Aust. Radiol. (1978), 22, 145
Computerised Tomography of the Pancreas M. R. SAGE, M.B.B.S.,M.R.A.C.R.,M.R.CP.,F.R.C.R. Director of Radwlogy (Computerized Tomogmphy). Hinders Medical Centre, Adelaide. L.V.PERRETT,M.B.B.S.,F.R.A.C.R., F.R.C.R. Senior Radiologist, Memorial Hospital, Adelaide. Body Scanners. Kreel, Haertel & Katz (1977) recommended that all patients should receive a low residue diet for three days prior to examination to reduce bowel gas, to ether with oral calcium phosphate (400mgtdsf for a similar period to outline the position of the colon. However, in our experience, such a regime appears unnecessary. Despite the relatively long scanning time of 20 seconds for each section, moving artefacts can usually be eliminated in most patients by breath holding, and anticholinergics. To decrease bowel movement, intravenous glucagon (Baert 1977) or intramuscular propantheline (Kreel 1977) have been recommended. However, intravenous buscopan appears adequate, given just MATERIALS AND METHOD Seventy (70) patients with suspected pancreatic prior to commencing the examination. The X-Ray attenuation of pancreatic tissue is disease were referred for diagnosis, the examinations being performed on E.M.I. 5005 Whole similar to that of muscle and fluid filled bowel
INTRODUCTION The undoubted value of Computerized Tomography of the head (Ambrose 1973; Paxton & Ambrose 1974) subsequently led to the development of equipment that can also examine the rest of the body. With the advent of Whole Body Computerized Tomography abdominal organs could be demonstrated in a transverse axial plane for the first time. The purpose of this paper is to relate our early experience in the use of Computerized Tomography in the diagnosis of pancreatic disease.
I.lGURt 1.-Normal C.T. Scan demonstrating the head ( h ) , body (b), and tail of the pancreas, with adjacent duodenum (d), outline by gastrografin and the superior mesenteric artery (a). Australasian Radiologv, VoI. X X l l ,
No. 2, June, I978
1:ICURE 2. -Poor defiition of retro-peritoneal structures in a cachectic patient due to paucity of fat.
145
M . R. SAGE AND L. V. PERRETT
FIGURE 3.-C.T. Scan showing marked enlargement of the body of the pancreas (p) in acute pancreatitis.
(Kreel et al. 1977), and therefore a clear difference in density between the pancreas and adjacent organs may not be detectable. In particular, the body of the stomach lies anterior to the pancreas while the head of the pancreas lies within the duodenal loop. Therefore to help distinguish the pancreas from adjacent bowel, lOOmls of dilute gastrografin (5%) is given orally approximately 10 minutes prior to the examination (Figure 1). Just prior to commencing the examination, a further lOOccs is given with the patient lying on their right side, followed by intravenous buscopan.
FIGURE 4. -Heterogeneous areas of decreased density (arrowed) in an enlarged pancreas due to acute pancreatitis.
NORMAL PANCREAS The normal pancreas is clearly shown in the majority of patients. X-Ray attenuation of pancreatic tissue is lower than that of the liver and spleen (Stanley et LIZ. 1976; Kreel 1977), but similar to that of muscle, kidneys, unenhanced blood vessels and fluid filled bowel (Kreel 1977). Visualization of the normal pancreas depends on the presence of retroperitoneal fat, because of the large difference in X-Ray attenuation between fat and pancreatic tissue. In children, there is sometimes a paucity of retroperitoneal fat, making visualization of the pancreas difficult. Similarly, in thin cachectic patients, the pancreas is frequently difficult to define (Figure 2). In the majority of patients, the pancreas has a smooth contour (Figure l), but in 20% of cases it may appear as a lobulated organ (Kreel et 01. 1977). The superior mesenteric artery is a useful landmark (Figure I), and the vessel is almost invariably seen in crosssection between the aorta and the body of the pancreas. Kreel (1977) recently reviewed the appearance of the normal pancreas, and the size of the normal pancreas was found to be up to 3cm for the head, 2.5cm for the neck and body, and 2cm for the tail. Haaga (1976) also proposed a method of measurement but in practise, we have not found direct measurements to be of specific value at this stage.
A preliminary plain film of the abdomen is taken in the supine position, with a radio-opaque marker on the skin approximately 8cms below the tip of the xiphisternum. The position of the pancreas in relationship to this marker is determined by review of any previous radiological studies while gas in the duodenal loop may also be a helpful localizing sign (Kreel et ul. 1977). Scans are then taken at lcm intervals through the pancreas. When indicated, intravenous urographic contrast medium is sometimes given, although scattering artefacts due to excessive contrast in the renal pelvi-calyceal system frequently reduces the quality of the image (Baert et al. 1977). Haaga (1976) recommended tilting the gantry 10-15" but this is not possible with the E.M.I. Whole Body Scanner. In our experience this did not appear to limit the ability to demonstrate the pancreas Contrast enhancement of normal or tumour tissue has not been observed. However Kreel( 1977) clearly.
146
Australasian Radiology, Vol. XXII. No. 2, June, I978
COMPUTERISED TOMOGRAPHY OF THE PANCREAS CHRONIC PANCREATlT IS found that the common bile duct can be identified in about 50% of cases and may act as a valuable In the one case of chronic pancreatitis in our landmark in locating the head by giving oral series, the characteristic finding was a marked calcium ipodate. diminution in the diameter of the body and tail of the pancreas, together with calcification, confirming the findings of others (Stanley 1976, PATHOLOGY Haaga 1976, Husband 1977). The final diagnosis in our cases was achieved In his series Kreel (1977) observed that unless by either laparotomy or a combination of clinical and biochemical data, together with conventional calcific pancreatitis is present on the plain film, calcification appears as a collection of irregular X-Ray examinations. white areas on C.T. sections but, when marked, these calcifications have been surrounded by low ACUTE PANCREATITIS Our experience in acute pancreatitis appears to confirm that of other reported series (Haaga 1976, Stanley 1976, Kreel 1977, Haaga 1977) that suggested that enlargement of the gland is perhaps the most common fmding. The enlargement may be diffuse or more localized (Figure 3). Localized enlargement may not be easy to distinguish from a neoplasm solely on the basis of the scan, and correct diagnosis was sometimes made because of elevated biochemical findings and clinical symptoms. In several cases, the normal homogeneous density of the pancreas was replaced by hetrogeneous areas of decreased density, presumably related to oedema and necrosis (Figure 4). Irregularity of the borders of the pancreas, infiltration of surrounding fat by strands of tissue, and thickening of the mesentry, pleura and peritoneum is sometimes observed (Husband 1977, Haaga 1976, Kreel 1977).
bIGURE S.-C.T. Scan showing well defined areas of low density in the body farrowed) and tail of the panneas, representing intra-pancreatic pseudocysts. Australasian Radiology, Vol X X I I , No. 2. June, I978
FIGURk 6. -C.T. Scan showing extensive extra-pancreatic pseudocysts fc),obliteratmg the normal pwas on the right, when compared With the left ( p ) and extending into the pelvis to lie adjacent to the right ilium fb).
147
M. R. SAGE AND L. V. PERRETT
FIGURE 8. -C.T. Scan showing a large extra-pancreatic mass (c), compressing the adjacent stomach (s) containing gastrografin. FIGURE 7.-C.T. Scan showing a large wellcircumscribed pseudocyst (c), displacing the spleen (s) anteriorly, and the aorta (a) to the right.
through the right lumbar region into the false and true pelvis. In another case (Figure 7) a large well density areas with tissue attenuation values suggest- circumscribed mass was demonstrated displacing ing fat replacement or infitration. In one of his the spleen anteriorly, and the aorta to the right, cases, C.T. demonstrated calcification although while the stomach may be compressed (Figure 8). there was no evidence of pancreatic calcification on plain fdm radiography. ADENOCARCINOMA AND OTHER NEOPLASTIC PROCESSES PSEUDOCYSTS Computerized Tomography not only shows the Perhaps the most immediate and obvious exact size and site of pancreatic tumours, but may application of C.T. has been in the diagnosis, also dem.onstrate secondary changes in other definition and monitoring of pseudocysts. organs. The most important finding is enlargement Pseudocysts produce a highly characteristic of the pancreatic contour beyond normal dimenappearance of a well defined, apparently encapsu- sions (Figure 9). Although Husband & Kreel(l977) lated area of low density continuous with or close to the pancreas (Figure 5). As such collections may arise from loculation of inflammatory processes, necrosis or haemorrhage (Waugh & Lynn 1958), there is considerable variation in the density of the fluid within. Therefore, although a pseudocyst may be clearly defined by C.T., the indications and timing of any surgical treatment should only be undertaken after discussion between the surgeon and radiologist. The intrapancreatic pseudocysts consist of areas of low density (Figure 5) with a well defined wall. The extent of extra pancreatic collections can be clearly demonstrated. In one of our cases, a patient with a history of recurrent pancreatitis presented with pain and swelling in the right scrotum. Computerized Tomography demonstrated an extrapancreatic collection (Figure 6) which was FIGURE 9.-C.T. Scan demonstrating a large adenosubsequently demonstrated to extend inferiorly carcinoma (T) indenting the adjacent stomach (s). 148
Australasian Radiology, Vol. X X I I , No. 2, June, I 9 7 8
COMPUTERISED TOMOGRAPHY OF THE PANCREAS
FIGURE 12.-C.T. Scan demonstrating a dilated common bile duct (arrowed), within the head of the pancreas (P). FIGURE 10.-C.T. Scan demonstrating a mass in the head of the pancreas (T), indenting the adjacent duodenum (d), outlined by gastrografm.
found that tumours do appear a little denser than the normal pancreatic tissue, our experience does not confirm this. When localized enlargement is prominent, the clinical picture, biochemistry and other investigations are essential to clearly differentiate between tumour and pancreatitis. Haaga (1976) found no attenuation difference between neoplasm and pancreatitis, either with or without contrast. Also other solid tumours in this region, such as lymphoma and duodenal carcinoma, may have a similar appearance (Kreel 1977). In several
cases, pressure effects on adjacent organs were helpful in making a correct diagnosis. The duodenum (Figure 10) may be deformed by a mass in the head of the pancreas, and similarly, direct invasion of the stomach may also be shown (Figure 11). Such changes are of interest but it would be hoped that such lesions would present no difficulty in diagnosis by more conventional techniques. Extension of a neoplasm into the retroperitoneum and peri-vascular structures produces loss of the normal fat planes (Haaga et a1 1977). In the presence of obstructive jaundice, we have been able to demonstrate dilatation of the intrahepatic biliary radicles in all cases. It is sometimes
FIGURE 11.-C.T.Scan showing direct invasion of the of the body of the stomach (S) by a carcinoma pancreas.
FIGURE 13.-C.T. Scan demonstrating a cystadenorna of the pancreas.
tn
Australasian Radiology, Val. X X l l ,
No. 2. June, I978
149
M . R. SAGE AND L. V. PERRETT E.R.C.P. and ultrasound done for the same patients. They concluded that the C.T. scan was the most effective for detection of the primary Lesion and the extent of the disease and, where available, should b e used for any patient in whom pancreatic disease is highly suspected clinically.
FIGURE 14. -C.T. Scan demonstrating a leiomyosarcoma of the duodenum (T) resulting in marked enlargement of the head of the pancreas by direct invasion.
possible to determine the level of obstruction. In one case the dilated bile duct was clearly demonstrated within the head o f t h e pancreas (Figure 12), and subsequent surgery confirmed the presence o f a tumour in the region of the ampulla. Further secondary changes include the presence of metastases in the liver, and it is important t o note that all this information is gained from a single noninvasive examination. In the two cases of cystadenoma, Computerized Tomography proved useful in making the diagnosis, delineating the lesion and monitoring subsequent therapy (Figure 13). Endocrine tumours of the pancreas are usually very small, and in the series reported so far, such tumours have not been demonstrated in the majority of cases. However, in one of our cases, an islet cell tumour produced localized enlargement. Direct invasion of the pancreas b y tumours of adjacent structures may b e delineated. A leiomyosarcoma of the second part of the duodenum was demonstrated t o extend into the adjacent pancreas, leading to extensive necrosis and swelling (Figure 14).
DISCUSSION The small number in our series does not allow us to compare C.T. with other modalities available. However recently Haaga et QZ (1977) reviewed 192 cases, comparing the accuracy of C.T. in detecting neoplastic and inflammatory disease of the pancreas with the accuracy of angiography, 150
SUMMARY Computerized Tomography has been performed in 70 patients with suspected pancreatic disease, and our early experience has been reviewed. Our results appear to confirm that pancreatic lesions can be clearly shown in the majority of patients. Provided that the patients are selected carefully, it seems likely that Computerized Tomography will have an important role in the demonstration and diagnosis of pancreatic disease in the future.
ACKNOWLEDGEMENTS We would like to thank the members of the Medical Illustrations Department, Flinders Medical Centre, and Mrs Wendy Foran for helping in the preparation of the manuscript. REFERENCES 1. Ambrose, J . (1973): “Computerized Transverse Axial Scanning (Tomography): (2) Clinical Application.” Brit. J. Radiol. 4 6 : 1023-1047. 2. Baert, A. L., Ponette, E., Pringot, J., Marchal, G., Dardenne, A. and Coenen, Y.: “C.A.T. in Acute and Chronic Pancreatitis.” First European Seminar on C.A.T. in Clinical Practice, Springer-Verlag. 382-387. 3. Haaga, J. R., Alfidi, R. J., Havrilla, T. R., Tubbs, R., Gonzalez, L., Meaney, T. F. and Corsi, M. A. (1977): “Definitive Role of C.T. Scanning of the Pancreas.” Radiology, 124 : 723-730. 4. Haaga, J. R., Alfidi, R. J., Zelch, M. G., Meaney, T. I:., Boller Mariella, Gonzalez, L. and Jelden, G. L. (1976): “Computed Tomography of the Pancreas.” Radiology, 120 : 589-595. 5 . Kreel, L. (1977): “Computerized Tomography of the Pancreas.” Computed Axial Tomography, 1 : 4, 287298. 6. Kreel, L., Haertel, M. andKatz, D. (1977): “Computed Tomography of the Normal Pancreas.” J. Comp. Ass. Tomography, 1 : 3,290-299. 7. Paxton, R. and Ambrose, J . (1974): “The E.M.I. Scanner A Brief Review of the First 650 Patients.” Brit. J. Radiol. 4 1 : 530-565. 8. Stanley, R. J., Sagel, S. S. and Levitt, R. G. (1976): “Computed Tomography of the Body: Early Trends in Application and Accuracy of the Method.” Amer. J. Roentgenol. 127 : 5 3 6 7 . 9. Waugh, J. M. and Lynn, T. E. (1958): “Clinical and Surgical Aspects of Pseudocyst: Analysis of 58 Cases.” Arch. Surg. 77 : 47. Auslralasian Radiology, Vol. X X t I , No. 2, J u w . 1978
Computerised Tomography of the Pancreas M. R. SAGE, M.B.B.S.,M.R.A.C.R.,M.R.CP.,F.R.C.R. Director of Radwlogy (Computerized Tomogmphy). Hinders Medical Centre, Adelaide. L.V.PERRETT,M.B.B.S.,F.R.A.C.R., F.R.C.R. Senior Radiologist, Memorial Hospital, Adelaide. Body Scanners. Kreel, Haertel & Katz (1977) recommended that all patients should receive a low residue diet for three days prior to examination to reduce bowel gas, to ether with oral calcium phosphate (400mgtdsf for a similar period to outline the position of the colon. However, in our experience, such a regime appears unnecessary. Despite the relatively long scanning time of 20 seconds for each section, moving artefacts can usually be eliminated in most patients by breath holding, and anticholinergics. To decrease bowel movement, intravenous glucagon (Baert 1977) or intramuscular propantheline (Kreel 1977) have been recommended. However, intravenous buscopan appears adequate, given just MATERIALS AND METHOD Seventy (70) patients with suspected pancreatic prior to commencing the examination. The X-Ray attenuation of pancreatic tissue is disease were referred for diagnosis, the examinations being performed on E.M.I. 5005 Whole similar to that of muscle and fluid filled bowel
INTRODUCTION The undoubted value of Computerized Tomography of the head (Ambrose 1973; Paxton & Ambrose 1974) subsequently led to the development of equipment that can also examine the rest of the body. With the advent of Whole Body Computerized Tomography abdominal organs could be demonstrated in a transverse axial plane for the first time. The purpose of this paper is to relate our early experience in the use of Computerized Tomography in the diagnosis of pancreatic disease.
I.lGURt 1.-Normal C.T. Scan demonstrating the head ( h ) , body (b), and tail of the pancreas, with adjacent duodenum (d), outline by gastrografin and the superior mesenteric artery (a). Australasian Radiologv, VoI. X X l l ,
No. 2, June, I978
1:ICURE 2. -Poor defiition of retro-peritoneal structures in a cachectic patient due to paucity of fat.
145
M . R. SAGE AND L. V. PERRETT
FIGURE 3.-C.T. Scan showing marked enlargement of the body of the pancreas (p) in acute pancreatitis.
(Kreel et al. 1977), and therefore a clear difference in density between the pancreas and adjacent organs may not be detectable. In particular, the body of the stomach lies anterior to the pancreas while the head of the pancreas lies within the duodenal loop. Therefore to help distinguish the pancreas from adjacent bowel, lOOmls of dilute gastrografin (5%) is given orally approximately 10 minutes prior to the examination (Figure 1). Just prior to commencing the examination, a further lOOccs is given with the patient lying on their right side, followed by intravenous buscopan.
FIGURE 4. -Heterogeneous areas of decreased density (arrowed) in an enlarged pancreas due to acute pancreatitis.
NORMAL PANCREAS The normal pancreas is clearly shown in the majority of patients. X-Ray attenuation of pancreatic tissue is lower than that of the liver and spleen (Stanley et LIZ. 1976; Kreel 1977), but similar to that of muscle, kidneys, unenhanced blood vessels and fluid filled bowel (Kreel 1977). Visualization of the normal pancreas depends on the presence of retroperitoneal fat, because of the large difference in X-Ray attenuation between fat and pancreatic tissue. In children, there is sometimes a paucity of retroperitoneal fat, making visualization of the pancreas difficult. Similarly, in thin cachectic patients, the pancreas is frequently difficult to define (Figure 2). In the majority of patients, the pancreas has a smooth contour (Figure l), but in 20% of cases it may appear as a lobulated organ (Kreel et 01. 1977). The superior mesenteric artery is a useful landmark (Figure I), and the vessel is almost invariably seen in crosssection between the aorta and the body of the pancreas. Kreel (1977) recently reviewed the appearance of the normal pancreas, and the size of the normal pancreas was found to be up to 3cm for the head, 2.5cm for the neck and body, and 2cm for the tail. Haaga (1976) also proposed a method of measurement but in practise, we have not found direct measurements to be of specific value at this stage.
A preliminary plain film of the abdomen is taken in the supine position, with a radio-opaque marker on the skin approximately 8cms below the tip of the xiphisternum. The position of the pancreas in relationship to this marker is determined by review of any previous radiological studies while gas in the duodenal loop may also be a helpful localizing sign (Kreel et ul. 1977). Scans are then taken at lcm intervals through the pancreas. When indicated, intravenous urographic contrast medium is sometimes given, although scattering artefacts due to excessive contrast in the renal pelvi-calyceal system frequently reduces the quality of the image (Baert et al. 1977). Haaga (1976) recommended tilting the gantry 10-15" but this is not possible with the E.M.I. Whole Body Scanner. In our experience this did not appear to limit the ability to demonstrate the pancreas Contrast enhancement of normal or tumour tissue has not been observed. However Kreel( 1977) clearly.
146
Australasian Radiology, Vol. XXII. No. 2, June, I978
COMPUTERISED TOMOGRAPHY OF THE PANCREAS CHRONIC PANCREATlT IS found that the common bile duct can be identified in about 50% of cases and may act as a valuable In the one case of chronic pancreatitis in our landmark in locating the head by giving oral series, the characteristic finding was a marked calcium ipodate. diminution in the diameter of the body and tail of the pancreas, together with calcification, confirming the findings of others (Stanley 1976, PATHOLOGY Haaga 1976, Husband 1977). The final diagnosis in our cases was achieved In his series Kreel (1977) observed that unless by either laparotomy or a combination of clinical and biochemical data, together with conventional calcific pancreatitis is present on the plain film, calcification appears as a collection of irregular X-Ray examinations. white areas on C.T. sections but, when marked, these calcifications have been surrounded by low ACUTE PANCREATITIS Our experience in acute pancreatitis appears to confirm that of other reported series (Haaga 1976, Stanley 1976, Kreel 1977, Haaga 1977) that suggested that enlargement of the gland is perhaps the most common fmding. The enlargement may be diffuse or more localized (Figure 3). Localized enlargement may not be easy to distinguish from a neoplasm solely on the basis of the scan, and correct diagnosis was sometimes made because of elevated biochemical findings and clinical symptoms. In several cases, the normal homogeneous density of the pancreas was replaced by hetrogeneous areas of decreased density, presumably related to oedema and necrosis (Figure 4). Irregularity of the borders of the pancreas, infiltration of surrounding fat by strands of tissue, and thickening of the mesentry, pleura and peritoneum is sometimes observed (Husband 1977, Haaga 1976, Kreel 1977).
bIGURE S.-C.T. Scan showing well defined areas of low density in the body farrowed) and tail of the panneas, representing intra-pancreatic pseudocysts. Australasian Radiology, Vol X X I I , No. 2. June, I978
FIGURk 6. -C.T. Scan showing extensive extra-pancreatic pseudocysts fc),obliteratmg the normal pwas on the right, when compared With the left ( p ) and extending into the pelvis to lie adjacent to the right ilium fb).
147
M. R. SAGE AND L. V. PERRETT
FIGURE 8. -C.T. Scan showing a large extra-pancreatic mass (c), compressing the adjacent stomach (s) containing gastrografin. FIGURE 7.-C.T. Scan showing a large wellcircumscribed pseudocyst (c), displacing the spleen (s) anteriorly, and the aorta (a) to the right.
through the right lumbar region into the false and true pelvis. In another case (Figure 7) a large well density areas with tissue attenuation values suggest- circumscribed mass was demonstrated displacing ing fat replacement or infitration. In one of his the spleen anteriorly, and the aorta to the right, cases, C.T. demonstrated calcification although while the stomach may be compressed (Figure 8). there was no evidence of pancreatic calcification on plain fdm radiography. ADENOCARCINOMA AND OTHER NEOPLASTIC PROCESSES PSEUDOCYSTS Computerized Tomography not only shows the Perhaps the most immediate and obvious exact size and site of pancreatic tumours, but may application of C.T. has been in the diagnosis, also dem.onstrate secondary changes in other definition and monitoring of pseudocysts. organs. The most important finding is enlargement Pseudocysts produce a highly characteristic of the pancreatic contour beyond normal dimenappearance of a well defined, apparently encapsu- sions (Figure 9). Although Husband & Kreel(l977) lated area of low density continuous with or close to the pancreas (Figure 5). As such collections may arise from loculation of inflammatory processes, necrosis or haemorrhage (Waugh & Lynn 1958), there is considerable variation in the density of the fluid within. Therefore, although a pseudocyst may be clearly defined by C.T., the indications and timing of any surgical treatment should only be undertaken after discussion between the surgeon and radiologist. The intrapancreatic pseudocysts consist of areas of low density (Figure 5) with a well defined wall. The extent of extra pancreatic collections can be clearly demonstrated. In one of our cases, a patient with a history of recurrent pancreatitis presented with pain and swelling in the right scrotum. Computerized Tomography demonstrated an extrapancreatic collection (Figure 6) which was FIGURE 9.-C.T. Scan demonstrating a large adenosubsequently demonstrated to extend inferiorly carcinoma (T) indenting the adjacent stomach (s). 148
Australasian Radiology, Vol. X X I I , No. 2, June, I 9 7 8
COMPUTERISED TOMOGRAPHY OF THE PANCREAS
FIGURE 12.-C.T. Scan demonstrating a dilated common bile duct (arrowed), within the head of the pancreas (P). FIGURE 10.-C.T. Scan demonstrating a mass in the head of the pancreas (T), indenting the adjacent duodenum (d), outlined by gastrografm.
found that tumours do appear a little denser than the normal pancreatic tissue, our experience does not confirm this. When localized enlargement is prominent, the clinical picture, biochemistry and other investigations are essential to clearly differentiate between tumour and pancreatitis. Haaga (1976) found no attenuation difference between neoplasm and pancreatitis, either with or without contrast. Also other solid tumours in this region, such as lymphoma and duodenal carcinoma, may have a similar appearance (Kreel 1977). In several
cases, pressure effects on adjacent organs were helpful in making a correct diagnosis. The duodenum (Figure 10) may be deformed by a mass in the head of the pancreas, and similarly, direct invasion of the stomach may also be shown (Figure 11). Such changes are of interest but it would be hoped that such lesions would present no difficulty in diagnosis by more conventional techniques. Extension of a neoplasm into the retroperitoneum and peri-vascular structures produces loss of the normal fat planes (Haaga et a1 1977). In the presence of obstructive jaundice, we have been able to demonstrate dilatation of the intrahepatic biliary radicles in all cases. It is sometimes
FIGURE 11.-C.T.Scan showing direct invasion of the of the body of the stomach (S) by a carcinoma pancreas.
FIGURE 13.-C.T. Scan demonstrating a cystadenorna of the pancreas.
tn
Australasian Radiology, Val. X X l l ,
No. 2. June, I978
149
M . R. SAGE AND L. V. PERRETT E.R.C.P. and ultrasound done for the same patients. They concluded that the C.T. scan was the most effective for detection of the primary Lesion and the extent of the disease and, where available, should b e used for any patient in whom pancreatic disease is highly suspected clinically.
FIGURE 14. -C.T. Scan demonstrating a leiomyosarcoma of the duodenum (T) resulting in marked enlargement of the head of the pancreas by direct invasion.
possible to determine the level of obstruction. In one case the dilated bile duct was clearly demonstrated within the head o f t h e pancreas (Figure 12), and subsequent surgery confirmed the presence o f a tumour in the region of the ampulla. Further secondary changes include the presence of metastases in the liver, and it is important t o note that all this information is gained from a single noninvasive examination. In the two cases of cystadenoma, Computerized Tomography proved useful in making the diagnosis, delineating the lesion and monitoring subsequent therapy (Figure 13). Endocrine tumours of the pancreas are usually very small, and in the series reported so far, such tumours have not been demonstrated in the majority of cases. However, in one of our cases, an islet cell tumour produced localized enlargement. Direct invasion of the pancreas b y tumours of adjacent structures may b e delineated. A leiomyosarcoma of the second part of the duodenum was demonstrated t o extend into the adjacent pancreas, leading to extensive necrosis and swelling (Figure 14).
DISCUSSION The small number in our series does not allow us to compare C.T. with other modalities available. However recently Haaga et QZ (1977) reviewed 192 cases, comparing the accuracy of C.T. in detecting neoplastic and inflammatory disease of the pancreas with the accuracy of angiography, 150
SUMMARY Computerized Tomography has been performed in 70 patients with suspected pancreatic disease, and our early experience has been reviewed. Our results appear to confirm that pancreatic lesions can be clearly shown in the majority of patients. Provided that the patients are selected carefully, it seems likely that Computerized Tomography will have an important role in the demonstration and diagnosis of pancreatic disease in the future.
ACKNOWLEDGEMENTS We would like to thank the members of the Medical Illustrations Department, Flinders Medical Centre, and Mrs Wendy Foran for helping in the preparation of the manuscript. REFERENCES 1. Ambrose, J . (1973): “Computerized Transverse Axial Scanning (Tomography): (2) Clinical Application.” Brit. J. Radiol. 4 6 : 1023-1047. 2. Baert, A. L., Ponette, E., Pringot, J., Marchal, G., Dardenne, A. and Coenen, Y.: “C.A.T. in Acute and Chronic Pancreatitis.” First European Seminar on C.A.T. in Clinical Practice, Springer-Verlag. 382-387. 3. Haaga, J. R., Alfidi, R. J., Havrilla, T. R., Tubbs, R., Gonzalez, L., Meaney, T. F. and Corsi, M. A. (1977): “Definitive Role of C.T. Scanning of the Pancreas.” Radiology, 124 : 723-730. 4. Haaga, J. R., Alfidi, R. J., Zelch, M. G., Meaney, T. I:., Boller Mariella, Gonzalez, L. and Jelden, G. L. (1976): “Computed Tomography of the Pancreas.” Radiology, 120 : 589-595. 5 . Kreel, L. (1977): “Computerized Tomography of the Pancreas.” Computed Axial Tomography, 1 : 4, 287298. 6. Kreel, L., Haertel, M. andKatz, D. (1977): “Computed Tomography of the Normal Pancreas.” J. Comp. Ass. Tomography, 1 : 3,290-299. 7. Paxton, R. and Ambrose, J . (1974): “The E.M.I. Scanner A Brief Review of the First 650 Patients.” Brit. J. Radiol. 4 1 : 530-565. 8. Stanley, R. J., Sagel, S. S. and Levitt, R. G. (1976): “Computed Tomography of the Body: Early Trends in Application and Accuracy of the Method.” Amer. J. Roentgenol. 127 : 5 3 6 7 . 9. Waugh, J. M. and Lynn, T. E. (1958): “Clinical and Surgical Aspects of Pseudocyst: Analysis of 58 Cases.” Arch. Surg. 77 : 47. Auslralasian Radiology, Vol. X X t I , No. 2, J u w . 1978
