Arthur M. De Schepper

Imaging features of musculoskeletal tuberculosis

Abstract. The purpose of this article is to review the imaging characteristics of musculoskeletal tuberculosis. Skeletal tuberculosis represents one-third of all cases of tuberculosis occurring in extrapulmonary sites. Hematogenous spread from a distant focus elsewhere in the body is the cornerstone in the understanding of imaging features of musculoskeletal tuberculosis. The most common presentations are tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue involvement. The diagnostic value of the different imaging techniques, which include conventional radiography, CT, and MR imaging, are emphasized. Whereas conventional radiography is the mainstay in the diagnosis of tuberculous arthritis and osteomyelitis, MR imaging may detect associated bone marrow and soft tissue abnormalities. MR imaging is generally accepted as the imaging modality of choice for diagnosis, demonstration of the extent of the disease of tuberculous spondylitis, and soft tissue tuberculosis. Moreover, it may be very helpful in the differential diagnosis with pyogenic spondylodiscitis, as it may easily demonstrate anterior corner destruction, the relative preservation of the intervertebral disk, multilevel involvement with or without skip lesions, and a large soft tissue abscess, as these are all arguments in favor of a tuberculous spondylitis. On the other hand, CT is still superior in the demonstration of calcifications, which are found in chronic tuberculous abscesses.

The Radiology Report as Seen by Radiologists and Referring Clinicians: Results of the COVER and ROVER Surveys

PURPOSE To investigate and compare the opinions and expectations regarding the radiology report of radiologists and referring clinicians and to identify trends, discordance, and discontent. MATERIALS AND METHODS A total of 3884 clinicians and 292 radiologists were invited by e-mail to participate in two internet surveys, COVER (for clinical specialists and general practitioners) and ROVER (for radiologists). Respondents were asked to state their level of agreement with 46 statements according to a Likert scale. Dichotomized results were compared by using the χ(2) statistic. RESULTS Eight hundred seventy-three completed forms were prepared for analysis, corresponding to a response rate of 21%. Most clinicians declared themselves satisfied with the radiology report. A large majority considered it an indispensable tool and accepted that the radiologist is the best person to interpret the images. Nearly all agreed that they need to provide adequate clinical information and state clearly what clinical question they want to have answered. Itemized reporting was preferred for complex examinations by both the clinicians and the radiologists. A majority in both groups were convinced that learning to report needs to be taught in a structured way. CONCLUSION The surveys emphasize the role of the radiologist as a well-informed medical imaging specialist; however, some of the preferences of radiologists and clinicians diverge fundamentally from the way radiology is practiced and taught today, and implementing these preferences may have far-reaching consequences.

Focal nodular hyperplasia of the liver: Radiologic findings

A retrospective analysis of the results of ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) of 24 cases (28 lesions) of proven focal nodular hyperplasia (FNH) is presented. While US exhibited nonspecific features, CT frequently showed characteristic features: hypodensity on precontrast scans (69%), transient immediate enhancement after bolus injection (96%), and homogeneity (85%). A scar was noted in 31% of the cases. The typical MR triad of isointensity on T1- and/or T2-weighted (T2-WI), homogeneity, and a scar which shows hyperintensity on T2-WI was seen in only 12% of our cases. The most common finding was homogeneity (94%). In two cases the scar was hypointense on T2-WI. To our knowledge, this finding has not been described before. We conclude that the features of FNH, although fairly constant, are at times indistinguishable from those of other hepatic tumors, such as hepatic adenoma (HA), fibrolamellar hepatocellular carcinoma (FLHCC), small hepatocellular carcinoma, and a hyperplastic nodule. Therefore, a multimodality approach is essential for the correct diagnosis in order to prevent unnecessary surgery.

Hereditary multiple exostoses: from genetics to clinical syndrome and complications

OBJECTIVE To give an overview of genetic, clinical and radiological aspects in two families over four generations with known hereditary multiple exostoses (HME). METHODS AND MATERIAL After linkage analysis in both families to localize the defective gene, mutation analysis was performed in these genes to identify the underlying mutation. In the 31 affected individuals, location, number and morphology and evolution of exostosis, evolution of remodeling defects at the metaphysis, and the extent of possible complications were evaluated on clinical and imaging (plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI)) data over a lifetime period. RESULTS AND CONCLUSIONS Both families demonstrate the gene defect in the same EXT-2 gene locus on chromosome 11p. Exostoses are preferentially located in the lower extremity (hip, knee and lower leg), humerus, and forearm. Any other bone may be involved, except for the calvaria of the skull and the mandible. Exostoses are rather sessile than pedunculated. Exostosis is rarely present at birth but develops gradually and may persist to grow slowly after closure of the growth plates. Preferential expression of the remodeling defect was seen in the hip, distal femur (trumpet-shaped metaphysis) and forearm (shortening of the ulna with secondary bowing of the radius and development of a pseudo-Madelung deformity). These radiological manifestations start at the age of 4-5 years and become more obvious as the enchondral bone formation progresses with age. Reported complications in these families consist of local entrapment phenomenons (vessel, tendon, nerve), frictional bursitis, and sarcomatous transformation. MRI was able to suggest these complications and is the imaging technique of choice in the evaluation of symptomatic exostoses.

Accuracy of MRI in characterization of soft tissue tumors and tumor-like lesions. A prospective study in 548 patients

The purpose of our study was to assess prospectively the value of MRI in characterization of soft tissue tumors (STT) and soft tissue tumor-like lesions in a multi-institutional setting by a group of experts. The material consisted of 548 untreated and proven STT or tumor-like lesions originating from a multi-institutional database of STT in which 930 consecutive patients with STT examined by MRI were registered between 1 January 2001 and 28 April 2003. Based on MRI findings, a suitably ordered differential diagnosis was made in consensus by two radiologists (J.L.M.A.G and A.M.D.S). MRI diagnoses were compared with histology results (455 cases, 83%) and/or 6-month follow-up (93 cases, 17%) as reference standards. The correlation between the MRI and histological diagnosis and between the radiological and histological phenotype were statistically determined. One hundred twenty-three patients presented with a malignant STT; 425 patients presented with a benign one. Concerning differentiation between malignant and benign lesions (dignity), a sensitivity of 93%, specificity of 82%, negative predictive value (NPV) of 98% and positive predictive value (PPV) of 60% with accuracy of 85% were obtained. Concerning phenotype characterization, if only the first MRI diagnosis was taken into account, a sensitivity of 67%, specificity of 98%, NPV of 98%, PPV of 70% and accuracy of 96% were obtained. For benign lesions, sensitivity of 75%, specificity of 98%, NPV of 98%, PPV of 76% and accuracy of 97% were obtained. The phenotype’s definition of malignant STT had a sensitivity of 37%, a specificity of 96%, NPV of 96%, PPV of 40% and an accuracy of 92%. A correct diagnosis compared with histological assessment was proposed in 227(50%) of the 455 histologically confirmed cases. Despite non-quantified MR parameter evaluation, the results of our prospective study were better than those reported in previous studies and demonstrated the need for a centralized approach to such rare pathology.

Brainstem hemorrhage in descending transtentorial herniation (Duret hemorrhage)

Objectives: To review clinical and radiological findings in patients with Duret hemorrhages and to discuss the pathophysiology and differential diagnosis of these lesions. Patients and methods: We reviewed the case records of four patients with Duret hemorrhages who had been admitted to the neurological intensive care unit with supratentorial mass lesions. Results: Descending transtentorial and subfalcine herniations were present in all cases. Three patients were admitted with acute subdural hematoma and one with intraparenchymal hemorrhage. Computed tomography revealed the presence of blood in the mesencephalon and upper pons. Three patients died; one survived with severe disabilities. Discussion: Duret hemorrhages are typically located in the ventral and paramedian aspects of the upper brainstem (mesencephalon and pons). The pathophysiology of Duret hemorrhage remains under debate: arterial origin (stretching and laceration of pontine perforating branches of the basilar artery), versus venous origin (thrombosis and venous infarction). Multifactorial causation seems likely. Conclusion: Duret hemorrhages are delayed, secondary brainstem hemorrhages. They occur in craniocerebral trauma victims with rapidly evolving descending transtentorial herniation. Diagnosis is made on computed tomography of the brain. In most cases the outcome is fatal. On the basis of our observations we believe that arterial hypertension and advanced age are risk factors for the development of Duret hemorrhage.

Low-field versus high-field MR imaging of the knee: a comparison of signal behaviour and diagnostic performance

A prospective study was undertaken to compare MR imaging of the knee obtained with low-field and high-field systems. In 10 subjects, MR imaging of the knee was performed on a 0.2 T permanent magnet and on a 1.5 T superconductive system. Similar spin echo (SE) and 3D-FISP (3D Fourier transform with steady state precession) acquisitions were obtained. Comparative image analysis was performed independently by four radiologists. Results show that the image quality and diagnostic performance delivered by state-of-the-art 0.2 T and 1.5 T systems is equivalent. Advantages of the 1.5 T system included: better signal-to-noise ratio, shorter scan times, better visualization of asymptomatic grade 1 meniscal degeneration on SE images. Advantages of 0.2 T images were: decreased chemical shift, susceptibility and flow artifacts, improved evaluation of subchondral bone on 3D-FISP images, slightly better patient tolerance. We conclude that, for MR imaging of the knee, a low-field system is a cost-effective alternative to more expensive superconducting units.

How do referring clinicians want radiologists to report? Suggestions from the COVER survey

ObjectiveTo investigate what referring clinicians suggest when asked how the quality of radiology reports can be improved.MethodsAt the end of the questionnaire of the COVER survey, a bi-national quantitative survey on the radiology report among referring physicians, clinical specialists and general practitioners were able to freely enter suggestions with regard to improving the quality of the report. These suggestions were isolated from the quantitative results. Subjects and themes were identified, examined, ordered, counted, compared and analysed.ResultsOf a total of 3,884 invitations to participate, we received 735 response forms from clinicians (18.9%), 233 (31.7%) of which contained suggestions. Issues mentioned most frequently were the need for clinical information and a clinical question, for a conclusion, structuring, communicating directly with the clinician, completeness, integrating images or referring to images, mentioning relevant findings outside of the clinical question, mentioning a diagnosis or suitable differential diagnosis, and concise reporting.ConclusionAlthough these spontaneous suggestions are erratic and sometimes contradictory, they summarise the ideas as well as the emotions of these clients of the radiology department. Therefore it is advisable to take them into account when developing new ways of reporting.

Subcutaneous diffuse neurofibroma of the neck: A case report

A case of a rare and unusual variant of neurofibroma, diffuse neurofibroma (paraneurofibroma), in a young patient is presented. The clinical, radiological and histopathological features of this case are reported. The magnetic resonance imaging (MRI) features of the diffuse neurofibroma are comparable with those described in other neurofibromas.

Computed tomography of the polysplenia syndrome in the adult

The computed tomographic appearance of the polysplenia syndrome in 2 cases is presented. Both are associated with absence of the hepatic segment of the inferior vena cava. Computed tomography can determine the exact location of the malpositioned organs, the presence of multiple spleens, and the type of the associated venous anomalies, which are the major features of the polysplenia syndrome.