Article Figures & Data
Figures
- FIG 1.
Post-GKR DSA and MRA of a study case in which the residual AVM was not visualized on ASL-MRA (case 30). Post-GKR DSA (A and B) shows a residual AVM nidus (white arrow) fed by the left posterior cerebral artery. CE-MRA (E–F) shows slow filling of the AVM nidus (white arrow) lateral to the deep venous system. No residual AVM is noted on ASL-MRA (C and D).
- FIG 2.
Representative case of a residual AVM not visualized on CE-MRA (case 13). The pre-GKR DSA (A) shows 2 AVM nidi (white arrows) at the time of GKR in a patient with previous partial surgical excision of a ruptured AVM. The most lateral nidus is not identified in post-GKR imaging; however, a residual of the most medial nidus (arrowheads) is identified on post-GKR DSA (B) and ASL-MRA (C and D). The small size of the lesion renders it not identifiable on the CE-MRA (E–F).
- FIG 3.
Characterization of a residual AVM (case 19) using ASL (D–F) and CE-MRA (G–I) compared with DSA (A–C) . The feeding arteries of this AVM, which are branches of the anterior and middle cerebral arteries (white arrows), are clearly depicted on ASL-MRA and CE-MRA . The draining veins (arrowheads) seen on DSA can also be identified on ASL and CE-MRA, and they involve both the superficial venous system via the superior sagittal sinus and the deep system via the left internal cerebral vein.
Tables
Characteristics Age (mean) (range) (yr) 37 (18–69) Female (%) 66% AVM location (No.) (%) Temporal 9 (30%) Frontal 6 (20%) Parietal 6 (20%) Occipital 3 (10%) Basal ganglia/brain stem 4 (13%) Posterior fossa 2 (7%) Lateralization (%) Right 30% Left 70% AVM volume (mean) (range) (mL) 7.01 (0.07–50.54) GKR (mean) (range) Dose (Gy) 17 (11–22) Percentage isodose 50% Mean time post-GKR (range) (mo) 53 (22–168) Parameter ASL-MRA CE-MRA MRA type Dynamic (4D) Dynamic (4D) Scan duration (min:sec) 5:58 3:19 Contrast Acquisition T1-TFEPI T1-FFE TR (ms) 12 3 TE (ms) 5 1 Flip angle 10° 25° Resolution FOV (RL × AP × CC mm) 210 × 210 × 90 150 × 210 × 210 Acquisition Transversal Sagittal Slabs 1 1 Acquisition matrix 172 × 172 × 70 50 × 248 × 248 Acquired voxel size (mm) 1.22 × 1.26 × 1.3 3 × 0.85 × 0.85 Reconstruction matrix 256 × 256 288 × 288 reconstructed voxel size (mm) 0.82 × 0.82 × 0.65 1.5 × 0.73 × 0.73 No. of slices 140 100 SENSE factor 2.5/1 4/2 Dynamic acquisition Dynamic imaging mode TFEPI CENTRA keyhole No. of dynamic phases 8 24 Phase interval (temporal resolution) (ms) 200 608 Label delay (ms) 200 – Contrast – Gadovist 0.1 mL/Kg; IV pump injection: 3.5 mL/s Note:—indicates non-applicable; TFEPI, Turbo-field echo-planar imaging; FFE, fast-field echo; CENTRA, enhanced robust-timing angiography; RL, right-left; AP, anterior-posterior; CC, caudo-cranial; SENSE, sensitivity encoding.
- Table 4:
Sensitivity, specificity, PPV, and NPV of ASL-MRA, CE-MRA, and the combination of the 2 for detection of residual AVMs
ASL-MRA CE-MRA Both Sensitivity 88% 77% 100% Specificity 100% 100% 100% PPV 100% 100% 100% NPV 95% 90% 100% Diagnostic accuracy (ROC) 0.94 (P < .001)a 0.89 (P = .002)a 1 (P < .001)a Agreement (κ) 0.92 (P < .001) 0.82 (P < .001) 1 (P < .001) ↵a Null hypothesis: true area = 0.5.
Observer 1 Observer 2 DSA MRA DSA MRA SMS Size <3 cm 7 7 7 7 3–6 cm 2 2 2 2 >6 cm – – – – Drainage Superficial only 5 5 5 5 Deep 4 4 4 4 Eloquence Noneloquent 5 4 3 4 Eloquent 4 5 6 5 Feeding arteries 14 14 17 15 Draining veins 13 13 15 12 Note:—indicates non-applicable; SMS, Spetzler-Martin Score.
