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Radiography is the appropriate initial imaging modality to assess for midfoot and forefoot pathology before turning to advanced imaging techniques. While most lesions of the mid- and forefoot can be diagnosed clinically, the exact nature and severity of the pathology is often unclear. This review addresses the use of the ultrasound, as well as the added value of magnetic resonance imaging, in diagnosing conditions of the midfoot and forefoot. Ultrasound allows a dynamic assessment as well as enabling imaging-guided interventions for diagnostic and therapeutic purposes. Practical tips for optimal examination of this area with ultrasound and magnetic resonance imaging are provided. Metatarsal stress fracture, Chopart’s injury, Lisfranc injury, as well as the 1st metatarsophalangeal joint injury and lesser metatarsophalangeal plantar plate injury are injuries unique to the mid- and forefoot. The imaging anatomy of the 1st and lesser metatarsophalangeal joints is reviewed, as such knowledge is key to correctly assessing injury of these joints. Characteristic imaging features of masses commonly encountered in the mid- and forefoot, such as ganglion cyst, Morton neuroma, gouty tophus, plantar fibroma, foreign body granuloma, and leiomyoma are reviewed. The use of ultrasound and magnetic resonance imaging in assessing degenerative and inflammatory joint disorders, and in particular rheumatoid arthritis, of the mid- and forefoot region is also reviewed. In summary, when necessary, most lesions of the mid-and forefoot can be adequately assessed with ultrasound, supplemented on occasion with radiographs, computed tomography, or magnetic resonance imaging.

When a low-energy trauma induces an acute vertebral fracture (VF) with clinical symptoms, a definitive diagnosis of osteoporotic vertebral fracture (OVF) can be made. Beyond that, a "gold" radiographic standard to distinguish osteoporotic from non-osteoporotic VFs does not exist. Fracture-shaped vertebral deformity (FSVD) is defined as a deformity radiographically indistinguishable from vertebral fracture according to the best of the reading radiologist's knowledge. FSVD is not uncommon among young populations with normal bone strength. FSVD among an older population is called osteoporotic-like vertebral fracture (OLVF) when the FSVD is likely to be associated with compromised bone strength. In more severe grade deformities or when a vertebra is collapsed, OVF diagnosis can be made with a relatively high degree of certainty by experienced readers. In "milder" cases, OVF is often diagnosed based on a high probability rather than an absolute diagnosis. After excluding known mimickers, singular vertebral wedging in older women is statistically most likely an OLVF. For older women, three non-adjacent minimal grade OLVF (< 20% height loss), one minimal grade OLVF and one mild OLVF (20–25% height loss), or one OLVF with ≥ 25% height loss, meet the diagnosis of osteoporosis. For older men, a single OLVF with < 40% height loss may be insufficient to suggest the subject is osteoporotic. Common OLVF differential diagnoses include X-ray projection artifacts and scoliosis, acquired and developmental short vertebrae, osteoarthritic wedging, oncological deformities, deformity due to high-energy trauma VF, lateral hyperosteogeny of a vertebral body, Cupid's bow, and expansive endplate, among others. [ABSTRACT FROM AUTHOR]

The 1994 WHO criterion of a T-score ≤ -2.5 for densitometric osteoporosis was chosen because it results in a prevalence commensurate with the observed lifetime risk of fragility fractures in Caucasian women aged ≥ 50 years. Due to the much lower risk of fragility fracture among East Asians, the application of the conventional WHO criterion to East Asians leads to an over inflated prevalence of osteoporosis, particularly for spine osteoporosis. According to statistical modeling and when a local BMD reference is used, we tentatively recommend the cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.7 for Hong Kong Chinese women. Using radiographic osteoporotic vertebral fracture as a surrogate clinical endpoint, we empirically demonstrated that a femoral neck T-score of -2.77 for Chinese women was equivalent to -2.60 for Italian women, a spine T-score of -3.75 for Chinese women was equivalent to -2.44 for Italian women, and for Chinese men a femoral neck T-score of -2.77 corresponded to spine T-score of -3.37. For older Chinese men, we tentatively recommend the cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.2. With the BMD reference published by IKi et al. applied, T-score of femoral neck, total hip, and spine of -2.75, -3.0, and -3.9 for Japanese women will be more in line with the WHO osteoporosis definition. The revised definition of osteoporosis cutpoint T-scores for East Asians will allow a more meaningful international comparison of disease burden. [ABSTRACT FROM AUTHOR]

The 2013 ISCD consensus recommended a Caucasian female reference database for T-score calculation in men, which says "A uniform Caucasian (non-race adjusted) female reference database should be used to calculate T-scores for men of all ethnic groups." However, this statement was recommended for the US population, and no position was taken with respect to BMD reference data or ethnicity matching outside of the USA. In East Asia, currently, a Japanese BMD reference database is universally adopted in Japan for clinical DXA diagnosis, while both local BMD and Caucasian BMD reference databases are in use in Mainland China, South Korea, Taiwan, and Singapore. In this article, we argue that an ethnicity- and gender-specific BMD database should be used for T-score calculations for East Asians, and we list the justifications why we advocate so. Use of a Caucasian BMD reference database leads to systematically lower T-scores for East Asians and an overestimation of the prevalence of osteoporosis. Using a female BMD reference database to calculate T-scores for male patients leads to higher T-score values and an underestimation of the prevalence of osteoporosis. Epidemiological evidence does not support using a female BMD reference database to calculate T-scores for men. We also note that BMD reference databases collected in Asia should be critically evaluated for their quality. [ABSTRACT FROM AUTHOR]

Chronic knee pain is a common condition. Causes of knee pain include trauma, inflammation, and degeneration, but in many patients the pathophysiology remains unknown. Recent developments in advanced magnetic resonance imaging (MRI) techniques and molecular imaging facilitate more in-depth research focused on the pathophysiology of chronic musculoskeletal pain and more specifically inflammation. The forthcoming new insights can help develop better targeted treatment, and some imaging techniques may even serve as imaging biomarkers for predicting and assessing treatment response in the future. This review highlights the latest developments in perfusion MRI, diffusion MRI, and molecular imaging with positron emission tomography/MRI and their application in the painful knee. The primary focus is synovial inflammation, also known as synovitis. Bone perfusion and bone metabolism are also addressed. [ABSTRACT FROM AUTHOR]

Image-guided synovial biopsy is generally a safe, well-tolerated procedure, with a high diagnostic yield. Percutaneous biopsy is indicated for synovial tumours visible on imaging studies where a definitive diagnosis is not possible on imaging grounds alone and/or when a definite diagnosis is necessary prior to initiating long-term treatment. Synovial biopsy for suspected synovial tumour differs from the technique used for joint aspiration, where the most convenient path between the skin and joint is usually chosen and, also, to a lesser degree, to that used for non-tumoural synovial biopsy. During synovial biopsy for tumour, the needle path should be aligned so that it passes along the length of the synovial tumour, including for suspected malignant tumours, the planned resection plane whenever possible. This review outlines the approach to image-guided biopsy of joint synovial tumours. [ABSTRACT FROM AUTHOR]

The physiology of bone perfusion is reviewed outlining how it can be measured with dynamic contrast-enhanced MRI as well as intravoxel incoherent imaging. Evaluation of bone perfusion provides a potential means of assessing tumor activity and treatment response beyond that possible with standard MR imaging. [ABSTRACT FROM AUTHOR]