Preoperative ultrasonography and magnetic resonance imaging evaluation of the position of the neurovascular bundle for Dupuytren's disease of the fifth digit.

BACKGROUND: Dupuytren's contracture (DC) is a fibrosing disor-der that produces pathological subcutaneous nodules and cords in the normal fascia. The isolated occurrence of Dupuytren's disease of the fifth digit is uncommon. This study is aimed to describe the imaging features of an isolated digital cord of the small finger and its relationship with the neurovascular bundle. METHODS: A total of 13 hands in 13 patients who were clinically diagnosed with an isolated occurrence of Dupuytren's disease of the small finger were included between October 2008 and October 2013. Two independent radiologists used ultrasound and magnetic reso-nance imaging (MRI) to record size, signal or echogenicity, contrast enhancement or hyperemia, calcification, and anatomical features of the cord and its relationship with the neurovascular bundle. RESULTS: We found that ultrasound and MRI were accurate for the detection of the cords and neurovascular bundles in the small finger. The intermodality agreement between MRI and ultrasound was 100% for the detection of 6 spiraling bundles containing 13 isolated cords (46.2%). Among the subjects examined, 100% of the hands had ab-ductor digiti minimi (ADM) area involvement, and the distal insertion of the cord was on the ulnar side of the base of the middle phalanx. On MRI, all of the cords showed predominantly low signal intensity on both T1- and T2-weighted images. On ultrasound, the ulnar cord showed a hyperechoic or isoechoic appearance in 69.3% of hands and a hypoechoic appearance in 30.7% of hands. CONCLUSIONS: The spiraling of the bundle in the isolated occurrence of Dupuytren's disease at the small finger is a frequent occurrence. MRI and ultrasound are good imaging modalities for the evaluation of the relationship between the neurovascular bundle and the isolated cord.

Tears at the myotendinous junction of the infraspinatus: ultrasound findings.

PURPOSE: Tears involving the myotendinous junction (MTJ) of the infraspinatus (IS) have been recently described on MRI. These occur centrally in the muscle belly, and are not associated with full thickness tears of the distal infraspinatus tendon. They also induce a rapidly progressive fatty infiltration of the muscles and amyotrophy. The purpose of this study is to assess the accuracy of ultrasonography in diagnosing MTJ tears of the infraspinatus and to describe the usual ultrasonographic appearance compared with MRI. MATERIALS AND METHODS: Retrospective study of 2403 US examinations of the shoulder (over 5 years). Fifteen patients with a reported suspicion of infraspinatus MTJ tears were included. MRI examination was available in all cases, CT arthrography in 13 cases, and one patient underwent surgical confirmation. RESULTS: All patients were sent for an ultrasound for suspect lesion of the tendons of the rotator cuff, with posterior pain in the infraspinatus fossa. All cases seen on ultrasonography were confirmed on MRI. CT arthrography confirmed the absence of tear of the IS tendon in all cases and did not reveal the MTJ tears. Two signs appeared to us as being of special interest: the "tadpole sign" on longitudinal views, and the "black eye sign" on sagittal views. The proximal retraction of the tendon at the MTJ is the anatomical explanation of both signs. CONCLUSION: Tears at the myotendinous junction of the infraspinatus are rare but can be diagnosed on US examination, provided that the sonographer pays attention to the infraspinatus fossa especially in cases of normality of the distal tendinous cuff.

[Harmonic sonography of rotator cuff tendons: are cleavage tears visible at last?]. / Echographie des tendons de la coiffe en mode harmonique: les clivages sont-ils enfin visibles?

PURPOSE: For some, cleavage tears remain a pitfall of sonography (US). The purpose of this study is to demonstrate the visibility of intratendinous tears of the supraspinatus and infraspinatus tendons and describe their imaging features on tissue harmonic US. MATERIALS AND METHODS: Prospective study of 52 patients with suspected cuff pathology who underwent US prior to CT-arthrography, CT-bursography or MR arthrography. The US examinations were performed using 7-15 MHz transducers with tissue harmonic mode (pulse subtraction). An intratendinous tear was suggested by the presence of a hypoechoic intratendinous line, extending from a partial or full thickness tear. Results from US were correlated to contrast material enhanced CT or MR findings. RESULTS: Ten cases of cleavage tears were detected on US compared to 18 on arthrographic examinations. False negative results occurred in poor US candidates (n=4), excessively retracted tendons (n=2) or postsurgical cuffs (n=2). Sensitivity was 55% and specificity was 94%, with PPV of 83% and NPV of 80% for the detection of intratendinous tear. The accuracy of US was lower for intratendinous tear associated with full thickness tears (5/11) compared to intratendinous tears associated with partial thickness tears (5/6). CONCLUSION: We demonstrate that cleavage tears are now visible on US using high-frequency transducers and tissue harmonic mode. However, the sensitivity remains too low, especially in patients with full thickness tear, postsurgical patients and patients that are poor candidates to US.

[Imaging of wrist injuries in athletes]. / Imagerie du poignet du sportif.

Wrist imaging is currently used for diagnosis of sport injuries as part of a global strategy of rapid recovery. Standard x-rays are the first step in this procedure. Although arthrography is still the reference for the diagnosis of intrinsic ligament and cartilaginous lesions, MRI can sometimes be sufficient. Ultrasonography is a dynamic process and is accurate in detecting tendon injuries. Wrist sport injuries are frequent and often asymptomatic. Here we review the usual aspects of bone, ligament, and tendon lesions encountered in each sport, while providing advice on the most appropriate imaging for each clinical symptom.

[Nerve and vascular entrapment in athletes]. / Syndromes canalaires du sportif.

Peripheral nerve entrapment syndromes involve the compression of a short segment of a nerve at a specific site, as a result of the vulnerability of that nerve as it passes through a fibroosseous tunnel or an opening in fibrous or muscular tissue. Injury of the nerve may occur as a result of compression by the overlying structures. Another mechanism of injury is traction of the nerve, with or without friction of the nerve, as it travels and sharply changes direction around critical points. Imaging can be particularly helpful for the diagnosis of these uncommon injuries. Percutaneous decompression of a ganglion cyst or perineural injection for therapeutic purposes with the aid of fluoroscopy, CT, or ultrasound guidance can be performed in specific areas.

Rotations of three-joint fingers: a radiological study.

The aim of the current study was to test a protocol of quantification of phalangeal three-dimensional (3D) rotations during flexion of three-joint digits. Three-dimensional-specific software was developed to analyze CT reconstruction images. A protocol was carried out with six fresh-frozen upper limbs from human cadavers free from any visible pathology (three females, three males). CT millimetric slices were done for reconstruction of hand bone units. Orthonormal coordinate systems of inertia were calculated for each unit. Three-dimensional phalangeal rotations were estimated between two static positions (fingers in extension and in a fist position). Results were displayed for the joints of each three-joint finger with calculation of 3D rotations. Mean longitudinal axial rotations of metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints ranged from 14 degrees pronation to 19 degrees supination. The index finger was in a global pronation position (4/6 specimens). The fourth and fifth fingers were in a global supination position in every case. The third finger was in a more variable global rotation (pronation in 2/6 specimens). MCP, PIP and DIP flexion angles ranged respectively from 71 degrees to 89 degrees, 65 degrees to 87 degrees, and 41degrees to 77 degrees. Lateral angles ranged from 19 degrees (ulnar angulation) to 23 degrees (radial angulation). The study of phalangeal rotations was possible in spite of a heavy protocol. This protocol could be partially automatated to speed up the analyses. Longitudinal axial rotations could be analyzed, in addition to flexion/extension or abduction/adduction rotations. CT scan reconstructions would be helpful for investigating pathological fingers. Abnormal rotations of digits could be quantified more precisely than during a current clinical examination of the hand.

Assessment of progression in knee osteoarthritis: results of a 1 year study comparing arthroscopy and MRI.

OBJECTIVE: The objectives of this study were to determine the sensitivity to change of magnetic resonance imaging (MRI) quantification of chondropathy after 1 year in osteoarthritis of the medial tibiofemoral compartment and to assess the predictive value of subchondral bone marrow edema and bone abnormalities on progression of chondropathy. DESIGN: Twenty patients with symptomatic knee osteoarthritis of the medial compartment underwent a prospective, longitudinal study. All patients were evaluated the same day at entry and after 1 year by plain weight-bearing radiographs, MRI with a three-dimensional gradient-echo sequence, using a 0.2-T dedicated MR unit, and arthroscopy. The medial tibiofemoral chondropathy was quantified blindly with MRI and arthroscopy using the French Society of Arthroscopy (SFA) score. Presence of subchondral bone marrow edema and bone abnormalities on initial MRI was recorded in order to evaluate their influence on both unchanged and worsened chondropathy after 1 year. RESULTS: After 1 year, no statistically significant changes were observed with plain radiographs and arthroscopy. At variance, a statistically significant worsening of chondropathy was found with MRI using the SFA-MR score (P=0.01). SFA-MR score was the most responsive outcome. Absence of subchondral bone abnormalities and bone marrow edema on initial MR assessment predicted absence of worsening of chondropathy after 1 year. CONCLUSION: MRI appears promising for evaluating progression of knee osteoarthritis.

Quantitative assessment of joint space width with an electronic caliper.

UNLABELLED: The progression of joint space narrowing (JSN) is considered to be the best available marker of osteoarthritis (OA) progression. Several techniques have been proposed for the measurement of joint space at its narrowest point in OA of the hips and knees. OBJECTIVE: To evaluate the properties of the technique using an electronic caliper for the measurement of JSN in OA patients. DESIGN: We used an electronic caliper to measure joint space width (JSW) for hips on 100 plain radiographs. JSW was measured in the vertical position at the center of the femoral head. Femoral head diameter was also determined to correct for variations due to differences in magnification of digitized X-rays. All films were read twice by each of two rheumatologists (one junior, one senior) and two radiologists (one junior, one senior). Intraclass correlation coefficients and their 95% confidence intervals were calculated. RESULTS: Detailed results are given for right hips (38 with OA, 18 inflammatory, 44 normal); very similar results were obtained for left hips. For JSW, the intraclass correlation coefficient was between 0.96 and 0.99 for intraobserver reliability. The level of reliability was similar for analysis of the diameter of the femoral head (R:0.84 to 0.98) and for the ratio of these two measurements (0.96 to 0.99). The most reliable measurements were those made by the senior radiologist, followed by those made by the two rheumatologists. In assessments of interobserver reliability for the measurement of JSW, R varied from 0.91 to 0.96 for the first reading and from 0.88 to 0.96 for the second reading. For the measurement of femoral head diameter, R varied from 0.86 to 0.96 for the first reading and from 0.74 to 0.96 for the second reading. CONCLUSION: The electronic caliper technique is an accurate method for measuring JSW in the hip. This technique seems to be reproducible, is simple, and could be used for routine evaluation. Further validation is required, with the measurement of serial X-rays from the same patients.

Study of the joint space of the hip on supine and weight-bearing digital radiographs.

AIM: To compare hip joint space on supine and weight-bearing anteroposterior digital radiographs. MATERIALS AND METHODS: Fifty anteroposterior views of the hip in 25 patients were taken in supine and weight-bearing positions on a fluoroscopic unit. Two observers in a double-blind study assessed the width of the joint space on an Easy Vision unit with an indirect method of measurement (metric index). RESULTS: Inter-observer and intra-observer variabilities of the metric index were less than 4.1%. There was no significant difference of the metric index of the hip (P>0.05), between supine and weight-bearing positions. CONCLUSION: There is no significant difference of the width of the joint space of the hip between supine and weight-bearing anteroposterior radiographs. Measuring joint space loss in osteoarthritis of the hip with anteroposterior views should be done with radiographs of the hip in the supine position to improve image quality.

The influence of highly active antiretroviral therapy on AIDS-associated Kaposi's sarcoma.

To assess the clinical and biological benefit of highly active antiretroviral therapy on AIDS-associated Kaposi's sarcoma (KS), 13 patients with AIDS-associated Kaposi's sarcoma (five pulmonary KS and eight cutaneous KS) were prospectively followed for a mean duration of 12 months. Six patients were treated with specific anti-KS chemotherapy before or simultaneously with the introduction of antiretroviral therapy. Clinical response was assessed according to the AIDS Clinical Trial Group (ACTG) criteria. CD4 cell counts, plasma HIV-1 RNA and human herpesvirus 8 (HHV-8) viraemia were measured at baseline and at different points. Among patients with pulmonary KS, we observed three complete responses (CR), one partial response (PR) and one progression. The median survival time after the diagnosis of pulmonary KS was 15 months with a median duration of the response after the discontinuation of specific chemotherapy for KS of 8 months. Among patients with cutaneous KS, we observed four CR, three PR and one stable response. A complete response was significantly associated with a reversal in HHV-8 viraemia (five of six vs. one of six; P = 0.02, Mann-Whitney test).

Lumbar facet joint arthrography with the posterior approach.

Lumbar facet joint (LFJ) arthrography with intraarticular injections of long-acting steroids and local anesthetics is routinely used for therapeutic purposes in selected patients for relief of low back pain. The procedure may also be used for diagnostic reasons to establish the source of such pain. However, because direct access to the LFJ space is not always possible owing to degenerative changes such as osteophytes, another posterior approach has been proposed for LFJ arthrography. With the patient in the prone position, a spinal needle is inserted vertically into the inferior recess of an LFJ with fluoroscopic guidance and the patient under local anesthesia. To facilitate puncture, cushions are placed under the patient's abdomen to flatten normal lumbar lordosis, which enlarges the inferior recess of the LFJ. Use of cushions also results in a decrease in tissue thickness in the patient, thereby improving image quality and decreasing radiation exposure. LFJ arthrography can demonstrate the causative role of facet disease in abnormalities responsible for low back pain or sciatica and can be performed easily and rapidly with this direct posterior approach.

[MRI and articular cartilage]. / IRM et cartilage articulaire.

Although plain films are fundamental for routine imaging of degenerative chondral lesions, MRI is a promising tool of investigation for the articular cartilage. Its modalities are still imprecise and debated, but, because of its noninvasiveness, it is destined to be preferred over arthroCT. The small size of the cartilage requires thin slices of less than 3-mm thick. The various features of normal cartilage images must be well known. They depend on acquisition parameters, zonal structure of the cartilage and numerous artifacts (partial volume average, chemical shift, magnetic susceptibility, truncation, "magic angle"). Fast SE images provide a good compromise between contrast and the signal-to-noise ratio. T2-weighted images take advantage of an arthrographic effect in case of joint effusion. 3D GE images allow a more accurate evaluation with 1-mm thick slices. In all sequences, adding of a fat-suppression presaturation increases contrast between the cartilage and the surrounding structures. The diagnostic accuracies of the different sequences and of MR arthrography are discussed. Quantitative measurements of cartilage thickness and volume remain the topic of clinical research.

Quantitative MR imaging evaluation of chondropathy in osteoarthritic knees.

PURPOSE: To determine the validity and the reliability of T1-weighted three-dimensional gradient-echo magnetic resonance (MR) imaging for quantification of articular cartilage abnormalities of osteoarthritic knees. MATERIALS AND METHODS: Forty-three patients (mean age, 63 years) with knee osteoarthritis (American College of Rheumatology criteria) of the medial tibiofemoral compartment underwent a prospective, cross-sectional study. Knees were examined with a T1-weighted three-dimensional gradient-echo sequence (1.4-mm contiguous sections), with use of a 0.2-T dedicated MR unit, before arthroscopic exploration. The tibiofemoral articular cartilage abnormalities were quantified blindly on both the MR and arthroscopic images with the French Society of Arthroscopy (SFA) score (0-100) and grading scheme (five grades). RESULTS: There was a statistically significant correlation between the SFA-arthroscopic score and the SFA-MR score (r = .83) and between the SFA-arthroscopic grade and the SFA-MR grade (weighted kappa = 0.84). The deepest cartilage lesions graded with arthroscopy and MR imaging showed correlation in the medial femoral condyle (weighted kappa = 0.83) and in the medial tibial plateau (weighted kappa = 0.84). The intraobserver reliability of the SFA-MR score was higher (r = .94) than the interobserver reliability (r = .80). CONCLUSION: Quantification of chondropathy with MR imaging is feasible and well correlated with anatomic cartilage breakdown.

Longitudinal stress fractures of the tibia: comparative study of CT and MR imaging.

The aim of this study was to compare the performance of CT and MRI in the diagnosis of longitudinal stress fracture of the tibia (LSFT). A retrospective study of imaging findings was performed in 15 patients with LSFT. The CT and MR images were compared for detection of fracture line, callus, bone marrow edema, and soft tissues changes. The CT and MRI techniques allowed the detection of the fracture line in 82 and 73 % of cases, respectively. The callus was always visualized with CT or MRI. The MRI technique had a markedly higher sensitivity than CT in the detection of bone marrow edema (73 vs 18 %) and soft tissue lesions (87 vs 9 %). This may cause a misleading aggressive appearance on MRI. Computed tomography remains the best imaging modality for diagnosis of LSFT. However, MRI findings should be known to obviate the performance of CT or bone biopsy.

[Imaging]. / Imagerie.

The panoply of imaging techniques useful in podology is essentially limited to X-rays. Standard "standing" and "lying" X-rays furnish most of the required information. Arthrography is sometimes performed, in particular for trauma or tumour of the ankle. CT scan and MRI make a decisive contribution in difficult cases, notably in fractures and in small fractures without displacement. The two latter techniques are useful in tendon, ligament and muscular disorders, where echography is also informative. Rigorous analysis of radiographies and a good knowledge of foot disorders make these imaging techniques efficacious.

Image-Guided Spinal Steroid Injections.

This paper has been written to stimulate the radiologist to consider the various aspects of spinal steroid injections as therapeutic procedures. Special emphasis is placed on needle guidance, asepsis, and possible problems involved. It constitutes a highly practical and variously illustrated and informative guide for the choice of steroids and various spinal joint approaches. It details the following target areas: lumbar facet joints, cervical facet joints, costovertebral joints, C1-C2 joint, intervertebral discs, epidural space, and interspinous bursa. Safety is the key element of the above-mentioned techniques. The radiologist must pay special attention to the omnipresent risk of iatrogenic infection.

[Limitations of ultrasonography in the detection of small cancers of the left kidney]. / Limites de l'échographie dans la détection des petits cancers du rein gauche.

Renal ultrasound seems to be more difficult on the left than on the right side. In a retrospective analysis of 343 patients in whom a radical nephrectomy for renal tumor diagnosed by abdominal ultrasonography had been carried out, we analyzed the characteristics of these tumors. TNM classification was used. Right kidney tumors (n = 170) were smaller than the left ones (n = 172), 58 +/- 31.7 mm and 66.8 +/- 31.5 mm respectively, the difference being statistically significant (p = 0.01). Right kidney tumors of a less advanced stage (p < 0.05). Asymptomatic renal tumors were found more frequently on the right side (58.7%) than on the left (41.3%) (p = 0.03) and were smaller on the right (44 mm +/- 19.6 vs 54.5 mm +/- 27.2) (p = 0.04). In conclusion, Ultrasound exploration of the left kidney seems to be more difficult, mostly because the exploration of the right kidney is facilitated by the acoustic window of the liver.