Enhanced MR imaging of tenosynovitis of hand and wrist in inflammatory arthritis

Objective The purpose of this study is to describe the appearance of tenosynovitis in various tendon groups in the wrist and hand and to compare MR enhanced and non-enhanced imaging evaluation of tenosynovitis of hand and wrist in inflammatory arthritis.Design and patients We reviewed 72 MRI studies of hands and wrists, including coronal, axial and sagittal images in 30 consecutive patients with inflammatory arthritis and tenosynovitis. We compared the degree of synovitis on T2-weighted vs contrast-enhanced T1-weighted images, using a predetermined scale. We also measured the extent of tenosynovitis in three dimensions. The tendons were assigned to volar, dorsal, ulnar and radial groups in the wrist and to extensor, flexor and thumb groups in the hand. Degree of tenosynovitis (graded 0–3), cross-sectional area and volume of the inflamed synovium in various tendon groups were then compared by statistical analysis.Results Review of the medical records revealed the following diagnoses in our patient population: rheumatoid arthritis (n=16), unspecified inflammatory polyarthritis (n=9), psoriatic arthritis (n=2), CREST syndrome (n=1), systemic lupus erythematosus (n=1), paraneoplastic syndrome with arthritis (n=1). The average T2 brightness scores and post-gadolinium enhancement scores were 1.0 and 1.7, respectively (P<0.001) in the wrist studies. The average T2 brightness scores and post-gadolinium enhancement scores were 0.7 and 1.4, respectively (P<0.001) in the hand studies. The average sensitivity of T2-weighted imaging for detection of tenosynovitis was 40% in the hand and 67% in the wrist tendons, when contrast-enhanced images were used as a reference. Carpal tunnel flexor tendons were the most frequently affected tendons of the wrist. The most frequently affected tendons of the hand were second and third flexor tendons. The hand flexors demonstrated higher degrees of enhancement and larger volumes of the inflamed tenosynovium than did the hand extensors and tendons of the thumb.Conclusion Enhanced MR imaging of the hand and wrist is a superior technique for detection of tenosynovitis. We observed carpal tunnel flexor tendons to be the most frequently affected tendons of the wrist. The flexor tendons of the second and third digits were the most frequently affected tendons of the hands. Higher contrast-enhancement scores and inflammation were noted in the hand flexor than in the extensor tendons.     

Extensor tendon rupture and three-dimensional computed tomography imaging of the rheumatoid wrist

Purpose

Extensor tendon rupture on the dorsum of the wrist is commonly seen in patients with rheumatoid arthritis (RA). The diagnosis of tendon rupture is usually straightforward, but it is sometimes difficult in the hand with complex deformity. The purposes of this study were to investigate the reliability of three-dimensional computed tomography (3DCT) imaging of extensor tendons in the rheumatoid wrist and in the normal wrist and to clarify the validity of its clinical application to the diagnosis of tendon rupture in the rheumatoid wrist.

Methods

Preoperative 3DCT images of 48 wrists of 45 patients with RA and 3DCT images of 38 wrists of 38 healthy volunteers were reviewed retrospectively by six orthopaedic surgeons who were unaware of all other study data. Extensor tendon rupture was verified by operation on 20 rheumatoid wrists.

Results

Regarding interobserver and intra-observer reliabilities of 3DCT imaging of the extensor tendons, agreement with respect to tendon rupture in this study group was high, and Cohen's kappa (κ) coefficient was variable, depending on the individual tendon. Positive predictive value (PPV) of tendon rupture in the extensor digiti minimi (EDM), extensor digitorum communis (EDC) V and IV and extensor pollicis longs (EPL) tendons was more than 60%, but those for the other extensor tendons were less than 50%. Negative predictive value (NPV) was more than 96% in all extensor tendons, in both rheumatoid and normal wrists.

Conclusions

Extensor tendons in normal and rheumatoid wrists were well depicted by 3DCT imaging. In the rheumatoid wrists, extensors of the ring and little fingers and the thumb were depicted more accurately than those to the other fingers. 3DCT imaging was clinically applicable to wrists for which it was difficult to diagnose by physical examination a definite cause for the loss of extension of the fingers.     

Extensor retinaculum of the wrist: gross anatomical correlation with MR imaging after ultrasound-guided tenography with emphasis on anatomical features in wrist dorsiflexion responsible for tendon impingement

Objective

To demonstrate the anatomy of the extensor retinaculum (ER) of the wrist using gross anatomical correlation with magnetic resonance (MR) imaging before and after ultrasound-guided tenography in four different positions, emphasizing the morphological appearance of the ER that occurs with dorsiflexion of the wrist to define the nature of extensor tendon impingement in athletes who perform repetitive wrist dorsiflexion.

Materials and methods

Institutional policies were followed regarding cadaver use. Ten upper extremities were harvested from fresh cadavers. MR imaging before and after ultrasound-guided tenography of the wrist was performed, followed by gross anatomical correlation. Two radiologists interpreted the MR images and sections by consensus for the anatomical landmarks of the ER, and morphological changes occurring during dorsiflexion of the wrist were analyzed and measured.

Results

The ER of the wrist appeared as a band of low signal intensity on T1- and PD-weighted images. Because of its orientation, axial images were best suited to depict the ER anatomy; specifically, localization of the bony landmarks and the septal attachments. On sagittal images, a consistent appearance of the ER was seen: appearing with fusiform morphology in the neutral position, and becoming shortened and thickened at the abutment point where the extensor tendons of the fourth compartment had a curved excursion during dorsiflexion. The width and thickness of the ER in neutral position averaged 13.56 mm and 1.67 mm respectively. In wrist dorsiflexion, the average width and thickness changed to 8.68 mm and 2.15 mm respectively.

Conclusion

Magnetic resonance imaging is a useful technique to demonstrate the ER of the wrist, the septal attachments, and morphological changes that occur during dorsiflexion of the wrist, which potentially can lead to impingement of the extensor tendons.     

Three-dimensional computed tomography imaging: its applicability in the evaluation of extensor tendons in the hand and wrist

OBJECTIVE: The purpose of this study was to determine whether 3-dimensional (3D) computed tomography (CT) imaging with volume rendering can accurately evaluate extensor tendons in the hand and wrist. METHODS: Three-dimensional CT imaging was used to evaluate 14 cases. The location where the rupture was suspected was the wrist level in all cases. The accuracy of the image diagnosis was confirmed during surgery in 13 cases. RESULTS: Three-dimensional CT could identify all extensor tendons proximal to the metacarpophalangeal joint. In the cases with rupture, the location of the distal stump could be identified, whereas that of the proximal stump was uncertain. The tendon stump location confirmed during surgery correlated well with the images. CONCLUSIONS: This study revealed the usefulness of 3D CT imaging in defining extensor tendons proximal to the metacarpophalangeal joint. This method increased the accuracy and ease of diagnosis and was always useful in surgical planning and patient education.     

Sonography and MR imaging of posterior tibial tendinopathy.

OBJECTIVE: The purpose of the study is to describe the appearance of the posterior tibialis tendon on MR imaging and high-resolution sonography with color and power Doppler imaging and to determine whether sonography is as accurate for diagnosing tendinosis as MR imaging. SUBJECTS AND METHODS: Fifteen healthy volunteers and 31 patients (44 tendons) who were clinically suspected of having posterior tibial tendinopathy were prospectively evaluated with MR imaging and sonography. RESULTS: On MR imaging, the normal tendon was elliptic on cross section and showed low signal intensity on all sequences. Minimal peritendinous enhancement and fluid were seen. On sonography, the tendon showed homogeneous longitudinal echogenic fibers. No flow was seen in or around the tendon. Tendinopathy was characterized by enhancement of the tendon on MR imaging (19/44 tendons); intratendinous flow on color Doppler sonography (16/44 tendons); increase in the anteroposterior diameter causing a rounding of the tendon (18/44 tendons); and inhomogeneity of the tendon (16/44 tendons on MR imaging and 21/44 tendons on sonography). Peritendinosis was characterized by peritendinous enhancement on MR imaging (29/44 tendons); flow on color Doppler sonography (20/44 tendons); and increased soft tissue (20/44 tendons on MR imaging and 27/44 tendons on sonography). When compared with MR imaging, the sensitivity and specificity of sonography for diagnosing tendinopathy were 80% and 90%, respectively, and for diagnosing peritendinosis were 90% and 80%. Addition of abnormal size to the structural abnormality criteria did not improve diagnostic ability. CONCLUSION: Sonography can be useful as the initial imaging study in evaluating abnormalities caused by posterior tibial tendinopathy.     

Radial and ulnar bursae of the wrist: cadaveric investigation of regional anatomy with ultrasonographic-guided tenography and MR imaging

Objective To demonstrate the anatomy of the radial and ulnar bursae of the wrist using MR and US images.Design Ultrasonographic-guided tenography of the tendon sheath of flexor pollicis longus (FPL) and the common tendon sheath of the flexor digitorum of the fifth digit (FD5) of ten cadaveric hands was performed, followed by magnetic resonance imaging and gross anatomic correlation. Patterns of communication were observed between these tendon sheaths and the radial and ulnar bursae of the wrist.Results The tendon sheath of the FPL communicated with the radial bursa in 100% (10/10) of cases, and the tendon sheath of the FD5 communicated with the ulnar bursa in 80% (8/10). Communication of the radial and ulnar bursae was evident in 100% (10/10), and presented an “hourglass” configuration in the longitudinal plane.Conclusions The ulnar and radial bursae often communicate. The radial bursa communicates with the FPL tendon sheath, and the ulnar bursa may communicate with the FD5 tendon sheath.     

Achilles tendon (TA) size and power Doppler ultrasound (PD) changes compared to MRI: a preliminary observational study

AIM: To assess whether abnormal Achilles tendon (TA) magnetic resonance imaging (MRI) and spectral ultrasound (US) features have associated development of microvascular power Doppler (PD) flow. MATERIALS AND METHODS: In a prospective, controlled and blinded study six patients with TA symptoms were compared to five with other ankle abnormalities. Two radiologists independently measured the mean maximal anteroposterior diameter on MRI and conventional US (categorized as normal <6 mm, mild 6.1-10 mm, moderate 1.1-1.5 cm and severely enlarged > 1.6 cm), assessed morphology and studied the vessels using power Doppler. They formed a consensus over discrepancies. Sonography of the contralateral side within 24 h was used as a control. RESULTS: Twenty-one tendons in six women and five men, aged 45-77 years (mean 57.6 years), were examined, 12 tendons were of normal US morphology and size (< 6 mm), and did not exhibit PD's flow (interobserver agreement K > 0.74). Of the 12 tendons studied by MRI five were normal, seven tendons were enlarged, five of which had a proportionate increase in PD flow at the margin on the deep surface and four also had vessels in the centre of the tendon. All five of these tendons had high signal on T2-weighting (T2W). Of the two mildly enlarged tendons of intermediate signal on T1 and T2W, one showed PD flow and the other did not. CONCLUSIONS: In patients with TA disease power Doppler ultrasound shows proliferation of vessels in enlarged, abnormal tendons demonstrated on MRI and standard ultrasound, in the absence of definite tears.     

Structural and functional analysis of the semitendinosus tendon after harvest for soft tissue reconstructive procedures: a dynamic ultrasonographic study

Purpose

To assess the potential for regeneration of the hamstring tendons after harvesting for various soft tissue reconstructive procedures, this study uses dynamic, high-resolution ultrasound to evaluate the presence of any tissue in the harvest gap and to characterize tissue functionality.

Methods

Patients who underwent ACL reconstruction using ipsilateral hamstring autograft were identified in the database of a single surgeon. Dynamic 12-MHz sonographic imaging was used to evaluate the ipsilateral and contralateral (control) semitendinosus tendons from their insertion sites to proximal muscle bellies. The presence or absence and echogenicity of tissue in the harvest defect, tissue appearance, degree of retraction of the proximal tendon stump, thickness of gap tissue, and motion of the proximal tendon stump were recorded. Data were analysed with Wilcoxon–Mann–Whitney, sign or binomial tests, with significance of P < 0.05.

Results

Eighteen knees in 15 patients (aged 17–51 years) were studied. The proximal amputated stump was retracted an average of 9.0 ± 7.6 cm (range, 0–18 cm; P = 0.0063). With dynamic testing, 9 of 15 knees demonstrated decreased excursion of the proximal tendon stump when compared to the native, contralateral muscle–tendon unit (P = 0.0039). Tissue was detected in the harvest gap in nine knees, five of which had harvest gap tissue with a disorganized appearance compared to the native tendon (P < 0.0001). Six of these nine knees had tissue in the gap demonstrating either less or no excursion with active knee flexion when compared to the native, contralateral side (P = 0.0313).

Conclusions

The presence of tissue in the harvest gap after ACL reconstruction is variable. When tissue is present, there is proximal retraction of the musculotendinous junction and disorganized appearance of the tissue that does not demonstrate normal excursion or physiological function similar to the native muscle-tendon unit.

Level of evidence

Case series, Level IV.     

Ultrasound imaging features of the Achilles tendon in dancers. Is there a correlation between the imaging and clinical findings? A cross-sectional study

ObjectivesTo analyze the prevalence of tendon pathology and performance associated in pre-professional classic dancers with no history of Achilles tendon (AT) pain. Design: A cross-sectional study was conducted.ParticipantsTwenty-nine classic ballet dancers without AT pain (58 tendons) were recruited. The tendons were classified (normal, abnormal) using ultrasound imaging (USI). Cross-sectional area (CSA) and thickness of flexor hallucis longus (FHL) muscle were measured using USI. Range of movement (ROM) of the first metatarsophalangeal join, balance test, endurance test and vertical jump were measured (bilaterally) as performance variables.ResultsMore than a half (62%) of the participants had at least one abnormal tendon, with 45% of the dancers in the abnormal group having bilateral abnormalities. Dancers with AT pathology had significantly more years of dancing and number of weekly pointe hours than those with no pathology on US imaging. No significant differences between the groups were identified for the rest of the variables. Dancing years were moderately correlated with AT thickness.ConclusionsAsymptomatic classic dancers had a high incidence of tendon pathology. Increased dancing years was associated with pathology in the AT. Nevertheless, these abnormalities may not affect dance performance.     

Accurate measurement of pulsatile flow velocity in a small tube phantom: comparison of phase-contrast cine magnetic resonance imaging and intraluminal Doppler guidewire

Purpose

We compared the accuracy of magnetic resonance imaging (MRI) measurements of pulsatile flow velocity in a small tube phantom using different spatial factors versus those obtained by intraluminal Doppler guidewire examination (as reference).

Materials and methods

We generated pulsatile flow velocities averaging about 20–290 cm/sec in a tube of 4 mm diameter; we performed phase-contrast cine MRI on pixels measuring 1.00²–2.50² mm². We quantified spatial peak flow velocities of a single pixel and a cluster of five pixels and spatial mean velocities within regions of interest enclosing the entire lumen in the phantom’s cross-section. Finally, we compared the measurements of temporally mean and maximum flow velocity with the Doppler measurements.

Results

Linear correlation was excellent between both measurements of spatial peak flow velocities in one pixel. The highest spatial resolution using spatial peak flow velocities of a single pixel allowed the most accurate MRI measurements of both temporally mean and maximum pulsatile flow velocity (r = 0.97 and 0.99, respectively: MRI measurement = 0.95x + 8.9 and 0.88x + 24.0 cm/s, respectively). Otherwise, MRI measurements were significantly underestimated at lower spatial resolutions.

Conclusion

High spatial resolution allowed accurate MRI measurement of temporally mean and maximum pulsatile flow velocity at spatial peak velocities of one pixel.     

The pilot study of dual-energy CT gemstone spectral imaging on the image quality of hand tendons

PurposeThe aim of this study was to evaluate the image quality of hand tendons using dual-energy computed tomographic gemstone spectral imaging (DECT GSI) compared with conventional CT images.Materials and methodsForty patients scanned with GSI mode on DECT were enrolled. The 65-keV optimal contrast-to-noise ratio for viewing hand tendons was selected. The image quality of monochromatic GSI images (65 keV) and conventional CT images was compared with two different methods including a subjective method and an objective method by two radiologists, respectively.ResultsIn the subjective method, the image quality in GSI images was superior to conventional CT images (P< .05). And in the objective method, the beam-hardening artifacts in the phalanges of finger space were reduced markedly, with hand tendons displaying more clearly in GSI images (P< .05). There was no significant difference between the two radiologists in both methods, with good correlation (kappa=0.75, kappa=0.85).ConclusionDECT GSI with the optimal 65-keV monochromatic images could reduce the artifacts and increase image quality significantly in hand tendons imaging. It might be very useful in detecting tendon diseases in routine work.     

Ultrasound imaging of non-traumatic lesions of wrist and hand tendons

Non-traumatic tendon lesions are common and diverse at the wrist and hand. Improvements in high-resolution ultrasound (US) are producing increasingly high-quality images of superficial structures, thus expanding the indications for this imaging modality as a tool for investigating musculoskeletal disorders. The objective of this work is to provide an update on the uses and performance of US in non-traumatic tendon disorders of the wrist and hand. The relevant anatomy is reviewed, and the normal and abnormal ultrasound scan features are described in detail, with attention not only to the tendons but also to closely related structures such as synovial sheaths and bands. The contribution of US to the evaluation of each of the most common disorders is discussed.     

Role of magnetic resonance imaging and ultrasonography in diagnosis and followup rheumatoid arthritis in hand and wrist joints

Purpose

To compare the role of ultrasonography and MRI in the diagnosis of synovitis involving wrist and hand joints in Rheumatoid arthritis patients.

Color Doppler-echo in rheumatoid arthritis with extra-articular location. Preliminary experience

INTRODUCTION: Chronic inflammation in rheumatoid arthritis usually involves articular synovia and extends to other joint components such as bursae, tendons and sheaths. Conventional US with high frequency transducers is an accurate tool for assessing abnormal changes in evolutive rheumatoid arthritis. We investigated the role of color and power Doppler imaging in staging extra-articular involvement, monitoring local inflammatory changes and drug treatment response. MATERIAL AND METHODS: We used a color Doppler unit with a 5-10 Mhz transducer and automatic power Doppler switch to examine 23 patients with tenosynovitis of the flexor (4/23) and extensor (8/23) tendons of the hand, Achilles (6/23) and posterior tibial (3/23) tendons, and long head of biceps (2/23) in acute rheumatoid arthritis. Only minimal pressure was exerted with the probe on the patients' skin to avoid compression and collapse of blood vessels. Ten normal volunteers were also examined as a control group. RESULTS: In all 23 acute rheumatoid arthritis patients, conventional US showed tendon involvement with intra-articular fluid, thickened tendons with partial tear and markedly hypoechoic thickened sheaths. Color signals were shown in all patients. Mid-caliber vessels were visualized coursing straight from the sheath deep into the tendon. Intra-articular signals were seen in 10/12 patients only. Spectral analysis showed arterial flow, with RI ranging .40-.70. Power Doppler added no important information, but improved vessel depiction relative to color Doppler thanks to its higher accuracy in detecting flow signals. There were no color signals in the tendons of the 10 healthy volunteers in the control group. No color signals were seen in both joints and tendons in 12 patients submitted to medical treatment. CONCLUSION: Color and power Doppler can be a necessary and useful integration to high resolution US for flow mapping in rheumatoid arthritis patients with tendon and extra-articular involvement. These modes depict local circulation changes related to disease stage and treatment response.     

Radiologic evaluation of tendon injuries.

This article reviews the imaging choices available to assess the tendons of the shoulder, knee, ankle, and wrist. Principles of tendon imaging and fundamental considerations of computer-derived image techniques are briefly discussed, with particular reference to magnetic resonance imaging. Although the criteria used to classify various tendon abnormalities are provided, the clinical role of imaging is emphasized.     

Doppler ultrasound signal in Achilles tendinopathy reduces immediately after activity

BACKGROUND: A relationship has been identified between vascularization on Doppler ultrasound (Doppler signal) and Achilles tendon pain. Doppler signal may increase minutes after prolonged activity, but the immediate effect is unknown. The aim of the study was to investigate the immediate effect of short term activity on Achilles tendon Doppler signal. Achilles tendinopathy patients (7 patients, 10 tendons) and asymptomatic controls (6 controls, 12 tendons) performed 2 activity tasks; a 2 minute continuous step task and one minute continuous calf raise task. Doppler signal was measured at rest and within a minute after each activity. The presence of Doppler signal was quantified using both semi quantitative (modified Ohberg scale; 0=no signal, 5 = > 90% of pathological area contains Doppler signal) and quantitative methods (pixel number). Doppler signal was present in 90% of symptomatic individuals and in none of the asymptomatic controls. The modified Ohberg scale and pixel number reduced significantly after both activity tasks and heart rate increased significantly (p < 0.05). Doppler signal in Achilles tendinopathy may decrease immediately after activities that load the calf muscle and increase heart rate, suggesting that this activity should be avoided prior to imaging to avoid false negative results.     

Comparison of myocardial velocities obtained with magnetic resonance phase velocity mapping and tissue Doppler imaging in normal subjects and patients with left ventricular dyssynchrony

PURPOSE: To compare longitudinal myocardial velocity and time to peak longitudinal velocity obtained with magnetic resonance phase velocity mapping (MR-PVM) and tissue Doppler imaging (TDI), and to assess the reproducibility of each method. MATERIALS AND METHODS: Longitudinal myocardial velocity was measured by TDI and MR-PVM in 10 normal volunteers and 10 patients with dyssynchrony. The reproducibility of MR-PVM and TDI was assessed on repeated measurements in the 10 normal volunteers. RESULTS: MR and TDI measurements of longitudinal myocardial velocity correlated well (r = 0.86) in both normal subjects and patients with dyssynchrony. However, myocardial velocities measured with MR consistently exceeded velocities measured with TDI. MR and TDI agreed strongly in measuring the time to peak velocity (r = 0.97). The reproducibility of TDI and MR-PVM appeared similar in measuring peak velocities (13.1% vs. 11.0%, respectively; P = NS) and time to peak velocity (9.1% vs. 5.7%, respectively; P = NS). CONCLUSION: Excellent correlation and reproducibility were observed between MR-PVM and TDI in measuring longitudinal myocardial velocity and time to peak velocity in both normal subjects and patients with dyssynchrony.     

Comparison of transcranial Doppler sonography with and without imaging in the evaluation of children with sickle cell anemia

OBJECTIVE: High blood flow velocity in the middle cerebral artery or distal internal carotid artery, as measured by nonduplex transcranial Doppler sonography, predicts stroke in children with sickle cell anemia. However, velocities measured using the more widely available duplex transcranial Doppler imaging equipment may not be comparable. We sought to determine the magnitude and significance of the potential differences. SUBJECTS AND METHODS: We performed 55 paired examinations with duplex imaging and nonduplex nonimaging sonography machines on 53 children with sickle cell anemia. Examinations were performed consecutively by three sonographers blinded to the results of the opposing study. Velocities were measured in five clinically relevant vessels. RESULTS: Time-averaged mean maximum (TAMx) velocity measurements obtained with the duplex equipment were significantly lower than those made with the nonduplex equipment for all vessels except the posterior cerebral artery. The mean differences were 10.9% (p < 0.0001) in the middle cerebral artery, 12.7% (p = 0.002) in the anterior cerebral artery, 2.2% (p = 0.69) in the posterior cerebral artery, 21.0% (p < 0.0001) in the distal internal carotid artery, and 15.3% (p < 0.0001) at the bifurcation of the distal internal carotid artery. CONCLUSION: If TAMx velocities measured with duplex equipment are used to assign stroke risk in children with sickle cell anemia, we suggest that 180 cm/sec or more should be considered abnormal, and 153-179 cm/sec, as conditional. These values are 10% lower than those obtained from the nonduplex equipment used in the Stroke Prevention Trial in Sickle Cell Anemia study.     

High reproducibility of patellar tendon vascularity assessed by colour Doppler ultrasonography: a reliable measurement tool for quantifying tendon pathology

Background: This study examined whether patellar tendon vascularity could be quantified accurately in the clinical setting using colour Doppler ultrasonography. Methods: A sonographer and two radiologists visually estimated tendon vascularity in millimetres in 74 tendons during ultrasound (US) examination and from hard copy films. These estimates were then compared to the length of vessels measured from the digital image in millimetres and the correlation between them was determined. A subset of 16 tendons was used to compare the estimates of vascularity by two examiners at US examination. Results: The estimation of vascular length at US examination correlated highly with the measured vascular length (r = 0.92; 95% confidence interval (CI) 0.87 to 0.94), as did the length estimated from the films (r = 0.94; 95% CI 0.9 to 0.96). The correlation between examiners was 0.84 (95% CI 0.51 to 0.94) for the estimates made during US examination and 0.85 (95% CI 0.59 to 0.95) for the vessel lengths measured from the digital images. Conclusions: These excellent correlations indicate that tendon vascularity can be reliably estimated using colour Doppler ultrasonography and tendon vascularity could therefore be used by clinicians to rate clinical change. This method of quantifying tendon vascularity could also be used in research to investigate the effects of tendon treatments on vascularity.     

Initial experience with visualizing hand and foot tendons by dual-energy computed tomography

PurposeTo assess the feasibility of visualizing hand and foot tendons by dual-energy computed tomography (CT).Methods and materialsTwenty patients who suffered from hand or feet pains were scanned on dual-source CT (Definition, Forchheim, Germany) with dual-energy mode at tube voltages of 140 and 80 kV and a corresponding ratio of 1:4 between tube currents. The reconstructed images were postprocessed by volume rendering techniques (VRT) and multiplanar reconstruction (MPR). All of the suspected lesions were confirmed by surgery or follow-up studies.ResultsTwelve patients (total of 24 hands and feet, respectively) were found to be normal and the other eight patients (total of nine hands and feet, respectively) were found abnormal. Dual-energy techniques are very useful in visualizing tendons of the hands and feet, such as flexor pollicis longus tendon, flexor digitorum superficialis/profundus tendon, Achilles tendon, extensor hallucis longus tendon, and extensor digitorum longus tendon, etc. It can depict the whole shape of the tendons and their fixation points clearly. Peroneus longus tendon in the sole of the foot was not displayed very well. The distal ends of metacarpophalangeal joints with extensor digitoium tendon and extensor pollicis longus tendon were poorly shown. The lesions of tendons such as the circuitry, thickening, and adherence were also shown clearly.ConclusionDual-energy CT offers a new method to visualize tendons of the hand and foot. It could clearly display both anatomical structures and pathologic changes of hand and foot tendons.