Intrinsic ligament and triangular fibrocartilage complex tears of the wrist: comparison of MDCT arthrography, conventional 3-T MRI, and MR arthrography

Purpose

This study compares the diagnostic performance of multidetector CT arthrography (CTA), conventional 3-T MR and MR arthrography (MRA) in detecting intrinsic ligament and triangular fibrocartilage complex (TFCC) tears of the wrist.

Materials and methods

Ten cadaveric wrists of five male subjects with an average age 49.6 years (range 26–59 years) were evaluated using CTA, conventional 3-T MR and MRA. We assessed the presence of scapholunate ligament (SLL), lunotriquetral ligament (LTL), and TFCC tears using a combination of conventional arthrography and arthroscopy as a gold standard. All images were evaluated in consensus by two musculoskeletal radiologists with sensitivity, specificity, and accuracy being calculated.

Results

Sensitivities/specificity/accuracy of CTA, conventional MRI, and MRA were 100 %/100 %/100 %, 66 %/86 %/80 %, 100 %/86 %/90 % for the detection of SLL tear, 100 %/80 %/90 %, 60 %/80 %/70 %, 100 %/80 %/90 % for the detection of LTL tear, and 100 %/100 %/100 %, 100 %/86 %/90 %, 100 %/100 %/100 % for the detection of TFCC tear. Overall CTA had the highest sensitivity, specificity, and accuracy among the three investigations while MRA performed better than conventional MR. CTA also had the highest sensitivity, specificity, and accuracy for identifying which component of the SLL and LTL was torn. Membranous tears of both SLL and LTL were better visualized than dorsal or volar tears on all three imaging modalities.

Conclusion

Both CT and MR arthrography have a very high degree of accuracy for diagnosing tears of the SLL, LTL, and TFCC with both being more accurate than conventional MR imaging.     

CT arthrography of the wrist using a novel, mobile, dedicated extremity cone-beam CT (CBCT)

Purpose

To evaluate the feasibility and intra- and interobserver agreement of CBCT arthrography of wrist ligaments, triangular fibrocartilaginous complex (TFCC), and to assess the sensitivity (SE), specificity (SP), accuracy (ACC), and positive and negative predictive value (PPV, NPV) of CBCT arthrography in the diagnosis of scapholunate (SLL) and lunotriquetral (LTL) ligament tears, TFCC, and cartilage abnormalities of the scaphoid and lunate with their corresponding radial surfaces (scaphoid and lunate fossa) using a novel, mobile, dedicated extremity CBCT scanner.

Materials and methods

Fifty-two consecutively enrolled subjects (26 M, 26 F, mean age 38 years, range 18–66 years) with suspected wrist ligament tears underwent CBCT-arthrography before normally scheduled MR arthrography.An extremity CBCT was used for imaging with isotropic voxel size of 0.4 × 0.4 × 0.4 mm³. Subsequent routine 1.5 T MRI was performed using a dedicated wrist coil.Two observers reviewed the anonymized CBCT images twice for contrast enhancement (CE) and technical details (TD), for tears of the SLL, LTL, and TFCC. Also, cartilage abnormalities of the scaphoid and lunate with their corresponding radial surfaces (scaphoid and lunate fossa) were evaluated. Inter- and intraobserver agreement was determined using weighted kappa statistics. Since no surgery was performed, MRI served as a reference standard, and SE and SP, ACC, PPV, and NPV were calculated.

Results

Intra- and interobserver kappa values for both readers (reader 1/reader 2; first reading/second reading) with 95 % confidence limits were: CE 0.54 (0.08–1.00)/ 0.75 (0.46–1.00); 0.73 (0.29–1.00)/ 0.45 (0.07–0.83), TD 0.53 (0.30–0.88)/ 0.86 (0.60–1.00); 0.56 (0.22–0.91)/ 0.67 (0.37–0.98), SLL 0.59 (0.25–0.93)/ 0.66 (0.42–0.91); 0.31 (0.06–0.56)/ 0.49 (0.26–0.73), LTL 0.83 (0.66–1.00)/ 0.68 (0.46–0.91); 0.90 (0.79–1.00)/ 0.48 (0.22–0.74); TFCC (0.72–1.00)/ (0.79–1.00); 0.65 (0.43–0.87)/ 0.59 (0.35–0.83), radius (scaphoid fossa) 0.45 (0.12–0.77)/ 0.64 (0.31–0.96); 0.58 (0.19–0.96)/ 0.38 (0.09–0.66), scaphoid 0.43 (0.12–0.74)/ 0.76 (0.55–0.96); 0.37 (0.00–0.75)/ 0.32 (0.04–0.59), radius (lunate fossa) 0.68 (0.36–1.00)/ 0.42 (0.00–0.86); 0.62 (0.29–0.96)/ 0.51 (0.12–0.91), and lunate 0.53 (0.16–0.90)/ 0.68 (0.44–0.91); 0.59 (0.29–0.88)/ 0.42 (0.00–0.84), respectively. The overall mean accuracy was 82–92 % and specificity was 81–94 %. Sensitivity for LTL and TFCC tears was 76–83, but for SLL tears it was 58 %. For cartilage abnormalities, the accuracy and negative predictive value were high, 90–98 %.

Conclusions

A dedicated CBCT extremity scanner is a new method for evaluating the wrist ligaments and radiocarpal cartilage. The method has an overall accuracy of 82–86 % and specificity 81–91 %. For cartilage abnormalities, the accuracy and negative predictive value were high.     

Cone-beam computed tomography arthrography: an innovative modality for the evaluation of wrist ligament and cartilage injuries

Purpose

Cone-beam computed tomography (CBCT) has become an important modality in dento-facial imaging but remains poorly used in the exploration of the musculoskeletal system. The purpose of this study was to prospectively evaluate the performance and radiation exposure of CBCT arthrography in the evaluation of ligament and cartilage injuries in cadaveric wrists, with gross pathology findings as the standard of reference.

Materials and methods

Conventional arthrography was performed under fluoroscopic guidance on 10 cadaveric wrists, followed by MDCT acquisition and CBCT acquisition. CBCT arthrography and MDCT arthrography images were independently analyzed by two musculoskeletal radiologists working independently and then in consensus. The following items were observed: scapholunate and lunotriquetral ligaments, triangular fibrocartilage complex (TFCC) (tear, integrity), and proximal carpal row cartilage (chondral tears). Wrists were dissected and served as the standard of reference for comparisons. Interobserver agreement, sensitivity, specificity, and accuracy were determined. Radiation dose (CTDI) of both modalities was recorded.

Results

CBCT arthrography provides equivalent results to MDCT arthrography in the evaluation of ligaments and cartilage with sensitivity and specificity between 82 and 100%, and interobserver agreement between 0.83 and 0.97. However, radiation dose was significantly lower (p?Conclusion CBCT arthrography appears to be an innovative alternative to MDCT arthrography of the wrist as it allows an accurate and low radiation dose evaluation of ligaments and cartilage.     

Visualization of joint and bone using dual-energy CT arthrography with contrast subtraction: in vitro feasibility study using porcine joints

Objective

To assess the feasibility of subtracting various concentrations of iodinated contrast material on dual-energy computed tomographic (DECT) arthrography to provide both CT arthrography and virtual unenhanced CT (VUCT) in a single CT acquisition.

Materials and Methods

This was an in vitro study for which institutional review board approval was not required. CT arthrographies of 12 joints of pig cadavers were obtained using dual-energy CT. Various concentrations of iodinated contrast material, 25% (75 mg/ml), 50% (150 mg/ml), 75% (225 mg/ml), and 100% (300 mg/ml) were used for the DECT arthrography. The paired regions of interest (ROI) were drawn over the same location on two paired CT scans at different tube voltages (80 kVp and 140 kVp). The average Hounsfield units (HU) ratio of the contrast media(HU on CT at 80 kVp/HU on CT at 140 kVp) was calculated for each joint. Subtraction of contrast material was carried out using VUCT application

Results

The 25% iodinated contrast mixture was successfully subtracted from DECT arthrography of four joints, in which the average HU ratio ranged from 1.95 to 2.0. The subtraction of the 50%,75%, and 100% iodine contrast mixtures was not successful, because of the upper demonstrable HU limit in dual-energy CT.

Conclusions

DECT arthrography with 25% iodinated contrast medium injection can provide both CT arthrography and virtual unenhanced images in a single CT acquisition     

Internal derangement of the wrist: indirect MR arthrography versus unenhanced MR imaging

PURPOSE: To compare indirect magnetic resonance (MR) arthrography with unenhanced MR imaging of the wrist for evaluation of the central disk of the triangular fibrocartilage complex (TFCC) and the scapholunate and lunotriquetral interosseous ligaments. MATERIALS AND METHODS: Eighty-six wrists were evaluated at MR imaging (41 indirect MR arthrography and 45 unenhanced MR imaging examinations). Three musculoskeletal radiologists independently evaluated the central disk of the TFCC and scapholunate and lunotriquetral ligaments and compared the results with those of wrist arthroscopy. Sensitivity and specificity were calculated for each of the readers, and the means were obtained. Sensitivities and specificities were compared with the Student t test. RESULTS: Thirty-three tears of the central disk of the TFCC and 13 scapholunate and 18 lunotriquetral ligament tears were identified at arthroscopy. Sensitivities and specificities were 54%-73% and 83%-91%, respectively, in the evaluation of the central disk of the TFCC, with no significant difference between indirect MR arthrography (P =.666) and unenhanced MR imaging (P =.559). Sensitivities and specificities in the evaluation of the scapholunate ligament were 38%-69% and 75%-99%, respectively, with a significant improvement in sensitivity at indirect MR arthrography (P =.017) and no significant difference in specificity (P =.876). Sensitivities in the evaluation of the lunotriquetral ligament were poor, 0%-22%, though the specificities were 88%-99%, with no significant difference between indirect MR arthrography and unenhanced MR imaging (P =.592 and P =.354, respectively, for sensitivity and specificity. CONCLUSION: Indirect MR arthrography significantly improves sensitivity in the evaluation of the scapholunate ligament when compared with unenhanced MR imaging of the wrist but does not significantly improve the ability to evaluate the central disk of the TFCC or the lunotriquetral ligament.     

MR evaluation of triangular fibrocartilage complex tears in the wrist: comparison with arthrography and arthroscopy

To evaluate the accuracy of magnetic resonance (MR) in the detection of tears of the triangular fibrocartilage complex (TFCC), 10 consecutive patients with posttraumatic chronic wrist pain were examined with MR, arthrography, and arthroscopy and the results were compared. The MR images of 16 control subjects were also examined to define the MR appearance of the normal TFCC. When compared with arthroscopic findings, both MR and arthrography had two false-negative results (sensitivity, 80%) and no false-positive results. Regarding the sites of the TFCC tears, the findings on MR did not always correlate with the findings on arthrography. In no case was MR able to visualize the cartilaginous lesions visible by arthroscopy. These preliminary results illustrate the ability of MR to assess the integrity of the TFCC and suggest its use as the first imaging technique following plain radiography in the evaluation of patients with chronic posttraumatic pain on the ulnar side of the wrist.     

The role of MDCT arthrography in the follow-up of scapholunate stabilisation

Purpose

The aim of this study was to assess outcomes in a group of patients with scapholunate dissociation treated with stabilisation surgery (Brunelli-Stanley) and to compare arthrography with multidetector computed tomography (MDCT) with conventional radiography, the gold standard in the follow-up of wrist surgery.

Materials and methods

Twelve patients (13 wrists) underwent surgery for scapholunate dissociation and were followed up with clinical (visual analogue scale, Mayo Wrist Score, Patient-Rated Wrist Evaluation, and Disabilities of the Arm, Shoulder, and Hand) and radiological assessment (conventional radiography and CT arthrography). Conventional radiography was assessed for: the scapholunate gap, scapholunate angle, radiolunate angle, capitate-lunate angle, and carpal height index; the CT arthrography images were also evaluated for: the distance between the dorsal exit hole of the bone tunnel and the proximal scaphoid pole, the thickness and tension of the flexor carpi radialis (FCR) strip, and any signs of joint degeneration.

Results

Analysis of the data from conventional radiography and MDCT arthrography demonstrated a significant statistical correlation among the measurements obtained on the radiograms and multiplanar CT reconstructions and the patients’ clinical outcome.

Conclusions

Our results show that MDCT arthrography has the same value as conventional radiography in the evaluation of standard parameters (scapholunate gap, scapholunate angle, radiolunate angle, capitolunate angle, carpal height index), but in addition provides an accurate delineation of the FCR tendon graft, allowing differentiation of its thickness, direction and degree of tension.     

Supraspinatus tendon tears: comparison of 3D US and MR arthrography with surgical correlation

Objective

The objective of the study was to compare the diagnostic reliability of 3D US with MR arthrography in diagnosing supraspinatus tendon tears, with arthroscopic findings used as the standard.

Materials and methods

In a prospective study 50 patients who later underwent arthroscopic surgery of the rotator cuff were examined pre-operatively by 3D US with MR arthrography. The presence or absence of a full- or partial-thickness supraspinatus tendon tear and the tear size as demonstrated by each imaging and arthroscopy was recorded. The tear size was divided into three grades: small (<1 cm), medium (1-3 cm), and large (>3 cm).

Results

The arthroscopic diagnosis was a full-thickness tear in 40 patients, partial-thickness tears in 5, and intact supraspinatus tendon in 5. 3D US correctly diagnosed 35 out of 40 full-thickness tears and MR arthrography 39 out of 40 full-thickness tears. Regarding partial-thickness tears, 3D US underestimated 2 cases as no tear and overestimated 1 case as a full-thickness tear. MR arthrography underestimated 1 case as a partial-thickness tear and overestimated 2 cases as full-thickness and partial-thickness tears respectively. 3D US and MR arthrography yield a sensitivity for full-thickness tears of 87.5% and 97.5% with specificity of 90.0% and 90.0%. Based on the grading system, 3D US measurements correctly predicted the tear size of 23 (65.7%) of the 35 full-thickness tears and MR arthrography 30 (75.0%) of the 39 full-thickness tears.

Conclusion

Three-dimensional ultrasound seems to be a promising imaging modality comparable to MR arthrography for the assessment of the supraspinatus tendon tears.     

Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee

Purpose

This study assesses the accuracy of 3-Tesla (3-T) conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography in the diagnosis of meniscal retears as compared with arthroscopy. The study also assess whether there are false-negative cases in which injected contrast does not extend into the meniscus despite a meniscal retear being seen on arthroscopy.

Materials and methods

One hundred consecutive knee MR arthrograms performed on patients with previous knee surgery were reviewed retrospectively. 3-T conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography were assessed for meniscal retears as compared with arthroscopy. The criterion used to diagnose a meniscal retear on MR arthrogram was injected contrast tracking into the meniscus. All patients underwent second-look arthroscopy.

Results

Seventy-four patients had conventional MR findings consistent with a meniscal retear. In 83 of the 100 patients, intraarticular contrast helped in demonstrating a retear. In ten patients, there were MR findings consistent with a meniscal retear despite intra-articular contrast not tracking into the meniscus. Ninety-four of the 100 patients had meniscal retears on second-look arthroscopy. Three-Tesla conventional MR examination was 78 % sensitive and 75 % specific, MR arthrogram examination was 88 % sensitive and 100 % specific, and the combined use of MR and MR arthrogram imaging was 98 % sensitive and 75 % specific in the diagnosis of a meniscal retear.

Conclusions

The combined use of 3-T MR and MR arthrography allows for high sensitivity and specificity in meniscal retear detection. In some patients, intraarticular contrast will not track into a meniscal retear. When MR findings are consistent with a meniscal retear but contrast does not extend into the meniscus, a meniscal retear is likely.     

MR arthrography including abduction and external rotation images in the assessment of atraumatic multidirectional instability of the shoulder

Objective

To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atraumatic multidirectional instability (MDI) of the shoulder on MR arthrography (MR-A) including abduction/external rotation (ABER) images.

Methods

Twenty-one MR-A including ABER position of 20 patients with clinically diagnosed MDI and 17 patients without instability were assessed by three radiologists. On ABER images, presence of a layer of contrast between the humeral head (HH) and the anteroinferior glenohumeral ligament (AIGHL) (crescent sign) and a triangular-shaped space between the HH, AIGHL and glenoid (triangle sign) were evaluated; centring of the HH was measured. Anterosuperior herniation of the rotator interval (RI) capsule and glenoid version were determined on standard imaging planes.

Results

The crescent sign had a sensitivity of 57 %/62 %/48 % (observers 1/2/3) and specificity of 100 %/100 %/94 % in the diagnosis of MDI. The triangle sign had a sensitivity of 48 %/57 %/48 % and specificity of 94 %/94 %/100 %. The combination of both signs had a sensitivity of 86 %/90 %/81 % and specificity of 94 %/94 %/94 %. A positive triangle sign was significantly associated with decentring of the HH. Measurements of RI herniation, RI width and glenoid were not significantly different between both groups.

Conclusions

Combined assessment of redundancy signs on ABER position MR-A allows for accurate differentiation between patients with atraumatic MDI and patients with clinically stable shoulders; measurements on standard imaging planes appear inappropriate.

Key Points

? MR arthrography has the possibility to accurately identify patients with atraumatic MDI. ? Imaging of the shoulder in abduction and external rotation provides additive information. ? Capsular enlargement of the shoulder can be diagnosed on MR arthrography.     

Interosseous ligament tears of the wrist: comparison of multi-detector row CT arthrography and MR imaging

PURPOSE: To compare the accuracy of multi-detector row computed tomographic (CT) arthrography and magnetic resonance (MR) imaging in depicting tears of dorsal, central, and palmar segments of scapholunate (SL) and lunotriquetral (LT) ligaments in cadavers. MATERIALS AND METHODS: Cadaver wrists were obtained and used according to institutional guidelines and with informed consent of donors prior to death. Nine cadaver wrists of eight subjects were evaluated. MR images were obtained with a 1.5-T MR unit. Imaging protocol included intermediate-weighted coronal and transverse fast spin-echo and coronal three-dimensional gradient-echo sequences. Multi-detector row CT arthrography was performed after tricompartmental injection of 3-6 mL of contrast material with a concentration of 160 mg per milliliter of iodine. Palmar, dorsal, and central segments of both ligaments were analyzed on transverse and coronal MR images and multiplanar multi-detector row CT reconstructions by two musculoskeletal radiologists working independently. Open inspection of the wrists was the reference standard. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated from the imaging and gross pathologic readings. Statistical significance was calculated with the McNemar test. Weighted kappa values for interobserver agreement were calculated for both imaging modalities. RESULTS: All ligament segments could be visualized in all cases with both imaging modalities. CT arthrography was more sensitive (100%) than MR imaging (60%) in detection of palmar segment tears (P = .62); specificity of both imaging modalities was 77%. Sensitivity (CT arthrography, 86%; MR imaging, 79%) and specificity (CT arthrography, 50%; MR imaging, 25%) for detection of the central segment tears were determined. Dorsal segment tears were detected only with CT arthrography, while all tears were missed with MR imaging (P = .02). Interobserver agreement was better for multi-detector row CT arthrography (kappa = 0.37-0.78) than for MR imaging (kappa = -0.33 to -0.10). CONCLUSION: Performance in depiction of palmar and central segment tears of SL and LT ligaments is almost equal for multi-detector row CT arthrography and MR imaging, with much higher interobserver reliability for CT arthrography. CT arthrography is significantly superior to MR imaging in the detection of dorsal segment tears of SL and LT ligaments.     

MDCT arthrography of the wrist: Diagnostic accuracy and indications

Purpose

To evaluate the diagnostic accuracy and indications of arthrography with Multidetector Computed Tomography (arthro-MDCT) of the wrist in patients with absolute or relative contraindications to magnetic resonance imaging (MRI) studies and in patients with periarticular metal implants using diagnostic arthroscopy as the gold standard.

Materials and methods

After intra-articular injection of iodixanol and volumetric acquisition, 43 wrists in patients of both genders (18 females, 25 males, age range 32-60 years) were examined with a 16-detector-row CT scanner. Fifteen patients had prior wrist surgery. The patients had arthralgia, degenerative and traumatic arthropathies as well as limited range of motion, but no radiologically detected fractures. All examinations were interpreted by two experienced musculoskeletal radiologists.The findings were compared with arthroscopic findings carried out within 28 days of the CT study.

Results

In non-operated and operated wrists the comparison between arthro-MDCT and arthroscopy showed sensitivity, specificity and accuracy ranging between 92% and 94% for triangular fibrocartilage complex (TFCC), between 80% and 100% for intrinsic ligaments located within the proximal carpal compartment, and between 94% and 100% for articular cartilage.Inter-observer agreement between two radiologists, in the evaluation of all types of lesions, was almost perfect (k = 0.96) and statistically significant (p < 0.05).

Conclusions

Arthro-MDCT of the wrist provides an accurate diagnosis to identify chondral, fibrocartilaginous and intra-articular ligament lesions in patients who cannot be evaluated by MRI, and in post-surgical patients.     

Injuries of the scapholunate and lunotriquetral ligaments as well as the TFCC in intra-articular distal radius fractures. Prevalence assessed with MDCT arthrography

Objectives

To evaluate the prevalence of injuries of the scapholunate and lunotriquetral interosseous ligaments (SLIL, LTIL) as well as the triangular fibrocartilage complex (TFCC) in intra-articular distal radius fractures (iaDRF).

Methods

Two hundred and thirty-three patients with acute iaDRF underwent MDCT arthrography. The SLIL and LTIL were described as normal, partially or completely ruptured. Major injuries of the SLIL were defined as completely ruptured dorsal segments, those of the LTIL as completely ruptured palmar segments. The TFCC was judged as normal or injured. Interobserver variability was calculated. Injury findings were correlated with the types of iaDRF (AO classification).

Results

In 159 patients (68.2 %), no SLIL injuries were seen. Minor SLIL injuries were detected in 54 patients (23.2 %), major injuries in 20 patients (8.6 %). No correlation was found between the presence of SLIL lesions and the types of iaDRF. Minor LTIL injuries were seen in 23 patients (9.9 %), major injuries in only 5 patients (2.2 %). The TFCC was altered in 141 patients (60.5 %). Interobserver variability was high for MDCT arthrography in assessing SLIL and TFC lesions, and fair for LTIL lesions.

Conclusion

In iaDRF, prevalence of major injuries of the most relevant SLIL is about 9 % as evaluated with CT arthrography.

Key Points

? The C-shaped SLIL is built of dorsal, middle and palmar segments. ? In iaDRF, major SLIL injuries are associated in 8.6 % of the cases. ? In iaDRF, the SLIL remains intact in 68.3 % of the cases. ? IaDRF and SLIL ruptures can comprehensively be depicted with MDCT arthrography. ? A three-compartment approach is recommended to assess intrinsic ligaments and the TFCC.

     

Direct MR arthrography of cadaveric wrists: comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

Purpose:

To prospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography for the detection of articular cartilage abnormalities at 3.0T and 7.0T in cadaveric wrists.

Materials and Methods:

MR imaging (MRI) was performed in nine cadaveric wrists (four right wrists, five left; mean age, 81.0 ± 9.8 years) after the intraarticular administration of gadoterate‐meglumine. A 3.0T and 7.0T MR system, mechanically identical custom‐built 8‐channel wrist coil arrays and a similar standard MRI protocol, were used. MR images were evaluated for visibility of articular cartilage surfaces, presence of cartilage lesions, and confidence of diagnosis by two independent radiologists. Open pathologic inspection served as reference standard. Sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV), and accuracy (ACC) were calculated. Wilcoxon signed rank test was used to assess differences in the diagnostic performance.

Results:

Visibility of articular cartilage surfaces was significantly better at 3.0T than at 7.0T (P < 0.001). Mean sensitivity, specificity, NPV, PPV, ACC for both readers were 63%, 90%, 85%, 76%, 82% at 3.0T, respectively, and 52%, 91%, 82%, 75%, 79% at 7.0T. The difference between 3.0T and 7.0T was not significant for reader 1 (P = 0.51), but was significant for reader 2 (P = 0.01). The level of confidence was significantly higher at 3.0T than at 7.0T for both readers (P = 0.004; P = 0.03).

Conclusion:

MR arthrography of the wrist at 7.0T is still limited by the lack of commercially available radiofrequency coils and limited experience in sequence optimization, resulting in a significantly lower visibility of anatomy, lower diagnostic accuracy, and level of confidence in judging cartilage lesions compared to 3.0T. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.     

Chronic wrist pain: spin-echo and short tau inversion recovery MR imaging and conventional and MR arthrography.

The accuracy of T1-, proton-density-, and T2-weighted magnetic resonance (MR) imaging sequences and gadolinium-enhanced MR arthrography in evaluation of the triangular fibro-cartilage complex (TFCC) and the scapholunate (SL) and lunotriquetral (LT) ligaments was studied in 15 patients with chronic wrist pain. Arthrography and arthroscopy were used as standards of reference. Twelve patients also underwent imaging with short tau inversion recovery (STIR) sequences. MR imaging was more reliable in evaluation of the morphology of the TFCC and SL ligament than in that of the LT ligament. With arthrography as the standard, sensitivity was 0.721, specificity was 0.947, and accuracy was 0.887 for the TFCC; these values were 0.500, 0.864, and 0.765 for the SL ligament and 0.519, 0.455, and 0.490 for the LT ligament. No visualization of the SL ligament indicated a tear, but this sign was not helpful in evaluation of the LT ligament. Fluid in the distal radioulnar joint had a high association with TFCC tears. Accuracy with MR arthrography was higher than with the other sequences. STIR images were effective in evaluation of the TFCC. The combination of proton-density-and T2-weighted images appears to be useful because morphologic characteristics and the presence of fluid can be evaluated.     

MR直接关节造影在腕三角纤维软骨复合体损伤中的应用

目的 通过与腕关节镜结果对照,探讨MR直接关节造影在腕三角纤维软骨复合体(TFCC)损伤中的作用.方法 14例临床怀疑腕TFCC损伤的患者接受了常规MRI和MR直接关节造影,其中10例行腕关节镜检查.MR直接关节造影在腕拇长伸肌腱与伸指总肌腱间隙(相当于桡舟关节间隙)处进针,注入5～7 ml的钆喷替酸葡甲胺(0.1 mmol/L)混合液(0.3 ml钆喷替酸葡甲胺+100 ml生理盐水),与腕关节镜结果相对照,分析常规MRI和MR直接关节造影表现.结果 (1)14例中TFCC尺侧撕裂5例,桡侧撕裂4例,整体损伤5例(包括2例长期类风湿关节炎).(2)在脂肪抑制序列(STIR)及T2和T1WI序列上,损伤的TFCC表现为高信号或等信号,正常的低信号部分或完全消失,MR直接关节造影显示4例桡侧撕裂在腕TFCC的下尺桡关节和5例尺侧撕裂在尺骨茎突附着处可见不同程度的高信号对比剂聚集,5例整体损伤在下尺桡关节和尺骨茎突附着处均可见对比剂.MR直接关节造影表现与腕关节镜结果在损伤部位相符合,包括4例桡侧撕裂,3例尺侧撕裂和3例整体损伤.(3)14例腕TFCC损伤患者,8例伴有下尺桡关节半脱位,6例伴有尺桡骨骨挫伤,常规MRI和MR直接关节造影均可清晰地显示其滑膜反应和骨髓水肿等表现.结论 MR直接关节造影可以清晰地显示腕TFCC损伤,同时与常规MRI相结合能显示伴随的滑膜反应和骨髓水肿.     

Whole-body SPECT/CT for bone scintigraphy: diagnostic value and effect on patient management in oncological patients

Purpose

This study was designed to assess the additional value of SPECT/CT of the trunk used in conjunction with conventional nuclear imaging and its effects on patient management in a large patient series.

Methods

In 353 patients, whole-body scintigraphy (WBS), SPECT, and SPECT/CT were prospectively performed for staging and restaging. SPECT/CT of the trunk was performed in all patients. In the 308 evaluable patients (211 with breast cancer, 97 with prostate cancer), clinical follow-up was used as the gold standard. Bone metastases were confirmed in 72 patients and excluded in 236. Multistep analyses per lesion and per patient were performed. Clinical relevance was expressed in terms of downstaging and upstaging rates on a per-patient basis.

Results

In the total patient group, sensitivities, specificities, and negative and positive predictive values on a per-patient basis were 93 %, 78 %, 95 % and 59 % for WBS, 94 %, 71 %, 97 % and 53 % for SPECT, and 97 %, 94 %, 97 % and 88 % for SPECT/CT, respectively. In all subgroups, specificity and positive predictive value were significantly (p?<?0.01) better with SPECT/CT. Downstaging of metastatic disease in the total, breast cancer and prostate cancer groups using SPECT/CT was possible in 32.1 %, 33.8 % and 29.5 % of patients, respectively. Upstaging in previously negative patients by additional SPECT/CT was observed in three breast cancer patients (2.1 %). Further diagnostic imaging procedures for unclear scintigraphic findings were necessary in only 2.5 % of patients. SPECT/CT improved diagnostic accuracy for defining the extent of multifocal metastatic disease in 34.6 % of these patients.

Conclusions

SPECT/CT significantly improved the specificity and positive predictive value of bone scintigraphy in cancer patients. In breast cancer patients, we found a slight increase in sensitivity. SPECT/CT had a significant effect on clinical management because of correct downstaging and upstaging, better definition of the extent of metastases, and a reduction in further diagnostic procedures.     

Ulnar-sided wrist pain. II. Clinical imaging and treatment

Pain at the ulnar aspect of the wrist is a diagnostic challenge for hand surgeons and radiologists due to the small and complex anatomical structures involved. In this article, imaging modalities including radiography, arthrography, ultrasound (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography are compared with regard to differential diagnosis. Clinical imaging findings are reviewed for a more comprehensive understanding of this disorder. Treatments for the common diseases that cause the ulnar-sided wrist pain including extensor carpi ulnaris (ECU) tendonitis, flexor carpi ulnaris (FCU) tendonitis, pisotriquetral arthritis, triangular fibrocartilage complex (TFCC) lesions, ulnar impaction, lunotriquetral (LT) instability, and distal radioulnar joint (DRUJ) instability are reviewed.     

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.     

C-arm flat-panel CT arthrography of the wrist and elbow: first experiences in human cadavers

Objective

To determine the optimal intra-articular iodine concentration for C-arm flat-panel computed tomography (FPCT) arthrography using advanced joint phantoms and to evaluate its application in human cadaveric wrists and elbows. Multi-detector (MD) CT served as the standard of reference.

Materials and methods

Joint phantoms and 10 human cadaveric wrist and elbow joints were scanned with C-arm FPCT (5-s, 8-s, and 20-s runs) and standard MDCT using different and optimal concentrations of iodinated contrast material. CT numbers of contrast material, tissue, and noise were measured and contrast-to-noise ratios (CNR) calculated for quantitative analysis. Image and depiction of cartilage, bone, and soft tissues were rated. Radiation doses were compared.

Results

In FPCT, iodine concentrations positively correlated with CT numbers and noise of contrast material and with radiation dose (r?=?0.713–0.996, p?<?0.05 each). At an iodine concentration of 45 mg/ml, CNR of cartilage and soft tissues were highest for all FPCT acquisitions and higher than in MDCT. The 20-s FPCT run performed best for image quality and depiction of anatomical structures and was rated overall equal to MDCT (p?=?0.857).

Conclusion

The optimal iodine concentration for C-arm FPCT arthrography in this study is 45 mg/ml, leading to superior CNR and image quality for an optimal FPCT protocol compared with standard MDCT arthrography in human cadaveric joints.