Pisotriquetral joint: assessment with MR imaging and MR arthrography

PURPOSE: To evaluate magnetic resonance (MR) imaging and MR arthrographic findings in the pisotriquetral joint (PTJ) and their contribution to assessment of PTJ osteoarthritis. MATERIALS AND METHODS: Images of 22 fresh human cadaveric PTJs were obtained with both conventional and arthrographic MR techniques. The MR appearances of all intraarticular and periarticular structures were analyzed and correlated with anatomic slices. Two readers graded visibility of anatomic structures and severity of joint abnormalities. Differences in the visibility ratings at standard MR imaging and at MR arthrography were calculated. Association between the type of pisiform insertion of ligament or muscle with cartilaginous abnormalities of the PTJ was assessed. The association between cartilaginous lesions and osteoarthritic changes was calculated. RESULTS: The tendon sheath, the fibrous capsule, and cartilaginous surfaces were better visualized at MR arthrography than at MR imaging. Pisohamate and pisometacarpal ligaments were slightly better seen on MR arthrograms. Tendons, muscles, and retinacular structures were well demonstrated at both conventional MR and MR arthrography. Cartilaginous lesions and osteophytes were easily identified and were detected more often in the pisiform bone than in the triquetral bone. Communication of the PTJ with the radiocarpal joint was noted in 18 (82%) of 22 wrists. CONCLUSION: MR imaging and/or MR arthrography allows visualization of all anatomic structures of the PTJ. MR arthrography improves visualization of findings of osteoarthritis.     

Temporomandibular joint: multislab, three-dimensional Fourier transformation MR imaging

High-resolution three-dimensional Fourier transformation (3DFT) multislab acquisitions and a specially designed counter-rotating loop surface coil were used to increase the quality and clinical efficacy of imaging of the temporomandibular joint. The results were compared with those of 2D multisection imaging. Multislab 3DFT magnetic resonance imaging combines the advantages of volume imaging for viewing small structures and the clinical efficiency of 2DFT multisection acquisitions. A 3DFT multislab acquisition, coupled with a specially designed coil, yields two slabs of 16 sections each. The thin-section 3D imaging method facilitates the diagnosis of medially and laterally displaced disks and allows a bilateral examination.     

Temporomandibular joint after meniscoplasty: appearance at MR imaging

Twenty-five temporomandibular joints (TMJs) were studied in 20 patients who had undergone meniscoplasty. In all patients, preoperative magnetic resonance (MR) images showed anteriorly dislocated disks; all patients underwent a similar postoperative MR examination an average of 6 months after surgery. The results of these studies were correlated with clinical results of surgery, which were classified as poor, fair, good, or excellent at follow-up MR imaging. In 10 TMJs (eight patients [40%]) the clinical results were excellent or good; in 15 TMJs (12 patients [60%]), fair or poor. The position of the disk relative to its preoperative position was a good discriminator in determination of the clinical success of meniscoplasty. After surgery, in all patients with good or excellent results, the disks appeared to be in a normal or an improved position compared with that prior to surgery; in those with poor or fair results, the TMJs had anteriorly dislocated disks that showed no improvement.     

Temporomandibular joint: comparison of single- and double-contrast arthrography

Lower-space, single-contrast arthrography and dual-space, double-contrast arthrotomography were sequentially applied to 58 fresh temporomandibular joint (TMJ) autopsy specimens, and the findings were compared with observations in corresponding cryosections. Both modalities had high accuracy rates (greater than or equal to 84%) and no statistically significant differences between the two techniques were found. A side-by-side comparison of the two types of arthrograms, however, revealed that video tape recording of lower-space, single-contrast arthrography was superior in demonstrating joint dynamics and that dual-space, double-contrast arthrotomography was superior in demonstrating the soft-tissue anatomic features of the joint. It appears that lower-space, single-contrast arthrography can be recommended for examination of patients with clicking, catching, and intermittent locking, and that dual-space, double-contrast arthrotomography is preferable when information about morphologic alterations is clinically more important than information about joint dynamics.     

Temporomandibular joint: MR imaging of internal derangements and postoperative changes

Nineteen abnormal temporomandibular joints (TMJs) imaged with high-field-strength surface-coil MR are presented to illustrate specific changes associated with disk derangement, trauma, and previous surgery. Cases were selected from a series of 248 TMJ MR studies in 144 patients (9-68 year old, 130 females and 14 males) performed during a 5-month period. Surgical findings were available for correlation in 44 of the 248 joints studied. Increased signal caused by myxoid degeneration within the degenerating meniscus was seen, as were pathologic changes including atrophy, fibrosis, and contracture of masticatory muscles occurring with internal derangements. Advantages and limitations of MR are discussed with reference to arthrography and videofluoroscopy. High-resolution and partial-flip-angle images of a normal joint are provided for comparison. In most clinical circumstances, MR is the procedure of choice when examining the TMJ, because it provides contrast resolution of soft-tissue structures superior to that of conventional imaging techniques.     

Temporomandibular joint arthrography: dynamic study by videorecording

Temporomandibular joint symptoms are common. Patients not successfully treated by conservative methods require accurate assessment of the internal derangements of the joint. Temporomandibular joint arthrography using only videorecorded intensifier fluorography displays the anatomy and function accurately with a low radiation dose.     

Temporomandibular joint motion: efficacy of fast low-angle shot MR imaging

One hundred temporomandibular joints (TMJs) in 62 symptomatic patients and two healthy volunteers were prospectively examined with T1-weighted spin-echo and fast low-angle shot (FLASH) gradient-echo sequences. FLASH sequences were performed during opening of the mouth and provided a pseudodynamic depiction of TMJ motion. In 49 joints, FLASH sequences provided information that potentially influenced the therapeutic approach to the patient. This information was not available from standard T1-weighted images. The additional information fell into four general categories: (a) determination of the exact time of disk recapture, (b) distinction of normal variants from pathologically displaced disks, (c) clarification of discrepancies found between clinical examination results and T1-weighted images, and (d) elimination of motion degradation of images.     

Meniscal abnormalities: prospective correlation of double-contrast arthrography and arthroscopy

In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed.     

MR imaging,MR arthrography,and specimen correlation of the posterolateral corner of the knee: an anatomic study

OBJECTIVE: We sought to evaluate the anatomy of the posterolateral aspect of the knee with anatomic dissection, MR imaging, MR arthrography, and sectional anatomy. MATERIALS AND METHODS: We assessed the posterolateral corner of the knee during dissection of one gross anatomic specimen. MR imaging and MR arthrography were performed in seven additional knee specimens. T1-weighted spin-echo MR images were obtained in the standard imaging planes as well as in the coronal oblique plane. The specimens underwent T1-weighted spin-echo MR imaging after administration of intraarticular contrast material and were sectioned into planes corresponding to those of the MR images. RESULTS: At anatomic dissection, the following posterolateral structures were identified: the arcuate ligament (medial and lateral limbs), fabellofibular ligament, popliteofibular ligament, popliteus tendon and its two posterior attachments to the lateral meniscus, fibular collateral ligament, direct and anterior arms of the tendon of the long head of the biceps femoris muscle, and direct and anterior arms of the tendon of the short head of the biceps femoris muscle. Correlation of MR imaging and anatomic findings showed that the popliteofibular ligament and oblique popliteal ligament were found in 57% and 100% of specimens, respectively. At least one of the two limbs of the arcuate ligament was identified in 71% of specimens. The fabellofibular ligament was not identified on MR images in any of the specimens. The anteroinferior and posterosuperior popliteomeniscal fascicles were identified in all specimens. CONCLUSION: The posterolateral corner of the knee comprises complex and variable anatomic structures. Recognition of these variations is important in the assessment of MR images of the knee.     

The carpal ligaments in MR arthrography of the wrist: correlation with standard MRI and wrist arthroscopy

We assessed the value of three-compartment magnetic resonance (MR) wrist arthrography in comparison with non-enhanced magnetic resonance imaging (MRI) for the evaluation of 13 individual wrist ligaments in 35 patients with refractory wrist pain. In 20 of these patients MR findings were correlated with the findings from multiportal wrist arthroscopy. For MR imaging (1.5-T magnet) a three-dimensional volume acquisition with a gradient-recalled echo sequence and 0.6-1.0 mm effective slice thickness was used. The delineation of individual wrist ligaments was rated as "good" in 10% of non-enhanced MR and 90% of MR arthrography images. Ligament evaluation was possible with high diagnostic confidence in 11% by non-enhanced MR imaging and 90% by MR arthrography. With wrist arthroscopy as the standard of reference, average sensitivities/specificities/accuracies for the diagnosis of full-thickness ligamentous defects were 0.81/0.75/0.77 for non-enhanced MR imaging and 0.97/0.96/0.96 for MR arthrography. Our findings suggest that MR arthrography is more accurate than standard MRI in delineating and evaluating the ligaments of the wrist.     

Diagnosis of recurrent meniscal tears: prospective evaluation of conventional MR imaging, indirect MR arthrography, and direct MR arthrography

PURPOSE: To prospectively investigate the accuracy of conventional magnetic resonance (MR) imaging, direct MR arthrography, and indirect MR arthrography in assessment of possible recurrent or residual meniscal tears. MATERIALS AND METHODS: Three hundred sixty-four patients who had previously undergone meniscal preservation surgery were prospectively examined with conventional MR imaging, indirect MR arthrography, and direct MR arthrography. Ninety-four patients (104 postoperative menisci) underwent subsequent second-look arthroscopic surgery. Each case was evaluated for (a) surfacing intrameniscal intermediate- or T1-weighted signal intensity, (b) surfacing intrameniscal T2-weighted signal intensity, (c) morphologic changes beyond those expected postoperatively, (d) joint effusion on conventional MR or indirect MR arthrographic studies, and (e) overall presence or absence of recurrent meniscal tear. RESULTS: Seventy-one arthroscopically proved recurrent meniscal tears were found. In the diagnosis of recurrent meniscal tears, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 86%, 67%, 83%, 71%, and 80%, respectively, for conventional MR imaging; 83%, 78%, 90%, 64%, and 81%, respectively, for indirect MR arthrography; and 90%, 78%, 90%, 78%, and 85%, respectively, for direct MR arthrography. No significant difference in the diagnostic accuracy of one method relative to another was observed (P >.54). Surfacing intrameniscal T2-weighted signal intensity was the most specific sign, with the highest positive predictive value of a recurrent tear. CONCLUSION: Although a small incremental increase in accuracy is associated with the use of direct MR arthrography over conventional MR imaging and indirect MR arthrography, no significant difference in diagnostic accuracy among the three techniques was demonstrated for detection of recurrent or residual meniscal tear.     

MR arthrography of the glenohumeral joint: modified posterior approach without imaging guidance

Institutional review board approval and informed consent were obtained. The purpose of the study was to prospectively perform magnetic resonance (MR) arthrography of the glenohumeral joint by using modified posterior approach without ultrasonographic or fluoroscopic guidance. A solution containing 0.1 mL of gadolinium chelate, 15 mL of saline, and 5 mL of 2% lidocaine was subsequently injected into the glenohumeral joint in 147 patients (81 men, 66 women; age range, 20-79 years). A 21-gauge needle was advanced along a trajectory connecting a skin mark 3-4 cm below and 2 cm medially to the posterolateral margin of the acromion and the coracoid process, as assessed with palpation, proceeding in posteroanterior direction. The joint was successfully entered at first attempt in 125 (85%) patients, at second attempt in 19 (13%), and at third attempt in three (2%). Contrast material-enhanced images were evaluated for presence, site, and maximal extent of contrast material extravasation; route of diffusion of the extravasation; compromised or noncompromised diagnostic quality; and presence of gas bubbles. Extravasation occurred in seven patients: at the interval between the teres minor muscle and infraspinatus muscle in five and within the infraspinatus muscle belly in two; extravasation had diffused along the teres minor muscle and infraspinatus muscle in five (71%) and along the teres minor muscle in two (29%). The mean extension of extravasation was 15 mm. Image quality was not compromised, and no gas bubbles were detected. The procedure was successful in all patients, with no complications.     

The scapholunate interosseous ligament in MR arthrography of the wrist: correlation with non-enhanced MRI and wrist arthroscopy

 Objective. To compare three-compartment MR wrist arthrography with non-enhanced MRI in correlation with wrist arthroscopy, and to evaluate the potential of MR arthrography for consistently visualizing all parts of the scapholunate interosseous ligament of the wrist (SLIL) and exactly diagnosing the site and extent of SLIL defects. Design and Patients. In 41 patients with wrist pain (34 patients with wrist pain for more than 6 months) plain radiographs, stress views, non-enhanced MRI and three-compartment MR arthrography were done within 2 h of each other, using three-dimensional volume acquisition (0.6–1.0 mm effective slice thickness) with a gradient-recalled echo sequence and a 1.5-T magnet. The MR arthrography findings were compared with the findings from non-enhanced MRI and correlated with the arthroscopic findings in all patients. Results. The dorsal, central and palmar segments of the SLIL could be delineated exactly by MR arthrography in 95% of the patients; with non-enhanced MRI only 28% of SLIL segments were seen consistently. Demonstration of SLIL defects was possible with high diagnostic confidence in 42% of SLIL segments by non-enhanced MRI and in 94% by MR arthrography. With wrist arthroscopy as the standard of reference, sensitivity and specificity values for SLIL perforations were 52%/34% for non-enhanced MRI and 90%/87% for MR arthrography. Conclusions. MR arthrography, using three-dimensional volume acquisition with thin slices (0.6–1.0 mm), combines the advantages of three-compartment arthrography and non-enhanced MRI. It shows the precise location and magnitude of ligamentous defects of all parts of the SLIL, correlates well with wrist arthroscopy and has potential implications for diagnosis and treatment planning.