Sonographic and radiographic evaluation of the extensor tendons in early postoperative period after total knee arthroplasty.

OBJECTIVE: To prospectively assess the early changes in the quadriceps and patellar tendons before and after total knee arthroplasty using ultrasound, shear wave elastography, and X-rays. MATERIALS AND METHODS: Radiographs, ultrasound, and shear wave elastography were performed on 23 patients (16 women; aged 51-85, mean 66 ± 9 years) before and after surgery at 6 weeks and on 11 patients at 3 months. Patellar position and patellar tendon lengths were evaluated by radiography; joint effusion or synovitis, quadriceps and patellar tendon lengths, and thicknesses, echogenicity, vascularity, and stiffness were assessed with ultrasound and shear wave elastography. RESULTS: In the early postoperative period, 87% of the patients had joint effusion, and 43% had signs of synovitis. There was a significant thickening of the quadriceps tendon in 51.5% (p < .0001) and of the patellar tendon in 93.8% (p < .0001) of patients with a significant shortening of the patellar tendon in 7.8% (p < .0001). A hypoechoic defect on the medial aspect of the quadriceps tendon was found in 87% of the patients. There was a significant increase in Young's modulus in the quadriceps tendon (p = .0006) but not in the patellar tendon. CONCLUSION: The following should not be considered to be pathological findings at early postoperative imaging: joint effusion, synovitis, increasing of stiffness and thickening of quadriceps tendons by more than 50%, thickening of patellar tendon by more than 90%, focal defect through the medial aspect of the quadriceps tendon, and shortening of the patellar tendon by 8%.

Case 247: Jersey Finger of the Fifth Finger.

History A 34-year-old man without underlying medical conditions came to the emergency department for evaluation of persistent pain over the volar portion of his right fifth finger after a fall during a football match 3 days before. At physical examination, the injured finger was swollen and purple. Passive and active flexion of the proximal and distal interphalangeal joints were compromised, without interphalangeal instability. Radiography was performed in the emergency department, and the patient was released with a diagnosis of a fifth digit sprain. After the senior radiologist (V.M.C.) reviewed the radiographs, the patient was called back for assessment with ultrasonography (US) on the same day. US was performed with an Aplio 500 unit (Toshiba Medical Systems, Tokyo, Japan) using a multifrequency linear array 7.2-18.0-MHz PLT-1204BX transducer focused at the level of the flexor tendon. The patient was sitting in front of the examiner, with the hand lying palm up on the examination bed. No abnormality was observed during color Doppler US.

Sonography of the Pronator Teres: Normal and Pathologic Appearances.

The pronator teres muscle is rarely examined during a routine sonographic examination of the elbow joint. Nevertheless, it can be affected by a variety of conditions, including trauma and tumors, and can be implicated in compression of the median nerve. This pictorial essay first illustrates the anatomy and biomechanics of the pronator teres. Then we present the sonographic technique for examination, normal sonographic appearance, and anatomic variations of the pronator teres and adjacent structures as well as sonography of their main disorders. Normal and pathologic sonographic appearances are correlated with magnetic resonance imaging and radiographic results.

Osteolytic femoral lesion detected by sonography in a case of light chain deposition disease.

We describe a case of light chain deposition disease presenting as worsening of renal failure with a lytic femoral bone lesion discovered by sonography. Although sonography cannot be considered to be the test of choice in evaluating multiple myeloma, this technique may allow the detection and the biopsy of osteolytic bone lesions, particularly in accessible locations. Differential diagnosis is discussed.

Atlas of Sonographic Anatomy of the Hand and Wrist.

Accurate knowledge of the technique of ultrasonographic (US) examination and of normal US appearance is a prerequisite for a successful US examination of the wrist and hand. In this article, we describe our standard US examination as well as the normal US findings of the hand and wrist.

Normal appendix in adults: reproducibility of detection with unenhanced and contrast-enhanced MDCT.

OBJECTIVE: The purposes of this study were to investigate whether readers' interpretations are reproducible and whether readers are confident in identifying a normal appendix with CT and to assess the influence of patient characteristics and IV contrast enhancement on visualization of the appendix. SUBJECTS AND METHODS: One hundred two patients without a history of abdominal surgery underwent unenhanced and contrast-enhanced CT for the evaluation of cancer. Three radiologists with varying degrees of experience read scans twice in separate sessions. They were asked to identify the appendix, to score their confidence in identification, and to mark the appendix on the images. Intraabdominal fat volume was measured with a computer-assisted method. Independent experts compared the readers' markings and indicated whether the findings were reproducible. RESULTS: Reproducibility differed significantly between reading sessions (p < 0.001) and readers (p = 0.003). On the images of 71% of the patients, there was perfect intrareader and interreader agreement with statistically significant and positive influences of patient body mass index (p = 0.005) and intraabdominal fat volume (p = 0.001). Contrast enhancement influenced intrareader reproducibility only for the reader who made less-reproducible interpretations (p = 0.033). Intrareader and interreader agreement in categorizing confidence in identification of the appendix ranged from fair to good (kappa = 0.221-0.620). Confidence was not influenced by contrast enhancement (p = 0.433-0.953), body mass index, or intraabdominal fat volume (p = 0.058-0.798). CONCLUSION: Reproducibility in identifying a normal appendix is reader dependent. Perfect intrareader and interreader agreement in marking the appendix occurs approximately 70% of the time and increases with patient body mass index and intraabdominal fat volume. Contrast enhancement does not influence the rate of identification of the appendix or reader confidence but may influence the reproducibility of findings.

Nerves Around the Shoulder: What the Radiologist Should Know?

Peripheral neuropathies of the shoulder are common and could be related to traumatic injury, shoulder surgery, infection or tumour but usually they result from an entrapment syndrome. Imaging plays an important role to detect the underlying causes, to assess the precise topography and the severity of nerve damage. The key points concerning the imaging of nerve entrapment syndrome are the knowledge of the particular topography of the injured nerve, and the morphology as well signal modifications of the corresponding muscles. Magnetic Resonance Imaging best shows these findings, although Ultrasounds and Computed Tomography sometimes allow the diagnosis of neuropathy.