Flow direction of ascending lumbar veins on magnetic resonance angiography and venography: would "descending lumbar veins" be a more precise name physiologically?
BACKGROUND
Physiological flow direction of ascending lumbar vein (ALV) is not well recognized.


METHODS
Two-dimensional time-of-flight magnetic resonance angiography (MRA) examinations of the lower extremities in 44 patients and venography (MRV) in 59 patients were retrospectively reviewed. chi2 analysis was used to compare the frequency of ALV detection between the MRA and MRV groups and between cases with filling defects above the ALV confluence and other cases in the MRV group.


RESULTS
Frequency of ALV detection was significantly higher in the MRA group (60 of 88 veins, 68.2%) than in the MRV group (9 of 118 veins, 7.6%, P < 0.0001) and in cases with filling defects above the ALV confluence (8 of 23 veins, 34.8%; 6 were compression of the left common iliac vein by the right common iliac artery, 2 were thrombus of the proximal bilateral common iliac veins) than in other cases (1 of 95 veins, 1.1%) in the MRV group (P < 0.0001).


CONCLUSIONS
Without compression or occlusion above the ALV confluence, the general flow direction of the ALVs is not ascending but descending, suggesting that "descending lumbar veins" is a more physiologically precise name for these veins than ALVs.
Morita
Satoru
S
Department of Radiology, Saiseikai Kurihashi Hospital, 714-6, Gotanda, Kouemon, Kurihashi-Machi, Kitakatsushika-Gun, Saitama, 349-1105, Japan. i@imodey.com
Kimura
Tomo
T
Masukawa
Ai
A
Saito
Naoko
N
Suzuki
Kazufumi
K
Mitsuhashi
Norio
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D016015:Logistic Models; D035002:Lower Extremity / Q000098:blood supply*; D008159:Lumbar Vertebrae / Q000098:blood supply*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D010690:Phlebography / Q000379:methods*; D012189:Retrospective Studies; D014680:Veins / Q000033:anatomy & histology*