Radiographic Findings in Child Abuse

These images were obtained from a 5-month-old boy who was brought to the emergency department (ED) by his parents who noted new-onset rectal prolapse. The prolapse promptly recurred following initial successful reduction under sedation in the ED. A surgical consultation was obtained and abdominal radiographs were requested.

1. What is your impression of the bowel gas pattern?

A. There is a soft tissue mound surrounded by a crescent of air, consistent with intussusception.
B. There is a mild focal ileus, but otherwise this is a nonobstructive bowel gas pattern.
C. The patient is constipated.
D. There is a small-bowel obstruction.

2. Closer inspection of the soft tissues reveals . . .

A. Abdominal situs inversus.
B. A distended urinary bladder.
C. No significant abnormality.
D. A left lower quadrant mass.

3. "Other findings" include . . .

A. Osseous abnormalities.
B. Cardiomegaly.
C. Basilar pneumonia.
D. Pneumoperitoneum.

Answers & Discussion

1. What is your impression of the bowel gas pattern? (B is the correct choice.)

The images show a nonobstructive bowel gas pattern. There is an air-filled loop of jejunum in the central abdomen slightly off to the right, best seen on the supine anteroposterior view. The caliber of this loop of bowel is mildly prominent but overall not alarming. There is air in the colon and cecum, and therefore a diagnosis of intussusception is unlikely. There are no significant air-fluid levels on the decubitus view. There is no pneumoperitoneum or pneumatosis.

2. Closer examination of the soft tissues reveals no significant abnormality. (C is correct.)

The soft tissue contours of the liver and spleen are perfectly unremarkable on the supine view. Because the contour of the liver may vary somewhat from patient to patient, I find it tricky to "diagnose" hepatomegaly based on radiographs alone. There are no established charts for the size of the liver according to patient age or weight (as there are for the spleen).

There are also no abnormal masses or calcifications on these images. There is no evidence to suggest urinary bladder distention or other pelvic mass.

3. The radiographs show no evidence of cardiomegaly, basilar pneumonia, or pneumoperitoneum. However, there are unexpected osseous abnormalities in the form of rib fractures. (Option A is correct.)

"Other findings" in the radiographs divert the focus from a simple rectal prolapse reduction to the possibility of child abuse. Careful inspection of the ribs reveals multiple bilateral anterior and posterior rib fractures in varying stages of healing (Figures 1 and 2). This is one of the most highly specific radiological findings of child abuse. The posterior rib fractures are particularly suspect, because essentially no other mechanism besides squeezing of the infant chest results in this fracture in a healthy child. Other fractures that are highly specific for child abuse include the classic metaphyseal corner fracture, scapular fractures, spinous process fractures, and sternal fractures.

Figure

Figure 1 - Magnified view of the ribs: there are multiple bilateral anterior, posterior, and lateral rib fractures with varying degrees of callus.

Figure 2 - Skeletal survey of the same child with oblique views reveals more rib fractures. Oblique views are not always included as part of the outine skeletal survery but may be useful in etecting additional fractures not seen on the anteroposterior and lateral views of the chest.

Any fracture that is inconsistent with the child's stage of development (a child cannot sustain a toddler's fracture if they don't toddle) and any fracture that would require a mechanism that is inconsistent with the reported history should prompt consideration of nonaccidental trauma. Rolling off of a couch does not result in multiple bruises and a displaced skull fracture.

RADIOLOGICAL CLUES TO CHILD ABUSE

Abuse and neglect are responsible for approximately 1200 deaths in the United States each year.¹ Children younger than 1 year are by far the most vulnerable: they account for slightly less than half of all abuse-related fatalities. Radiographic and physical evidence of abuse is sometimes quite obvious, but at other times can be quite subtle; rib fractures may be subtle or inapparent and may not be accompanied by chest wall bruising.² It is incumbent on all of us-clinicians, radiologists, family, and friends- not to miss evidence of abuse.

The American College of Radiology offers detailed guidelines for obtaining a complete skeletal survey, which specifies 19 standard images at a minimum.³ Additional images may be obtained as deemed necessary, particularly if there are questionable areas that deserve further evaluation. A follow-up skeletal survey in 10 to 14 days is an important option to consider, because some acute fractures may be very difficult to detect initially but will become more apparent as callus formation commences.

CNS imaging findings commonly seen in child abuse include subdural hematomas, axonal shear-type injury, focal or global ischemia, contusions, compression fractures of the spine, and skull fractures. Retinal hemorrhages may be documented by an ophthalmologist but often are not apparent on cross-sectional imaging such as CT or MRI.

Successful detection of child abuse requires close cooperation among many people involved in the evaluation and care of a child. Any individual may be the one to tip us off to abuse-the social worker in the ED who notes conflicting stories, the emergency or primary care physician who observes suspicious bruises, or the radiologist who identifies unsuspected rib fractures. The safety of our children, of course, always comes first.

References:

• Lonergan GJ, Baker AM, Morey MK, Boos SC. From the archives of the Armed Forces Institute of Pathology (AFIP). Child abuse: radiologic-pathologic correlation. Radiographics. 2003;23:811-845.

• Cadzow SP, Armstrong KL. Rib fractures in infants: red alert! The clinical features, investigations and child protection outcomes. J Paediatr Child Health. 2000;36:322-326.

• ACR practice guideline for skeletal surveys in children. Available at: http:// www.acr.org/SecondaryMainMenuCategories/quality_safety/guidelines/ pediatric/skeletal_surveys.aspx. Accessed January 18, 2008.

FOR MORE INFORMATION:

• Caffey J. Multiple fractures in the long bones of infants suffering from chronic subdural hematoma. AJR. 1946;56:163-173.

• Falcone RA, Brown RL, Garcia VF. Disparities in child abuse mortality are not explained by injury severity. J Pediatr Surg. 2007;42:1031-1037.

• Hudson M, Kaplan R. Clinical response to child abuse. Pediatr Clin North Am. 2006;53:27-39.

• Sugar NF, Taylor JA, Feldman KW. Bruises in infants and toddlers: those who don’t cruise rarely bruise. Puget Sound Pediatric Research Network. Arch Pediatr Adolesc Med. 1999;153:399-403.