Filip De Ridder

Posterolateral supporting structures of the knee: findings on anatomic dissection, anatomic slices and MR images

Abstract. In this article we study the ligaments and tendons of the posterolateral corner of the knee by anatomic dissection, MR-anatomic correlation, and MR imaging. The posterolateral aspect of two fresh cadaveric knee specimens was dissected. The MR-anatomic correlation was performed in three other specimens. The MR images of 122 patients were reviewed and assessed for the visualization of different posterolateral structures. Anatomic dissection and MR-anatomic correlation demonstrated the lateral collateral, fabellofibular, and arcuate ligaments, as well as the biceps and popliteus tendons. On MR images of patients the lateral collateral ligament was depicted in all cases. The fabellofibular, arcuate, and popliteofibular ligaments were visualized in 33, 25, and 38% of patients, respectively. Magnetic resonance imaging allows a detailed appreciation of the posterolateral corner of the knee.

Calcific tendinitis of the longus colli muscle: Case report

To the best of our knowledge, only one patient with calcium hydroxyapatite deposition disease (CHADD) of the longus colli muscle has been reported in the otolaryngology literature.

Postmastectomy lymphoedema: different patterns of fluid distribution visualised by ultrasound imaging compared with magnetic resonance imaging

OBJECTIVES Postmastectomy lymphoedema remains a disabling complication caused by treatment for breast cancer. The increased thickness of the dermal layer and the increased volume of the subcutis represent the most important contributions to the total swelling of the arm. Ultrasound imaging of the subcutaneous layer results in different patterns of reflected ultrasound waves depending on the morphological alternations that occurred due to impaired lymphatic drainage. The aim of this study was to compare these echographic images with those obtained using magnetic resonance imaging to explain the nature of the morphological changes. DESIGN Observational study. SETTING Patients were recruited from the Breast Clinic at the University Hospital Brussels. PARTICIPANTS Seven women (mean age 60 years) with unilateral breast cancer who subsequently developed lymphoedema. MAIN OUTCOME MEASURES The water displacement technique was applied to determine arm volumes, and echographic and magnetic resonance images were used to evaluate changes in tissue structures. RESULTS Volumetric measurements of the arm (mean affected arm 3241 ml vs unaffected arm 2538 ml) showed a significant increase in total arm volume of 703 ml (95% confidence interval 324 to 1084 ml). Using echography, the thickness of the dermal and subcutaneous layers showed an average increase of 0.2 to 0.8mm and 3.9 to 7.2mm, respectively. The differences between the affected arm and the unaffected arm for all upper and lower arm measurements (i.e. volumetry, dermal and subcutaneous thickness) were significant, but no significant differences were registered for hand measurements. On echography, the dermis showed uniform changes, with a homogenous hypo-echogenic appearance compared with the contralateral side due to water influx. Different patterns of structural changes could be visualised within the subcutis: (1) uniformly hypo-echogenic due to the diffuse spread of water through the subcutis; (2) hyperechogenic areas surrounded by hypo-echogenic streaks visualised on magnetic resonance imaging as adipose tissue surrounded by fluid embedded in fibrous tissue; and (3) homogenously hyperechogenic due to the overgrowth of adipose tissue with a minimal amount of water. CONCLUSIONS Echographic images can help to determine the likelihood that complex physical therapy will reduce lymphoedema, and evaluate treatment results by measuring tissue thickness and evaluating tissue consistency.

MR imaging of meniscal cysts: evaluation of location and extension using a three-layer approach.

PURPOSE To analyze the extension of medial and lateral meniscal cysts relative to the capuloligamentous planes of the knee. MATERIALS AND METHODS The MR images of 32 patients with meniscal cysts were reviewed. The location and extension of the meniscal cysts with reference to the capsule and ligaments were recorded. RESULTS Most medial meniscal cysts were located posteromedially. Posteromedial meniscal cysts usually penetrated the capsule and were located between layer I and the fused layers II+III. From this site some extended anteriorly and then became located superficial to the superficial MCL. The location of lateral meniscal cysts was more varied. Anteriorly the cysts were located deep to the iliotibial band, whereas posterolateral cysts were located deep to the lateral collateral ligament. CONCLUSION Although the site of capsular penetration of meniscal cysts is determined by the location of meniscal tears, the possible pathways of extension appear to be determined by the capsuloligamentous planes of the knee.

Histological Findings Compared with Magnetic Resonance and Ultrasonographic Imaging in Irreversible Postmastectomy Lymphedema: A Case Study

Postmastectomy edema is a current complication after axillary lymph node dissection in cases of breast cancer treatment. Staging is important in order to select those patients who can benefit from complex physical therapy (CPT). Different imaging techniques can be used to evaluate the edema. Ultrasonography (US) is a harmless, cheap, and easily applicable technique to visualize the dermal and subcutaneous tissue, but interpretation of the obtained images is not always evident. The aim of this study was to compare ultrasound images of irreversible edema with tissue histology, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Ultrasonographic images of the edematous dermis show an homogeneous hypoechogenic dermal layer that appears on tissue histology to be less compact, due to the excess of fluid in the interstitium separating the collagen fibres and making it more transparent on light microscopy. MRI of the dermis gives a hyperintense signal, indicating the presence of fluid. In the subcutis, increase of the adipose tissue could be observed on US, MRI, and tissue histology. In the case of lymphedema, the area and perimeter of fat cells is significantly (p < 0.05) increased. Hypoechogenic areas near the muscle fascia are registered on US corresponding with epifascial fluid on MRI, and hyperechogenic branches are embedded within the adipose tissue, on tissue histology seen as large fibrotic septa enclosing adipose cells. MRI has a honeycomb picture corresponding with fluid bound to fibrosis.

Magnetic resonance imaging of the heart in a case of hepatocellular carcinoma extending into the right atrium

Hepatocellular carcinoma is the most common primary malignant liver tumor occuring in more than 1 million cases a year all over the world. Vascular invasion is known to occur in 30% of patients at initial presentation [1]. An extension of the tumor into the right atrium is well described in the literature [2], with surgical resection as the only procedure available. But the diagnosis is often difficult before death. We report a case in which magnetic resonance imaging of liver and heart shows the extension of this tumor into the right atrium

Meniscal tears: comparison of half-Fourier technique and conventional MR imaging

PURPOSE To determine whether half-Fourier MR image acquisition technique can provide similar information to that of conventional MR acquisition technique for evaluation of meniscal tears. MATERIALS AND METHODS We studied 101 menisci in 52 patients who were referred for evaluation of meniscal tears. Sagittal MR images of the knee were obtained for all patients by using proton density and T2-weighted SE sequences on a 1-T clinical system. The half-Fourier technique and conventional technique were used for all patients. All other imaging parameters were identical for both sequences (TR/TE=2400/20,70; 3 mm slice thickness; 200 x 256 matrix; field of view, 200; one signal acquired). Both sets of images were filmed with standard window and level settings. Images were randomised and interpreted independently by two radiologists for the presence of meniscal tears. Images were also subjectively assessed for image quality using a five-point grading scale. RESULTS On half-Fourier images, Reader 1 interpreted 23 menisci as torn, compared to 28 for Reader 2. On conventional images, Reader 1 interpreted 24 menisci as torn, compared to 26 for Reader 2. Agreement between interpretation of the conventional and that of the half-Fourier images was 99% for Reader 1, and 98% for Reader 2. Agreement between readers for the half-Fourier images was 95%, and for the conventional images 96%. No statistically significant difference was found in the subjective evaluation of image quality between the conventional and half-Fourier images. CONCLUSION The half-Fourier acquisition technique compares favourably with the conventional technique for the evaluation of meniscal tears.

Comparison of Several White Matter Tracts in Feline and Canine Brain by Using Magnetic Resonance Diffusion Tensor Imaging

Recently, we published a first anatomical diffusion tensor imaging (DTI) atlas regarding white matter tracts in the canine brain. The purpose of this study was to show the significance of DTI in the revelation of the white matter fibres in the feline brain (i.e., to obtain an anatomical DTI atlas of images) and to descriptively compare these to previously obtained white matter fibre images of the canine brain. DTI MR Images of four cats euthanized for reasons other than neurological disorders were obtained with a 3 T system. Combined fractional anisotropic (FA) and directional maps were obtained within the hour after death. An experienced anatomist tracked white matter tracts of clinical relevance using the scanner software. After validation of these tracts, we compared relevant neurological connections between the cat and the dog. Comparison of cerebral structures between different species is easier when the three dimensional anatomy is visualized by using DTI. 3D rendered DTI images clearly show major differences in neurological architecture between cats and dogs for example, the more important space occupying role of the limbic system, and the less diffuse, less nodular, less pronounced and thinner fibre bundles in the feline brain compared to the canine brain (except for the cerebellum different parts connecting fibres passing through the brainstem which are pronouncedly developed). Anat Rec, 300:1270–1289, 2017.

Aorta dissection with two separate false lumina, diagnosed by magnetic resonance imaging—A case report

A forty-five-year—old woman with a history of arterial hypertension was diagnosed as having a dissection of the ascending aorta progressing toward the descending aorta, where two false lumina were shown on magnetic resonance dynamic and spin-echo imaging and confirmed at autopsy. The other imaging techniques used did not allow a precise visualization of this anomaly. The place of the different imaging techniques in this type of aortic dissection is discussed.