Clinical significance of increased density in the proximal femoral marrow detected by visual inspection on abdominopelvic postcontrast CT examination.
OBJECTIVE
The purpose of this study was to ascertain the clinical significance of increased density of the proximal femoral diaphyseal marrow when incidentally detected on postcontrast abdominopelvic CT examinations.


METHODS
The proximal femoral marrow of 63 patients was classified as normal or abnormal based on visual inspection by three attending radiologists. Abnormal density was defined as attenuation greater than that of adjacent musculature. The attenuation of the marrow was also measured. All patient medical records were reviewed for pertinent laboratory and clinical data.


RESULTS
Increased marrow density had a low sensitivity for anemia (28%) but a high specificity and positive predictive value (100%) for anemia. Three of these patients had unilaterally increased attenuation associated with local pathology. Visual inspection was adequate for identifying abnormalities in instances of underlying malignancy.


CONCLUSIONS
Increased density of the proximal femoral diaphysis is a highly specific finding for a marrow replacement process. Anemia was the most common clinical diagnosis in our series of patients with abnormal marrow density. Although the sensitivity for increased bone marrow attenuation is low, the extremely high specificity and positive predictive value of this finding for marrow reconversion and/or replacement suggest that even if detected incidentally, it should not be disregarded and, in the absence of a preexisting causative diagnosis, warrants further evaluation. The specific pattern of marrow abnormality may be helpful in differentiating localized processes from other processes that may affect hematopoietic function in a more widespread or global distribution. In particular, visual inspection of marrow density was more specific for identifying asymmetric marrow density in localized processes than was a quantitative measure of difference between the two femurs (>20 HU).
Maldjian
C
C
Department of Diagnostic Imaging, Temple University Hospital, Philadelphia, PA 19140, USA.
Curtis
B R
BR
Gatenby
R
R
Milestone
B
B
Revesz
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000175:diagnosis*; D001853:Bone Marrow / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D018483:Diaphyses / Q000000981:diagnostic imaging; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D003287:Contrast Media