Annals of the Royal College of Surgeons of England
(I979) vol 6i
ASPECTS OF DIAGNOSIS*
The plain abdominal radiograph in acute appendicitis TJ A C Thorpe
FRCS
FRCSEd.
Surgical Registrar, St James's University Hospital, Leedst
Summary Although the radiological features of acute appendicitis have been well documented, the value of the plain abdominal radiograph has not been fully appreciated. This article summarises the role of radiology in acute appendicitis, especially in atypical cases and extremes of age, where there is often delay in diagnosis.
signs. A recent report" shows less than o0% diagnostic accuracy for residents, 70% for surgeons, and 85% for radiologists when assessing radiographs of the acute abdomen. Few residents, who manage the majority of cases of acute appendicitis, are aware of the radiological criteria; hence the attitude that the plain abdominal radiograph is of little use.
Radiological signs in acute appendicitis6 Introduction The diagnosis of a classical case of acute appendicitis rarely presents any difficulty if particular attention is given to the history, pain distribution, and the finding of local and rebound tenderness in the right iliac fossa. However, in acute appendicitis there is a high rate of misdiagnosis, particularly in children'-', immigrants, the elderly4, and those who present with unusual or unimpressive clinical features. Diagnostic error is due to many factors, including observer error5; it is twice as common in the female as in the male patient4 and is
i) Air-fluid levels localised to the caecum and/or terminal small bowel are indicative of localised inflammation in the right lower quadrant of the abdomen.
2) Localised adynamic ileus.
3) Increased soft-tissue density in the right lower quadrant, presenting as a more radioopaque area on the radiographs, can usually best be seen by comparing the relative clarity and relative film density of the sacoiliac joints.
greater than average in the first two decades 4) Alteration of the right flank stripe. and in the over 5so. In accident and emergency departments many radiographs are Appendicoliths, the calcified concretions taken for acute abdominal pain. These are in 5) the are typical in appearance and obviously relevant and helpful in patients with locationappendix, and usually present as homogeneous intestinal obstruction. However, little signifi- or somewhat laminated densities in the right cance is attached to this investigation in ap- lower quadrant. pendicitis although the associated radiological features have been well documented'10. 6) Alteration of the psoas outline and blurA personal prospective study of IOO patients ring of its distal third. admitted with a diagnosis of acute appendicitis from the accident and emergency department 7) Gas-filled appendix, a rare but valuable of the Leeds General Infirmary showed that sign. only 45 had histologically proven appendicitis, 8) Extraluminal gas or free gas in the periof whom 75 7o had two or more radiological toneal or retroperitoneal space. tPresent address: Papworth Hospital, Papworth Everard, Cambs. 9) Deformity of the caecum. *Fellows and Members interested in submitting articles:for consideration with a view to publication in this series should first write to the Editor.
46
*'!,~ ~ .y'm
J A C Thorpe
sign of tenderness in the right iliac fossa and the symptom of localised pain may lie outside the usual area in I 2o and 24% of cases res-
pectively'2. Although acute appendicitis may present in many ways, failure of diagnosis is also attributed to observer error but with the use of standardised questionnaires and computer~ ied diagnssit is hoped to eliminate this factor. However, these techniques are in their infancy and have made little clinical impact
FIG. I Plain radiograph showing typical features of acute appendicitis in a I5-year-old Indian child. Note reactive scoliosis and blurring of psoas margin and right sacroiliac joint. There are prominent gas shadows and local ileus in the right lower quadrant. An appendicolith is visible.
Discussion Acute appendicitis is the commonest disease of the gastrointestinal tract and accounts for the largest number of hospital admissions for bowel disorder. The diagnosis is usually straightforward and detailed investigations are seldom necessary. However, recent literature suggests that a high proportion of cases are misdiagnosed, particularly in children and the elderly'"'. Immigrants also present a diagnostic challenge when the history cannot be relied upon because of language difficulties. Obese individuals and those in whom the appendix is subhepatic or retrocaecal commonly show atypical features of acute appendicitis. In addition, the classical
as yet.
Ancillary investigations in the diagnosis of appendicitis are limited to haematological tests, urine analysis, and, less frequently,
acute
radiological examination. A raised leucocyte neutrophilia is indicative of a septic focus, but this examination is of little value in infancy and childhood",",' Uriie
count with relative
3
FIG. 2 Plain radiograph (detail) showing features of acute appendicitis in a I2-year-old girl with atypical clinical signs. Film shows local ileus and blurring of the sacroiliac joint. In addition there is increased density of the properitoneal fat line.
I
The plain abdominal raliograph in acute appendicitis analysis is essential in the diagnosis of renal disease and should be performed routinely in cases of acute abdomen15. However, microscopic haematuria is commonly found in acute appendicitis. Radiology in acute appendicitis has attracted little surgical attention, though most authors suggest that the plain radiograph can aid and improve accuracy and speed of diagnosis1617'9. Since Weisflog in 1902 first noted an appendicolith in association with acute appendicitis many comprehensive studies of the radiological features in acute appendicitis have been carried out. Soter9, in a review of 4500 cases over a period of 23 years, concluded that 90-io00o had radiological evidence of disease; however, this high diagnostic rate was achieved by using the more elaborate radiological procedures. Steinart et al° showed in a classic paper that in 8o out of I04 cases an abnormal finding could be demonstrated in the radiograph. Most authors confirm the presence of an appendicolith as 8o-i100oo indicative of acute, often perforated, appendicitis18'8. In infants a perforated appendix greatly increases morbidity and mortality, radiology in this instance being of considerable use in diagnosis, thereby speeding subsequent management". Radiology is also of use in the differential diagnosis of renal stone, Crohn's disease, ileocaecal tuberculosis, intussusception, and malrotation of the gut'. Maingot"8 suggests that all patients suspected of acute appendicitis should have erect and supine abdominal and chest radiographs on presentation, as indeed should all patients presenting with an acute abdomen. It is of interest that 4 out of 5 patients with false-positive radiographs for acute appendicitis have other conditions9'20-for example, ruptured ovarian cyst, leaking carcinoma of the caecum, or a low-lying inflamed gallbladder. This emphasises that radiology reflects all diseases affecting the right lower quadrant, the commonest being acute appendicitis.
47
I would like to express my sincere thanks to Mr D Wilson, Consultanit Surgeon, Accident and Emergency Department, Leeds General Inifirmary, for his help and advice and the Department of Radiology for the use of their services.
References I
2 3
4 5 6
7 8
9
Caffey, J P (i973) Paediatric X-ray Diagnzosis, 6th edn, Chicago, Year Book Medical Publishers. Dennison, W M (1974) Surgery in Infancy and Childhood, 3rd edn. Edinburgh and London, Churchill Livingstone. Wilkinson, R H, et al (I969) American Journal of Diseases of Children, ii8, 687. Gilmore, 0 J, et al (i975) Lancet, 6, 42I. DeDombal, T, et al (1972) British Medical Journal, 2, 5. Brooks, D WV, and Killen, D A (1965) Surgery, 57, 377. Gough, M H, and Gear, M W L (I972) British Journal of Hospital Medicine, 7, 453. Soteropoulos, C, and Gilmore, J H (1958) Radiology, 71, 246. Soter, C S (i973) Seminars in Roentgenography, IOI, 104.
io II I2
I3 I4
I5 i6
I7 I8
I9
20
Steinart, R, et al (i943) Acta radiologica, 24, I3. Lee, P (1976) British Journal of Surgery, 63, 763. Kennedy, D W (I974) Pulse, 2Ist September. Longino, L A et al (1958) Pediatrics, 22, 238. Rowe, L M (I966) Pediatrics, I38, 1057. Shepherd, J A (1972) British Medical Journal, 2, 347. Shepherd, J A (I960) Suirgery of the Acute Abdonmen. Edinburgh, Livingstone. Boyer, B M, and Carroll, C (I957) Radiology, 68, 648. Maingot, R (974) Abdominal Operations, vol. 2, 6th edn. New York, Appleton Century Crofts. Jenkiins, D, and Lee, P (1970) Journal of the Royal College of Surgeons of Edinburgh, I5, 34. Graham, A D, and Johnson, G H (I966) Military Medicine, 131, 272.
(I979) vol 6i
ASPECTS OF DIAGNOSIS*
The plain abdominal radiograph in acute appendicitis TJ A C Thorpe
FRCS
FRCSEd.
Surgical Registrar, St James's University Hospital, Leedst
Summary Although the radiological features of acute appendicitis have been well documented, the value of the plain abdominal radiograph has not been fully appreciated. This article summarises the role of radiology in acute appendicitis, especially in atypical cases and extremes of age, where there is often delay in diagnosis.
signs. A recent report" shows less than o0% diagnostic accuracy for residents, 70% for surgeons, and 85% for radiologists when assessing radiographs of the acute abdomen. Few residents, who manage the majority of cases of acute appendicitis, are aware of the radiological criteria; hence the attitude that the plain abdominal radiograph is of little use.
Radiological signs in acute appendicitis6 Introduction The diagnosis of a classical case of acute appendicitis rarely presents any difficulty if particular attention is given to the history, pain distribution, and the finding of local and rebound tenderness in the right iliac fossa. However, in acute appendicitis there is a high rate of misdiagnosis, particularly in children'-', immigrants, the elderly4, and those who present with unusual or unimpressive clinical features. Diagnostic error is due to many factors, including observer error5; it is twice as common in the female as in the male patient4 and is
i) Air-fluid levels localised to the caecum and/or terminal small bowel are indicative of localised inflammation in the right lower quadrant of the abdomen.
2) Localised adynamic ileus.
3) Increased soft-tissue density in the right lower quadrant, presenting as a more radioopaque area on the radiographs, can usually best be seen by comparing the relative clarity and relative film density of the sacoiliac joints.
greater than average in the first two decades 4) Alteration of the right flank stripe. and in the over 5so. In accident and emergency departments many radiographs are Appendicoliths, the calcified concretions taken for acute abdominal pain. These are in 5) the are typical in appearance and obviously relevant and helpful in patients with locationappendix, and usually present as homogeneous intestinal obstruction. However, little signifi- or somewhat laminated densities in the right cance is attached to this investigation in ap- lower quadrant. pendicitis although the associated radiological features have been well documented'10. 6) Alteration of the psoas outline and blurA personal prospective study of IOO patients ring of its distal third. admitted with a diagnosis of acute appendicitis from the accident and emergency department 7) Gas-filled appendix, a rare but valuable of the Leeds General Infirmary showed that sign. only 45 had histologically proven appendicitis, 8) Extraluminal gas or free gas in the periof whom 75 7o had two or more radiological toneal or retroperitoneal space. tPresent address: Papworth Hospital, Papworth Everard, Cambs. 9) Deformity of the caecum. *Fellows and Members interested in submitting articles:for consideration with a view to publication in this series should first write to the Editor.
46
*'!,~ ~ .y'm
J A C Thorpe
sign of tenderness in the right iliac fossa and the symptom of localised pain may lie outside the usual area in I 2o and 24% of cases res-
pectively'2. Although acute appendicitis may present in many ways, failure of diagnosis is also attributed to observer error but with the use of standardised questionnaires and computer~ ied diagnssit is hoped to eliminate this factor. However, these techniques are in their infancy and have made little clinical impact
FIG. I Plain radiograph showing typical features of acute appendicitis in a I5-year-old Indian child. Note reactive scoliosis and blurring of psoas margin and right sacroiliac joint. There are prominent gas shadows and local ileus in the right lower quadrant. An appendicolith is visible.
Discussion Acute appendicitis is the commonest disease of the gastrointestinal tract and accounts for the largest number of hospital admissions for bowel disorder. The diagnosis is usually straightforward and detailed investigations are seldom necessary. However, recent literature suggests that a high proportion of cases are misdiagnosed, particularly in children and the elderly'"'. Immigrants also present a diagnostic challenge when the history cannot be relied upon because of language difficulties. Obese individuals and those in whom the appendix is subhepatic or retrocaecal commonly show atypical features of acute appendicitis. In addition, the classical
as yet.
Ancillary investigations in the diagnosis of appendicitis are limited to haematological tests, urine analysis, and, less frequently,
acute
radiological examination. A raised leucocyte neutrophilia is indicative of a septic focus, but this examination is of little value in infancy and childhood",",' Uriie
count with relative
3
FIG. 2 Plain radiograph (detail) showing features of acute appendicitis in a I2-year-old girl with atypical clinical signs. Film shows local ileus and blurring of the sacroiliac joint. In addition there is increased density of the properitoneal fat line.
I
The plain abdominal raliograph in acute appendicitis analysis is essential in the diagnosis of renal disease and should be performed routinely in cases of acute abdomen15. However, microscopic haematuria is commonly found in acute appendicitis. Radiology in acute appendicitis has attracted little surgical attention, though most authors suggest that the plain radiograph can aid and improve accuracy and speed of diagnosis1617'9. Since Weisflog in 1902 first noted an appendicolith in association with acute appendicitis many comprehensive studies of the radiological features in acute appendicitis have been carried out. Soter9, in a review of 4500 cases over a period of 23 years, concluded that 90-io00o had radiological evidence of disease; however, this high diagnostic rate was achieved by using the more elaborate radiological procedures. Steinart et al° showed in a classic paper that in 8o out of I04 cases an abnormal finding could be demonstrated in the radiograph. Most authors confirm the presence of an appendicolith as 8o-i100oo indicative of acute, often perforated, appendicitis18'8. In infants a perforated appendix greatly increases morbidity and mortality, radiology in this instance being of considerable use in diagnosis, thereby speeding subsequent management". Radiology is also of use in the differential diagnosis of renal stone, Crohn's disease, ileocaecal tuberculosis, intussusception, and malrotation of the gut'. Maingot"8 suggests that all patients suspected of acute appendicitis should have erect and supine abdominal and chest radiographs on presentation, as indeed should all patients presenting with an acute abdomen. It is of interest that 4 out of 5 patients with false-positive radiographs for acute appendicitis have other conditions9'20-for example, ruptured ovarian cyst, leaking carcinoma of the caecum, or a low-lying inflamed gallbladder. This emphasises that radiology reflects all diseases affecting the right lower quadrant, the commonest being acute appendicitis.
47
I would like to express my sincere thanks to Mr D Wilson, Consultanit Surgeon, Accident and Emergency Department, Leeds General Inifirmary, for his help and advice and the Department of Radiology for the use of their services.
References I
2 3
4 5 6
7 8
9
Caffey, J P (i973) Paediatric X-ray Diagnzosis, 6th edn, Chicago, Year Book Medical Publishers. Dennison, W M (1974) Surgery in Infancy and Childhood, 3rd edn. Edinburgh and London, Churchill Livingstone. Wilkinson, R H, et al (I969) American Journal of Diseases of Children, ii8, 687. Gilmore, 0 J, et al (i975) Lancet, 6, 42I. DeDombal, T, et al (1972) British Medical Journal, 2, 5. Brooks, D WV, and Killen, D A (1965) Surgery, 57, 377. Gough, M H, and Gear, M W L (I972) British Journal of Hospital Medicine, 7, 453. Soteropoulos, C, and Gilmore, J H (1958) Radiology, 71, 246. Soter, C S (i973) Seminars in Roentgenography, IOI, 104.
io II I2
I3 I4
I5 i6
I7 I8
I9
20
Steinart, R, et al (i943) Acta radiologica, 24, I3. Lee, P (1976) British Journal of Surgery, 63, 763. Kennedy, D W (I974) Pulse, 2Ist September. Longino, L A et al (1958) Pediatrics, 22, 238. Rowe, L M (I966) Pediatrics, I38, 1057. Shepherd, J A (1972) British Medical Journal, 2, 347. Shepherd, J A (I960) Suirgery of the Acute Abdonmen. Edinburgh, Livingstone. Boyer, B M, and Carroll, C (I957) Radiology, 68, 648. Maingot, R (974) Abdominal Operations, vol. 2, 6th edn. New York, Appleton Century Crofts. Jenkiins, D, and Lee, P (1970) Journal of the Royal College of Surgeons of Edinburgh, I5, 34. Graham, A D, and Johnson, G H (I966) Military Medicine, 131, 272.
