Juxtaphrenic peak in upper and middle lobe volume loss: assessment with CT.
OBJECTIVE
To investigate the anatomic basis for the juxtaphrenic peak (JP) in upper and/or middle lobe volume loss through radiographic and computed tomographic (CT) correlation.


METHODS
Chest radiographs and CT scans were reviewed in 32 patients with upper or middle lobe volume loss. The study included 33 cases of volume loss: 12 affected the left upper lobe; 12, the right upper lobe; five, the right upper and middle lobes; and four, the middle lobe. JPs and linear opacities identified on chest radiographs were correlated with juxtadiaphragmatic structures on CT scans.


RESULTS
A JP was identified in 22 of 33 (67%) cases, including nine of 12 (75%) with left upper lobe volume loss and eight of 12 (67%) with right upper lobe, four of five (80%) with combined upper and middle lobe, and one of four (25%) with middle lobe volume loss. The JP was due to an inferior accessory fissure in 14 of 22 (64%) cases. Other causes included a medial septum and an accessory fissure other than the inferior accessory fissure.


CONCLUSIONS
The JP sign is seen in the majority of cases with upper lobe or combined upper and middle lobe volume loss. The sign is most commonly related to an inferior accessory fissure.
Department of Radiology, New York Hospital-Cornell Medical Center, New York, NY 10021, USA.
S D
SD
Davis
D F
DF
Yankelevitz
A
A
Wand
D A
DA
Chiarella
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000528:radiation effects; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy; D014057:Tomography, X-Ray Computed