OBJECTIVE: We studied the frequency, location, extent, and signal characteristics of nonenhancing tissue in pedal infections and correlated those areas with surgical and histologic findings. MATERIALS AND METHODS: One hundred ten contrast-enhanced 1.5-T MR imaging foot examinations in 102 patients (28 women, 74 men; mean age, 59 years), 82% of whom had diabetes mellitus, were reviewed by two musculoskeletal radiologists for the presence of areas without recognizable enhancement. The number, size, location, signal characteristics, and enhancement ratio of nonenhancing regions were noted. MR imaging findings were compared with surgical and histology reports. RESULTS: Nonenhancing regions were found in 27 feet (24.5%, 96.3% in diabetic patients, p = 0.032) at the forefoot (n = 16), toes (n = 8), and heel (n = 3). The mean size of the nonenhancing regions was 4.1 x 2.7 x 1.4 cm. Signal characteristics on T1-weighted images were isointense to muscle (n = 21, 77.8%), hypointense to muscle (n = 3, 11.1%), heterogeneous (n = 2, 7.4%), and isointense to fat (n = 1, 3.7%). On T2-weighted images, the signal was hyperintense to muscle (n = 12, 44.4%), heterogeneous to muscle (n = 9, 33.3%), equal to fluid (n = 3, 11.1%), and hypointense to muscle (n = 3, 11.1%). The mean signal increase after contrast administration was 3.57% for observer 1 and 2.68% for observer 2. Necrotic tissue was surgically confirmed in the nonenhancing areas in 26 feet (96.3%). Five abscesses and three cases of osteomyelitis were misdiagnosed on MR images because of lack of enhancement. CONCLUSION: Nonenhancing areas are seen in one fourth of pedal infections, occur almost exclusively in diabetic patients, and represent necrotic tissue. Only contrast-enhanced images allow reliable recognition of these regions. Lack of enhancement in these areas can mask the presence of abscess and osteomyelitis.
OBJECTIVE: We studied the frequency, location, extent, and signal characteristics of nonenhancing tissue in pedal infections and correlated those areas with surgical and histologic findings. MATERIALS AND METHODS: One hundred ten contrast-enhanced 1.5-T MR imaging foot examinations in 102 patients (28 women, 74 men; mean age, 59 years), 82% of whom had diabetes mellitus, were reviewed by two musculoskeletal radiologists for the presence of areas without recognizable enhancement. The number, size, location, signal characteristics, and enhancement ratio of nonenhancing regions were noted. MR imaging findings were compared with surgical and histology reports. RESULTS: Nonenhancing regions were found in 27 feet (24.5%, 96.3% in diabeticpatients, p = 0.032) at the forefoot (n = 16), toes (n = 8), and heel (n = 3). The mean size of the nonenhancing regions was 4.1 x 2.7 x 1.4 cm. Signal characteristics on T1-weighted images were isointense to muscle (n = 21, 77.8%), hypointense to muscle (n = 3, 11.1%), heterogeneous (n = 2, 7.4%), and isointense to fat (n = 1, 3.7%). On T2-weighted images, the signal was hyperintense to muscle (n = 12, 44.4%), heterogeneous to muscle (n = 9, 33.3%), equal to fluid (n = 3, 11.1%), and hypointense to muscle (n = 3, 11.1%). The mean signal increase after contrast administration was 3.57% for observer 1 and 2.68% for observer 2. Necrotic tissue was surgically confirmed in the nonenhancing areas in 26 feet (96.3%). Five abscesses and three cases of osteomyelitis were misdiagnosed on MR images because of lack of enhancement. CONCLUSION: Nonenhancing areas are seen in one fourth of pedal infections, occur almost exclusively in diabeticpatients, and represent necrotic tissue. Only contrast-enhanced images allow reliable recognition of these regions. Lack of enhancement in these areas can mask the presence of abscess and osteomyelitis.
Authors: Adam D Singer; Monica Umpierrez; Aparna Kakarala; Marcos C Schechter; Michael Maceroli; Gulshan B Sharma; Ravi R Rajani Journal: Skeletal Radiol Date: 2020-01-14 Impact factor: 2.199
Authors: Jacob C Mandell; Bharti Khurana; Jeremy T Smith; Gregory J Czuczman; Varand Ghazikhanian; Stacy E Smith Journal: Emerg Radiol Date: 2017-10-20
Authors: Martina Gurgitano; Giulia Signorelli; Giovanni Maria Rodà; Alessandro Liguori; Marco Pandolfi; Giuseppe Granata; Antonio Arrichiello; Anna Maria Ierardi; Aldo Paolucci; Gianpaolo Carrafiello Journal: Acta Biomed Date: 2020-09-23
Authors: Erin F Alaia; Avneesh Chhabra; Claus S Simpfendorfer; Micah Cohen; Douglas N Mintz; Josephina A Vossen; Adam C Zoga; Jan Fritz; Charles E Spritzer; David G Armstrong; William B Morrison Journal: Skeletal Radiol Date: 2021-06-18 Impact factor: 2.128