphy in patients with cirrhosis. The differences may be explained by the prospective nature of this study, the whole-liver correlations available after transplantation, the end-stage cirrhosis of the patients in this study, and different body habitus (North American in this study vs Oriental). These preliminary results indicate that, although sonography is not a sensitive screening device for detecting malignant tumors in cirrhotic livers, its specificity is so high that any lesion shown by sonography in a cirrhotic liven should be considered malignant until proved otherwise. MR detection of hepatocellular carcinoma in patients with liver cirrhosis.-Ruedi F. Thoeni (San Francisco, CA) dis-
Downloaded from www.ajronline.org by 118.163.44.31 on 11/11/15 from IP address 118.163.44.31. Copyright ARRS. For personal use only; all rights reserved
AJA:159,
July 1992
MEETING
cussed a study in which he and his coauthons (G. Sicca, P. Shyn), who had no knowledge of the diagnosis beforehand, assessed the MR images of 29 patients with proved liven cirnhosis to evaluate the accuracy of MR imaging in detecting hepatocelluhar carcinoma (HCC). Five patients without cirrhosis also were imaged; four of these had HCC. In these 34 patients, the diagnosis of HCC was proved by surgery in nine patients, biopsy in 13, transplantation in 1 0, and 7- and 9year follow-up (respectively) in two. Several MR sequences were used (including Ti -weighted spin-echo, T2-weighted spin-echo, and contrast-enhanced gradient-recalled echo Sequences); for all imaging procedures, glucagon was administered to the patient, and fat-saturation and respiratory-.compensation techniques were used. MA criteria for liver cirrhosis included shrunken liver, nodular surface, inhomogeneity, splenomegaly, varices, and ascites. For HCC, MA criteria included inhomogeneity, vascular invasion, steatosis, presence of capsule, irregularity of margins, and extent beyond the capsule. In the subgroup of patients thought to have liver cirrhosis, MR imaging yielded excellent results in detecting cirrhosis: 90% for sensitivity, i 00% for specificity and positive predictive value, and 63% for negative predictive value. In detecting HCC, MR imaging accuracy was lower: sensitivity, 65%; specificity, 83%; positive predictive value, 92%; and negative predictive value, 45%. Investigating the relatively high numbars offalse-negative results revealed that one false-negative was a missed lesion, eight false-negatives were additional lesions (in patients with multiple lesions), two false-negatives were interpreted as abscesses, and one false-negative was called a regenerating nodule. The two false-positives consisted of one regenerating nodule and one focal fatty infiltration. The researchers concluded that in this subgroup of patients at risk, MA imaging was very accurate in detecting moderate to advanced cirrhosis, but not sensitive enough to discern the extent of HCC in these patients. They recommend that additional tests be done when MA does not show HCC in patients at risk or in patients with elevated a-fetoprotein levels. CT ofhepatocellular carcinoma.-Using contrast-enhanced CT, W. Ross Stevens and colleagues (C. D. Johnson, D. H. Stephens, K. P. Batts; Rochester, MN) investigated the CT appearance of HCC in patients with alcohol-related disease and in other patients with HCC (e.g., those with viral hepatitis). Their study group consisted of 1 00 consecutive patients with pathologically proved HCC: this report described the results of the review of these patients’ CT scans. On these CT scans, HCC was seen as a single mass in 47 (47%) of the cases, as multifocal masses in 46 (46%), and as a diffusely infiltrating lesion in four (4%). Most of the tumors appeared as heterogeneously hypodense masses with mixed vascularity. In 28 cases, CT showed portal vein involvement, and in 29 cases, it showed metastases or local extension of tumor. Tumor invasion of portal on hepatic veins was seen in 55% of alcoholic patients but in only 20% of patients with viral hepatitis. Tumor capsule was more common in patients with viral hepatitis: 33% of these scans showed tumor capsule, but tumor capsule was seen in only 1 2% of patients with disease related to alcohol. The findings from this retrospective review indicate four features that may help CT diagnosis of HCC:
NEWS
211
central scar, necrosis, vascular invasion (more commonly seen in larger, high-grade tumors from alcohol-related disease), and capsule (seen more commonly in patients with viral hepatitis).
Gallbladder Complications of laparoscopic cholecystectomy.-As pointed out by Ellen Ward (Rochester, MN), laparoscopic cholecystectomy has been used since 1 987 and has been preferred to traditional surgery for gallbladder removal-pantially because of a lower complication rate due to less traumatic and less lengthy surgery. However, some complications have been reported in patients who have undergone hapanoscopic chohecystectomy. Dr. Ward and colleagues (A. J. LeRoy, C. E. Bender, J. H. Donohue, A. W. Hughes) studied 29 patients with such complications, including injury of the bile duct (1 5), chohedocholithiasis (seven), leaking of the cystic duct stump (four), bowel perforation (two), intraabdominal abscess (two), and intnaperitoneal gallstones (two). Among the patients with bile duct injuries (none of whom had bile duct abnormalities), endoscopic retrograde cholangiognaphy was the first diagnostic test done and showed obstruction in nine of 1 1 cases; transhepatic cholangiography was used to see the proximal extent of the strictures. Of the bile duct injuries, 1 8% were classified as Bismuth I. The seven patients in whom choledochohithiasis developed after haparoscopic cholecystectomy were rehospitalized, and one patient underwent surgery; endoscopic retrograde cholangiography was used to diagnose the complication in these patients (two thirds also had sonographic examinations). In the four patients who suffered the complication of a leak in the cystic duct stump, cholangiography was necessary to distinguish this complication from injury of the bile duct. The leak was found to be aggravated by obstruction in 50% of these patients. Abdominal radiographs showed bowel perforations (one fatal) in two patients, and CT appeared to be most useful in recognizing both intraabdominah abscesses and calcification (indicating intrapenitoneal gallstones, which are clinically significant only if infected). These results suggest that imaging studies can be helpful in identifying the complications of laparoscopic cholecystectomy and in planning treatment. In answer to a question, Dr. Ward mentioned that, in this study, the complication rate decreased as the experience of the surgical team performing the procedure increased. Pericholecystic fluid collection as a prognostic indicator for percutaneous cholecystostomy.-David L. Harshfield (Little Rock, AK) discussed this evaluation of 50 patients with pericholecystic fluid collections. The study’s coauthors were S. K. Tephick, E. F. Ferris (Little Rock, AK), and S. A. Teefey (Seattle, WA). In 1 0 of the 50 patients, percutaneous cholecystostomy had been performed for acute chohecystitis. Three types of penicholecystic fluid collections were defined: type I, very mild to moderate, not associated with perforation; type II, moderate to mild to somewhat complex, almost always associated with perforation; and type Ill, so complex that the gallbladder cannot be delineated, almost always associated with perforation.
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212
MEETING
Type I penicholecystic fluid collections are amenable to treatment by percutaneous cholecystostomy; these are identified on sonograms by sonolucence, crescent shape, and small size (60% of patients with gallstones little or no gross pancreatitis); and penitoneal lavage. In acute
pancreatitis,
overall
prognosis
is correlated
July 1992
tissue; have with
the occurrence of pancreatic sepsis, and there is a relationship between the number of adverse prognostic signs (Ranson’s criteria) and death of pancreatic sepsis. Identification of highrisk patients early in the course of their disease could indicate which patients require specific and aggressive treatment. In collaboration with Dr. Emil Bahthazan and colleagues at New York University, Dr. Ranson developed a system based on CT findings that describes five classes of infection risk, from lowest risk to highest: A, normal pancreas; B, enlarged pancreas; C, local inflammation; D, one fluid collection; E, more than one fluid collection. A good relationship has been shown between early CT classification and hater development of infection. Penitoneal lavage is helpful: Research has shown that peritoneal havage for 7 days reduces the frequency of peritoneal sepsis and of deaths from pancreatic sepsis; death from abscess also were shown to decrease significantly with long-term (7-day) peritoneal havage. Therefore, CT appears to be extremely useful in suggesting infection by detecting fluid collections and in helping make the diagnosis of acute pancreatitis when significant clinical uncertainty exists. CT can also be used for progressive assessment of the disease (with or without bolus contrast material), including early identification
of any
local
complications
and
have undergone surgery to assess and to identify new fluid collections.
follow-up
of patients
adequacy
of debridement
who
209
Meeting ..,.
.
S.
S
,
.
The Society of Gastrointestinal Meeting, February 1992 Elizabeth
Radiologists:
21st Annual
Whalen1
The 21 st annual meeting of The Society of Gastrointestinal Radiologists (SGA) was held February i 6-21 , 1 992, at the Hyatt Regency Grand Cypress, Orlando, FL. Among the activities offered were the annual Walter B. Cannon lecture, presentations of 34 scientific papers, 36 workshops, six parallel focus sessions, a categorical course on frontiers in gastrointestinal radiology, a radiology-pathology mini-course, 24 poster presentations, and an “unknown” film panel. Regrettably, AJR space limitations do not allow complete coyerage of the entire prognam, but we have tried to include here a wide range of topics and types of presentations. Among the awards presented, Joseph T. Ferrucci (Boston, MA) received the annual Walter B. Cannon Medal, and John H. C. Ransom (New York, NY) presented the Cannon Lecture. Three prizes were given for excellence in scientific presentations. The Aoscoe E. Miller Award for the best scientific paper was presented to Lars G. Crabo and coauthors (P. C. Freeney, D. 0. Graney, D. M. Conley; Seattle, WA) for “Venous Drainage of the Pancreatic Head: Contrast-Enhanced CT Appearance” (described later: see the section on scientific presentations, pancreas and liven subsection). Gerald D. Dodd (Pittsburgh, PA) was the winner of the Memorial Award, which recognizes the best presentation by a first-time presenter at an SGA meeting. Dr. Dodd’s paper by himself and three coauthors (W. J. Miller, A. L. Baron, S. R. Confer) concerned sonographic screening of cirrhotic livers (described later: see the section on scientific presentations, pancreas and liver subsection). Dana Premer and colleagues (D. L. Day, J. Crowe, B. Carpenter; Minneapolis, MN) won an awand for 1
News
Contributing
editor,
American
Journal
of Roentgeno!ogy,
Ste. 103, 2223
their poster presentation, tions of Cystic Fibrosis.”
Scientific
“Imaging
of Abdominal
Presentations
Esophagus Malpositioned nasal enter/c feeding tubes.-Shayle Patzik (Chicago, IL) presented a study performed by himself and C. Smith concerning the prevalence of malpositioned nasal enteric feeding tubes at their institution, clinicians’ awareness of the problem, and the guidelines in place concerning use of feeding tubes. These flexible, small-bore, polyurethane tubes, often inserted at bedside, carry potential complications due to misplacement. Cane must be taken in the placement of these tubes and in follow-up studies to ensure against such complications. In a review of chest/abdominal radiographs of 1 00 consecutive patients with nasal entenic feeding tubes, these researchers found 1 9% were not in the optimal location-this figure is more than 1 00% higher than previously reported; moreover, approximately 8 hr after tube insertion, 21 % of the clinicians involved in the cases were unaware that tests had shown the tubes had been malpositioned. The problem appears to be unrecognized at teaching institutions; of the eight institutions contacted for this study, none had developed guidelines for either tube placement or follow-up. To avoid complications from tube malpositioning, these researchers recommend imaging-guided tube placement whenever possible, limiting “blind tube” placement to trained and
Avenida
de Ia Playa,
La Jolla,
CA 92037.
Editor’s note.-”Meeting News” articles report the highlights of important national radiology meetings. The articles will not undergo the peer required of AJR publications, nor will they offer a critique of the information provided. The sole purpose of the series is to provide Journal readers substantive, and accurate reviews of topics of current interest, written in a readable fashion and published promptly after the meeting. AJR 159:209-216,
July 1992 0361-803X/92/1591-0209
© American
Roentgen
Manifesta-
Ray Society
review usually with succinct,
MEETING
Downloaded from www.ajronline.org by 118.163.44.31 on 11/11/15 from IP address 118.163.44.31. Copyright ARRS. For personal use only; all rights reserved
2i 0
qualified personnel, and obtaining a radiograph immediately after the procedure to check tube placement. Gastroesophageal reflux.-The role of barium studies in detecting gastroesophageal reflux was discussed by J. Keith Thompson (Birmingham, AL). He and his coauthors (A. E. Koehher, J. E. Richter) had observed that, although barium studies are generally held in low regand because of presumed how sensitivity in detecting gastroesophageal reflux, radiology departments receive many referrals to assess this diagnosis. Moreover, the water siphon test is also held in low regard because of its presumed oversensitivity. In this study, all patients were referred for either barium swallow or upper gastrointestinal studies, and reflux as seen on images was graded on a scale of 0 to 5 (clearance time also was recorded). All 83 patients had both barium studies and 24-hr pH monitoning within a period of 14 days; elicitation maneuvers were used in all patients. The 24-hr pH testing (despite its admitted problem with reproducibility values between 80% and 85%) was used as the gold standard to determine reflux. According to this standard, 55% of the patients did have gastroesophageal reflux. When results of barium studies were considered without the water siphon results, the success of barium studies in detecting reflux was as follows: sensitivity, 44%; specificity, 89%; positive predictive value, 84%; and negative predictive value, 53%. When the water siphon results were considered along with the barium study results, the success in detecting gastroesophageal reflux was as follows: sensitivity, 65%; specificity, 80%; positive predictive value, 82%; and negative predictive value, 62%. These results suggest that barium studies are reasonable screening tests for gastroesophageal reflux; they yield fain sensitivity and high positive predictive value when elicitation maneuvers are used, and addition of the water siphon test increases sensitivity significantly with only minimal effects on positive predictive values. Michael Y. M. Chen (Winston-Salem, NC) presented an investigation of the correlation of esophageal pH testing and radiographic findings in gastroesophageah reflux (coauthors: D. J. Ott, W. C. Wu, J. W. Sinclair, D. W. Gelfand). They studied 1 i 2 consecutive patients who had undergone both pH monitoring and multiphasic esophagography. For pH studies, the investigators recorded the percentage of time during which pH was less than 4, the number of reflux episodes, the duration of reflux episodes, and the symptoms. Cases of gastroesophageal reflux were categorized as mild, moderate, or severe on the basis of total acid exposure. In 62 patients, pH monitoring results showed no reflux; in six (1 0%) of these, however, reflux was diagnosed radiographically. Of the 50 patients with abnormal results on pH tests, reflux was diagnosed radiographically in 1 5 (30%). Detection rates of gastroesophageal reflux by radiography increased with severity of the disease: mild, 25%; moderate, 27%; and severe, 57%. On the basis of these findings, radiographic findings do not correlate with gastrointestinal reflux found by pH monitoring, particularly in patients with mild or moderate disease. Pancreas
and Liver
Contrast-enhanced CT appearance of venous drainage of the pancreatic head.-Lars G. Crabo (Seattle, WA) was
NEWS
AJR:159,
July 1992
awarded the Roscoe E. Miller Award for his and his coworkens’ (P. C. Fneeney, D. 0. Graney, D. M. Conley) study on CT of the pancreatic head. They wanted to investigate the clinical significance of anatomic findings on CT of the small pancreatic veins because CT is currently the most widely used diagnostic test for pancreatic adenocarcinoma. However, when this imaging method is used, the number of resectable pancreatic tumors is overestimated by 36-62%. CT of these pancreatic veins may improve results because these veins are abnormal in pancreatic cancer. Studying CT scans from 1 00 consecutive patients without evidence of pancreatic disease, these investigators found ranges in size as follows: anterior pancreaticoduodenal veins (APDV5), 1 -4 mm; posterior pancreaticoduodenal veins (PPDV5), 1 -4 mm; and gastrocohic venous trunk (Gd), 3-7 mm. In their dynamic CT study of venous anatomy, they found that the APDVs and PPDVs lie just within the parenchyma on the anterior and posterior surfaces of the head of the pancreas, and the GCT joins the superior mesenteric vein anterior to the uncinate process. The frequencies of visualization of small pancreatic veins on contrastenhanced CT were as follows: APDV, 98%; PPDV, 88%; and GCT, 89%. Dynamic CT can show the APDVs, the PPDVs, and the GCT; CT can help reassess patients with pancreatic head carcinoma; and CT evaluation of pancreaticoduodenal vein involvement may be useful in staging pancreatic cancer. Sonographic screening for hepatic malignancies in cirrhotic livers.-ln a presentation that won him the Memorial Award, Gerald D. Dodd (Pittsburgh, PA) presented the preliminary results of a prospective study by himself and his coauthors (W. J. Miller, A. L. Baron, S. R. Confer). They investigated sonographic detection of malignant tumors in 200 consecutive liver transplant recipients. Although several previous studies have investigated associated applications of hepatic imaging, these studies have been limited by three factors: their retrospective nature, limited pathologic correlation, and nonscreening protocol. In this study, sonognams were obtained in all 200 patients before liven transplantation to check for number, size, and location of tumors; state-of-the-art equipment was used; and staff radiologists interpreted all the images. About 86% of the sonographic examinations were performed within 1 20 days before the transplantation, and the sonographic criteria for tumor included heterogeneity and focal mass. The preoperative sonograms yielded low sensitivity but very high specificity for malignant tumor; most of the tumors missed were small (i cm), and the largest tumor missed was a diffusely infiltrating lesion that could not be seen even retrospectively. Previous studies have shown higher detection rates for sonognaphy in patients with cirrhosis. The differences may be explained by the prospective nature of this study, the whole-liver correlations available after transplantation, the end-stage cirrhosis of the patients in this study, and different body habitus (North American in this study vs Oriental). These preliminary results indicate that, although sonography is not a sensitive screening device for detecting malignant tumors in cirrhotic livers, its specificity is so high that any lesion shown by sonography in a cirrhotic liven should be considered malignant until proved otherwise. MR detection of hepatocellular carcinoma in patients with liver cirrhosis.-Ruedi F. Thoeni (San Francisco, CA) dis-
Downloaded from www.ajronline.org by 118.163.44.31 on 11/11/15 from IP address 118.163.44.31. Copyright ARRS. For personal use only; all rights reserved
AJA:159,
July 1992
MEETING
cussed a study in which he and his coauthons (G. Sicca, P. Shyn), who had no knowledge of the diagnosis beforehand, assessed the MR images of 29 patients with proved liven cirnhosis to evaluate the accuracy of MR imaging in detecting hepatocelluhar carcinoma (HCC). Five patients without cirrhosis also were imaged; four of these had HCC. In these 34 patients, the diagnosis of HCC was proved by surgery in nine patients, biopsy in 13, transplantation in 1 0, and 7- and 9year follow-up (respectively) in two. Several MR sequences were used (including Ti -weighted spin-echo, T2-weighted spin-echo, and contrast-enhanced gradient-recalled echo Sequences); for all imaging procedures, glucagon was administered to the patient, and fat-saturation and respiratory-.compensation techniques were used. MA criteria for liver cirrhosis included shrunken liver, nodular surface, inhomogeneity, splenomegaly, varices, and ascites. For HCC, MA criteria included inhomogeneity, vascular invasion, steatosis, presence of capsule, irregularity of margins, and extent beyond the capsule. In the subgroup of patients thought to have liver cirrhosis, MR imaging yielded excellent results in detecting cirrhosis: 90% for sensitivity, i 00% for specificity and positive predictive value, and 63% for negative predictive value. In detecting HCC, MR imaging accuracy was lower: sensitivity, 65%; specificity, 83%; positive predictive value, 92%; and negative predictive value, 45%. Investigating the relatively high numbars offalse-negative results revealed that one false-negative was a missed lesion, eight false-negatives were additional lesions (in patients with multiple lesions), two false-negatives were interpreted as abscesses, and one false-negative was called a regenerating nodule. The two false-positives consisted of one regenerating nodule and one focal fatty infiltration. The researchers concluded that in this subgroup of patients at risk, MA imaging was very accurate in detecting moderate to advanced cirrhosis, but not sensitive enough to discern the extent of HCC in these patients. They recommend that additional tests be done when MA does not show HCC in patients at risk or in patients with elevated a-fetoprotein levels. CT ofhepatocellular carcinoma.-Using contrast-enhanced CT, W. Ross Stevens and colleagues (C. D. Johnson, D. H. Stephens, K. P. Batts; Rochester, MN) investigated the CT appearance of HCC in patients with alcohol-related disease and in other patients with HCC (e.g., those with viral hepatitis). Their study group consisted of 1 00 consecutive patients with pathologically proved HCC: this report described the results of the review of these patients’ CT scans. On these CT scans, HCC was seen as a single mass in 47 (47%) of the cases, as multifocal masses in 46 (46%), and as a diffusely infiltrating lesion in four (4%). Most of the tumors appeared as heterogeneously hypodense masses with mixed vascularity. In 28 cases, CT showed portal vein involvement, and in 29 cases, it showed metastases or local extension of tumor. Tumor invasion of portal on hepatic veins was seen in 55% of alcoholic patients but in only 20% of patients with viral hepatitis. Tumor capsule was more common in patients with viral hepatitis: 33% of these scans showed tumor capsule, but tumor capsule was seen in only 1 2% of patients with disease related to alcohol. The findings from this retrospective review indicate four features that may help CT diagnosis of HCC:
NEWS
211
central scar, necrosis, vascular invasion (more commonly seen in larger, high-grade tumors from alcohol-related disease), and capsule (seen more commonly in patients with viral hepatitis).
Gallbladder Complications of laparoscopic cholecystectomy.-As pointed out by Ellen Ward (Rochester, MN), laparoscopic cholecystectomy has been used since 1 987 and has been preferred to traditional surgery for gallbladder removal-pantially because of a lower complication rate due to less traumatic and less lengthy surgery. However, some complications have been reported in patients who have undergone hapanoscopic chohecystectomy. Dr. Ward and colleagues (A. J. LeRoy, C. E. Bender, J. H. Donohue, A. W. Hughes) studied 29 patients with such complications, including injury of the bile duct (1 5), chohedocholithiasis (seven), leaking of the cystic duct stump (four), bowel perforation (two), intraabdominal abscess (two), and intnaperitoneal gallstones (two). Among the patients with bile duct injuries (none of whom had bile duct abnormalities), endoscopic retrograde cholangiognaphy was the first diagnostic test done and showed obstruction in nine of 1 1 cases; transhepatic cholangiography was used to see the proximal extent of the strictures. Of the bile duct injuries, 1 8% were classified as Bismuth I. The seven patients in whom choledochohithiasis developed after haparoscopic cholecystectomy were rehospitalized, and one patient underwent surgery; endoscopic retrograde cholangiography was used to diagnose the complication in these patients (two thirds also had sonographic examinations). In the four patients who suffered the complication of a leak in the cystic duct stump, cholangiography was necessary to distinguish this complication from injury of the bile duct. The leak was found to be aggravated by obstruction in 50% of these patients. Abdominal radiographs showed bowel perforations (one fatal) in two patients, and CT appeared to be most useful in recognizing both intraabdominah abscesses and calcification (indicating intrapenitoneal gallstones, which are clinically significant only if infected). These results suggest that imaging studies can be helpful in identifying the complications of laparoscopic cholecystectomy and in planning treatment. In answer to a question, Dr. Ward mentioned that, in this study, the complication rate decreased as the experience of the surgical team performing the procedure increased. Pericholecystic fluid collection as a prognostic indicator for percutaneous cholecystostomy.-David L. Harshfield (Little Rock, AK) discussed this evaluation of 50 patients with pericholecystic fluid collections. The study’s coauthors were S. K. Tephick, E. F. Ferris (Little Rock, AK), and S. A. Teefey (Seattle, WA). In 1 0 of the 50 patients, percutaneous cholecystostomy had been performed for acute chohecystitis. Three types of penicholecystic fluid collections were defined: type I, very mild to moderate, not associated with perforation; type II, moderate to mild to somewhat complex, almost always associated with perforation; and type Ill, so complex that the gallbladder cannot be delineated, almost always associated with perforation.
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MEETING
Type I penicholecystic fluid collections are amenable to treatment by percutaneous cholecystostomy; these are identified on sonograms by sonolucence, crescent shape, and small size (60% of patients with gallstones little or no gross pancreatitis); and penitoneal lavage. In acute
pancreatitis,
overall
prognosis
is correlated
July 1992
tissue; have with
the occurrence of pancreatic sepsis, and there is a relationship between the number of adverse prognostic signs (Ranson’s criteria) and death of pancreatic sepsis. Identification of highrisk patients early in the course of their disease could indicate which patients require specific and aggressive treatment. In collaboration with Dr. Emil Bahthazan and colleagues at New York University, Dr. Ranson developed a system based on CT findings that describes five classes of infection risk, from lowest risk to highest: A, normal pancreas; B, enlarged pancreas; C, local inflammation; D, one fluid collection; E, more than one fluid collection. A good relationship has been shown between early CT classification and hater development of infection. Penitoneal lavage is helpful: Research has shown that peritoneal havage for 7 days reduces the frequency of peritoneal sepsis and of deaths from pancreatic sepsis; death from abscess also were shown to decrease significantly with long-term (7-day) peritoneal havage. Therefore, CT appears to be extremely useful in suggesting infection by detecting fluid collections and in helping make the diagnosis of acute pancreatitis when significant clinical uncertainty exists. CT can also be used for progressive assessment of the disease (with or without bolus contrast material), including early identification
of any
local
complications
and
have undergone surgery to assess and to identify new fluid collections.
follow-up
of patients
adequacy
of debridement
who
