Imaging algorithms and CT protocols in trauma patients: survey of Swiss emergency centers.

OBJECTIVES: To identify imaging algorithms and indications, CT protocols, and radiation doses in polytrauma patients in Swiss trauma centres. METHODS: An online survey with multiple choice questions and free-text responses was sent to authorized level-I trauma centres in Switzerland. RESULTS: All centres responded and indicated that they have internal standardized imaging algorithms for polytrauma patients. Nine of 12 centres (75 %) perform whole-body CT (WBCT) after focused assessment with sonography for trauma (FAST) and conventional radiography; 3/12 (25 %) use WBCT for initial imaging. Indications for WBCT were similar across centres being based on trauma mechanisms, vital signs, and presence of multiple injuries. Seven of 12 centres (58 %) perform an arterial and venous phase of the abdomen in split-bolus technique. Six of 12 centres (50 %) use multiphase protocols of the head (n = 3) and abdomen (n = 4), whereas 6/12 (50 %) use single-phase protocols for WBCT. Arm position was on the patient`s body during scanning (3/12, 25 %), alongside the body (2/12, 17 %), above the head (2/12, 17 %), or was changed during scanning (5/12, 42 %). Radiation doses showed large variations across centres ranging from 1268-3988 mGy*cm (DLP) per WBCT. CONCLUSIONS: Imaging algorithms in polytrauma patients are standardized within, but vary across Swiss trauma centres, similar to the individual WBCT protocols, resulting in large variations in associated radiation doses. KEY POINTS: • Swiss trauma centres have internal standardized imaging algorithms for trauma patients • Whole-body CT is most commonly used for imaging of trauma patients • CT protocols and radiation doses vary greatly across Swiss trauma centres.

Prognostic value of different CT measurements in early therapy response evaluation in patients with metastatic colorectal cancer.

OBJECTIVES: Patients with advanced stage colorectal carcinoma (CRC) display hepatic metastases on initial staging in up to 20% of cases. The effectiveness of chemotherapy is generally evaluated by computed tomography (CT) imaging using standardized criteria (RECIST). However, RECIST is not always optimal, and other criteria have been shown to correlate with pathologic response and overall survival. The aim of this study was to evaluate the prognostic value of different CT measurement for response assessment after initiation of chemotherapy in patients with synchronous colorectal cancer liver metastases. METHODS: Fifty-five patients with CRC and synchronous hepatic metastases were evaluated retrospectively at 2 academic centers. Different size, volume, ratio and attenuation parameters were determined at baseline and after 3 cycles of chemotherapy. The prognostic value of baseline measurements and of the change between baseline and second measurements was analyzed using Kaplan-Meier estimates. RESULTS: Median time to progression was 279 days, median overall survival was 704 days. In this selective patient population, neither a significant prognostic value of initial baseline CT parameters nor a prognostic value of the change between the first and the second CT measurements was found. CONCLUSION: Initial morphological response assessment using different CT measurements has no prognostic value concerning time to progression or overall survival in patients with synchronous colorectal liver metastases.

[Degenerative rupture of the hip abductors. Missed diagnosis with therapy-resistant trochanteric pain of the hips and positive Trendelenburg sign in elderly patients]. / Degenerative Ruptur der Hüftabduktoren. Verpasste Diagnose bei therapieresistenter Periarthropathie der Hüfte und positivem Trendelenburg-Zeichen des älteren Patienten.

The cases of four elderly patients with persistent trochanteric pain and tears of the gluteus medius and/or gluteus minimus tendons detected in magnetic resonance imaging (MRI) are presented. There was no history of local trauma in any patient but three patients had a positive Trendelenburg sign. Magnetic resonance imaging showed either an obvious discontinuity of the affected tendon or an increased T2 signal above, or less specifically lateral to the greater trochanter. The presence of an elongated tendon on MRI is most likely indicative of a partial rupture of the tendon. Pain and local tenderness over the lateral aspect of the hip in clinical examination is commonly attributed to trochanteric bursitis or trochanteric pain syndrome. Partial or complete tears of the gluteus medius and/or gluteus minimus tendons are thought to represent an unusual finding. However, the true incidence and the clinical significance of hip abductor degeneration and rupture remain to be determined. More studies are needed to examine the prevalence of ruptures in asymptomatic patients, to evaluate the subsequent risk for developing osteoarthritis of the hip (caused by impaired protective reflexes originating from proprioceptive nerve endings in muscle spindles) and to determine the risk for falls related to weakness of hip abduction. Furthermore, no data exist regarding the success rate of conservative treatment. Tears of the gluteus medius and minimus tendons in the elderly population are likely to be a more common cause of pain in the greater trochanteric region than previously thought. In patients who do not respond to conservative treatment, weakness of hip abduction (positive Trendelenburg sign) and new limping should point to the possibility of hip abductor ruptures. The most useful examination technique for diagnosis is MRI.

The Agger Nasi cell and uncinate process, the keys to proper access to the nasolacrimal drainage system.

BACKGROUND: Profound knowledge of the surgical anatomy is required to perform any dacryo-cysto-rhinostomy (DCR) procedure. In endoscopic endonasal DCR surgery, the uncinate process (UP) and/or agger nasi (AN) cell are frequently found to obstruct access to the lacrimal fossa. The aim of this study was to analyse the radiological anatomy of the UP and the AN cell in relation to the lacrimal sac. METHODS: Preoperative computed tomography (CT) scans of patients undergoing DCR and other endoscopic sinus surgeries were analysed regarding their anatomical variations concerning the UP and the AN cell at the level of the common canaliculus. The covering of the lacrimal fossa by the UP was graded and a surgically relevant AN cell was sought after. RESULTS: CT datasets of 60 sides were included. Analysis showed an AN cell overlying the upper parts of the lacrimal sac in 55% of patients. An anteriorly attaching UP covering at least 50% of the lacrimal fossa was found in 63% of individuals. CONCLUSION: In this study more than 80% of all patients presented with either a very anteriorly attached UP or an AN cell that would have to be removed to perform effective endoscopic DCR. The AN cell and the UP need to be included in the endonasal surgical concept.

The impact of stereo-visualisation of three-dimensional CT datasets on the inter- and intraobserver reliability of the AO/OTA and Neer classifications in the assessment of fractures of the proximal humerus.

We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus.

Induction of complete and sustained remission of rheumatoid pachymeningitis by rituximab.

Aseptic pachymeningitis is a rare and serious complication of rheumatoid arthritis (RA). Herein, we describe a patient with rheumatoid factor-positive and anti-cyclic citrullinated peptide-positive RA who experienced a focal seizure, with aphasia and convulsions of the right side of the body. The findings of magnetic resonance imaging and histologic analysis led to a diagnosis of rheumatoid pachymeningitis. Because the patient had a large number of CD20-expressing B lymphocytes, therapy with rituximab was started and has resulted in complete and sustained remission of both the pachymeningitis and the RA for >2 years. Despite a decrease in immunoglobulins, the patient has remained free of infections, which illustrates the favorable outcome that can result from therapeutic B cell depletion in this potentially lethal manifestation of RA.

[Thenar hammer syndrome]. / Thenar-Hammer-Syndrom.

Chronic traumatic aneurysm of the distal radial artery is rare. The literature offers only 20 cases of chronic traumatic vascular lesions of the thenar region. We present the case of a 58-year-old cheese maker who had done manual work for years and who experienced swelling at the thenar eminence, pain, cold and warm paresthesia and circulatory disturbance in his index finger. Duplex ultrasound and CT angiography revealed an aneurysm of the superficial branch of the radial artery indicating a thenar hammer syndrome. He was subjected to a microsurgical end-to-end repair after resection of the aneurysm. This is the first closely documented case of a true aneurysm of the superficial branch of the radial artery. We also present a comprehensive survey of published studies of chronic vascular lesions of the thenar region related to thenar hammer syndrome and patient occupation, symptoms, diagnostis and therapy.

[Avascular necrosis of the hamate--case report]. / Durchblutungsstörung des Os hamatum--Fallbericht.

Avascular necrosis of the hamate is a very rare condition. After repetitive stress a young male developed left wrist pain which was found to be an avascular necrosis of the hamate. After progression of the necrosis with cyst formation on follow-up magnetic resonance imaging (MRI) and persisting pain, the patient underwent successful revascularisation with a vascular bone graft of the distal radius.

[Significance of computed tomography evaluation before revision stapes surgery]. / Stellenwert der CT-Diagnostik vor Revisions-Stapedotomien.

BACKGROUND: Stapedectomy and, more recently, stapedotomy have been widely accepted as the primary surgical techniques to improve conductive hearing in patients suffering from otosclerosis. Unsuccessful outcomes are infrequent, but revision surgery may become necessary. We have analyzed the value of computed tomography (CT) scanning following unsuccessful stapes surgery. PATIENTS AND METHODS: In a total of 37 CT scans, the depth of insertion, angle between prosthesis and footplate, location of prosthesis within the oval niche, visibility of the prosthesis, dehiscence of the superior semicircular canal, and extent of otospongiotic foci were evaluated and compared with the audiometric results. RESULTS: There was no significant correlation between CT parameters and audiologic results, except for patients with cochlear otosclerosis or lateral dislocation of the piston. One previously unknown dehiscence of the superior semicircular canal was diagnosed. Otospongiotic foci were seen in 13 ears (35%). CONCLUSION: Displacements of the stapes piston and rare causes for an insufficient result, such as a dehiscence of the superior semicircular canal, can be diagnosed accurately by CT. However, correlation between the audiologic results and the findings on CT scans was possible in only a few cases. Nevertheless, CT scans provide additional information for surgical planning in revision stapes surgery and may become increasingly important to reduce unanticipated intraoperative risks; they may even guide the surgeon not to perform unnecessary revision surgeries.

[Long-term results following reconstruction of maxillary sinus wall defects with titanium micro-mesh: a CT-based study]. / CT-kontrollierte Spätergebnisse nach Defektdeckung im Kieferhöhlenbereich mit dem Mikrotitangitter.

BACKGROUND: Extensive bony defects of maxillary sinus walls have to be reconstructed to prevent long-term complications. Different autogenous, allogeneic, and alloplastic materials, e.g., titanium mesh, are used for reconstruction. MATERIAL AND METHODS: In 26 patients large defects of the facial and laterodorsal walls of the maxillary sinus were reconstructed using titanium micro-mesh. The mean follow-up period was 49 months (5 months-10 years). All patients were examined with computed tomography applying multiplanar reconstruction techniques and three-dimensional volume rendering. RESULTS: In the CT scans stable scars of 3-6 mm thickness could be found on the antral surfaces of all titanium meshes bridging the defects. In 70% of the patients the volume of the reconstructed maxillary sinus reached 80-100% of the contralateral side. Volume losses were not due to poor adaptation of the titanium mesh but were caused by thickening of maxillary sinus walls or traumatic malpositions. In 77% of the patients ventilation of the maxillary sinus was undisturbed. After mesh removal neither facial contour disturbances nor changes of sinus volume were noted. Soft tissue invasion into the sinus was prevented by a stable scar which had formed underneath the mesh. Three-dimensional reconstruction confirmed symmetrical facial contours in all patients. CONCLUSIONS: The titanium micro-mesh offers a simple and effective alternative to autogenous tissue with stable long-term results for reconstruction of large maxillary sinus wall defects.

[Cine MRI of the temporomandibular joint in comparison to static MRI and axiography]. / Cine-MRT des Kiefergelenks im Vergleich zur konventionellen MRT und Achsiographie.

PURPOSE: To evaluate Cine MRI (cMRI) of the temporomandibular joint in comparison to static MRI (sMRI) and axiography. MATERIALS AND METHODS: In a prospective study with 57 healthy volunteers as well as 33 patients after temporomandibular joint (TMJ) surgery or with severe joint dysfunction, we measured the mobility of both condyle and disc as well as the sagittal angle of condylar inclination with sMRI and cMRI. Measurements and image analysis were performed by a radiologist and a maxillofacial surgeon in consensus. The results of axiography served as standard of reference. RESULT: Concerning the assessment of the discoligamentous complex, sMRI was superior to cMRI in the patient-group (sensitivity sMRI 85 %, cMRI 76 %), while no significant difference was found in the volunteer-group (sensitivity sMRI 97.4 %, cMRI 98.3 %). The results of cMRI and sMRI showed a highly significant correlation with each other, as well as with the axiographic reference tracings (r = 0.90). The average mobility of the disc and condyle was 6 % and 10 % higher in sMRI compared to cMRI (p = 0.001) and showed a slightly higher variance (0.043 vs. 0.038). Concerning the condylar inclination angle, both MRI-procedures had the best correlation (r = 0.94) with each other and axiography. CONCLUSION: Real-time MRI of the TMJ is comparable to axiography in its accuracy and is a useful adjunct to conventional static MRI.

[Teleradiology for emergency cranial computed tomography]. / Teleradiologie bei notfallmässigen Schädel-CT-Untersuchungen.

PURPOSE: We report our experience with the teleradiologic service provided by a center hospital (CH) for emergency cranial computed tomography (CCT) in two regional hospitals (RH) during a 12-month period. The clinical and economic impact of teleradiology will be discussed as well as the acceptance by the clinicians of the regional hospitals. MATERIAL AND METHODS: In 2001, 213 CT-scans in 202 patients were performed and reported using teleradiology. Teleradiologic and final medical diagnosis were analysed by the medical reports. The transfer of the patients to a CH and their further treatment were checked. The referring physicians in the RH were asked to complete a questionnaire about the teleradiological support. RESULTS: 18 (9 %) patients had to be urgently transferred to a CH based on the CT findings in the teleradiological reports. 24 patients (11 %) were transferred to a center hospital during further treatment. 80 % of patients were treated in the RH. CONCLUSION: CT data transfer is reliable and efficient. Teleradiology reduces costs by avoiding unnecessary transport of patients for diagnostic procedures. Teleradiology improves patient management by reducing time from admittance to decide about further treatment. Teleradiology enables rapid selection of the best-equipped center hospital for the management of the patient's disease. Teleradiology is well accepted by the physicians in the RH. In the RH, teleradiology has become an indispensable standard procedure in the emergency diagnostic workup of cerebral trauma patients and in patients with acute unclear neurological symptoms.

[Significance of endorectal nuclear magnetic resonance tomography and transrectal ultrasound diagnosis in local staging of prostatic carcinoma]. / Bedeutung von endorektaler Kernspintomographie und transrektaler Sonographie beim lokalen Staging des Prostatakarzinoms.

METHODS: We assessed the staging accuracy of endorectal magnetic resonance imaging (eMRI) and transrectal ultrasonography (TRUS) for localized prostate cancer. 54 patients with biopsy proven prostate cancer underwent TRUS and eMRI prior to radical retropubic prostatectomy. The MR images were prospectively interpreted by two radiologists. These findings were compared with the histopathological results. RESULTS: Overall accuracy of eMRI in defining local tumor stage was 93% by radiologist A and 56% by radiologist B. Overall accuracy by TRUS was 63%. Analysis of interobserver agreement showed a poor correlation regarding MRI studies. Endorectal MRI was more sensitive than TRUS for detecting capsular penetration and seminal vesicle involvement. TRUS revealed a relatively high specificity and was superior to eMRI in this regard. CONCLUSION: This series shows the current limited value of TRUS and eMRI for planning treatment in patients with clinically localized prostate cancer.

[Diagnostic imaging in vascular diagnosis]. / Bildgebende Gefässdiagnostik.

Previously, vascular imaging was done exclusively using angiography (X-ray projectional imaging of vessels opacified by iodinated contrast media). Recently angiography especially is used in combination with angioplasty (percutaneous enlargement of a closed or stenotic vessel). There has been a change from invasive to non invasive procedures. New developments in computed tomography (CT), magnetic resonance imaging (MR) and ultrasound have reduced the indications for the invasive digital subtraction angiography (DSA). Further improvement especially im MR-angiography and colour-coded dopplersonography will cover all primary diagnostic vascular examinations.

Limited value of endorectal magnetic resonance imaging and transrectal ultrasonography in the staging of clinically localized prostate cancer.

OBJECTIVE: To examine the role of endorectal magnetic resonance imaging (eMRI) and transrectal ultrasonography (TRUS) for clinically localized prostate cancer and to assess interobserver agreement in interpreting MRI studies. PATIENTS AND METHODS: Fifty-four patients with biopsy-confirmed prostate cancer underwent TRUS and eMRI before radical retropubic prostatectomy. The MR images were prospectively interpreted by two radiologists with special expertise in this field. The criteria evaluated prospectively in each patient were extracapsular extension (ECE) and seminal vesicle invasion (SVI). The results were correlated with the histopathological findings after radical prostatectomy. RESULTS: At pathology, 27 patients had stage pT2, 15 had stage pT3a and 12 had stage pT3b lesions. The overall accuracy of eMRI in defining local tumour stage was 93% by radiologist A and 56% by radiologist B; the overall accuracy by TRUS was 63%. There was a poor correlation for the MRI studies between observers. The eMRI was more sensitive than TRUS for detecting ECE and SVI in organ-confined prostate cancer. TRUS had a relatively high specificity for ECE and SVI, and was better than eMRI in this regard. CONCLUSION: Whereas MRI tended to over-stage, TRUS under-staged prostate cancer. This series shows the current limited value of TRUS and eMRI for planning treatment in patients with clinically localized prostate cancer. Treatment decisions should not be altered based on TRUS or eMRI findings alone.

Imaging of lung cancer with fluorine-18 fluorodeoxyglucose: comparison of a dual-head gamma camera in coincidence mode with a full-ring positron emission tomography system.

Dual-head gamma cameras operated in coincidence mode are a new approach for tumour imaging using fluorine-18 fluorodeoxyglucose (FDG). The aim of this study was to assess the diagnostic accuracy of such a camera system in comparison with a full-ring positron emission tomography (PET) system in patients with lung cancer. Twenty-seven patients (1 female, 26 males, age 62+/-9 years) with lung cancer or indeterminate pulmonary nodules were studied on the same day with a full-ring PET scanner (Siemens ECAT EXACT) and a coincidence gamma camera system (ADAC Vertex MCD). Sixty minutes after injection of 185-370 MBq FDG, a scan of the chest was performed with the full-ring system. Approximately 2 h p.i., the coincidence camera study was performed. Coincidence gamma camera (CGC) and PET images with (PETac) and without attenuation correction (PETnac) were analysed independently by two blinded observers. In addition, FDG uptake in primary tumours and involved lymph nodes was quantified relative to normal contralateral lung (T/L ratios). All primary tumours were histologically proven. The lymph node status was histologically determined in 23 patients. In four patients, no lymph node sampling was performed because of extensive disease or concurrent illnesses. In the 27 patients, 25 primary lung cancers and two metastatic lesions were histologically diagnosed. The number of coincidences per centimetre axial field of view was 3.33+/-0. 93x10(5) for the CGC and 1.09+/-0.36x10(6) for the dedicated PET system. All primary tumours (size: 4.6+/-2.6 cm) were correctly identified in the CGC and dedicated PET studies. T/L ratios were 4. 7+/-2.5 for CGC and 6.9+/-2.8 for PETnac (P <0.001). Histopathological evaluation revealed lymph node metastases in 11 of 88 sampled lymph node stations (size: 2.3+/-1.0 cm). All lymph node metastases were identified in the PETac studies, while PETnac detected 10/11 and CGC 8/11. For positive lymph nodes that were visible in CGC and PETnac studies, T/L ratios were 3.7+/-2.3 for CGC and 6.6+/-3.1 for PETnac (P=0.02). The diameters of false-negative lymph nodes in the CGC studies were 0.75, 1.5 and 2 cm. False-positive FDG uptake in lymph nodes was found in two patients with all three imaging methods. For all lesions combined, T/L ratios in CGC relative to PETnac studies decreased significantly with decreasing lesion size (r=0.62; P<0.001). In conclusion, compared with a full-ring PET system the sensitivity of CGC imaging for detection of lung cancer is limited by a lower image contrast which deteriorates with decreasing lesion size. Nevertheless, the ability of CGC imaging to detect pulmonary lesions with a diameter of at least 2 cm appears to be similar to that of a full-ring system. Both systems provide a similar specificity for the evaluation of lymph node involvement.

Controlled prospective study of positron emission tomography using the glucose analogue [18f]fluorodeoxyglucose in the evaluation of pulmonary nodules.

BACKGROUND: Positron emission tomography (PET) is a new imaging technique which, by measuring focal metabolic activities, can make a qualitative statement (benign or malignant) about a tumour. PET has been described in many studies to provide a high diagnostic accuracy for the evaluation of pulmonary coin lesions. However, these studies were not always supported by histological confirmation of the results. In a controlled prospective study, it was investigated whether the diagnostic accuracy of PET is sufficiently high to allow omission of diagnostic thoracotomy or thoracoscopy in the case of a negative finding. METHODS: A PET scan was carried out before operation using [18F]fluorodeoxyglucose (FDG) in 50 patients with pulmonary coin lesions (diameter 30 mm or less). All of these lesions were completely removed thoracoscopically or by a formal thoracotomy and were examined histologically. Using the histology results, the diagnostic accuracy of the PET procedure with regard to a benign or malignant diagnosis was evaluated and compared with that of computed tomography (CT). Results From a total of 54 coin lesions (four of the 50 patients had two lesions) there were 31 malignant (19 primary bronchial carcinomas, 12 metastases) and 23 benign diagnoses. With the PET procedure 28 of 31 malignant and 19 of 23 benign lesions were classified correctly (sensitivity 90 per cent, specificity 83 per cent). False negatives included two bronchial carcinomas and one metastasis. CT had a sensitivity of 100 per cent and specificity of 52 per cent. CONCLUSION: FDG PET cannot generally be considered as a replacement for diagnostic thoracoscopy or thoracotomy at the present time. However, by combining FDG PET with radiological follow-up, clinical applications may evolve in patients at low risk for a malignant tumour or at high risk for surgical complications.