simple bone cyst -MR IMAGING AN OVERVIEW.

1. CASE REVIEW SIMPLE BONE CYST WITH FRACTURE MERCURY IMAGING INSTITUTE SCO 172-173 SEC 9C CHANDIGARH MERCURY IMAGING CENTRE SCO 16-17 SEC 20D CHANDIGARH 24 Yr old Female H/o fall and pain in the Rt hip joint .

2. Altered MR signal is appreciated in the Rt femur - subcapitate , neck , interochanteric and proximal shaft region. The lesion has following morphological characters : Central / expansible lesion with Lobulated contour. Narrow zone of the transition. Primarily involving medullary cavity with associated thinning of the cortex . Size : 82mm x 39mmx 38mm ( longitudinal x anteroposterior x transverse ). MR signal character : Intermediate on T1, heterogeneously hyperintense on t2/ stir, with interspread bloom On GRE . Features are corroborative with fluid and interspread haemorrhage in the core of the lesion. Cortical break appreciated along the medial aspect of the proximal femoral shaft (just below the lesser trochanter ) . Reactionary edema / hematoma appreciated in the adjacent myofascial planes ( primarily vastusintermedius involved ) . MR Bilateral hip joints done

3. HETEROGENOUSLY HYPERINTENSE ON T2 INTERMEDIATE ON T1W HETEROGENOUSLY HYPERINTENSE ON FATSAT INTERSPREAD BLOOM ON GRE S/O HAEMORRHAGE

4. INTERSPREAD BLOOM ON GRE SUGGESTIVE OF HAEMORRHAGE IN THE LESION.

5. HYPERINTENSE SIGNAL OF THE LESION ON FAT SATURATION- SEQUENCE CORTICAL BREAK

6. ALTERED MR SIGNAL IN RT PROXIMAL FEMORAL SHAFT WITH INTERSPREAD HETEROGENOUSITY . APPRECIATE : NARROW ZONE OF THE TRANSITION . EXPANSILE NATURE CENTRAL LOCATION CORTICAL BREAK

7. SHARP ZONE OF TRANSITION . LESION LIMITED BY THE PHYSEAL SCAR SMOOTH HOMOGENOUS INTERMEDIATE SIGNAL ON T1 W

8. Simple bone cyst / unicameral bone cyst a brief .................................... Unicameral / simple bone cyst . 5 % of primary bone tumors Etiology ? Trauma ? Vascular anomaly 3 to 19 years Occurs during active phase of growth Asymptomatic unless fractured. Usually in proximal femur , proximal humerus Intramedullary centric metaphyseal lesion adjacent to epiphyseal cartilage migrating to diaphysis with growth. 2 to 3 cm radiolucent with long axis parallel to the long axis of the bone . Fine sclerotic boundary . Fallen fragment sign if fractured ( centrally dislodged fragment falls into the dependant position) .