Impact of successive freezing-thawing cycles on 3-T magnetic resonance images of the digits of isolated equine limbs

in American Journal of Veterinary Research (2011), 72(6), 780-790

The purpose of this study was to assess the impact of freezing and thawing on MR images of equine feet examined ex vivo. Nine equine cadaver digits were first imaged at room temperature (T0). Among the 9 ... [more ▼]

The purpose of this study was to assess the impact of freezing and thawing on MR images of equine feet examined ex vivo. Nine equine cadaver digits were first imaged at room temperature (T0). Among the 9 digits, 3 (group 1) were imaged in a 3 Tesla MR system after one and after 2 freezing-thawing cycles. Digits of group 1 were thawed in a cold room at 4°C for 36h. Three other digits (group 2) were imaged after one freezing-thawing cycle. Digits of group 2 were thawed in a cold room at 4°C and then rescanned after 24h at room temperature. The last 3 digits (group 3) were scanned after one freezing-thawing cycle. Digits of group 3 were thawed at room temperature for 24h. Sequences used were Spin Echo (SE) T1, Turbo Spin Echo (TSE) T2 and proton density (PD), Short Tau Inversion Recovery (STIR), Double Echo Steady State (DESS), 3D Gradient Echo (GE) T1 and 2D GE T2*. Images obtained on the fresh limbs at room temperature were subjectively compared side by side to images obtained at the different freezing-thawing cycles. A quantitative analysis to assess signal change between examinations was realized by measuring signal to noise ratio (SNR). Visibility and margination of the anatomical structures of the foot and overall image quality were subjectively considered unchanged except for the hoof where the lamina was considered less visible distally after freezing and thawing in the GE T2* and in TSE T2 and PD sequences. Quantitative analysis demonstrated SNR changes in the bone marrow only in the distal phalanx in the SE T1 sequence when the feet were thawed at room temperature. When the feet were thawed in a cold room at 4°C, bone marrow SNR changes were present in the SE T1, GE T1 and TSE PD sequences. Signal changes were significant in the synovial recess when the thawing process was made at 4°C and not when the thawing process was at ambient temperature. The soft tissue structures and the hoof capsule showed significant changes with an increase of SNR, except in STIR, after freezing and thawing at 4°C and at room temperature. SNR changes in the soft tissues were mainly present in GE sequences. [less ▲]

Changes during time in MR Images of isolated limbs refrigerated at 4°C

Poster (2009)

Wall stent placement to prevent coils migration during intrahepatic embolisation of porto-systemic shunt in a dog

Poster (2007, September)

Selective coil occlusion of a large arterioportal fistula in a liver graft

in Liver Transplantation (2006), 12(5), 888-889

Magnetic resonance imaging findings in the equine deep digital flexor tendon and distal sesamoid bone in advanced navicular disease--an ex vivo study.

in Veterinary Radiology & Ultrasound (2005), 46(4), 279-86

We describe the abnormal magnetic resonance (MR) imaging findings in the deep digital flexor tendon (DDFT) and distal sesamoid bone in horses with radiographic changes compatible with navicular syndrome ... [more ▼]

We describe the abnormal magnetic resonance (MR) imaging findings in the deep digital flexor tendon (DDFT) and distal sesamoid bone in horses with radiographic changes compatible with navicular syndrome. Thirteen postmortem specimens were examined using a 1.5-T magnetic field, with spin echo (SE) T1-weighted, turbo SE (TSE) proton density-weighted (with and without fat saturation), and fat saturation TSE T2-weighted sequences. The limbs were then dissected to compare the MR findings with the gross assessment and histologic examination of the DDFT and distal sesamoid bones. Tendonous abnormalities were detected by MR imaging in 12 DDFTs and confirmed at necropsy. Most tendon lesions were located at the level of the distal sesamoid bone and the proximal recess of the podotrochlear bursa. Tendon lesions were classified based on their MR imaging features as core lesions, dorsal lesions, dorsal abrasions, and parasagittal splits. Areas of increased MR signal in the DDFTs were characterized by tendon fiber disturbance and lack of continuity of the collagen fibers, foci of edema, hemorrhages, and formation of lakes containing eosinophilic plasma-like material or amphophilic material of low density. Bone marrow signal alterations in the distal sesamoid bone were seen in all digits. Two main phenomena were responsible for the abnormal signal, respectively, in T1-weighted (decreased signal) and in T2-weighted fat-suppressed images (increased signal): a decrease in the fat marrow content in the trabecular spaces and an increase in the fluid content. Histologic examination revealed foci of bone marrow edema, hemorrhage, necrosis, and fibrosis. Cyst formation and trabecular abnormalities (disorganization, thinning, remodelling) were also observed in areas of abnormal signal intensity. Increased bone density because of trabecular thickening induced a decrease in signal in all sequences. [less ▲]

Interet et limites du depistage de masse du cancer du sein par mammographie seule (mammotest)

in Revue Médicale de Liège (2003), 58(5), 331-7

The literature on screening mammography provides ample opportunity for doubt (the sceptics) and dogma (the screening zealots), and can be interpreted to prove both benefit and harm. The benefit of ... [more ▼]

The literature on screening mammography provides ample opportunity for doubt (the sceptics) and dogma (the screening zealots), and can be interpreted to prove both benefit and harm. The benefit of mammography screening, if any, is modest and the balance between beneficial (potentially, a 20% relative reduction in breast cancer mortality with no significant benefit on all-cause mortality) and harmful (physical and psychological morbidity related to the 15-40% missed cancers and the 80-90% false-positive diagnoses) effects is still delicate. The mammogram alone is a modest weapon. Concurrent clinical breast examination is mandatory. Women that are concerned about breast cancer should be fully informed of the potential benefits and risks of screening mammography. These women should benefit from mammography with concurrent clinical breast examination, and possible whole-breast ultrasound in heterogeneously dense and extremely dense breast patterns. [less ▲]

Percutaneous stereotactic en bloc excision of nonpalpable breast carcinoma: a step in the direction of supraconservative surgery

in Breast (Edinburgh, Scotland ) (2002), 11(6), 501-508

Recently, the advanced breast biopsy instrumentation (ABBI) system has been introduced as an alternative to conventional breast biopsy techniques. This study was prospectively conducted to evaluate the ... [more ▼]

Recently, the advanced breast biopsy instrumentation (ABBI) system has been introduced as an alternative to conventional breast biopsy techniques. This study was prospectively conducted to evaluate the potential of the ABBI method in locoregional management of a consecutive series of patients with nonpalpable mammographically detected breast carcinomas. Sixty-one consecutive patients underwent an ABBI procedure as a first step before possible surgery for nonpalpable breast lesions that would in any case require complete excision. For the 27 patients in whom the ABBI biopsy revealed malignancy further surgery was recommended, including re-excision of the biopsy site and axillary dissection in cases of infiltrating carcinoma. We calculated the probabilities that the ABBI specimen would have tumor-free margins and that a definitely complete excision had been achieved as a function of the mammographic or pathological diameter of the cancer. For cancer with a pathological diameter less than 10 mm, measured on the ABBI specimen, the probability (92%) of obtaining complete resection was significantly better than for larger lesions (P = 0.01, Fisher's exact test). Although the therapeutic perspectives for the ABBI method are limited at present, we suggest that this approach is a first step in the direction of a surgical strategy that is better adapted to the pathological characteristics peculiar to these small tumors, whose incidence is increasing. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

Canina aspergillosis : diagnosis with computed tomography and magnetic resonance

Conference (2002)

Liver transplantation in a Jehovah's witness

in Lancet (1999), 353

Evaluation of us-guided percutaneous fine needle aspiration biopsyin thyroïd nodules

in International Congress of Head and neck Radiology - Abstract book (1997)