Debra Trudell

Calcification in calcium pyrophosphate dihydrate (CPPD) crystalline deposits in the knee: anatomic, radiographic, MR imaging, and histologic study in cadavers.

ObjectiveTo demonstrate and determine the frequency and location of calcification within cadaveric knees with or without calcification typical of calcium pyrophosphate dihydrate (CPPD), utilizing histologic, radiographic and MR imaging techniques.Design and patientsTen cadaveric knees of elderly individuals that demonstrated no radiographic evidence of prior surgery or trauma were studied with MR imaging and subsequently sectioned in planes corresponding to those obtained with MR imaging. The slices were imaged with high-resolution radiography. Two musculoskeletal radiologists correlated the anatomic, MR and radiographic findings. Three of the knees, which did not demonstrate calcifications, were utilized as controls. Histologic sections were obtained from four knees that contained calcifications and from the three controls, and analyzed with special histologic stains that demonstrate phosphorus and calcium.ResultsRadiographic imaging and histologic analysis demonstrated widespread CPPD crystal deposition in four of the 10 knee specimens (40%). MR imaging demonstrated some calcifications only within the articular cartilage of the femoral condyles in three of the four (75%) specimens that had CPPD deposits. In all four specimens radiographs and histologic analysis were more sensitive than MR imaging. Histologic analysis demonstrated no evidence of CPPD crystals in the control specimens.ConclusionMR imaging is insensitive to the presence of CPPD deposits in the knee, even when such deposits are widespread. Our study suggests that the sensitivity of MR imaging was significantly better in detecting CPPD deposits in the hyaline cartilage of the femoral condyles when compared with other internal structures, even when such structures contained a higher amount of calcification.

Rotator cuff interval : Evaluation with MR imaging and MR arthrography of the shoulder in 32 cadavers

Purpose The purpose of this work was to establish the optimal means of evaluation of the rotator cuff interval (RCI) and rotator interval capsule and demonstrate normal anatomy of the RCI using MR imaging and MR arthrography. Method MR arthrography was performed in 32 cadaveric shoulders. In 20 cases, MR imaging was completed prior to arthrography. Pre-and postarthrography studies included standard imaging planes. Images were evaluated by the consensus of two musculoskeletal radiologists with attention to the RCI, rotator interval capsule (measurements on postarthrographic studies), and crossing structures. In five cases, specialized imaging planes were performed after arthrography. Results The RCI, rotator interval capsule, and crossing structures were best evaluated by MR arthrography. The anteroposterior dimension of the rotator interval capsule could be best depicted on postarthrogram images. Conclusion MR arthrography, with both standard and specialized imaging planes, is a useful way to evaluate the RCI, the rotator interval capsule, and its crossing structures.

Posteromedial corner of the knee: MR imaging with gross anatomic correlation

Abstract Objective. The objective of this study was to illustrate the magnetic resonance (MR) image appearance of the structures of the posteromedial ”corner” of the knee with particular emphasis on the anatomy and differentiation between the medial collateral ligament and the posterior oblique ligament. Design. Six cadaveric knee specimens underwent MR imaging, before and following instillation of intra-articular contrast material. The knees were sectioned in the axial, coronal, and coronal oblique planes and the gross morphology of the posteromedial corner and surrounding structures was studied and correlated with the MR images. Patients. The human cadaveric specimens were from two female and four male patients (age at death, 72–86 years; average, 78 years). Results and conclusions. The contrast-enhanced sequences and the coronal oblique images allowed for improved visualization of the structures.

Tibiofibular syndesmosis: high-resolution MRI using a local gradient coil.

PURPOSE Our goal was to correlate high-resolution MR images of the tibiofibular syndesmosis with anatomic sections. METHOD MRI was performed inside a local gradient coil on six cadaveric feet taped in 10-20 degrees dorsiflexion and 40-50 degrees plantar flexion by using axial and coronal T1-weighted SE sequences. After imaging, the specimens were frozen and sectioned into 3-mm-thick slices along the MR planes. Images were correlated with the anatomic sections. RESULTS MRI depicted the anatomy of the tibiofibular syndesmosis and surrounding structures. With the foot taped in dorsiflexion, axial imaging provided optimum views of the anterior, posterior, interosseous, and transverse tibiofibular ligaments. Coronal images allowed visualization of the entire course of the anterior, posterior, and transverse tibiofibular ligaments. The multifascicular appearance of the anterior tibiofibular ligament was best visualized in coronal sections. With the foot taped in dorsiflexion or in plantar flexion, it was possible to distinguish the posterior tibiofibular ligament and transverse tibiofibular ligament from the posterior talofibular ligament in all specimens. CONCLUSION High-resolution MRI using a local gradient coil provides excellent delineation of the ligaments of the distal tibiofibular syndesmosis.

Capsular Ligaments of the Hip: Anatomic, Histologic, and Positional Study in Cadaveric Specimens with MR Arthrography

PURPOSE To demonstrate the anatomy of the capsular ligaments of the hip by using magnetic resonance (MR) arthrography. MATERIALS AND METHODS Institutional policies were followed regarding cadaver use. MR arthrographic images of 10 fresh human cadaveric hips were obtained by using a positioning device to arrange the hip joint in different controlled positions. MR appearances of the capsular structures were noted and correlated with those seen on anatomic slices and dissections. Two readers working in consensus graded the visibility of these structures. Tissue samples were collected for histologic analysis. An MR positional study was performed to evaluate the length of these capsular ligaments and the subjective classification of their appearance as either taut or lax in extension, flexion, abduction, adduction, and internal and external rotation. RESULTS The hip capsule inserts proximally and continuously to the acetabular rim periosteum. Distally, it has a firm anterior insertion at the femoral intertrochanteric line and no posterior osseous insertion. The inferior band of the iliofemoral ligament was best evaluated in the sagittal, axial, and axial oblique planes, and it serves a restrictive function in extension; the superior band of the iliofemoral ligament was best evaluated in the coronal and axial oblique planes, and it serves a restrictive function in external rotation; the ischiofemoral ligament was best evaluated in the axial and axial oblique planes, and it serves a restrictive role in internal rotation; the pubofemoral ligament was best evaluated in the sagittal plane, and it serves a restrictive function in abduction; and the zona orbicularis could be evaluated equally well in any imaging plane. CONCLUSION MR arthrography enables visualization of the capsular ligaments of the hip.

Ligaments of the Ankle: Normal Anatomy with MR Arthrography

PURPOSE Our purpose was to define the normal MR arthrographic anatomy of ankle ligaments. METHOD Prior to injection of intraarticular gadolinium in cadaveric ankle joints, proton density and T2-weighted images were obtained to assess the integrity of the ligaments and tendons as well as the amount of preexisting joint effusion. Following injection of 10 ml of contrast agent (gadopentetate dimeglumine 1:250, Omnipaqe 300, Knox gelatin 50%, and methylene blue), T1-weighted images with fat saturation in axial, oblique axial, coronal, and sagittal planes were obtained in neutral, dorsiflexion, and plantar flexion positions. Specimens were sectioned, allowing anatomic and MR correlation. RESULTS Contrast agent outlining anterior and posterior aspects of the anterior talofibular ligament and posterior talofibular ligament (PTAF) was a normal finding, related to anterior and posterior recesses of the ankle joint that extend out beyond these ligaments in an anteroposterior direction above the level of the ligaments. Intraarticular contrast material allowed resolution of superficial and deep components of the posterior tibiofibular ligament. Both were seen separately from PTAF with dorsiflexion. Posterior intermalleolar ligament was not present in our specimens. Visualization of calcaneofibular ligament was much improved by contrast material outlining the articular aspect of the ligament. Visualization of the syndesmotic ligamentous complex also was improved by contrast material outlining the articular side of the ligaments and separating them from adjacent bone. Superiorly, the distribution of contrast agent was limited by the interosseous ligament. Visualization of the medial collateral ligaments was not improved by the presence of the intraarticular contrast material. CONCLUSION MR arthrography of the ankle allows improved visualization and evaluation of the lateral and syndesmotic ligamentous complex.

Intracapsular origin of the long head of the biceps tendon

Abstract A developmental anomaly of the long head of the biceps tendon was found in a cadaveric shoulder. Findings on arthroscopy, routine MR imaging, and MR arthrography were compared and correlated with results of anatomic dissection. MR arthrography appears to be a very good diagnostic imaging method for depicting this anomaly prior to arthroscopy.

Retinacula of the Foot and Ankle: MRI with Anatomic Correlation in Cadavers

OBJECTIVE The retinacula of the ankle are regions of localized thickening of superficial aponeurosis that provide mechanical strength to prevent tendon bowstringing. The purpose of this study was to define the foot and ankle retinacula as seen on MRI with anatomic correlation in cadavers. MATERIALS AND METHODS Ten fresh foot and ankle specimens from humans were imaged with 1.5-T MRI. T1- and intermediate-weighted images were obtained in the axial, coronal, and sagittal planes. Specimens then were sectioned into 3-mm-thick sections in either the axial or the coronal plane to correspond with the MR images. Two radiologists interpreted the MR images and sections by consensus for the anatomic landmarks and best imaging planes for identification of the retinacula and discernment of their shape, thickness, and relations to adjacent tendons. RESULTS Normal retinacula of the ankle appeared as bands of low signal intensity in both MRI sequences. The bony landmarks were helpful in localization of the attachment sites of the retinacula. The superior extensor retinaculum and superior and inferior peroneal retinacula were optimally visualized on axial images. Their thicknesses averaged 0.9, 1.0, and 0.8 mm, respectively. The flexor retinaculum and three root components (medial, intermediate, and lateral) of the stem ligament of the inferior extensor retinaculum were well seen in the coronal plane. The average thicknesses of these structures were 0.9, 1.5, 1.0, and 0.9 mm, respectively. CONCLUSION MRI in standard orthogonal planes is a useful technique for visualizing the attachment sites, signal intensity, and normal thickness of foot and ankle retinacula.

What happens to the triangular fibrocartilage complex during pronation and supination of the forearm? Analysis of its morphology and diagnostic assessment with MR arthrography

Objective: To evaluate the dynamic morphologic changes of the triangular fibrocartilage complex (TFCC) during pronation and supination of the forearm using high-resolution MR arthrography in cadavers and to evaluate the impact of these changes on the diagnostic assessment of the normal and abnormal TFCC. Design and specimens: High-resolution MR arthrography of 10 wrists of cadaveric specimens was obtained in maximum pronation, in the neutral position, and in maximum supination of the forearm. The structures of the TFCC were evaluated by two musculoskeletal radiologists and correlated with anatomic sections. The position of the forearm that allowed the best visualization of normal structures and lesions of the TFCC was determined. Results: The shape and extent of the articular disc as well as the radial portions of the radioulnar ligaments did not change with pronation and supination. The articular disc was horizontal in the neutral position and tilted more distally to align with the proximal carpal row in pronation and supination. The fibers of the ulnar part of the radioulnar ligaments (ulnar attachment of the articular disc) revealed the most significant changes: their orientation was coronal in the neutral position and sagittal in positions of pronation and supination. The ulnomeniscal homologue was largest in the neutral position and was reduced in size during pronation and supination. The extensor carpi ulnaris tendon was centered in its groove in the neutral position and pronation. In supination this tendon revealed subluxation from this groove. The dorsal capsule of the distal radioulnar joint was taut in pronation, and the palmar capsule was taut in supination. The preferred forearm position for analysis of most of the structures of the TFCC was the neutral position, followed by the pronated position. The neutral position was rated best for the detection of ulnar and radial detachments of the TFCC, followed by the pronated position, except for two central perforations of the TFCC which were best seen with supination. Conclusion: The articular disc and the surrounding radial portions of the radioulnar ligaments form a rigid, unified complex with the radius without change in their shape in positions of pronation and supination of the forearm, while the ulnar attachment of the TFCC shows important dynamic changes. The neutral forearm position is the best position to analyze both the normal and the abnormal TFCC.

Tendons in the plantar aspect of the foot: MR imaging and anatomic correlation in cadavers.

Objective:The purpose of this anatomic imaging study was to illustrate the normal complex anatomy of tendons of the plantar aspect of the ankle and foot using magnetic resonance (MR) imaging with anatomic correlation in cadavers.Design:Seven fresh cadaveric feet (obtained and used according to institutional guidelines, with informed consent from relatives of the deceased) were studied with intermediate-weighted fast-spin-echo MR imaging. For anatomic analysis, cadaveric specimens were sectioned in 3-mm-thick slices in the coronal and axial planes that approximated the sections acquired at MR imaging.Results:The entire courses of the tendons into the plantar aspect of the foot were analyzed. The tibialis posterior tendon has a complex distal insertion. The insertions in the navicular, second, and third cuneiforms bones were identify in all cases using axial and coronal planes. A tendinous connection between the flexor hallucis longus and the flexor digitorum longus tendons was identified in five of our specimens (71%). The coronal plane provided the best evaluation. The peroneus longus tendon changes its direction at three points then obliquely crosses the sole and inserts in the base of the first metatarsal bone and the plantar aspect of the first cuneiform.Conclusions:MR imaging provides detailed information about the anatomy of tendons in the plantar aspect of the ankle and foot. It allows analysis of their insertions and the intertendinous connection between the flexor hallucis longus and the flexor digitorum longus tendons.