Ebook Differential diagnosis in radiology (2e): Part 2

(BQ) Part 2 book “Differential diagnosis in radiology” has contents: Skeletal system and joints, urogenital system, head, neck and spine, obstetrics and gynecology.

6.1 ABNORMAL SKELETAL MATURATION Skeletal Maturation Disorders

Retarded

1 Chronic ill health

– Congenital cardiac disorders

– Chronic renal failure

– Inflammatory bowel disease

– Malnutrition including rickets

Fig 6.1: Anteroposterior radiograph of foot shows Macrodystrophia

lipomatosa involving 2nd and 3rd digits

2 Radiation treatment in childhood.

Premature closure of growth plate

1 Localized hyperemia due to chronic inflammation as in arthritides or infection, hemophilia

2 Vascular malformation—AVM

3 Trauma

4 Radiation treatment during childhood

5 Thermal injury—Burns and frostbite

6 Multiple exostoses and enchondromatosis

– Short ribs with deep concavities to anterior ends.

– Decreased interpedicular distance caudally in lumbar spine

– Short pedicles with narrow lumbar canal

– Posterior scalloping with anterior vertebral body beaking – Square iliac wings with champagne glass pelvic cavity

– Rhizomelic micromelic with bowing of long bones (Fig 6.2) – Trident hands

2 Hypochondroplasia

– Similar to achondroplasia except skull never affected

– Height normal or mildly reduced

3 Pseudochondroplasia

– Similar to achondroplasia

– Except that skull is normal

– No changes seen in first year of life

4 Chondrodysplasia punctata

– Stippling in long bone epiphysis, spine or larynx

Fig 6.2: Anteroposterior radiograph shows bowing of both

femurs with right relatively shorter than left

(Middle Segment Shortening)

1 Dyschondrosteosis

– Also known as Léri-Weill’s disease

– Usually affects females

– Also known as Ellis-van Creveld syndrome

– Paired long bones are short with dome-shaped physes

– Abnormal medial tibial plateau with defective epiphyses laterally

– Postaxial polysyndactyly

– Carpal fusions seen esp capitate and hamate with delayed development of carpal bones

– Partial/total absence of teeth

– Abnormal hair and nails

– Rib cage similar to asphyxiating thoracic dystrophy

(Distal Segment Shortening)

1 Asphyxiating Thoracic Dystrophy

– Also known as Jeune’s disease

Spinal abnormality besides short spine

– Platyspondyly with exaggerated grooves for ring apophyses

– C1 and C2 dislocation

Fig 6.3: Anteroposterior radiograph of foot shows polydactyly

Other features

– Short limbs

– Marked joints laxity

2 Spondylometaphyseal dysplasia

Like type Kozowski

– Limb abnormalities besides spine involvement

– Severe tubular bone involvement

– Retinal detachment common

b X-linked-tarda

Spinal abnormality besides short spine

– Mounds of dense bone are found on superior and inferior surfaces of the posterior part of vertebral endplates

Other features

– Tubular bones minimally affected

– Iliac wings are small

– Hip degeneration frequently occurs prema turely

c Recessive

Spinal abnormality besides short limbs

– Generalized platyspondyly of least severity

Other features

Nil

4 Diastrophic dwarfism

Spinal abnormality besides other limb abnormalities

– Interpedicular narrowing in lumbar spine

– Limited and painful joint movements.

6.4 LETHAL NEONATAL DYSPLASIA

1 Osteogenesis imperfecta

Type II

– Lethal in utero/early infancy.

– Sclerae are dark blue

– Bones are grossly demineralized with thin cortices

– Numerous healed or healing rib fractures

Type II A – Long bones are short, broad and bowed.

– Ribs are broad with continuous beading

Type II B – Long bones as in Type II A

– Ribs show less or no beading

Type II C – Long bones are thinned and show

multiple fractures

– Ribs are too thin and beaded

– Skull is enlarged with numerous wormian bones; Mineralization may be retarded

2 Thanatophoric dwarfism

– Infants are stillborn or die immediately after birth

Rhizomelic dwarfism with bowing of long bones.

– Metaphyses are irregular

– Epiphyses of knee absent

– Short, wide, metacarpals and phalanges

– Marked platyspondyly with ‘H-shaped’ vertebra on AP view

of spine

– Poor mineralization of pelvic bones with small square iliac blades

– Clover leaf skull

– Ribs are short and flared anteriorly

3 Chondrodysplasia punctata

– Rhizomelic type (recessive) is lethal

– Stippling or punctate calcification of tarsus and carpus, long bone epiphyses, vertebral transverse processes and pubic bones

– Long bones show gross asymmetric shortening and metaphyseal irregularity

4 Asphyxiating thoracic dystrophy—Patients die in infancy from

respiratory distress

– Thorax is stenotic

– Ribs are short and horizontal

– Clavicles are highly placed

5 Campomelic dwarfism

– Long bones are bowed

6 Achondrogenesis Type I and II

7 Short rib syndromes with or without polydactyly (Type I, II, III)

8 Homozygous achondroplasia

9 Hypophosphatasia—Gross general failure of ossification of skeleton.

6.5 DUMB-BELL-SHAPED LONG BONES

1 Metatropic dwarfism—Short spine and short limb dwarfism.

2 Pseudochondroplasia—Short limb (Rhizomelic dwarfism).

3 Kniest syndrome—Short spine and short limb dwarfism.

4 Diastrophic dwarfism—Short spine and short limb dwarfism.

– Long bone show multiple fracture and bowing.

– Sutures are wide with multiple wormian bones

a Abnormal bone texture

b Widening of diaphyses

c Tilting of distal radius and ulna towards each other

d Pointing of proximal ends of metacarpals

e Large skull with calvarial thickening

Fig 6.4: Appendicular skeleton

f Anterior beaking of upper lumbar vertebrae.

g J-shaped sella

h Flared ilia

i Fragmented femoral ossific nucleus

6.7 MUCOLIPIDOSES

1 Type I (Neuraminidase deficiency)

2 Type II (I-cell disease)

3 Type III (Pseudopolydystrophy of Maroteaux)

– Fluorosis = Thickened cortex with narrow medulla

– Ossification of tendons, ligaments and interosseous membranes

– Hyper- = Dense metaphyseal bands

vitaminosis D = Widened zone of provisional calcification – Soft tissue calcification

– Hyper- = Subperiosteal new bone

vitaminosis A formation

– Reduced metaphyseal density

– Marrow cavity narrowed by endosteal reaction.

– Patchy lucencies due to fibrous tissue

– Osteoblastic metastases (Figs 6.5A and B)

Figs 6.5A and B: Anteroposterior and lateral radiographs of LS spine

show osteoblastic metastases

b Bone islands (Enostosis)

Fig 6.6: Paget’s disease: Early long-bone changes Lateral view of the

humerus in a middle-aged man shows an “advancing wedge” (“blade of grass” or “flame shadow”) appearance at the end of the bone, characteris- tic of early Paget’s disease Since the disease process generally proceeds from one articular end of the long bone to the other, all three phases— early, intermediate and late—may be seen in the same bone

– Round/Oval dense lesion in medullary location with radiating thorn-like spicules.

– Age = 3 to 15 years

c Osteopoikilosis/Osteopathia condensans disseminata

– Dense round/oval/Lanceolate lesion arranged parallel

to long-axis of bone

Fig 6.7: Paget’s disease: Late long-bone changes Lateral view of the

tibia shows anterior bowing secondary to late-phase

Fig 6.8: Progression of Paget’s disease: a, c and e early (osteolytic) “hot”

phase and b, d and f late (osteoblastic) “cold” phase manifestations of Paget’s disease in (a, b) the skull, (c, d) vertebrae, and (e, f) long bones,

a Osteoporosis circumscripta, b “Cotton-wool” appearance c Biconcave vertebra d “Picture frame” ivory vertebra e “Flame,” “blade of grass” deformities f Dense, larger diameter deformities

1 Osteoporosis circumscripta 2 Basilar invagination

3 Advancing wedge

Fig 6.9: Osteoid osteoma The frontal projection shows an enlarged,

dense right pedicle (3) and pars interarticularis (5), characteristic of oid osteoma (compare with normal pedicle on left (4 & 6).

oste-Fig 6.10: Osteoid osteoma

– Seen usually at ends of long bones and around joints; in the carpus and tarsus.

– No interval change

d Osteopathia striata/voorhoeve’s disease

Sclerotic striations in long bones parallel to long-axis affecting both diaphysis and metaphyses

• Sclerosing osteomyelitis of Garré

– Localized gross sclerosis in absence of apparent bone destruction

– Usually skull, PNS and mandible.

d Ivory or dense type; spongy or trabeculated type

Broad-based with smooth well-defined margins

e Osteoid osteoma (Figs 6.9 and 6.10)

– Round/oval radiolucent lesion with dense surrounding sclerosis with a central nidus <1 cm

– Lesion sited in relation to cortical bone with dense scleroses extending into medullary cavity as well

f Osteoblastoma

– Similar to osteoid osteoma but central radiolucency is larger, approx 2–10 cm in diameter

g Primary bone sarcoma

– Commonest being osteosarcoma

– Wide zone of transition with periosteal reaction and soft tissue extension

– Healed/Healing benign or malignant bone lesions as lytic areas following RT on CT, bone cyst, fibrous cortical defect, etc

Figs 6.11A and B: (A) Nonossifying fibroma; (B) Osteoblastoma

– Circumscribed areas of increased density due to thickening

of medullary trabeculae (Figs 6.11A and B)

– Coarsened appearance of bone with indistinct endosteum

b Multifocal osteosarcomas

– Multiple myeloma

– in 2 to 3%

c Multiple healed/healing benign or malignant bone lesions.

6.10 BONE SCLEROSIS ASSOCIATED

WITH PERIOSTEAL REACTION

i Infantile cortical hyperostoses (Caffey’s disease)

– Age of onset is nine weeks

– Marked periosteal proliferation and cortical thicken ing beneath soft tissue swellings

– Bones affected are mandible, ribs, scapula, ulna and any other bone except phalanges and spine

– In long bones, diaphysis is only involved

ii Melorheostosis/Leri’s disease

– Dense irregular bone running along cortex of long bone, both externally and internally

(Dripping candle wax appearance)

– Lower limbs are commonly involved

– Lesions are segmental and unilateral in distribution

– Metaphyseal lytic lesion with surrounding sclerosis

– Tunnelling toward epiphyseal plate is pathogno monic

ii Granulomatous

(Syphilis, Tuberculosis)

6.12 COARSE TRABECULAR PATTERN OF BONE

8 Fibrogenesis imperfecta ossium

– Obliteration of trabecular architecture with coarsen ing of remaining trabeculae

9 Gaucher’s disease

– Associated with hypoplasia of vertebral bodies, thinning

of cortices of tubular bones and subperiosteal new bone formation

10 Neoplasms as chondromyxoid fibroma where new bone is laid in pattern of coarse trabeculae

6.13 RELATIONSHIP OF METASTATIC

LESIONS TO THE PRIMARY TUMORS

Location of primary tumor/variety of

primary tumor Characteristic of metastatic lesions

Lytic Blastic Mixed Expansile

6.14 CHILDHOOD TUMORS

METASTASIZING TO BONE (TABLE 6.13)

1 Neuroblastoma

2 Leukemias and lymphoma

3 Clear cell sarcoma

(Variant of Wilms’ tumor)

4 Rhabdomyosarcoma

Fig 6.12: Ewing’s sarcoma A permeative destructive lesion can be

ob-served in the diaphysis of the distal ulna Fracture callus merges with a

“sunburst” periosteal reaction The cortex on the radial aspect of the ulna

is destroyed by a soft-tissue mass growing out into the soft tissue A short, oblique pathologic fracture is also evident Ewing’s sarcoma cannot be differentiated radiologically from a nonHodgkin’s lymphoma The latter oc- curs in an older age group (third and fourth decades) Differentiation from osteomyelitis can be difficult However, unlike Ewing’s sarcoma, metaphy- seal involvement is usually a prominent feature of childhood osteomyelitis (See labelling on the next page in Figure 6.13)

6 Well-organized periosteal reaction

Fig 6.13: Ewing’s tumor

Fig 6.17: Aneurysmal bone cyst

Tumor-like lesions

1 Nonossifying fibroma (Fig 6.11)

2 Aneurysmal bone cyst (Fig 6.17)

FEA-Fig 6.19: Locations of tumors within a bone

Fig 6.20: Patterns of bone destruction

Figs 6.21A to E: Types of periosteal reaction (A) Well-organized;

(B) Buttress; (C) Onion skin; (D) Codman’s triangle; and (E) Sunburst

Fig 6.22: Chondroblastoma Fig 6.23: Chondromyxoid fibroma

Fig 6.24: Osteochondroma (Exostosis)

Fig 6.25: Non-ossifying fibroma (Fibrous cortical defect)

Fig 6.26: Chondrosarcoma

6.17 RADIOLOGIC CHARACTERISTICS OF

BENIGN AND MALIGNANT BONE LESIONS

1 Margination Well-defined Destructive, poorly-defined

3 Periosteal reaction Less aggressive More aggressive

4 Zone of transition Narrow Wide

5 Soft tissue mass Absent Present

6.18 SUBARTICULAR LYTIC BONE LESION

Arthritides (Figs 6.28 to 6.38)

1 Osteoarthritis

– Marginal osteophytes

– Subchondral sclerosis

– Reduced joint space

– Multiple cysts in load-bearing regions

Fig 6.27: Diaphyseal infarct

Lat-eral view of the distal femur in a 50-year-old man shows a typical diaphyseal infarct This lesion, which is remote from the knee joint, was asymptomatic The ab- sence of punctate calcifications and lobular margins differentiates

a bone infarct from an droma

enchon-Fig 6.28: Diarthrodial joint with neuropathic arthritis

Fig 6.29: Diarthrodial joint in lupus erythematosus

Fig 6.30: Reiter’s syndrome

Dorsiplantar projection of the foot shows marked resorption

of the proximal side of the phalangeal joint of the great toe resulting in a “mortar-and-pes- tle” or “pencil-in-cup” deformity Also note the resorption at the distal interphalangeal joint of the fourth toe, fusion of the dis- tal interphalangeal joint of the fifth toe, and marginal erosion

inter-at the proximal interphalangeal joint of the fifth toe Involvement

of the distal interphalangeal joints is not uncommon in the arthritis of Reiter’s syndrome

Fig 6.31: Rheumatoid arthritis Anteroposterior projection of the hips

shows concentric narrowing of both the hip joints with axial migration of the femoral heads resulting in protrusio acetabulum (i.e the medial wall of the acetabulum is medial to the iliopubic line) The intense sclerosis of the left femoral head and left acetabulum indicates secondary osteoarthritis; however, osteophytes are absent

2 Rheumatoid arthritis

– Cysts at/near the regions of capsular insertion

– Joint space narrowing

– Juxta-articular osteoporosis

– No sclerosis

3 Calcium pyrophosphate arthropathy

– More collapsed and fragmented articular surface

– Cysts larger than osteoarthritis

– Rest similar changes as in osteoarthritis

5 Pigmented villonodular synovitis

– Mainly lower limbs especially knees

– Soft tissue mass

– Cyst-like defects with sharp sclerotic margins

– Joint space destruction

– Geode (associated with arthritis).

– Healing benign/malignant osseous lesion.– Brodie’s abscess

– Simple bone cyst.

Fig 6.33: Osteoarthritis of spine Lateral tomogram of an old woman

shows advanced degenerative change in the posterior apophyseal (facet) joints of the lumbar spine Hypertrophic bone encroaches on the central spinal canal Also note the spondylolisthesis at L4-L5, with calcification

in the outer fibers of the annulus fibrosus at this level The intervertebral discs are relatively well-maintained Note that the spinal apophyseal (fac- et) joints are synovial joints which may undergo degenerative change The resulting sclerosis and hypertrophic bone may encroach upon the central spinal canal and produce a secondary form of spinal stenosis, as in this patient

1 Synovium

2 Capsule 3 Articular cartilage 4 Synovial fluid

Fig 6.34: Normal diarthrodial joint

Fig 6.35: Chronic tophaceous gout

– Giant cell tumor.

– Aneurysmal bone cyst

i Without periosteal reaction

• Nonexpansile (Figs 6.38A and B)

Fig 6.37: Diarthrodial joint with chronic tophaceous gout

Figs 6.38A and B: Anteroposterior and lateral radiographs of lower

thigh shows nonHodgkin’s lymphoma of femur

B A

– Giant cell tumor

– Metastases from kidney/thyroid