Radiologic Manifestations of
Lead Poisoning
Jonathan Kenyon, Harvard Medical School, Year IIIJonathan Kenyon, Harvard Medical School, Year III
Gillian Lieberman, MDGillian Lieberman, MD
January 2001
Jonathan Kenyon
Gillian Lieberman, MD
2
Lead Poisoning or Plumbism
Remains a significant problem in the United Remains a significant problem in the United
States, despite an effort to reduce lead States, despite an effort to reduce lead
contaminants.contaminants.
The department of health and human The department of health and human
services called lead poisoning “the most services called lead poisoning “the most
important environmental problem for young important environmental problem for young
children.”children.”
Jonathan Kenyon
Gillian Lieberman, MD
3
Epidemiology
Most common sources for lead in a home Most common sources for lead in a home
are: leadare: lead--based paint, drinking water, and based paint, drinking water, and
pottery.pottery.
Lead is either ingested or inhaled.Lead is either ingested or inhaled.
98% of lead poisoning cases in children 98% of lead poisoning cases in children
between 2between 2--6 years old.6 years old.
Jonathan Kenyon
Gillian Lieberman, MD
4
Toxicity of Lead Exposure
Mild ToxicityMild Toxicity Moderate ToxicityModerate Toxicity Severe ToxicitySevere Toxicity
MyalgiasMyalgias
ParesthesiasParesthesias
FatigueFatigue
IrritabilityIrritability
Abdominal PainAbdominal Pain
VomitingVomiting
ArthralgiasArthralgias
HeadacheHeadache
TremorTremor
ParesisParesis
EncephalopathyEncephalopathy
DeathDeath
Jonathan Kenyon
Gillian Lieberman, MD
5
Chronic Lead Exposure
Shown to have neurological, behavioral, Shown to have neurological, behavioral,
and cognitive effects.and cognitive effects.
Has been correlated with a direct decrease Has been correlated with a direct decrease
in exposed children’s IQ scores.in exposed children’s IQ scores.
Jonathan Kenyon
Gillian Lieberman, MD
6
Radiology and Lead Poisoning
Between 70%Between 70%--95% of total body lead is 95% of total body lead is
found in osseous tissues.found in osseous tissues.
The halfThe half--life of lead in bone is up to 10 yrs.life of lead in bone is up to 10 yrs.
Nearly 70 years ago, Nearly 70 years ago, CaffeyCaffey and Park and Park
described radiologic manifestations of described radiologic manifestations of
chronic exposure to lead in children.chronic exposure to lead in children.
Jonathan Kenyon
Gillian Lieberman, MD
7
Patient A:
2.5 Year Old Female
Image courtesy of Children’s Hospital, Boston, MA
Film findings:
Dense Line at the metaphyses- a “lead line” or
“lead band.” This appears at a blood lead level
of between 70-80 micrograms/dl.
Jonathan Kenyon
Gillian Lieberman, MD
8
The Lead Line, A Disruption of
Balance
Normal growth at the Normal growth at the metaphysismetaphysis is the result of a is the result of a
balance between balance between osteoblasticosteoblastic bone deposition and bone deposition and
osteoclasticosteoclastic bone bone resorptionresorption at the Zone of at the Zone of
Provisional Calcification.Provisional Calcification.
Lead ions are preferentially deposited at the ZPC, Lead ions are preferentially deposited at the ZPC,
and disrupt this balance by inhibiting and disrupt this balance by inhibiting osteoclasticosteoclastic
activity.activity.
Thus a “lead line” does NOT represent the Thus a “lead line” does NOT represent the
radiopacityradiopacity of the lead itself, but rather increased of the lead itself, but rather increased
calcium deposition.calcium deposition.
Jonathan Kenyon
Gillian Lieberman, MD
9
Differential Diagnosis
of Dense Metaphyseal Lines
1)1) Normal variantNormal variant
2)2) Lead PoisoningLead Poisoning
3)3) Treated LeukemiaTreated Leukemia
4)4) Healing RicketsHealing Rickets
5)5) Other Heavy Metal PoisoningOther Heavy Metal Poisoning
6)6) Recovery from ScurvyRecovery from Scurvy
7)7) Vitamin D Vitamin D hypervitamintosishypervitamintosis
8)8) HypothyroidismHypothyroidism
9)9) HypoparathyroidismHypoparathyroidism
10)10) TransplacentalTransplacental InfectionsInfections
Jonathan Kenyon
Gillian Lieberman, MD
10
Image courtesy of Children’s Hospital, Boston, MA
Patient B:
20 Month Old Female
Note Fibular
Density
Jonathan Kenyon
Gillian Lieberman, MD
11
Plumbism or Normal Variant?
Identification of a Identification of a metaphysealmetaphyseal density in density in
the proximal fibula is a strong indicator of the proximal fibula is a strong indicator of
lead poisoning.lead poisoning.
This sign is the most reliable marker in This sign is the most reliable marker in
differentiating between a normal and differentiating between a normal and
pathologic state.pathologic state.
Jonathan Kenyon
Gillian Lieberman, MD
12
Diagnosis
Lead bands are NOT an early manifestation of Lead bands are NOT an early manifestation of
lead toxicity and thus should NOT be used to lead toxicity and thus should NOT be used to
assess acute toxicity.assess acute toxicity.
A clinical history of lead ingestion, symptoms, A clinical history of lead ingestion, symptoms,
and blood lead levels are more reliable indicators.and blood lead levels are more reliable indicators.
However, if blood lead levels are not readily However, if blood lead levels are not readily
available, radiography of knees should be available, radiography of knees should be
considered in a symptomatic patient. Though not considered in a symptomatic patient. Though not
helpful in acute poisoning, they demonstrate helpful in acute poisoning, they demonstrate
findings with chronic exposure.findings with chronic exposure.
Jonathan Kenyon
Gillian Lieberman, MD
13
Patient C;
The evolution of a lead line
4.5 year old female admitted with coma. 4.5 year old female admitted with coma.
History notable for fever, vomiting, and History notable for fever, vomiting, and
progressive lethargy. progressive lethargy.
Parents also noted that she had a “history of Parents also noted that she had a “history of
eating paint from the veranda of her home.”eating paint from the veranda of her home.”
Jonathan Kenyon
Gillian Lieberman, MD
14
Patient C
8/20/66
Image courtesy of Children’s Hospital, Boston, MA
Jonathan Kenyon
Gillian Lieberman, MD
15
Patient C
1/18/67
Image courtesy of Children’s Hospital, Boston, MA
Jonathan Kenyon
Gillian Lieberman, MD
16
Migration of Lead Lines
Lead lines undergo a constant migration Lead lines undergo a constant migration
from the ZPC into the from the ZPC into the diaphysisdiaphysis. .
Different bones have different migration Different bones have different migration
ratesrates
Distal femur Distal femur -- ~22mm/year~22mm/year
Proximal tibia Proximal tibia -- ~15mm/year~15mm/year
This growth related migration occurs for This growth related migration occurs for
about 4 years, after which the lines about 4 years, after which the lines
disappear.disappear.
Jonathan Kenyon
Gillian Lieberman, MD
17
Image courtesy of Children’s Hospital, Boston, MA
Patient D;
Unknown History,
Evidence of Chronic
Lead Exposure
Note the alternating
Narrow-Broad-Narrow pattern
consistent among different
bones
Jonathan Kenyon
Gillian Lieberman, MD
18
Patient D - Chronic Lead
Exposure
Image courtesy of Children’s Hospital, Boston, MA
Jonathan Kenyon
Gillian Lieberman, MD
19
KUB as a means of Diagnosis
Evidence of lead ingestion Evidence of lead ingestion -- Multiple Multiple
radiopaqueradiopaque flakes representing paint chips flakes representing paint chips
may be seen on plain abdominal film.may be seen on plain abdominal film.
Jonathan Kenyon
Gillian Lieberman, MD
20
Patient E
Image courtesy of Children’s Hospital, Boston, MA
Film findings
Radioopaque lead
ingested in paint
chips
Jonathan Kenyon
Gillian Lieberman, MD
21
Another Radiographic
Manifestation
Widened cranial sutures may also be Widened cranial sutures may also be
present in chronic lead poisoning, present in chronic lead poisoning,
secondary to increased intracranial pressuresecondary to increased intracranial pressure
Jonathan Kenyon
Gillian Lieberman, MD
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Summary
Lead poisoning is a serious and potentially Lead poisoning is a serious and potentially
lifelife--threatening condition affecting threatening condition affecting
primarily children.primarily children.
Chronically, lead poisoning results in the Chronically, lead poisoning results in the
inhibition of inhibition of osteoclasticosteoclastic activity. This is activity. This is
visualized on plain films as dense visualized on plain films as dense
metaphysealmetaphyseal thickening in growing bones.thickening in growing bones.
Acutely lead toxicity should be diagnosed Acutely lead toxicity should be diagnosed
by H+P, and measurement of blood lead by H+P, and measurement of blood lead
levels, though sometimes evidence of lead levels, though sometimes evidence of lead
ingestion is visible on KUB. ingestion is visible on KUB.
Jonathan Kenyon
Gillian Lieberman, MD
23
Sources
Sachs HK. The evolution of the radiologic lead Sachs HK. The evolution of the radiologic lead
line. Radiology 1981; 139: 81line. Radiology 1981; 139: 81--85.85.
BlickmanBlickman JG, Wilkinson RH, JG, Wilkinson RH, GraefGraef JW. The JW. The
radiologic “lead band” revisited. American radiologic “lead band” revisited. American
Journal of Journal of RoentgenologyRoentgenology 1986; 146: 2451986; 146: 245--247.247.
RaberRaber S. The dense S. The dense metaphysealmetaphyseal band sign. band sign.
Radiology 1999; 211: 773Radiology 1999; 211: 773--774774
CaffeyCaffey J. Pediatric XJ. Pediatric X--ray Diagnosis. 7th edition. ray Diagnosis. 7th edition.
19781978
EllenhorEllenhor M. M. Ellenhorn’sEllenhorn’s Medical Toxicology. Medical Toxicology.
19971997
Children’s Hospital Radiology teaching files. Children’s Hospital Radiology teaching files.
Boston, MABoston, MA
Jonathan Kenyon
Gillian Lieberman, MD
24
Acknowlegements
BeverleeBeverlee Turner for her support and PowerPoint expertiseTurner for her support and PowerPoint expertise
Larry Barbaras and Ben Crandall our Larry Barbaras and Ben Crandall our WebMastersWebMasters
Radiologic Manifestations of Lead Poisoning
Lead Poisoning or Plumbism
Epidemiology
Toxicity of Lead Exposure
Chronic Lead Exposure
Radiology and Lead Poisoning
Patient A:�2.5 Year Old Female
The Lead Line, A Disruption of Balance
Differential Diagnosis� of Dense Metaphyseal Lines
Patient B:�20 Month Old Female
Plumbism or Normal Variant?
Diagnosis
Patient C;�The evolution of a lead line
Patient C�8/20/66
Patient C�1/18/67
Migration of Lead Lines
Slide Number 17
Patient D - Chronic Lead Exposure
KUB as a means of Diagnosis
Patient E
Another Radiographic Manifestation
Summary
Sources
Acknowlegements