Soft tissue enhancement on time‐resolved peripheral magnetic resonance angiography

Abstract

Purpose: To evaluate the incidence and locations of soft tissue enhancement on time-resolved two-dimensional projection magnetic resonance angiography (MRA) of the calf and foot. Materials and Methods:Time-resolved two-dimensional projection MRA of the knee, calf, and foot, performed at 1.5 Tesla using the head coil, was retrospectively reviewed in 326 patients. Soft tissue enhancement of the foot was identified and graded by blinded review. Subsequently, patient medical records were reviewed to determine the presence or absence of diabetes, cellulitis, gangrene, and ulceration of the foot and presence of neuropathic joints.Results: Enhancing spots were identified in 228 patients. For those feet without clinical abnormalities, diabetic patients had an average of 1.2 enhancing spots per foot, while nondiabetics had only 0.6 (P Ͻ 0.001). Higher-grade lesions were more prevalent in diabetics and in heavier patients. Of 64 patients with follow-up, 8 (13%) developed cellulitis (N ϭ 4) or ulceration (N ϭ 4) at the location of an enhancing spot, including 5 diabetic and 3 nondiabetic patients. Conclusion:Pedal soft tissue enhancement frequently occurs on time-resolved gadolinium (Gd):MRA of the feet. The etiology is uncertain, but the high frequency in diabetic patients and observation of progression to cellulitis/ulceration suggest this soft tissue enhancement may identify sites of subclinical pedal soft tissue injury.

Dynamic MR venography: An intrinsic benefit of time‐resolved MR angiography

“…The use of venous contrast dynamics permits accurate visualization of the venous structure, especially in sites where soft‐tissue enhancement quickly obscures the vasculature. Furthermore, the time‐resolved data can be used to generate contrast dynamics in soft tissues, which may help to identify sites of subclinical soft‐tissue injury (19). High temporal resolution is critical for the simultaneous generation of arterial and venous contrast dynamics.…”

Noncontrast MRA of Pedal Arteries in Type II Diabetes

“…Its mechanism remains unclear. Impaired local biomechanics due to the altered local pharmacokinetic dynamics in the subclinical tissue injury (22), irregular local microcirculation (23), increased permeability, and exudation with a high content of protein as a result of fragile capillary bed may contribute to the unexpected prominent signal intensity of soft tissue in MRA. These may partially explain the finding that SC in NC-MRA with FSD-SSFP worsened with increased degree of diabetic foot wound indexed by RDF in this study.…”

Comprehensive MR angiography of the lower limbs: a hybrid dual-bolus approach including the pedal arteries

“…However, we observed areas with focal or diffuse softtissue enhancement patterns in about 32% of all feet. These hyperemic areas are frequently seen on late phases of timeresolved 3DceMRA images in diabetic patients suffering from cellulites, gangrene, or ulceration [38].…”