[Systematics of injuries of the rotator cuff and biceps tendon]. / Systematik der Verletzungen von Rotatorenmanschette und Bizepssehne.

PERFORMANCE: Injuries of the rotator cuff and the biceps tendon demonstrate different patterns, which can be recognized clinically and radiologically. ACHIEVEMENTS: These patterns are impingement syndrome with additional trauma, isolated trauma of the rotator cuff and shoulder dislocation causing rotator cuff tears. Furthermore, it is clinically crucial to evaluate the extent of a rotator cuff injury. PRACTICAL RECOMMENDATION: Magnetic resonance imaging (MRI) is the modality of choice to differentiate these patterns.

[Arthrosis - update 2012]. / Arthrose - Update 2012.

Osteoarthritis is the most common joint disease in adults. With higher life expectancy and a growing proportion of elderly people in society, the relevance of osteoarthritis is becoming higher, especially in terms of socioeconomic effects and burdens for the healthcare system. In this review the pathogenesis and risk factors of the disease are presented with the focus on the knee, hip and shoulder, clinical symptoms, diagnosis and especially radiological imaging and therapy options.

Estimates of volumetric bone density from projectional measurements improve the discriminatory capability of dual X-ray absorptiometry.

To determine whether estimates of volumetric bone density from projectional scans of the lumbar spine have weaker associations with height and weight and stronger associations with prevalent vertebral fractures than standard projectional bone mineral density (BMD) and bone mineral content (BMC), we obtained posteroanterior (PA) dual X-ray absorptiometry (DXA), lateral supine DXA (Hologic QDR 2000), and quantitative computed tomography (QCT, GE 9800 scanner) in 260 postmenopausal women enrolled in two trials of treatment for osteoporosis. In 223 women, all vertebral levels, i.e., L2-L4 in the DXA scan and L1-L3 in the QCT scan, could be evaluated. Fifty-five women were diagnosed as having at least one mild fracture (age 67.9 +/- 6.5 years) and 168 women did not have any fractures (age 62.3 +/- 6.9 years). We derived three estimates of "volumetric bone density" from PA DXA (BMAD, BMAD*, and BMD*) and three from paired PA and lateral DXA (WA BMD, WA BMDHol, and eVBMD). While PA BMC and PA BMD were significantly correlated with height (r = 0.49 and r = 0.28) or weight (r = 0.38 and r = 0.37), QCT and the volumetric bone density estimates from paired PA and lateral scans were not (r = -0.083 to r = 0.050). BMAD, BMAD*, and BMD* correlated with weight but not height. The associations with vertebral fracture were stronger for QCT (odds ratio [QR] = 3.17; 95% confidence interval [CI] = 1.90-5.27), eVBMD (OR = 2.87; CI 1.80-4.57), WA BMDHol (OR = 2.86; CI 1.80-4.55) and WA-BMD (OR = 2.77; CI 1.75-4.39) than for BMAD*/BMD* (OR = 2.03; CI 1.32-3.12), BMAD (OR = 1.68; CI 1.14-2.48), lateral BMD (OR = 1.88; CI 1.28-2.77), standard PA BMD (OR = 1.47; CI 1.02-2.13) or PA BMC (OR = 1.22; CI 0.86-1.74). The areas under the receiver operating characteristic (ROC) curves for QCT and all estimates of volumetric BMD were significantly higher compared with standard PA BMD and PA BMC. We conclude that, like QCT, estimates of volumetric bone density from paired PA and lateral scans are unaffected by height and weight and are more strongly associated with vertebral fracture than standard PA BMD or BMC, or estimates of volumetric density that are solely based on PA DXA scans.

Alveolar rhabdomyosarcoma in a 68-year-old patient identified by cytogenetic analysis of bone marrow.

Pancytopenia and fulminant disseminated intravascular coagulation in a 68-year-old woman suggested an acute hematologic malignancy. However, cytogenetic analysis on a bone marrow sample revealed a near-tetraploid karyotype with an isochromosome 1q and a translocation (2;13) (q35;q14), which was suggestive of an alveolar rhabdomyosarcoma (ARMS). This diagnosis was subsequently confirmed by indirect immunohistochemistry. ARMS has not yet been observed in a patient of this age. Thus, our case underlines the importance of cytogenetics, to establish an a priori unexpected tumor diagnosis.

Osteometry of the mandible performed using dental MR imaging.

BACKGROUND AND PURPOSE: On cross-sectional and panoramic reformatted images from axial (dental) CT scans of the mandible it may be difficult to identify the inferior alveolar neurovascular bundle (IANB) in patients lacking a clear-cut bony delimitation of the mandibular canal. Dental MR images are comparable to dental CT scans, which directly show the IANB; however, measurements of length may not be reliable owing to susceptibility artifacts and field inhomogeneities in the oral cavity. Therefore, the accuracy of length measurements on dental MR images was compared with that on dental CT scans and direct osteometry. METHODS: Dental T1-weighted MR imaging using a high-resolution turbo gradient-echo sequence and dental CT were performed in six anatomic specimens. The axial scans were reformatted as panoramic and cross-sectional reconstructions on a workstation and characteristic cross sections were obtained from all mandibles. The longest axis in the bucco-lingual and apico-basal directions, the distances from the top of the mandibular canal to the top of the alveolar ridge and from the bottom of the mandibular canal to the base of the mandible, and the diameter of the bone cortex at the alveolar ridge were measured with direct osteometry on the cross sections and compared with measurements on corresponding MR and CT reformatted images. RESULTS: The correlation between direct osteometry and dental MR and CT was strong, except for the bone cortex diameter at the top of the alveolar ridge, where only a moderate correlation was found. Means of comparable length measurements were not significantly different among the three methods. CONCLUSION: The accuracy of length measurements in the jaw bones obtained using dental MR is comparable to that of dental CT and is not significantly different from direct osteometry. Thus, dental MR is a potential alternative to CT for dental imaging.

Importance of subchondral bone to articular cartilage in health and disease.

The almost absolute barrier to diffusion of nutrients between articular cartilage and subchondral bone does not exist. These anatomic regions represent a functional unit. Repetitive overloading in degenerative disease leads primarily to lesions in the subchondral region (including vessels), which in turn impede flow of nutrition to articular cartilage. As a result, in degenerative joint disease the subchondral region shows reactive enhanced vascularization and heightened metabolism with insufficient repair. In aging, however, vascularization and metabolism are decreased; no repair takes place. In many cases, MRI allows visualization of these subchondral abnormalities. It also demonstrates the basic similarities of degenerative osteoarthritis, osteochondritis dissecans, and avascular necrosis. These different entities may have the same basic etiology but with different disease severity.

The postoperative shoulder.

Because disability and pain may persist or recur after shoulder surgery, visualization of the postoperative shoulder before further treatment is of great interest. Postoperative status is reevaluated most frequently after rotator cuff repair, capsulorrhaphy in patients with chronic instability, and acromioplasty, where postoperative symptoms are clinically difficult to distinguish from rerupture or inadequate surgical results. Postoperative evaluation or follow-up after surgical treatment of tumors or surgical repair of shoulder injuries are other potential indications. Whereas surgical procedures for osseous components primarily will be evaluated by plain film radiographs, magnetic resonance imaging is a valuable tool for other sites of surgical treatment, such as soft-tissue components, with further potential indication for magnetic resonance arthrography. This article focuses on normal and abnormal postoperative findings in the shoulder, with emphasis of magnetic resonance imaging, and discusses specific findings based on magnetic resonance arthrography.

Magnetic resonance imaging of the postoperative knee.

Due to the recent development of arthroscopic techniques in meniscal surgery and anterior cruciate ligament reconstruction, an increasing number of postoperative patients are referred for a magnetic resonance examination of the knee because of recurrent injury. Contrary to the nonoperative patient, T2-weighted sequences and, in unequivocal cases, magnetic resonance arthrography play the most important role in the evaluation of a possible meniscal retear. In patients with anterior cruciate ligament reconstruction, the changes of the magnetic resonance appearance of the anterior cruciate ligament graft during the first year after surgery must be considered in the diagnosis of retears. Recent developments in articular cartilage defect repair and the possible role of magnetic resonance imaging in the follow-up are discussed.

The postoperative spine.

During the last decade, magnetic resonance imaging (MRI) mostly has replaced computed tomography for evaluation of spinal surgery patients. The inherent advantages of MRI are obvious for this particularly difficult field of imaging. With MRI, it is possible to demonstrate anatomic as well as pathological and iatrogenic changes in three different imaging planes and countless neighboring planes and to obtain a superior view of the complex postoperative situation regardless of the spinal level imaged. Soft-tissue masses in particular can be identified more readily and located within three-dimensional space. One of the major advantages is that the nature and histology of the mass can be estimated precisely using different MR sequences in combination with intravenous contrast media. The most important benefit may be demonstration of inflammatory and hemorrhagic masses in the early postoperative periods (with special emphasis on alterations visible in the spinal cord itself) as well as repair processes and ongoing degeneration in later stages. This visualization is possible even when their extent is limited. In the postoperative spine, the application of MRI was facilitated with the advent of new materials, such as titanium alloys, used for surgical instrumentation. These new materials limit the amount of artifacts visible on MR images. Earlier implants made of other metallic material prohibit the use of computed tomography in the spine. This article provides a brief overview of the progress in spinal surgery and focuses on the developments in MRI techniques during the last decade. Technical questions about imaging of spinal instrumentation are discussed. "Normal" postoperative findings needed for interpretation of pathologic conditions are also discussed. Finally, the most important frequently asked questions from referring surgeons that radiologists must be able to answer by MRI are presented.

MRI visualization of proteoglycan depletion in articular cartilage via intravenous administration of Gd-DTPA.

The effect of intravenous administration of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) on MR images was studied in vitro, using pathologic osteochondral specimens removed during surgery for total endoprosthesis, and in vivo, on a group of volunteers. In ex vivo specimens, lesions of different shape having lower T1 were detected which corresponded to areas with depleted proteoglycans found histologically. In vivo experiments on young volunteers showed that the time course of cartilage enhancement was different for different anatomies. The time for maximum enhancement ranged from 45 min for the ventral femoral condyle to 270 min for patellar cartilage.

Magnetic resonance arthrography (MRA) in the postoperative shoulder.

To evaluate changes in capsular mechanisms and the labroligamentous complex with magnetic resonance arthrography (MRA) after shoulder surgery and to establish possible criteria for the expected post-operative appearance of the shoulder. MRA of the shoulder was performed in 16 patients, before and 6 months after undergoing arthroscopic surgery for recurrent unidirectional dislocation. MR studies were performed after application of a constant amount of contrast solution (2 mmol Gd-DTPA). Axial and coronal oblique T1-weighted images were obtained with and without fat suppression techniques. Anterior (a) and posterior (p) capsular distances were measured, and the p/a ratio was established. Capsule thickness, capsular leaking, estimation of the volume of the axillary recess, appearance of the glenohumeral ligaments, and evidence of labral lesions were compared on pre- and postoperative images. Mean anterior capsular distance (a) decreased from 9.73 +/- 1.03 mm preoperatively to 5.27 +/- 2.49 mm postoperatively, whereas dorsal capsular distance (p) increased from 6.13 +/- 2.36 to 8.93 +/- 2.37. The p/a ratio increased from 0.64 +/- 0.25 to 2.36 +/- 2.54 (p = 0.007). Capsular leaking was suspected preoperatively in seven patients, but was not evident postoperatively. Capsular thickness and the estimated volume in the axillary recess did not change significantly. Contrast extension into pre-existent labral tears (nine patients) decreased or were not evident postoperatively. Changes in the appearance of the glenohumeral ligaments were found in six patients. Changes in capsular distances might be indicative of a decreased capsular laxity and could be a valuable criterion in the evaluation of the postoperative shoulder. Postoperative follow-up of labral tears is demonstrated by a decrease in contrast extension into or under a tear. Reactive capsular thickening or scar tissue formation can be reactive or preexistent. Changes in ligaments might be secondary to surgery. MRA may be helpful in the reevaluation of patients with suspected recurrent instability.

Trauma of the wrist.

In wrist injury, plain radiographs form the basis of diagnostic imaging, and can provide definitive answers in most cases. MR imaging is the method of choice for several diagnostic problem cases. These problems can include radiographically occult fractures where MRI enables early diagnosis compared to follow-up radiographs. Early stage diagnosis of a post-traumatic avascular osteonecrosis with high sensitivity and specificity, is only possible with MRI. In these instances, radiographs are only sensitive in later stages and scintigraphy is quite nonspecific. Stress fractures, invisible with other modalities, are also demonstrable with MRI. In addition, MRI is helpful in special circumstances with regard to non-union or pseudarthrosis. In wrist instability, radiographs in combination with stress views and fluoroscopy are still the initial diagnostic step. MRI, with the advantage of direct visualization of the wrist ligaments and triangular fibrocartilage complex, offers very promising results in this area. Generally, for the evaluation of wrist injury, MRI can be considered the most important second-step procedure in patients where radiographs are nondiagnostic.

Assessment of chronic constipation: colon transit time versus defecography.

OBJECTIVE: The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. MATERIALS AND METHODS: In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. RESULTS: Group I, idiopathic constipation (n = 11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n = 10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n =9), rectal prolapse (n = 5) or spastic pelvic floor syndrome (n = 4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P < 0.05). CONCLUSION: The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG.

The value of MRI in silicone granuloma of the breast.

MRI can be a valuable technique in patients with silicone-granulomas to screen for cancers which are not visible on mammography and/or sonography.

Rotator cuff tears in asymptomatic individuals: a clinical and ultrasonographic screening study.

OBJECTIVE: To determine the prevalence and clinical impact of rotator cuff tears in asymptomatic volunteers. MATERIALS AND METHODS: Sonographic examinations of the shoulder of 212 asymptomatic individuals between 18 and 85 years old were performed by a single experienced operator. The prevalence and location of complete rotator cuff tears were evaluated. The clinical assessment was based on the Constant Score. Magnetic resonance imaging (MRI) of the shoulder was obtained in those patients where US showed rotator cuff pathology. RESULTS: Ultrasound showed a complete rupture of the supraspinatus tendon in 6% of 212 patients from 56 to 83 years of age (mean: 67 years). MRI confirmed a complete rupture of the supraspinatus tendon in 90%. All patients reported no functional deficits, although strength was significantly lower in the patient group with complete supraspinatus tendon tear (P < 0.01). CONCLUSION: There is a higher prevalence in older individuals of rotator cuff tendon tears that cause no pain or decrease in activities of daily living.

[MRI of the lateral ankle ligaments: value of three-dimensional orientation]. / MR-Diagnostik der lateralen Sprunggelenksbänder: Bedeutung der dreidimensionalen Orientierung.

PURPOSE: To determine the three-dimensional orientation of the lateral ankle ligaments with MRI. MATERIALS AND METHODS: Twenty healthy volunteers without previous injury to the ankle were included in the study. With the right ankle in the normal anatomic position stabilized in a splint, coronal T2-weighted spin-echo sequences (TSE) were obtained. The three-dimensional orientation was determined by placing paths through the ligaments and by measuring the angles between corresponding tangents and the three main imaging planes. RESULTS: Using the calculated angles, full-length visualization of the lateral ligaments of the ankle was achieved. The angles deviating from the axial imaging plane were 18.0 degrees for the anterior talofibular ligament, 52.3 degrees for the calcaneofibular ligament and 28.2 degrees for the posterior talofibular ligament. CONCLUSION: MRI enables the exact determination of the three-dimensional orientation of the lateral ankle ligaments. Orienting the imaging planes according to the calculated angular deviation allows the full-length visualization of the ligaments and is the basis for optimal imaging of the lateral ankle ligaments.

[Pseudo-stenosis of the renal artery: a possible defect of color Doppler sonography]. / Pseudostenose der Nierenarterien: Mögliche Fehler der Farbdopplersonographie.

The diagnostic value of pulsed Doppler sonography for the detection of renal artery stenosis was questioned by recent studies. Until now, the diagnostic value of colour-coded Doppler sonography of the renal arteries is not clearly defined in relation to pulsed Doppler. This study deals with specific problems of colour-coded Doppler sonography in the examination of the renal arteries. Because of basic technical principles of colour-coded Doppler sonography a stenosis can be imitated especially at the origin of the right renal artery by using a ventral approach to the vessel. This pseudo-stenosis is due to a change of colour similar to an aliasing-phenomenon in a curved vessel. In order to avoid false positive results, a laterodorsal approach to the vessel should be applied additionally. A spectral waveform should be also registered routinely.

[Hallux rigidus operated on by Keller and Brandes method: radiological parameters of success and prognosis]. / Hallux rigidus operiert nach Keller und Brandes: Radiologische Erfolgs- und Prognoseparameter.

PURPOSE: The aim of this study was to evaluate the pre- and postoperative radiographic findings of hallux rigidus treated with Keller and Brandes arthroplasty to determine the radiographic outcome and to identify a prognostic marker. METHODS: 83 patients with a total of 121 cases of hallux rigidus operated using Keller and Brandes arthroplasty were followed up (mean 9.7 y). A comparison of the pre- and postoperative radiographs, the clinical and subjective findings was predicated on a five point scale: 1. percentage of proximal phalanx resected ( < 33%, 33-50%, > 50%), 2. joint space, 3. ratio of the length of the first and second metatarsals, 4. first intermetatarsal angle, and 5. hallux valgus angle. RESULTS: In the patient group which had 33-50% of the proximal phalanx excised (n = 67. 55%) the highest patient satisfaction was observed (96%). If resection of the proximal phalanx exceeded 50% (n = 13. 11%), non physiologic dorsiflexion of the toe occurred and patients were dissatisfied (62%). Excision of less than 33% of the hallux (n = 41. 34%) was associated with a recurrent hallux rigidus. No other evaluated radiological parameter proved to be of significance. CONCLUSION: The most important radiological parameter in the evaluation of the outcome of Keller and Brandes arthroplasty as a surgical treatment method for hallux rigidus was the percentage of the proximal phalanx which had ben excised.

[The screening of renal artery stenoses. The initial results with the value of color Doppler sonography]. / Screening von Nierenarterienstenosen. Erste Ergebnisse zur Aussagekraft der Farbdopplersonographie.

The value of colour Doppler sonography in the diagnosis of renal artery stenosis has been studied retrospectively. 17 patients were examined (34 main renal arteries and 7 accessory renal arteries; ages 37 to 84 years; 7 males and 10 females). We studied 1) ability to study the main renal arteries, 2) visibility of accessory renal arteries and 3) the sensitivity and specificity of colour Doppler sonography for the diagnosis of renal artery stenosis. The results were compared with intraarterial angiography. Demonstration of the main renal arteries with colour Doppler sonography was possible in 23 of the 34 vessels. Not a single of the 7 accessory renal arteries was demonstrated by colour Doppler sonography. Of 8 angiographically demonstrated stenoses (more than 50% narrowing) 2 were missed by colour Doppler sonography. One stenosis was correctly diagnosed and 5 were incorrectly evaluated by sonography. 16 out of 18 angiographically normal main renal arteries were correctly evaluated by colour Doppler sonography but 2 showed a false positive finding. This results in a sensitivity of 17% and a specificity of 89% per kidney. Colour Doppler sonography cannot be recommended as a screening method for renal artery stenosis in view of its limited accuracy.

[Renal osteodystrophy: the spectrum of the x-ray symptoms in modern forms of kidney transplantation and long-term dialysis therapy]. / Renale Osteodystrophie: Spektrum der Röntgensymptomatik bei modernen Formen der Nierentransplantation und Dauerdialysetherapie.

Plain film radiography and microradioscopy represent standard imaging for diagnosis and grading of renal osteodystrophy. The aim of this retrospective study was to evaluate the effects of modern therapeutic regimens on skeletal abnormalities as diagnosed radiographically. 198 patients were investigated. X-ray findings of 38 patients from 1981-1983 (16-66 years, 40.1 +/- 13.4; 23 male, 15 female) were compared with those of 160 patients from 1991 (20-71 years, 48.4 +/- 12.5; 98 male, 62 female). We found significant differences in respect of the spectrum and the degree of skeletal abnormalities. The prevalence of phalangeal resorptions lowered from 87 to 50%, the prevalence of soft tissue calcification from 68 to 57%. Therefore, renal osteodystrophy is not as extensive as it was ten years ago, but it still continues to be an unavoidable complication of renal insufficiency.