[CT strategy for patients with suspected acute appendicitis; comparison of conditional and immediate CT]. / CT-strategie bij vermoeden van acute appendicitis; vergelijking van conditionele en directe CT.

OBJECTIVE: To compare the diagnostic accuracy of conditional CT strategy, i.e. CT if ultrasound findings are negative or inconclusive, with immediate CT strategy for patients with suspected appendicitis. DESIGN: Subanalysis of a prospective multicenter diagnostic accuracy study. METHOD: Only data of patients with signs of appendicitis based on medical history, physical examination, and laboratory tests were analyzed. All patients underwent both ultrasound and CT. Images of each were read by different observers who were blinded to the results of the other imaging modality. The observer then selected the most likely diagnosis. These diagnoses were compared with the reference standard, i.e. final diagnoses as assigned by an expert panel based on all available data and at least 6 months of follow-up. RESULTS: A total of 422 patients with suspected appendicitis were included. In 251 patients the final diagnosis was acute appendicitis (59%). In 199 patients (47%), ultrasound findings were inconclusive or negative. Use of conditional CT strategy resulted in correctly identified number of correctly identified patients with appendicitis, i.e. 96% (95% CI 93-98), versus 95% identified by immediate CT (95% CI 91-97). However, conditional CT strategy resulted in more false positive diagnoses compared with immediate CT (39 versus 22), had an accompanying lower specificity of 77% (95% CI 70-83) versus 87% (95% CI 81-91), and a lower positive predictive value of 86% (95% CI 81-90) versus 92% (95% CI 87-95). CONCLUSION: Use of a conditional CT strategy results in exactly the same number of patients with correctly identified acute appendicitis while halving the number of CTs needed. However, conditional strategy results in more false positive diagnoses.

Feasibility study of needle placement in percutaneous vertebroplasty: cone-beam computed tomography guidance versus conventional fluoroscopy.

OBJECTIVE: To investigate the accuracy, procedure time, fluoroscopy time, and dose area product (DAP) of needle placement during percutaneous vertebroplasty (PVP) using cone-beam computed tomography (CBCT) guidance versus fluoroscopy. MATERIALS AND METHODS: On 4 spine phantoms with 11 vertebrae (Th7-L5), 4 interventional radiologists (2 experienced with CBCT guidance and two inexperienced) punctured all vertebrae in a bipedicular fashion. Each side was randomization to either CBCT guidance or fluoroscopy. CBCT guidance is a sophisticated needle guidance technique using CBCT, navigation software, and real-time fluoroscopy. The placement of the needle had to be to a specific target point. After the procedure, CBCT was performed to determine the accuracy, procedure time, fluoroscopy time, and DAP. Analysis of the difference between methods and experience level was performed. RESULTS: Mean accuracy using CBCT guidance (2.61 mm) was significantly better compared with fluoroscopy (5.86 mm) (p < 0.0001). Procedure time was in favor of fluoroscopy (7.39 vs. 10.13 min; p = 0.001). Fluoroscopy time during CBCT guidance was lower, but this difference is not significant (71.3 vs. 95.8 s; p = 0.056). DAP values for CBCT guidance and fluoroscopy were 514 and 174 mGy cm(2), respectively (p < 0.0001). There was a significant difference in favor of experienced CBCT guidance users regarding accuracy for both methods, procedure time of CBCT guidance, and added DAP values for fluoroscopy. CONCLUSION: CBCT guidance allows users to perform PVP more accurately at the cost of higher patient dose and longer procedure time. Because procedural complications (e.g., cement leakage) are related to the accuracy of the needle placement, improvements in accuracy are clinically relevant. Training in CBCT guidance is essential to achieve greater accuracy and decrease procedure time/dose values.

The effects of dynamic isolated lumbar extensor training on lumbar multifidus functional cross-sectional area and functional status of patients with chronic nonspecific low back pain.

STUDY DESIGN: A prospective single-arm trial. OBJECTIVE: To investigate whether dynamic isolated resistance training of global lumbar extensor muscles leads to changes in lumbar multifidus (LM) morphology in terms of cross-sectional muscle, and, if so, whether these changes are associated with observed changes in self-experienced functional status of chronic nonspecific low back pain (CNSLBP). SUMMARY OF BACKGROUND DATA: LM morphology is associated with the recurrence of CNSLBP. METHODS: Sixteen male patients underwent a dynamic isolated resistance-training program for the lower back muscles of approximately 10 sessions in 12 weeks. In the next 12 weeks, frequency of training was tailored to the patients' need. Participants underwent lumbar magnetic resonance imaging at baseline (T0), after 12 weeks (T12), and after 24 weeks (T24). Functional cross-sectional area was obtained by analyzing the magnetic resonance images. Functional status was assessed using the patient-specific functional scale, Roland-Morris disability questionnaire, and global perceived effect scale. RESULTS: Roland-Morris disability questionnaire and patient-specific functional scale scores showed significant and clinically relevant improvements between baseline and T12, with 44% and 39%, respectively. Between T12 and T24, these scores did not change significantly. Seven participants (44%) reported clinically relevant improvements in global perceived effect at T12. At T24, 1 more participant reported a relevant global perceived effect improvement, whereas 2 participants (13%) reported worsening of their condition. The magnetic resonance imaging analysis showed minor nonsignificant changes in functional cross-sectional area. CONCLUSION: Our study shows that 10 weeks of dynamic isolated training of the lumbar extensors, once a week, leads to clinically relevant improvements in functional status of men with CNSLBP, without accompanying improvements in functional cross-sectional area of LM. These findings suggest that improvement in LM morphology is not a critical success factor in restoring functional status of patients with CNSLBP, at least in the short term (6 mo).

3D cone-beam CT guidance, a novel technique in renal biopsy--results in 41 patients with suspected renal masses.

OBJECTIVE: To determine whether 3D cone-beam computed tomography (CBCT) guidance allows safe and accurate biopsy of suspected small renal masses (SRM), especially in hard-to-reach anatomical locations. MATERIALS AND METHODS: CBCT guidance was used to perform 41 stereotactic biopsy procedures of lesions that were inaccessible for ultrasound guidance or CT guidance. In CBCT guidance, a 3D-volume data set is acquired by rotating a C-arm flat-panel detector angiosystem around the patient. In the data set, a needle trajectory is determined and, after co-registration, a fusion image is created from fluoroscopy and a slice from the data set, enabling the needle to be positioned in real time. RESULTS: Of the 41 lesions, 22 were malignant, 17 were benign, and 2 were nondiagnostic. The two nondiagnostic lesions proved to be renal cell carcinoma. There was no growth during follow-up imaging of the benign lesions (mean 29 months). This resulted in a sensitivity, specificity, PPV, NPV, and accuracy of 91.7, 100, 100, 89.5, and 95.1%, respectively. Mean dose-area product value was 44.0 Gy·cm(2) (range 16.5-126.5). There was one minor bleeding complication. CONCLUSION: With CBCT guidance, safe and accurate biopsy of a suspected SRM is feasible, especially in hard-to-reach locations of the kidney. KEY POINTS : • Cone-beam computed tomography has potential advantages over conventional CT for interventional procedures. • CBCT guidance incorporates 3D CBCT data, fluoroscopy, and guidance software. • In hard-to-reach renal masses, CBCT guidance offers an alternative biopsy method. • CBCT guidance offers good outcome and safety and has potential clinical significance.

Pulmonary masses: initial results of cone-beam CT guidance with needle planning software for percutaneous lung biopsy.

PURPOSE: To evaluate the outcome of percutaneous lung biopsy (PLB) findings using cone-beam computed tomographic (CT) guidance (CBCT guidance) and compared to conventional biopsy guidance techniques. METHODS: CBCT guidance is a stereotactic technique for needle interventions, combining 3D soft-tissue cone-beam CT, needle planning software, and real-time fluoroscopy. Between March 2007 and August 2010, we performed 84 Tru-Cut PLBs, where bronchoscopy did not provide histopathologic diagnosis. Mean patient age was 64.6 (range 24-85) years; 57 patients were men, and 25 were women. Records were prospectively collected for calculating sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. We also registered fluoroscopy time, room time, interventional time, dose-area product (DAP), and complications. Procedures were divided into subgroups (e.g., location, size, operator). RESULTS: Mean lesion diameter was 32.5 (range 3.0-93.0) mm, and the mean number of samples per biopsy procedure was 3.2 (range 1-7). Mean fluoroscopy time was 161 (range 104-551) s, room time was 34 (range 15-79) min, mean DAP value was 25.9 (range 3.9-80.5) Gy·cm(-2), and interventional time was 18 (range 5-65) min. Of 84 lesions, 70 were malignant (83.3%) and 14 were benign (16.7%). Seven (8.3%) of the biopsy samples were nondiagnostic. All nondiagnostic biopsied lesions proved to be malignant during surgical resection. The outcome for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy was 90% (95% confidence interval [CI] 86-96), 100% (95% CI 82-100), 100% (95% CI 96-100), 66.7% (95% CI 55-83), and 91.7% (95% CI 86-96), respectively. Sixteen patients (19%) had minor and 2 (2.4%) had major complications. CONCLUSION: CBCT guidance is an effective method for PLB, with results comparable to CT/CT fluoroscopy guidance.

Effective dose during needle interventions: cone-beam CT guidance compared with conventional CT guidance.

PURPOSE: To determine effective radiation dose to patients during needle interventions with cone-beam computed tomography (CT) guidance and compare it with the dose during conventional CT-guided interventions. MATERIALS AND METHODS: Cone-beam CT guidance is a recently developed technique with image acquisition on a flat-panel detector digital angiography system. It is based on a combination of acquired three-dimensional soft-tissue cone-beam CT, dedicated needle trajectory software, and fluoroscopy, providing stereotactic needle guidance. To analyze effective dose, we prospectively recorded all contributing parameters necessary to calculate it in 92 needle interventions (in 88 patients [60 men]; mean age, 63.9 y) using a Monte Carlo program. For CT guidance, we retrospectively scored the necessary parameters during 137 needle interventions (118 patients [81 men]; mean age, 59.5 y) to calculate effective dose with a CT patient dosimetry calculator. The needle interventions were categorized in four regions. RESULTS: Total mean effective doses with cone-beam CT guidance were 7.6 mSv in the upper thorax, 12.3 mSv in the lower thorax, 16.1 mSv in the upper abdomen, and 13.4 mSv in the lower abdomen. Effective doses with uncollimated cone-beam CT alone were 2.0, 2.9, 4.2, and 3.5 mSv in the respective regions. Effective doses with CT-guided interventions were 13.0, 15.1, 20.4, and 15.4 mSv in the respective regions. Cone-beam CT guidance results in a reduction of 13%-42% of total effective dose compared with conventional CT guidance. The dose reduction is mainly attributable to cone-beam CT, not to fluoroscopy. CONCLUSIONS: A new needle intervention technique with cone-beam CT guidance results in a considerable effective dose reduction for patients compared with conventional CT guidance.

Cardiac magnetic resonance imaging showing complete resolution of subendocardial involvement in Churg-Strauss syndrome.

Churg-Strauss syndrome or allergic angiitis and granulomatosis is a rare systemic vasculitis. Cardiac involvement is the leading cause of mortality and includes eosinophilic endomyocarditis. We present a case of complete resolution of subendocardial involvement after high-dose corticosteroids, diagnosed by contrast-enhanced cardiovascular magnetic resonance imaging.

Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study.

OBJECTIVE: To identify an optimal imaging strategy for the accurate detection of urgent conditions in patients with acute abdominal pain. DESIGN: Fully paired multicentre diagnostic accuracy study with prospective data collection. SETTING: Emergency departments of two university hospitals and four large teaching hospitals in the Netherlands. PARTICIPANTS: 1021 patients with non-traumatic abdominal pain of >2 hours' and <5 days' duration. Exclusion criteria were discharge from the emergency department with no imaging considered warranted by the treating physician, pregnancy, and haemorrhagic shock. INTERVENTION: All patients had plain radiographs (upright chest and supine abdominal), ultrasonography, and computed tomography (CT) after clinical and laboratory examination. A panel of experienced physicians assigned a final diagnosis after six months and classified the condition as urgent or non-urgent. MAIN OUTCOME MEASURES: Sensitivity and specificity for urgent conditions, percentage of missed cases and false positives, and exposure to radiation for single imaging strategies, conditional imaging strategies (CT after initial ultrasonography), and strategies driven by body mass index and age or by location of pain. RESULTS: 661 (65%) patients had a final diagnosis classified as urgent. The initial clinical diagnosis resulted in many false positive urgent diagnoses, which were significantly reduced after ultrasonography or CT. CT detected more urgent diagnoses than did ultrasonography: sensitivity was 89% (95% confidence interval 87% to 92%) for CT and 70% (67% to 74%) for ultrasonography (P<0.001). A conditional strategy with CT only after negative or inconclusive ultrasonography yielded the highest sensitivity, missing only 6% of urgent cases. With this strategy, only 49% (46% to 52%) of patients would have CT. Alternative strategies guided by body mass index, age, or location of the pain would all result in a loss of sensitivity. CONCLUSION: Although CT is the most sensitive imaging investigation for detecting urgent conditions in patients with abdominal pain, using ultrasonography first and CT only in those with negative or inconclusive ultrasonography results in the best sensitivity and lowers exposure to radiation.

Digital chest imaging: selenium radiography versus storage phosphor imaging. Comparison of visualization of specific anatomic regions of the chest.

RATIONALE AND OBJECTIVES: To compare selenium- versus phosphor-based digital chest imaging for visualization of various anatomic regions of the chest. METHODS: Thirteen observers analyzed pairs of posteroanterior (PA) and lateral chest radiographs of 63 patients. One radiograph in each pair was obtained with a digital selenium chest radiography system, and the other with a storage phosphor-based technique. Each observer rated the visibility and the radiographic quality of 21 anatomic regions. RESULTS: The observers rated visualization obtained with the selenium system as better than that obtained with the storage phosphor system in 12 anatomic regions (right lower lobe, retrodiaphragmatic, upper lobes, minor fissure, hilum, carina, azygoesophageal recess, ribs, soft tissue, upper mediastinum on the PA image, and major fissure and sternum on the lateral image). Five regions were equally appreciated (retrocardiac on the PA, lower lobes, lingual-middle lobe, soft tissue, and subdiaphragmatic region on lateral images). Four regions were rated better on phosphor imaging than on selenium films (thoracic spine on PA, upper lobes, lower, and upper thoracic spine on lateral films) (17,199 observations, P < 0.05, sign test). CONCLUSIONS: On PA images the digital selenium chest system provides better visualization of most anatomic structures than the phosphor system. Lateral images show an almost equal preference.