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PART
7
PRINCIPLES OF
IMAGING IN
CHILDHOOD
7.1
Diagnostic imaging in infancy
and childhood
R. Teele
Paediatric radiology became a subspecialty of radiology and of paediatrics because of two men: John Caffey,
paediatrician, and Edward B. D. Neuhauser, radiologist. A quirk of fate resulted in this ‘infant’ subspecialty,
born in the 1940s, being affiliated with radiology rather than with paediatrics – and the fact that ionizing
radiation as a means of imaging was the province of radiology. Paediatric radiology has developed dramatically
in the interim. Now, the tools of the radiologist include plain radiography, fluoroscopy (screening), intravenous,
intracavitary and gastrointestinal contrast media, angiography, nuclear medicine, ultrasonography, computed
tomography (CT) and magnetic resonance imaging (MRI).
There are many differences between imaging the child and imaging the adult. Most importantly, the diseases
are different. Congenital disease as well as acquired disease must be considered in the differential list. Usually a
child has a single diagnosis to explain symptoms. History taking and clinical examination is not easy for infants
and children and thus information from imaging is crucial in certain situations. Radiation protection is important
both for the child and for the society as a whole. The child’s physical and psychological welfare during
diagnostic imaging must also be considered.
Imagine yourself as a 4-month-old infant, starving hungry, being held down on a cold, hard table by strangers.
A rubber nipple is being pushed into your mouth and it is full of strawberry-flavoured chalk fluid that you are
supposed to swallow while a machine makes horrible noises over your head. Now imagine yourself as a 2-year-
old (on the same hard, cold table), being held down and catheterized. Soon, your bladder feels like it will burst
and you have to micturate all over the table (in the presence of your mother who has just started to toilet train
you!).
The upper gastrointestinal series and micturating cystourethrogram are touted as both anatomical and
physiological studies but, if you reread the paragraph above, you can understand why they may be lacking in
their representation of normal human physiology.
Paediatric radiologists play an important intermediary role between paediatrics and radiology, both in the
conduct and the interpretation of an examination. They are the clinician’s friend and the patient’s advocate.
Imaging has to be problem-oriented. The most important information on a requisition form, apart from the
child’s name and age, is the question to be answered. The next most important items are the legible name and
contact number of the person asking the question. In this age of computerization, the telephone remains an
invaluable instrument of technology because it allows one person to talk to another person. The paediatric
radiologist should do the least possible investigation to achieve the most possible information about a child’s
condition.
In concluding this introductory section, it is important to recognize that there is little evidence-based
information to support many of the recommendations that are in print regarding appropriate algorithms for
paediatric imaging. There are few clinical situations and ethical guidelines that allow the performance of several
studies on a child simply to compare their utility. Clinical information is frequently imperfect; ‘comparable’
studies are rarely comparable (for example, consider the problems in defining infection of the urinary tract).
Furthermore, local traditions, biased by the practitioners of the area, available facilities and economic conditions,
usually prevail over expert opinions and recommendations in textbooks. If you have any question about the
appropriate imaging for your patient, ask a radiologist who is experienced in paediatric diagnosis for help. With
these caveats, and encouragement to you, the reader, to challenge algorithms when they seem less than sensible,
the following sections outline appropriate imaging considerations for particular situations, and are arranged
anatomically, for easy reference.
Practical points
• Find out if there are clinical guidelines for your department/institution. They may include guidelines for imaging
• Generally, in a complicated case, it is best to begin with uncomplicated imaging, such as plain radiographs. They may provide the
diagnosis; if not, they can help point the way to other studies
• Provide relevant clinical information to the radiologist when requesting examinations
• Consult a paediatric radiologist, or one experienced in paediatric diagnosis, when you have questions about the imaging of a specific
clinical problem
• Be familiar with the preparation, immediate complications and sequelae of invasive imaging procedures
Neurology
Newborn
• Portable ultrasonography when screening for germinal matrix/intraventricular and intraparenchymal
haemorrhage in the premature infant
• CT for: suspected extra-axial collections (bleeding, infection)
• MRI for: suspected non-haemorrhagic parenchymal disease, e.g. hypoxic–ischaemic insult, neuronal
migrational disorders.
Notes
Follow local protocols for timing/frequency of ultrasonographic screening for premature infants. Generally, a
scan is performed at 3–4 days of age in those infants who weigh less than 1500 g unless there is clinical concern
that prompts an earlier study.
Acute trauma, all ages
See Chapter 3.6.
• Include lateral cervical spine film, in collar to include the C7–T1 disc space, when injury to the neck is
suspected
• CT scanning of brain when neurological signs/symptoms present
• MRI when CT scanning is negative in an infant/child with persisting abnormal neurological signs
Notes
Radiographs of the skull are poorly predictive of intracranial pathology. They are of use in the situation of
suspected inflicted injury (non-accidental injury) where multiple fractures or fractures of different ages are
helpful in establishing the diagnosis.
A normal lateral neck film, in collar, can be followed by anteroposterior (AP) view of the cervical spine and
odontoid view. Remember that the thyroid gland is in the field of view. CT scanning of the cervical spine, often
routinely acquired in adults, gives up to 15 times the radiation of plain films and is only used when there is
credible utility.
Seizures
See Chapter 17.1.
CT scanning:
• without intravenous contrast media, then
• with intravenous contrast media or MRI and/or angiography if vascular etiology likely.
Altered neurological state
CT scanning:
• without intravenous contrast media, then
• with intravenous contrast media or MRI and/or angiography if vascular etiology likely (Fig. 7.1.1).
Notes
Simple febrile seizures (single or recurrent) do not usually warrant imaging.
Imaging following a single generalized afebrile seizure in children is an area of controversy. Focal afebrile
seizures will usually be investigated by electroencephalography (EEG) and cerebral imaging. Because of the
variable availability of MRI, local protocols should be consulted for neurologic diagnostic work-up.
Cardiology
See Chapter 15.1.
Suspected congenital heart disease
(e.g. abnormal prenatal ultrasonogram, cyanosis, murmur, unexplained oxygen requirement)
• Posteroanterior (PA) and lateral chest film to include upper abdomen
• Cardiology referral/echocardiography
• CT or MRI for anatomical detail of vascular rings as necessary
Cardiac angiography/interventional procedures are arranged by paediatric cardiologists in most centres.
Central/cardiac pain
• PA and lateral chest film to include upper abdomen
• Cardiology referral/echocardiography
Notes
Plain films of the chest can be remarkably uninformative in some infants with complex congenital heart disease;
echocardiography is the gold standard. There can be clues to the presence of congenital heart disease on plain
films (Fig. 7.1.2). Check the six Ss: cardiac size, cardiac shape, side of aortic arch, status of pulmonary
vasculature, abdominal situs and skeletal anomaly. Barium swallow is a very useful ancillary study for
characterizing a suspected vascular ring if CT and MRI are unavailable. In most centres, echocardiography is the
province of the cardiologist. Most echocardiographic examinations are time-consuming; some centres use
sedation for transthoracic scanning. Transoesophageal echocardiography gives excellent detail of the heart and
great vessels but the child needs sedation for the procedure.
Pulmonary/airway
See Chapter 14.5.
Cough and fever
• PA and lateral chest film
Pleuritic pain
• PA and lateral chest film
Suspected sepsis in a neonate
• PA and lateral chest film
First episode of wheezing
See Chapter 14.3.
• PA and lateral chest film
• Fluoroscopy/screening if foreign body is suspected
Imaging is usually only indicated if the history is suggestive of inhaled or ingested foreign body, the child has no
coryzal illness or the child doesn’t get better as expected for bronchiolitis/asthma.
Unexplained stridor
See Chapter 14.2.
• PA and lateral chest film
• Lateral film of the neck
• Fluoroscopy/screening/barium swallow
Trauma to the chest
• AP supine chest film
• Computed tomographic angiography (CTA) with intravenous contrast if mediastinal injury suspected
• Angiography for rare situation of aortic injury
Thoracic mass
• PA and lateral films
• CT or MRI or, occasionally, both, depending on the organ(s) of origin and involvement
• Echocardiography for mass related to the heart
Notes
There is great debate as to whether a previously well child who has clinical symptoms and signs of pneumonia
requires radiography at all. Likewise, there is argument as to whether the workup of sepsis in an infant, and the
first episode of wheezing (without history of aspiration of foreign body), requires imaging. Remember that
normal radiographs and fluoroscopy do not rule out the presence of an endobronchial foreign body. There has to
be enough obstruction of an airway to provide radiographic evidence of its presence. Bronchoscopy should
follow if there is a good history of aspiration, even if films are normal.
Some centres perform only PA films and no lateral for indications such as suspected pneumonia. There is no
good prospective study that compares the utility of the PA only radiograph with PA and lateral views of the
chest. There is anecdotal evidence that supports the acquisition of both views. In many cases, lower lobe
pneumonia is difficult to diagnose from the PA view alone. The cardiac size is easier to judge when the shape of
the chest is defined by two views. When both films are normal, the radiologist can state with certainty that the
chest is normal to radiographic examination. It is just as important to document normality in some situations as to
find an abnormality.
There is general consensus that follow-up radiography for an uncomplicated pneumonia is unnecessary.
Follow-up films are reserved for children who have persisting symptoms of chest disease or who have had
unusual radiographs on presentation.
Stridulous breathing implies narrowing of the trachea. A vascular ring, endotracheal haemangioma, tracheitis
or epiglottitis are all possible causes. Imaging is not needed in children with classic croup and can be dangerous
in children who are suspected of having epiglottitis from Haemophilus influenzae. No child or infant with
respiratory compromise should be sent for imaging without adequate safeguards for provision of an airway.
A chest mass is usually diagnosed on a PA and lateral film after a child presents with pain, cough, respiratory
compromise, etc. It may also be an incidental finding on a film. For example, a posterior mediastinal mass may
be clinically silent. The diagnostic approach is tailored to the clinical situation. An anterior mediastinal mass in
the setting of T cell leukaemia needs no further imaging. A posterior mass with vertebral involvement will
require MRI if available and CT for assessing the possibility of lung metastases.
Abdomen/gastroenterology
Abdominal pain
See Chapter 20.1.
• Supine and upright or decubitus plain radiography for acute abdominal pain
• No imaging, or ultrasonography only, for non-specific, periumbilical abdominal pain
Constipation
• Plain radiograph of the abdomen
• Plain radiograph then contrast enema for the neonate who fails to pass meconium
Notes
Constipation/encopresis is a clinical diagnosis but there is often a plain film obtained at the initial evaluation of a
child who has constipation. The radiograph is used for assessment of the degree of distension of bowel and for
examining the lumbosacral spine for occult dysraphism. Ultrasonography is often used as a means of reassuring
parents, child and clinician that there is no anatomical abnormality of the liver, spleen, pancreas and kidneys.
Limiting radiographs to patients who have had prior abdominal surgery, suspected ingestion of foreign body,
abnormal bowel sounds, abdominal distension or peritoneal signs identifies virtually all patients with significant
disease.
Constipation/encopresis is a clinical diagnosis but there is often a plain film obtained at the initial evaluation
of a child who has constipation for assessment of the degree of distension of bowel and the lumbosacral spine for
occult dysraphism. Rarely do plain films reveal a specific cause for chronic constipation and some question their
value in this setting. Hirschsprung disease is usually diagnosed in infancy; some patients present late and are
diagnosed by contrast enema and/or suction rectal biopsy.
Evaluation of transit time through the gastrointestinal tract can be performed with sequential films following
ingestion of special radio-opaque markers. This study is usually at the request of a specialist paediatric
gastroenterologist or surgeon.
The evaluation of a child suspected of having appendicitis (Fig. 7.1.4) is heavily reliant on the clinical practice
guidelines established at the point of care. For example, in one major centre in São Paulo, Brazil, the
investigations are limited to clinical assessment then ultrasonography if the diagnosis is questionable. In many
parts of the USA, CT is virtually the norm. Many institutions rely on an approach that limits CT scanning to
those with negative ultrasonography or those suspected of rupture/abscess. Ultrasonography requires competent
practitioners and good equipment, and is far easier in children who are not obese. CT scanning requires injection
of contrast media, irradiation and good interpretation of the resultant images.
Abdominal mass
•
•
•
•
Plain radiograph of abdomen except for adolescent female with pelvic mass
Ultrasonography
CT if necessary
MRI for neurogenic tumour, soft tissue tumour, bony involvement by tumour, choledochal cyst or an unusual
mass
Notes
Plain radiography provides a road map; it also provides information regarding the bases of the lungs, presence of
calcification, effects of the mass on contiguous organs and/or gastrointestinal tract. Most abdominal masses in
childhood are related to the retroperitoneum and, in particular, the kidney. Examples are obstructive
hydronephrosis or multicystic dysplastic kidney. A mass that is gastrointestinal in origin, e.g. intussusception,
requires a different approach from a mass that is hepatobiliary, such as a choledochal cyst. The plain radiograph
and ultrasonography provide a means for triage to further imaging. When intussusception is diagnosed, air enema
for reduction is the first therapeutic method of choice. Remember to consider pregnancy in an adolescent female
who has a pelvic mass! If a malignant tumour is diagnosed, the affected child may be enrolled in treatment
protocols that have very specific requirements in terms of imaging at staging and follow-up.
Abdominal trauma
• Supine radiograph, with decubitus if possible, and lateral view of lumbar spine if there has been hyperflexion
of the spine, such as with a lapbelt injury
• CT with intravenous contrast
Notes
Many trauma protocols for evaluating the severely injured child have been based on the approach to adults, who
have different mechanisms and types of abdominal injury. For example, a screening pelvic film is part of the
‘adult’ trauma series. Its use in children has not been proved to be helpful. If any screening view is considered, it
should be an abdominal film, which will include the pelvis. Peritoneal lavage is not a helpful diagnostic test in
paediatric trauma. Major organ injury can occur without there being free intra-abdominal fluid. Ultrasonography
is not as sensitive a method of diagnosis as CT but in some remote areas may be the only tool available to search
for free fluid, intraparenchymal laceration/haematoma and renal perfusion.
A child should be stabilized before being moved to a CT scanner. Cervical spine and head injury should be
considered. Oral contrast medium is not usually used for the following reasons: risk of aspiration; time needed to
allow contrast to pass through intestinal tract; and relative ileus in the situation of severe injury. However, some
centres use positive contrast and some instil water through the nasogastric tube to outline the duodenum.
Non-bilious vomiting
See Chapter 20.1.
• Ultrasonography when pyloric stenosis is suspected but a pyloric mass is not palpated.
• Upper gastrointestinal series with barium
Bilious vomiting
• Plain films
• Upper gastrointestinal series with barium if the obstruction seems proximal
Diarrhoea
• Upper gastrointestinal series with follow-through examination of small bowel when the cause is not obvious
from clinical and laboratory data, cultures and small bowel biopsy, or when idiopathic inflammatory bowel
disease is suspected
Failure to thrive
• Upper gastrointestinal series with follow-through examination of small bowel when all other investigations and
therapeutic interventions are unhelpful
Subacute small bowel obstruction
• CT scanning after ingestion of water soluble oral contrast may be more revealing of the site and source of
obstruction than follow-through AP films after the ingestion of barium
Gastrointestinal bleeding
• Technetium-99m pertechnetate scintiscan when a Meckel diverticulum is suspected.
• Upper gastrointestinal series with follow-through examination of small bowel and antegrade evaluation of
colon and/or air-contrast barium enema when all other investigations are unhelpful (e.g. upper gastrointestinal
endoscopy and colonoscopy).
Notes
The availability of consultants trained in paediatric gastroenterology and their skill in endoscopy affects the role
of radiology in gastrointestinal diseases. If there is no one available to perform colonoscopy, there is reliance on
air-contrast barium enema for evaluation of the colon.
Normal infants vomit, spill, regurgitate or posset. If an infant younger than 6 months is ‘a happy chucker’,
imaging is unnecessary. Pulmonary symptomatology, failure to thrive, feeding difficulty and gastrointestinal
blood loss are reasons to pursue imaging with upper gastrointestinal series.
Problems in the neonatal period, such as failure to pass meconium, bilious vomiting and distension, tend to be
congenital in origin and the appropriate sequence of imaging requires close cooperation between paediatric
surgery and radiology. One cannot rely on ultrasonography to confirm or exclude malrotation: a contrast study of
the upper gastrointestinal tract is the gold standard. Where there are appropriate ultrasonic facilities and
practitioners, pyloric stenosis should be diagnosed with ultrasonography if the pyloric tumour is impalpable (Fig.
7.1.5).
Radiological studies of the child who has intermittent or chronic intestinal blood loss are rarely revealing in
the absence of a Meckel diverticulum, and if endoscopy has been normal.
Hepatobiliary
Neonatal jaundice
See Chapter 11.2.
• Ultrasonography to establish anatomy
• MRC and/or radionuclide study with technetium-99m IDA derivative when biliary atresia is a consideration
Right upper abdominal pain
• Plain radiograph and often the addition of ultrasonography (Fig. 7.1.6)
Notes
Right lower lobe pneumonia may present as severe right upper abdominal pain; therefore, always look at the
bases of the lungs on abdominal radiographs. Gallstones in childhood are more likely to be pigment stones than
cholesterol stones and may contain enough calcium to be visible on radiography.
Juvenile/adolescent jaundice
• Ultrasonography of liver, biliary tract, pancreas and spleen
• CT or MRI, depending on the results of ultrasonography
Abnormal hepatic function
• Ultrasonography when the clinical situation is atypical for hepatitis
• Ultrasound guided biopsy if the diagnosis is uncertain
Nephrology/urology
Urinary infection
See Chapter 18.1.
• Ultrasonography of the urinary tract in neonates, at the time of infection, to rule out an obvious surgical
problem, such as obstruction (The recommendation from the American Pediatric Society is that ultrasonography
should also be performed in infants and young children 2 months to 2 years of age who do not demonstrate the
expected clinical response within 2 days of antimicrobial therapy)
• Ultrasonography and micturating cystourethrography (MCU) in some infants and children who have had a
documented urinary tract infection (Fig. 7.1.7)
• Intravenous urogram (IVU) or technetium-99m DTPA or Mag 3 scans, with furosemide, for evaluation of the
child with possible obstruction at the pelviureteric junction or ureterovesical junction
• Technetium-99m DMSA or Mag 3 scans during the acute illness can support the diagnosis of pyelonephritis,
and/or after infection has cleared can document renal scars
• RNC for follow-up of known reflux
Notes
The type of imaging, the timing of investigation and the age of the child requiring radiological evaluation are
some of the most contentious issues in paediatrics today (Ch. 18.1). The American Academy of Pediatrics has
issued guidelines regarding diagnostic imaging in young children (aged 2 months to 2 years) but has not
addressed the issue of whether children up to the age of 5 years should have an MCU as part of their evaluation.
The prevalence of urinary tract infection and of dilating vesicoureteric reflux varies between populations.
Furthermore, the approach to imaging often depends on the services involved in a child’s care. Paediatricians,
paediatric urologists and paediatric nephrologists may have differing opinions. There has been a gradual change
over the last 25 years from performing MCU in most children who present with infection to investigating those
who are younger than 5 years, or 3 years, or 6 months, depending on the institution and the other imaging that is
available. There are data to suggest that reflux is just one of many factors that result in symptomatic, culturepositive urinary infection.
Radionuclide cystogram is a method of documenting reflux with far less radiation than standard MCU. The
availability of this study is often limited to tertiary centres. Ultrasonographic MCU requires catheterization, the
instillation of ultrasonographic contrast medium, a cooperative patient and technical expertise; it is not currently
available as a routine study.
Magnetic resonance urography (MRU) with injection of gadolinium shows great promise in its ability to show
parenchymal abnormalities, display split renal function and reveal anatomical abnormalities. Currently under
investigation in a few centres, it has the potential to replace many of the classic investigative tools.
Renal failure
• Ultrasonography of urinary tract
• Ultrasound guided biopsy of kidney if necessary for diagnosis
Note
Ultrasonography, which does not rely on renal function for images, can usually aid in triage of the patient by
determining a surgical or medical cause for renal failure.
Hypertension
See Chapter 18.2.
• Ultrasonography of urinary tract and adrenal glands
• Abdominal CT if an endocrine tumour such as phaeochromocytoma is suspected from laboratory data. Consult
the radiology department regarding premedication prior to injection of intravenous contrast at the time of the
study
• Nuclear medicine for quantitative, divided renal vascular flow and function (This may be superseded by MRU
in the future)
• Angiography/angioplasty in the rare situation of suspected renal vascular disease
Note
Examination of the kidneys with Doppler is difficult, time-consuming and often insensitive to subtle vascular
narrowing. Accessory renal vessels may be overlooked. Mid-aortic syndrome and neurofibromatosis are rare and
when present, typically have other signs and symptoms. A ‘negative’ examination does not rule out renal
vascular disease.
CTA can define renal vascularity with greater clarity than ultrasonography; MRU (discussed above) has
potential for the future.
Haematuria unrelated to trauma
•
•
•
•
Ultrasonography of urinary tract
CT if there is strong likelihood of renal/ureteral stone that has not been identified with ultrasonography
CT if a renal tumour is suspected
MCU or retrograde urethrography if a distal site of bleeding is suspected and cystoscopy is unavailable
Musculoskeletal
Trauma
See Chapters 3.6, 8.1.
• Two orthogonal views of the bone or joint that has been injured (Fig. 7.1.8). Oblique/special views as needed
of areas such as scaphoid, radial head, shoulder
• CT for special cases such as intra-articular fractures of ankle, pelvic fracture
Fever/pain/swelling in the musculoskeletal system
•
•
•
•
Two orthogonal views of the symptomatic bone or joint
Nuclear medicine technetium-99m diphosphonate bone scan
MRI for difficult diagnoses, tumour, occult infection
Ultrasonography for specific questions: localization of collection of fluid, joint effusion
Notes
MRI is fast replacing radionuclide studies in cases where there is localized pain or swelling and clinical concern
regarding a single septic joint or focus of osteomyelitis. Follow-up studies of children with diagnosed bone
tumour should be performed with MRI rather than CT; they give far more information regarding adjacent soft
tissues and bone marrow.
Metabolic disease
• AP plain radiograph of wrist and/or knee
Note
Because metabolic disease such as rickets is more obvious in areas of rapid bone growth, the wrists and knees are
more revealing of abnormality than other sites. Other views (hands, clavicles) may show changes of secondary
hyperparathyroidism in those with renal failure.
Syndrome with potential skeletal involvement
• Plain radiographs of chest, spine, pelvis, skull, leg and arm to include hand for determination of bone age
Developmental dysplasia of the hip
See Chapter 8.1.
• Ultrasonography at 4–6 weeks of age if developmental dysplasia of the hip (DDH) suspected but not obvious
on physical examination, or if risk factors (female, breech, positive family history) present or
• Plain radiograph at 4–6 months of age if DDH suspected but not obvious on physical examination
Notes
This is another area of contention. Ultrasonography of the infant’s hips requires training and practice. Early
radiography of neonates is unhelpful because so much of the anatomy is cartilaginous. Radiographs at 4–6
months are more informative and still allow intervention if necessary. In some areas of Europe, ultrasonography
is used to screen all newborns. Such studies have a high false-positive rate of diagnosis of DDH. Repeated
physical examination is the cornerstone of diagnosis. Infants may not have an obvious problem until after the
neonatal period; hence the change in name from CDH (congenital dysplasia of the hip) to DDH. The availability
of experienced paediatric orthopaedic surgeons has an effect on the local imaging protocols.
Inflicted injury (non-accidental injury)
See Chapter 3.9.
•
•
•
•
CT or MRI of brain to assess extra-axial spaces, parenchymal injury
Complete skeletal survey (infants) with high-detail images to search for evidence of fracture
Nuclear medicine technetium-99m diphosphonate bone scan in unusual cases
CT of abdomen, with intravenous contrast, if evidence of abdominal trauma
Notes
Some centres use nuclear medicine in imaging protocols for infants and young children if there is availability and
local expertise in interpretation.
Often a follow up skeletal survey or limited survey may be very revealing. Periosteal reaction takes about 7–
10 days to appear. The acute fracture may be occult.
Acknowledgements
The support of the Paedatric Radiologists at Starship Hospital during the preparation of this manuscript is
gratefully acknowledged. Dr George Taylor of Boston Children’s Hospital helped with the illustrations.
Abbreviations
The following abbreviations are in common use in imaging:
AP, Anteroposterior
PA, Posteroanterior
These terms relate to the course of the X-ray beam through the body. Anteroposterior, supine chest radiographs
are much easier to accomplish in infants who cannot sit without support. Magnification of the heart is not as
significant an issue as it is in adults.
CR, Computed radiography
Radiographs, films, or images are the result of X-rays passing through part of the body. 100 years ago, the
images were on glass plates – hence the use of the term ‘plate’ by some radiologists and clinicians. You may also
read of ‘roentgenogram’ – another relatively old-fashioned term highlighting Roentgen’s contribution. With
computed radiology now routine, the image is likely to be digital, and viewed on a computer screen.
CT, Computed tomography
(The older term, CAT, which is the acronym for computed axial tomography, has been dropped because,
although axial scans are acquired, modern machines allow reconstruction in coronal, sagittal and threedimensional formats.)
CTA, Computed tomographic angiography (rapid injection of contrast with imaging in the arterial phase)
IVU, Intravenous urography, synonymous with the old term of intravenous pyelogram (IVP)
MCU, Micturating cystourethrography
MRA, Magnetic resonance angiography
MRC, Magnetic resonance cholangiography
MRI, Magnetic resonance imaging
MRU, Magnetic resonance urography
MRV, Magnetic resonance venography
NM, Nuclear medicine
RNC, Radionuclide cystography
US, Ultrasound or ultrasonography
Fig. 7.1.1 CT scan without contrast following acute change in mental status associated with severe headache in this 10-year-old boy.
Note the large dense lesion, representing haemorrhage, in the right posterior temporal region. The ring of lucency is surrounding
oedema. Because of the strong suspicion, from clinical presentation and CT scan, that this child had a vascular aetiology for his
haemorrhage, he went to angiography. This showed vessels from both anterior and posterior cerebral circulation, along with an early
draining vein that identified this as an arteriovenous malformation.
Fig. 7.1.2 The anteroposterior radiograph of this newborn who presented in severe respiratory distress has features that identify
cardiac abnormality as the likely aetiology, although the heart is normal in size. Note that the nasogastric tube is entering a right-sided
stomach, while the apex of the heart is left-sided. The tracheostomy tube is deviated leftward by a right-sided aortic arch and the
umbilical artery catheter is in a right-sided descending aorta. This infant has heterotaxy syndrome with multiple cardiac anomalies.
The venous congestion that is apparent in the lungs is from obstructed anomalous pulmonary venous return, the major cause of the
respiratory distress.
Fig. 7.1.3 This child presented with unexplained fever. The soft tissue density (arrow) on the posteroanterior film (A) might have
been overlooked without the lateral view. The lateral film (B) demonstrates a smoothly outlined mass (arrow) that proved to be a
bronchopulmonary foregut malformation.
Fig. 7.1.4 Appendicitis is diagnosed on ultrasonography (A) when there is a blind-ending tubular structure that can be connected to
the caecum, that is non-compressible, and that measures 6 mm or more in transverse diameter as shown on this scan. The presence of
a shadowing appendicolith, although helpful in the diagnosis, is not a necessary feature. In another case, (B), retrocaecal appendicitis
is evident on this slice from a CT scan. The appendix (arrow) is thick-walled, measured 8 mm in diameter and had adjacent
inflammation, including thickening of the posterior peritoneum.
Fig. 7.1.5 Ultrasonography was performed after this 4-week-old infant presented with persistent vomiting. Scan along the long axis
of the antropyloric region shows the typical features of pyloric stenosis with thickening of the muscle and elongation of the channel.
Fig. 7.1.6 Increasing jaundice and intermittent abdominal pain in this boy with sickle cell disease was evaluated with abdominal
ultrasonography. Scans show sludge and stones in the gallbladder (A) and obstruction of the distal common bile duct by similar debris
(arrow, B).
Fig. 7.1.7 Micturating cystourethrography reveals severe reflux into the left kidney in this infant who presented acutely ill with
infection. Because of the degree of distension of the collecting system, this would be classified as grade 5 reflux.
Fig. 7.1.8 Anteroposterior (A), mortise (B) and lateral (C) views of the ankle were obtained in this girl who had tripped while
running. Note that the fracture of the posterior malleolus (arrow) can only be identified on the lateral view. Two or more views are
often necessary for diagnosing bony injury.