 |
||
| G. Gastrointestinal System | |||||||
|
CLINICAL/DIAGNOSTIC PROBLEM |
INVESTIGATION |
RECOMMENDATION (GRADE) |
COMMENT |
DOSE |
|||
| Gastrointestinal tract | |||||||
| Difficulty in swallowing: high dysphagia (lesion may be high or low) | Video-fluoroscopy and Ba swallow | Indicated (B) | Video
recording of swallow is essential, Webs and pouches are well
demonstrated. Motility disorders, which must be looked for in
prone or supine position, may be seen despite normal endoscopy.
Subtle strictures, not seen at endoscopy, best demonstrated by
marshmallow or other bolus study. Multi-disciplinary approach with
speech therapist and ENT surgeon is optimal. |
III | |||
| Difficulty in swallowing: low dysphagia (lesion will be low) | Ba swallow | Indicated only in specific circumstances (B) | Endoscopy
is required (biopsy of strictures essential). Ba swallow used to
demonstrate motility disorder or subtle stricture, if endoscopy normal. |
II | |||
| NM | Indicated only in specific circumstances (B) | Radionuclide oesophageal transit study is indicated as an alternative non-invasive assessment of oesophageal motility. | II | ||||
| Heart burn/chest pain: hiatus hernia or reflux | Ba swallow/meal | Indicated only in specific circumstances (B) | Reflux
is common and investigation is only indicated where lifestyle changes
and empirical therapy fail. While pH monitoring is the gold
standard for reflux, endoscopy alone will reliably show early changes of
reflux oesophagitis and allows detection and biopsy of metaplasia.
Ba studies aimed at assessing oesophageal motility prior to anti-reflux
surgery do not reliably predict post-operative dysphagia. |
II | |||
| Oesophageal perforation | CXR | Indicated (B) | Will be abnormal in 80% of cases, but pneumomediastinum is present in only 60%. | I | |||
| Contrast swallow | Indicated
(B)
|
Non-ionic
iodinated contrast is the only safe agent. It is sensitive, but if
no leak is seen then proceed to immediate CT. |
II | ||||
| CT | Indicated (A) | CT is sensitive both for the presence of perforation and for the detection of mediastinal and pleural complications. | III | ||||
| Acute GI bleeding: haematemesis/melena | Endoscopy | Indicated (A) | Endoscopy provides diagnosis in the majority of cases of upper GI bleeding and can be used to deliver haemostatic therapy | 0 | |||
| AXR | Not indicated (B) | Of no value | I | ||||
| Abdominal US | Indicated only in specific circumstances (B) | Only useful to look for signs of chronic liver disease. | 0 | ||||
| Ba studies | Not indicated (B) | Precludes angiography. | II | ||||
| NM | Specialised investigation (B) | After endoscopy. Red cell labelling can detect bleeding rates as low as 0.1 ml/minute; more sensitive than angiography. Red cell study is most useful in intermittent bleeding. | II | ||||
| Angiography | Specialised investigation (B) | In uncontrollable bleeding. Angiography can accurately direct surgery and transcatheter embolisation may be used as the primary treatment. | III | ||||
| Dyspepsia in the younger patient (e.g. <45 years) | Ba studies | Indicated only in specific circumstances (B) | Most patients <45 years can be treated without investigations and will undergo a trail of therapy (anti-ulcer or reflux). If symptoms recur of persist, the Helicobacter pylori status should be assessed serologically or by using the C-14 urea breath test. If positive or patient has alarm symptoms (weight loss, anorexia, iron deficiency anaemia, severe pain or non-steroid anti-inflammatory drug use), endoscopy is the investigation of choice. | II | |||
| Dyspepsia in the older patient (e.g.> 45 years) | Ba studies | Indicated only in specific circumstances (B) | Endoscopy is the investigation of choice. The main concern is the early detection of cancer. If endoscopy is negative and symptoms persist, then Ba meal should be considered. | II | |||
| Ulcer: follow up | Ba studies | Not indicated (B) | Scarring precludes accurate assessment. Endoscopy is preferred to confirm complete healing and to obtain biopsies where necessary. | II | |||
| NM | Indicated only in specific circumstances (B) | Most centres use C-14 urea breath test to assess effect of treatment for Helicobacter pylori. | I-II | ||||
| Previous upper GI surgery (recent) to check for anastomotic leaks. | Contrast swallow/meal | Indicated (B) | If water-soluble contrast swallow does not demonstrate a leak in the anastomotic site and there is a clinical concern, then immediate CT should be performed as it is more sensitive. Ba should not be used as the contrast agent. | II | |||
| Previous upper GI surgery (not recent): dyspeptic symptoms | Ba studies | Indicated only in specific circumstances (B) | Gastric remnant best assessed by endoscopy (gastritis, ulceration, dysplasia, recurrent tumour, etc.) | II | |||
| Previous upper GI surgery (not recent): dysmotility/obstructive symptoms | Ba studies | Indicated (B) | Shows surgical anatomy and may demonstrate dilated afferent loop, narrowed anastomoses, internal hernias, closed loops, etc | II | |||
| NM | Specialised investigation (B) | Good method for assessment of gastric emptying, dumping, and stasis. | II | ||||
| Intestinal blood loss: chronic or recurrent | Ba studies | Not indicated initially (B) | The initial investigation is endoscopy of the upper GI tract and colon. Small bowel follow-through is not sufficiently sensitive for lesions likely to cause chronic bleeding and should not be used. | II | |||
| Small bowel enema | Indicated (B) | More sensitive than Ba follow-through for small discrete lesions. However, early results or 'capsule' endoscopy in chronic bleeding suggest that this will be the investigation of choice when small bowel strictures have been excluded | II | ||||
| NM | Indicated (B) | When all other investigations are negative, labelled red cell and/or Meckel's study may be useful in detecting and localising the site of chronic and/or recurrent bleeding. | II | ||||
| CT | Indicated (B) | IV contrast-enhanced CT is a useful technique to look for lesions that may be bleeding (e.g. tumours). CTA may demonstrate bowel angiodysplasia. | III | ||||
| Angiography | Specialised investigation (B) | Angiography is sensitive for angiodysplasia (with early filling vein) and to demonstrate tumour neovascularity. | III | ||||
| Acute
abdominal pain: perforation/obstruction
(For children see section M) |
AXR and CXR erect | Indicated (B) | Supine AXR may be sufficient to establish diagnosis of obstruction and point to an anatomical level. Consider erect AXR if supine AXR normal and strong clinical suspicion of obstruction. Lateral decubitus AXR indicated to show free gas if CXR has to be supine. | I + I | |||
| US | Indicated (C) | Widely used as a survey following AXR. It is sensitive for free fluid in perforation. | 0 | ||||
| CT | Indicated (B) | For
small sealed perforations and for establishing site and cause of
obstruction.
This recommendation does not apply to children. |
III | ||||
| Small bowel obstruction: acute | Contrast studies | Indicated only in specific circumstances (B) | Frequently unhelpful | II | |||
| CT | Indicated (B) | When AXR suggests small bowel obstruction, CT confirms diagnosis, indicates level, and may show cause. When AXR equivocal but small bowel obstruction suspected clinically, volume challenge (i.e. CT with water or methylcellulose ingestion) may be required for complete assessment. | III
|
||||
| Small bowel obstruction: chronic or recurrent | Ba small bowel enema | Indicated (B) | Will reveal presence and level of obstruction in most cases and may suggest a cause. | II | |||
| CT | Indicated (B) | Performed with or without volume challenge. CT will be diagnostic as for small bowel enema, but may be a better guide to management in complex cases, e.g. in patients with a previous malignancy or following complicated abdominal surgery | III | ||||
| Suspected small bowel disease (Crohn's disease) | Ba small bowel meal | Indicated (B) | A useful survey examination for the diagnosis of small bowel disease, including Crohn's disease. | II | |||
| Ba small bowel enema | Indicated (B) | This is the investigation of choice to establish extent of disease prior to surgery, in cases where fistula is suspected, and to diagnose the cause of obstructive symptoms in patients with known Crohn's disease. | II | ||||
| US/CT/MRI | Specialised investigation (B) | Use of these techniques is evolving, e.g. in assessment of disease activity, and they are particularly useful to assess extramural complications. | 0/III/0 | ||||
| NM | Specialised investigation (B) | Labelled white cell scintigraphy reveals activity and extent of disease and is complementary to Ba studies | III | ||||
| Change of bowel habit to diarrhoea and rectal bleeding in the absence of perianal symptoms: colorectal neoplasia | Ba enema | Indicated (B) | Colonoscopy is often the first-line investigation. Ba enema is an alternative to colonoscopy and is widely used as the first-line investigation of change of bowel habit in the absence of rectal bleeding. Ba enema is insufficient with rectal bleeding, but flexible sigmoidoscopy followed by immediate Ba enema is a good alternative to colonoscopy. Defer Ba enema for seven days after full thickness biopsy via rigid sigmoidoscope. No delay is needed for superficial biopsies taken via flexible sigmoidoscopy. | III | |||
| CT | Specialised investigation (B) | CT has an established and developing role in the demonstration and exclusion of colorectal neoplasia. Its use can range from a minimally invasive approach with no oral contrast and no bowel preparation to full CT colonography. The minimally invasive approach is preferable to Ba enema in frail elderly patients. Accuracy is increased by oral contrast over 24 hours with no purgation. Alternatively, a water enema is helpful. CT colonography with full bowel preparation and air enema is more accurate than Ba enema and closely approaches the accuracy of colonoscopy. It is already the technique of choice for the proximal colon when colonoscopy has been incomplete. | III | ||||
| Large bowel obstruction: acute | AXR | Indicated (B) | May suggest diagnosis and indicate likely level | I-II | |||
| Contrast enema | Indicated
(B)
|
Water-soluble or air-contrast enema can confirm diagnosis and level of obstruction and may indicate likely cause. In some cases interpretation is difficult and if no abnormality is seen it is important to understand that although this may indicate pseudo-obstruction, a significant obstructing lesion may have been missed. | III | ||||
| CT | Special investigation (B) | The value of CT, particularly in sick and very frail patients, is becoming established. It is likely that it will prove a more accurate and less uncomfortable alternative to water soluble enema. | III | ||||
| Inflammatory bowel disease of the colon: acute exacerbation | AXR | Indicated (B) | Often sufficient to determine disease severity and extent | I-II | |||
| Ba enema | Indicated
(B)
|
Unprepared 'instant' enema complements AXR and confirms extent of disease. It is contraindicated in toxic megacolon. | III | ||||
| NM | Indicated
(B)
|
Labelled white cell study will reveal activity and extent of disease | III | ||||
| MRI | Specialised investigation (B) | MRI is extremely valuable in guiding surgical management of patients with anorectal sepsis | 0 | ||||
| Inflammatory bowel disease of colon: long-term follow-up | Ba enema | Indicated only in specific circumstances | Ba enema has a limited role after complex surgery and in the evaluation of fistulae. Colonoscopy is the most reliable investigation to identify complications including dysplasia, stricture, and carcinoma. | III | |||
| General abdominal problems | |||||||
| Acute abdominal pain warranting hospital admission for consideration of surgery | AXR and CXR erect/US | Indicated
(B)
|
Local policy will determine strategy. Supine AXR 9for gas pattern, etc.) is usually sufficient; erect AXR is indicated only in specific circumstances. Erect CXR is used for exclusion of perforation. US is widely used as a preliminary survey | I-II/0 | |||
| CT | Indicated (B) | CT is increasingly used | III | ||||
| Palpable mass | AXR | Indicated only in specific circumstances (C) | Rarely of value | I-II | |||
| US | Indicated
(B)
|
Often solves the problem | 0 | ||||
| CT | Indicated
(B)
|
Where US is inconclusive and to provide more complete assessment of disease extent prior to definitive treatment | III | ||||
| Malabsorption | Ba small bowel meal | Indicated only in specific circumstances (B) | Imaging is not required for the diagnosis of coeliac disease but may be indicated for other causes of small bowel malabsorption or when biopsy is normal/equivocal. | II | |||
| NM | Specialised investigation (B) | Numerous NM investigations are available, which should establish presence of malabsorption. Some of there are non-radiological (e.g. breath test). | II | ||||
| Constipation
(For children see section M) |
AXR | Indicated only in specific circumstances (B) | May be useful in geriatric and psychiatric specialties to show extent of fecal impaction | II | |||
| Intestinal transit studies | Specialised investigation (B) | A simple investigation using radio-opaque shapes can confirm normal intestinal transit. | I-II | ||||
| NM | Specialised investigation (B) | In-111 colonic transit study enables a more detailed study of colonic delay than radio-labelled pellets. Important before colectomy is undertaken | III | ||||
| Evacuation proctography | Specialised investigation (B) | In some patients constipation is secondary to a disorder of evacuation, which can be demonstrated and characterised by this investigation. | II | ||||
| Abdominal sepsis; pyrexia of unknown origin | US | Indicated (C) | Seek early radiological advice. US is often used first and may be definitive, particularly when there are localising signs; it is especially good for subphrenic/subhepatic spaces and pelvis | 0 | |||
| CT | Indicated (C) | CT is probably best test overall. Infection and tumour are usually identified or excluded. It also allows biopsy of nodes or tumour and drainage of collections (especially recent post-operative when US is difficult) | III | ||||
| NM | Indicated (C) | NM is particularly good when there are no localising features. Labelled white blood cell (WBC) study is good for chronic post-operative sepsis; Ga will accumulate at sites of tumour (e.g. lymphoma) and infection. | III | ||||
| Liver, gallbladder and pancreas | |||||||
| Hepatic metastases | US | Indicated (B) | Will
often be the initial investigation. US is reliable for lesions
>2 cm in diameter, but for smaller lesions the sensitivity is
reduced. Developments in therapy for hepatic metastases,
particularly in colorectal cancer, dictate the use of more sensitive
tests. US, however, will often be used as the first-line exclusion
of hepatic metastases. |
0 | |||
| CT | Indicated (B) | CT
is significantly more sensitive than US for detection of liver
metastases, particularly smaller lesions. It is essential for
accurate staging of patients with metastases being considered for liver
resection. |
III | ||||
| MRI | Specialised investigation (B) | With
liver-specific contrast agents MRI is even more sensitive than CT in
detecting metastases, but it is also useful in accurate characterisation
of small lesions. It is widely used in the pre-operative
assessment of candidates for liver resection. |
0 | ||||
| Solitary hepatic lesion on US, haemangioma, metastases , other | CT/MRI | Specialised investigation (B) | Both
techniques reliably show characteristic features of haemangioma and many
other solitary hepatic lesions. |
III/0 | |||
| Known cirrhosis, complications | US | Indicated (B) | Very sensitive for ascites. US may show varices, particularly in the splenic hilum in portal hypertension. It is the initial screening test for hepatoma. | 0 | |||
| CT | Specialised investigation (B) | Particularly
when US is equivocal in the presence of raised alpha feto-protein and in
the staging of hepatoma. |
III | ||||
| MRI | Specialised investigation (B) | With
liver-specific contrast agents MRI is at least as sensitive as CT for
hepatoma. |
0 | ||||
| Jaundice | US | Indicated (B) | US reliably differentiates between obstructive and non-obstructive jaundice, but bile duct dilatation may be subtle in early obstruction. When US indicates obstructive jaundice, subsequent investigation will depend on the level of obstruction, presence or absence of stones in the gall bladder and ducts, as well as the clinical situation. Early discussion with radiologist is required. | 0 | |||
| ERCP | Specialised investigation (B) | If
US shows duct stones, proceed to ERCP for confirmation and therapy.
ERCP remains the gold standard for intrahepatic duct changes in
sclerosing cholangitis. |
II | ||||
| CT | Specialised investigation (B) | Frequently
the next investigation for US-proven obstructive jaundice, particularly
if US level of obstruction is below the hilum. For pancreatic
cancer CT reliably predicts unresectability. In malignant
hilar-level obstruction, CT may provide staging information critical to
the planning of surgery or palliative therapy. |
III | ||||
| MRI, including MRCP | Specialised investigation (B) | In
hilar-level obstruction, MRCP (magnetic resonance
cholangiopancreatography) is now the investigation of choice following
US. MRCP reliably and non-invasively depicts the pattern and extent of
duct involvement, thus facilitating planning of curative surgery or
interventional treatment.
In malignant hilar-level obstruction, MRI may provide staging information critical to the planning of surgery or palliative treatment. If US shows gallstones, but no definite duct stones, then MRCP is indicated prior to ERCP |
0 | ||||
| Endoscopic US | Specialised investigation (B) | Is the most accurate method for detection of small duct stones and small papillary or peri-ampullary tumours. It allows biopsy of pancreas without risk of tumour seeding | 0 | ||||
| Biliary disease (e.g. gallstones, post-cholecystectomy pain) | AXR | Not indicated (C) | Only shows about 10% of gallstones | I-II | |||
| US | Indicated (B) | Is the investigation of choice for the demonstration or exclusion of gallstones and acute cholecystitis. It is the initial investigation of biliary pain but cannot reliably exclude common duct stones. Cholecystography is virtually never used. | 0 | ||||
| CT | Specialised investigation (B) | Has a limited role in cholelithiasis but is useful in the evaluation of gallbladder wall and gallbladder masses. | III | ||||
| MRCP | Specialised investigation (B) | Indicated in stone disease where the symptoms, signs, and/or liver function tests suggest the possibility of duct calculi not confirmed by US, and in the investigation of post-cholecystectomy pain. | 0 | ||||
| NM | Specialised investigation (B) | Biliary scintigraphy shows cystic duct obstruction in acute cholecystitis. | II | ||||
| Post-operative biliary leak | US | Indicated (B) | First investigation of suspected leak. US ill show the size and anatomical position of collections | 0 | |||
| ERCP | Indicated (B) | Definitive investigation to detect and demonstrate the site of the leakage and for treatment by stent placement. | II | ||||
| NM | Specialised investigation (B) | HIDA scan will show activity at site of leak. | II | ||||
| Pancreatitis: acute | AXR | Indicated (C) | Presents as non-specific acute abdominal pain. AXR is needed to exclude other causes. | I-II | |||
| US | Indicated (B) | Must be performed early to identify patients with gallstones, indicating a diagnosis of gallstone pancreatitis, in which case early ERCP may be considered. | 0 | ||||
| CT | Indicated (B) | CT with IV contrast enhancement is used early in severe cases to assess extent of necrosis, which is helpful in prognosis. In follow-up, it is used to detect and monitor complications, and for this purpose it is superior to US. US is used to monitor more chronic pseudocysts, to avoid high radiation dose of CT. | III | ||||
| Pancreatitis: chronic | AXR | Indicated (B) | To show calcification (calcified duct stones) but is of limited value in exclusion. | I | |||
| US/CT | Indicated (B) | US may be definitive, particularly in thin patients. CT is highly sensitive for pancreatic calcification but poorly sensitive for early parenchymal changes. | 0/III | ||||
| ERCP/MRCP | Specialised investigation (B) | ERCP shows duct morphology. MRCP (particularly with secretin) shows moderate and severe ductal changes and may indicate exocrine function. MRCP does not reliably show minor side branch changes in mild pancreatitis. | II/0 | ||||
| Pancreatic tumour | US | Indicated (B) | US is good at detecting the primary lesion in thin patients, particularly for lesions in the head and body, but is insufficient where precise staging is required. | 0 | |||
| CT | Indicated (B) | CT is of value in diagnosis, when US is inconclusive, and in staging, where IV contrast-enhanced spiral CT reliably predicts unresectability. | III | ||||
| Endoscopic US | Specialised investigation (B) | May provide detailed staging information in candidates for surgical resection after CT and allows image-guided biopsy of pancreatic masses | 0 | ||||
| ERCP | Specialised investigation (B) | Demonstrates anatomy of strictures and facilitates tissue diagnosis and interventions, e.g. stent placement in selected cases. | II | ||||
| Insulinoma | Endoscopic US | Specialised investigation (B) | Accurate localisation of tumours is essential if surgery is to be curative. Invasive preoperative vascular techniques (i.e. arterial stimulation with venous sampling) combined with intra-operative US and operative palpation represent the gold standard for localisation and surgical planning. Endoscopic US appears promising and may offer a less invasive alternative to angiography in the future. US, CT, MRI and NM are non-invasive but often fail to demonstrate insulinoma(s) responsible for clinical hyperinsulinaemia. These studies are probably of greatest value in the diagnosis of metastatic disease. | 0 | |||
| Back to contents | |||||||
|
||
 |
|