Thomas L. Pope

Gout: A clinical and radiologic review

Gout is a group of diseases characterized by arthritis and results from a disturbance of urate metabolism with the deposition of monosodium urate crystals in the joints and soft tissues. Often, but not invariably, the serum urate levels are elevated as a result of overproduction or underexcretion of uric acid. Clinical manifestations include acute and chronic arthritis, tophaceous deposits, interstitial renal disease, and uric acid nephrolithiasis. The diagnosis is based on the identification of uric acid crystals in joints, tissues, or body fluids. Acute episodes are treated with colchicine, NSAIDs, or steroids. Long-term management includes treatment with uricosuric agents or xanthine oxidase inhibitors.

Magnetic Resonance Imaging of Iliotibial Band Syndrome

Seven cases of iliotibial band syndrome and the patho anatomic findings of each, as demonstrated by mag netic resonance imaging, are presented. These findings were compared with magnetic resonance imaging scans of 10 age- and sex-matched control knees with out evidence of lateral knee pain. Magnetic resonance imaging signal consistent with fluid was seen deep to the iliotibial band in the region of the lateral femoral epicondyle in five of the seven cases. Additionally, when compared with the control group, patients with iliotibial band syndrome demonstrated a significantly thicker ili otibial band over the lateral femoral epicondyle (P < 0.05). Thickness of the iliotibial band in the disease group was 5.49 ± 2.12 mm, as opposed to 2.52 ± 1.56 mm in the control group. Cadaveric dis sections were performed on 10 normal knees to further elucidate the exact nature of the area under the iliotibial band. A potential space, i.e., a bursa, was found between the iliotibial band and the knee capsule. This series suggests that magnetic resonance imag ing demonstrates objective evidence of iliotibial band syndrome and can be helpful when a definitive diag nosis is essential. Furthermore, correlated with ana tomic dissection, magnetic resonance imaging identi fies this as a problem within a bursa beneath the iliotibial band and not a problem within the knee joint.

Are magnetic resonance flexion views useful in evaluating the cervical spine of patients with rheumatoid arthritis

Abstract  Objective. To determine whether MR imaging in flexion adds value relative to imaging in the neutral position with respect to displaying involvement of the subarachnoid space, brainstem and spinal cord. Design and patients. T1-weighted MR images of the cervical spine in 42 rheumatoid arthritis patients with cervical spine involvement were obtained and analyzed prospectively. We assessed changes between images obtained in the neutral position and following active flexion, especially horizontal atlantoaxial and subaxial motion, presence or absence of brainstem compression, subarachnoid space involvement at the atlantoaxial and subaxial level and the cervicomedullary angle. Vertical atlantoaxial subluxation and the amount of pannus were correlated with motion and change in subarachnoid space. Results. The flexion images showed horizontal atlantoaxial motion in 21 patients and subaxial motion in one patient. The flexion view displayed brainstem compression in only one patient. Involvement of the subarachnoid space increased at the atlantoaxial level in eight (19%) patients (P=0.004) and at the level below C2 in five (12%) patients (P=0.03). There were no patients with a normal subarachnoid space in neutral position and compression in the flexed position. The cervicomedullary angle changed significantly with flexion. Vertical atlantoaxial subluxation and the amount of pannus did not show a significant correlation with motion or subarachnoid space involvement. Conclusion. MR imaging in the flexed position shows a statistically significant narrowing of the subarachnoid space at the atlantoaxial level and below C2. Cord compression is only observed on flexion views if the subarachnoid space in neutral position is already decreased. MR imaging in the flexed position might be useful, since subarachnoid space involvement may be an indicator for the development of neurologic dysfunction.

Rare breast lesions: correlation of imaging and histologic features with WHO classification.

Mammographers occasionally are surprised by the diagnosis of a rare lesion at breast biopsy. The imaging features of some breast lesions are unfamiliar because they are rarely seen in routine mammographic practice and they are not well described or well documented in the radiologic literature. Moreover, there may be wide variation in the appearances of rare breast lesions at mammography and ultrasonography (US). In addition, although a few rare breast lesions have a typical imaging appearance, most have mammographic and US features similar to those of breast carcinomas, and a needle biopsy is almost always necessary to obtain a diagnosis. However, even when a rare breast lesion is diagnosed on the basis of a needle biopsy, knowledge of the imaging features of such lesions may help the radiologist decide whether the results of pathologic analysis concur with the imaging findings and whether surgical excision is necessary. It is therefore important that radiologists be familiar with the broad spectrum of imaging features of rare breast lesions as well as with the correlation between their histopathologic features and their current classification according to the World Health Organization classification system.

The positive predictive value of the breast imaging reporting and data system (BI-RADS) as a method of quality assessment in breast imaging in a hospital population

Evaluation of the diagnostic performance of mammography and US in our hospital, based upon the positive predictive value (PPV) for breast cancer of the breast imaging reporting and data system (BI-RADS) final assessment categories, has been performed. A follow-up study of 2,762 mammograms was performed, along with 955 diagnostic exams and 1,807 screening exams. Additional US was performed in 655 patients (23.7%). The combined reports were assigned a BI-RADS category. Follow-up was obtained by pathologic examination, mammography at 12 months or from PALGA, a nationwide network and registry of histo- and cytopathology. Overall sensitivity was 85% (specificity 98.7%); sensitivity of the diagnostic examinations was 92.9% (specificity 97.7%) and of the screening examinations 69.2% (specificity 99.2%). The PPV of BI-RADS 1 was 5 of 1,542 (0.3%), and of BI-RADS 2, it was 6 of 935 (0.6%). BI-RADS 3 was 6 of 154 (3.9%), BI-RADS 4 was 39 of 74 (52.7%) and BI-RADS 5 was 57 of 57 (100%). The difference between BI-RADS 1 and 2 vs. BI-RADS 3 was statistically significant (P<0.01). Analysis of BI-RADS 3 cases revealed inconsistencies in its assignment. Evaluation of the BI-RADS final assessment categories enables a valid analysis of the diagnostic performance of mammography and US and reveals tools to improve future outcomes.

Magnetic resonance imaging of the musculoskeletal system. Part 9. Primary tumors

Magnetic resonance imaging, because of its exquisite soft tissue contrast, has dramatically improved the ability to preoperatively stage primary osseous and soft tissue neoplasms. This technique also has allowed the monitoring of the effects of chemotherapy and the screening for recurrence of neoplasms. The role of magnetic resonance imaging in the preoperative evaluation of the patient with a suspected primary osseous or soft tissue neoplasm is outlined, instances where magnetic resonance imaging potentially may make a specific diagnosis are outlined, the importance of gadolinium enhancement as an adjunct to native magnetic resonance imaging is stressed, and an algorithm for followup of patients after chemotherapy or definitive surgical treatment is presented. In all cases, the magnetic resonance images should be correlated with the plain film, which is still an important aspect of the diagnosis of osseous lesions.

Dedifferentiated chondrosarcoma in patients with multiple osteochondromatosis: report of a case and review of the literature

Abstract Multiple osteochondromatosis (MOS) is a familial disorder of autosomal dominant transmission characterized by the development of multiple exostoses and often derangements of epiphyseal cartilage, sometimes resulting in long bone growth retardation. Patients with the disorder appear to be at increased risk for developing secondary chondrosarcomas. Rarely, dedifferentiated chondrosarcomas may also occur. We report a single case of a 27-year-old man with multiple osteochondromatosis who developed a fatal dedifferentiated chondrosarcoma. Radiographically, the neoplasm arose from the pelvis completely destroying the left pubic ramus. Subsequently, the patient underwent preoperative chemotherapy followed by a left external hemipelvectomy. On pathologic examination, the tumor was characterized by high-grade pleomorphic sarcoma sharply juxtaposed to a low-grade chondrosarcoma. The patient ultimately died of widespread metastatic sarcoma.

FDG-PET uptake in occult acute pelvic fracture.

The role of FDG-PET in the diagnosis of bone metastases remains unsettled, although it is hoped that PET scans will add specificity to or replace bone scintigraphy. We report a case in which an acute traumatic fracture presented with a level of uptake generally considered indicative of neoplasm. It is important to recognize that increased FDG-PET activity in bone should not be accepted as definitive evidence of metastatic disease.

Characterization of Sonographic and Mammographic Features of Granular Cell Tumors of the Breast and Estimation of Their Incidence

Objective. The purpose of this series was to review the spectrum of sonographic and mammographic features of granular cell tumors (GCTs) of the breast and to compare their frequency relative to breast carcinoma. Methods. Ten cases of a breast GCT diagnosed during the last 13 years were analyzed for the imaging characteristics and clinical features. Sonographic images were reviewed for location, size, echogenicity, margins, height‐width ratio, and sound transmission. Mammograms were reviewed for tumor size, location, margin characteristics, spiculations, and calcifications. The frequency of GCTs was compared with that of breast carcinoma during the same study period. Results. Of 10 GCT cases, 9 tumors occurred in female patients, and 1 occurred in a male patient. The mean patient age was 51.8 years, and the mean lesion size was 1.57 cm. All 7 tumors visualized on sonography were hypoechoic masses. Posterior enhancement was noted in 3 of 7 cases, and posterior shadowing was noted in 2 of 7 cases. Two of 7 did not show any posterior enhancement or shadowing. Two of 7 masses were taller than wide. Of 8 tumors visualized on mammography, 5 were spiculated, and 3 were well circumscribed. Calcifications were not visualized in any tumor. During the same period, 1482 cases of breast carcinoma were diagnosed, making the frequency of GCTs of the breast about 6.7 per thousand breast carcinomas. Conclusions. Granular cell tumors of the breast are rare neoplasms with a relative frequency of 6.7 per thousand breast carcinomas in our series, which was higher than reported in literature. Spiculations are a common imaging feature and mimic carcinoma when present.

Magnetic resonance imaging of the musculoskeletal system. Part 4. The knee.

Since its introduction to musculoskeletal imaging in the early 1980s, magnetic resonance imaging has proven to be an excellent technique for evaluating patients with knee problems. Studies have shown it to be accurate in the identification of abnormalities of the menisci, ligaments, patellofemoral joints, and other soft tissue and osseous structures in the knee. The main advantages of magnetic resonance imaging are its noninvasive nature and its high accuracy and negative predictive value in evaluating the menisci and anterior cruciate ligament. Magnetic resonance imaging has been shown to be useful in the detection and diagnosis of various traumatic and nontraumatic knee abnormalities. It has also proved useful in the diagnosis of occult or unsuspected bone lesions. Magnetic resonance imaging can therefore help in the selection of those patients who need therapeutic arthroscopy. There is evidence that magnetic resonance imaging of the knee is a cost effective screening technique when used in conjunction with the clinical findings in patients who are candidates for arthroscopy. Magnetic resonance imaging of the knee is still a relatively expensive modality.