Evaluation of lower back pain with bone scintigraphy and SPECT.

Bone scintigraphy and single photon emission computed tomography (SPECT) may be performed for evaluation of lower back pain, especially when a bone abnormality is suspected. Various patterns of tracer activity based on precise identification of the anatomic location of increased uptake may be observed and used to evaluate bones and joints. Lesions centered about the disk space and vertebral body include spondylodiskitis, metastatic disease, vertebral body fracture, and degenerative disease (disk disease, spondylosis deformans). In diskitis, tracer uptake has a vertical orientation. Metastatic involvement should be suspected in solitary lesions evaluated with SPECT when the area of increased uptake extends from the vertebral body into the pedicle. Fractures are seen on planar and SPECT images as a linear, horizontally oriented area of increased uptake centered in the vertebral body. In degenerative disease, increased uptake is centered about the disk space and may be seen in and project beyond the surface of the vertebral body. Lesions of the posterior arch (comprising the pedicle, lamina, and facet joints) include spondylolysis, pedicle lesions, osteoarthritis of the facet joints, and fracture of the transverse process. Scintigraphy may help differentiate long-standing asymptomatic spondylolysis from ongoing disease. In osteoarthritis of the facet joints, SPECT may be used to select patients to be treated with therapeutic injections. Increased uptake in the transverse process most often indicates a fracture, although tumors may also occur in this location. These findings at planar bone scintigraphy and SPECT allow differentiation of common pathologic conditions and can lead to a specific diagnosis.

Low back pain and nuclear medicine.

Low back pain (LBP) is a major cause of disability in many patients during some time of their lives. In this article the role of nuclear medicine, and more in particular the role of single photon emission tomography (SPECT), in the investigation of LBP is discussed by reviewing the literature. Because of the improved anatomical localization of lesions in the vertebral body when up-to-date SPECT is used, this technique is a powerful imaging modality in patients with LBP. Bone scintigraphy therefore can contribute significantly in the diagnosis of patients with LBP. In cases where conventional radiological techniques fail to elucidate the cause of LBP performing a bone scintigraphy with SPECT should strongly be recommended.

Squamous cell carcinoma of the urethra: ultrasonographic findings.

Urethral carcinoma is a rare neoplasm and only recently MR imaging has been applied to evaluate these tumors. Ultrasonography has mainly been used in the evaluation of urethral strictures. In the present paper a patient with squamous cell carcinoma of the urethra is reported and findings on ultrasonograms are described. Ultrasonography depicted the intraluminal tumor, in contrast to retrograde urethrocystograms, which appeared inconspicuous.

Florid reactive periostitis.

Florid reactive periostitis (FRP) is a benign entity, mostly involving the tubular bones of the hands and feet. It is important to distinguish FRP from malignant processes such as periosteal osteosarcoma and parosteal osteosarcoma, to give an adequate treatment and to avoid amputation of the total digit. The final diagnosis of FRP is usually based on the combination of clinical, radiological, and pathological findings. The pattern seen on the isotope bone scan can be very helpful in orienting the differential diagnosis.

Detecting clustered microcalcifications in the female breast: secondary digitized images versus mammograms.

We compared the detection of clustered microcalcifications by means of conventional mammograms and by means of secondary digitized images with a spatial resolution of 2048 x 1684 pixels and a contrast resolution of 12 bit. A Receiver Operating Characteristic (ROC) study was carried out using a cadaver breast showing phantom microcalcifications. A set of 100 mammograms was evaluated by two experienced senior radiologists. The ROC scores obtained with the digital images were 10% lower than those obtained with the conventional images. This difference however does not reach statistical significance. The use of a digital zoom function based on pixel duplication is also investigated. This zoom function does not produce a change in the diagnostic accuracy of the digital method. Attention is also paid to the advantages and disadvantages encountered by the radiologists when working on the digital viewing system. The most important drawback seems to be that it is considerably more time consuming than the conventional procedure, and this is especially due to the long loading time of the images and to the absence of window and level preselections.

The ultrasound aspect of the skin and subcutaneous fat layer in various benign and malignant breast conditions.

In a series of 260 consecutive X-ray mammography examinations in symptomatic patients, 25 patients proved to have breast cancer, and 41 had various benign breast conditions. In the 66 patients with abnormal mammograms a real-time ultrasound examination with a 7.5 MHz linear array transducer and a fluid offset pad was performed. This paper focuses on the ultrasound aspect of the skin and the subcutaneous fat layer in various benign and malignant breast conditions. In most of the malignant tumors studied as well as in cases of fat necrosis and breast abscesses, the following ultrasound signs were encountered: discontinuity of the sharp echogenic subcutaneous specular reflector, thickening of the skin, and locally increased echogenicity of the subcutaneous fat layer. In breast cancer these signs were seen in some patients with small tumors, in deeply located tumors as well as in patients with no skin retraction on clinical examination. The differential diagnosis between cancer and benign breast tumors cannot be based upon the ultrasound aspect of the skin and subcutaneous fat layer alone. X-ray mammography as well as clinical criteria and anamnestic factors should be used for the diagnosis of breast abscesses (calor, rubor, tumor, dolor) and for the diagnosis of fat necrosis (surgery, trauma).