Stefan P. Lemburg

CT Angiography in Suspected Pulmonary Embolism: Impact of Patient Characteristics and Different Venous Lines on Vessel Enhancement and Image Quality

OBJECTIVE The objective of our study was to compare image quality, patient characteristics, and different catheters in pulmonary CT angiography (CTA) performed with bolus tracking and z-axis automated tube current modulation (ATCM) in patients with suspected pulmonary embolism. SUBJECTS AND METHODS One hundred twenty-six patients were referred to undergo pulmonary CTA with bolus tracking and ATCM. Besides patient characteristics, the type, position, size, and side of venous catheters were documented. Pulmonary vessel enhancement and image noise were quantified; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective vessel contrast was assessed by two radiologists in consensus. RESULTS Patient age showed a moderate but significant positive correlation to vessel enhancement (r = 0.244, p = 0.006), CNR (r = 0.178, p = 0.046), and subjective image quality (r = 0.344, p < 0.001). Patient weight revealed a significant negative correlation to vessel enhancement (r = -0.496, p < 0.001), SNR (r = -0.446, p < 0.001), CNR (r = -0.425, p < 0.001), and subjective image quality (r = -0.422, p < 0.001). In univariate analysis, SNR and CNR were significantly higher in patients who received contrast medium through peripheral catheters (30 +/- 13 and 27 +/- 13, respectively) than in those in whom central catheters were used (22 +/- 8 and 19 +/- 7, p = 0.041 and p = 0.029, respectively). Neither patient sex nor catheter size, position, or side had any significant impact on image quality. CONCLUSION Patient age and weight showed significant impact on vascular attenuation and image quality in pulmonary CTA with bolus tracking and ATCM, whereas patient sex and different peripheral catheters did not significantly influence image parameters.

Detection of a double right coronary artery with 16-row multidetector computed tomography.

We present the case of a 46-year-old male patient with known history of coronary artery disease and recurrent episodes of angina pectoris. Coronary angiography revealed two vessels originating from the right coronary sinus. However, a clear distinction between a double RCA and a high take off of a large right ventricular branch could not be made. Contrast-enhanced MDCT was performed on a 16-row scanner which clearly depicted cardiac anatomy and finally established the diagnosis of a double RCA. To our knowledge, this is the first report of a true double RCA diagnosed by MDCT.

Evaluation of chronic infectious interstitial pulmonary disease in children by low-dose CT-guided transthoracic lung biopsy.

BackgroundChildren with chronic infectious interstitial lung disease often have to undergo open lung biopsy to establish a final diagnosis. Open lung biopsy is an invasive procedure with major potential complications. Transthoracic lung biopsy (TLB) guided by computed tomography (CT) is a less-invasive well-established procedure in adults.ObjectiveDetailing the role of low-dose CT-guided TLB in the enhanced diagnosis of chronic lung diseases related to infection in children.Materials and methodsA group of 11 children (age 8 months to 16 years) underwent CT-guided TLB with a 20-gauge biopsy device. All investigations were done under general anaesthesia on a multidetector CT scanner (SOMATOM Volume Zoom, Siemens, Erlangen, Germany) using a low-dose protocol (single slices, 120 kV, 20 mAs). Specimens were processed by histopathological, bacteriological, and virological techniques.ResultsAll biopsies were performed without major complications; one child developed a small pneumothorax that resolved spontaneously. A diagnosis could be obtained in 10 of the 11 patients. Biopsy specimens revealed chronic interstitial alveolitis in ten patients. In five patients Chlamydia pneumoniae PCR was positive, in three Mycoplasma pneumoniae PCR was positive, and in two Cytomegalovirus PCR was positive. The average effective dose was 0.83 mSv.ConclusionLow-dose CT-guided TLB can be a helpful tool in investigating chronic infectious inflammatory processes in children with minimal radiation exposure. It should be considered prior to any open surgical procedure performed for biopsy alone. In our patient group no significant complication occurred. A disadvantage of the method is that it does not allow smaller airways and vessels to be assessed.

Efficacy of CT-guided biopsies of the spine in patients with spondylitis--an analysis of 164 procedures.

OBJECTIVE To evaluate efficacy of CT-guided spinal biopsy (CTSB) in patients with spondylitis considering patient characteristics, technical issues, antibiotic therapy, histopathological, and microbiological findings. MATERIALS AND METHODS All CTSB procedures performed between 1995 and 2009 in patients with proven spondylitis were re-evaluated. Patient sex and age, antibiotic treatment, biopsy approach, number of specimens, length of needle path, laboratory results (CRP, WBC), and histopathological/microbiological findings were documented and compared to the final diagnosis of spondylitis. Statistical analysis was performed using Chi-square test and Students t-test. The p-value was set to 5%. RESULTS 164 CTSB procedures were performed in 159 patients (mean age 65 years, 60% men) in which spondylitis was histopathologically verified in 95%. Neither patient sex nor age, positioning, localization of the spinal lesion, bioptic approach, number of specimens, or depth of the needle showed significant impact on the rate of positive histopathological findings. A causative germ was identified in 40/127 biopsies (32%) with Staphylococcus aureus being identified in 50%. Tuberculous spondylitis was diagnosed in ten cases (6%). CRP significantly correlated with bacterial growth (13.3±12.2 mg/dl versus 8.8±7.6 mg/dl; p=.015) whereas administration of antibiotics did not show any significant impact on bacterial growth (29% versus 36% in patients without antibiotics; p=0.428). Patients with histopathological signs of active spondylitis showed a significantly higher CRP (16.5±15.8 mg/dl versus 8.9±8.0 mg/dl, p<.001). Complication rate was 0.6% (one focal bleeding). CONCLUSION CTSB of the spine in suspected spondylitis is an effective and safe procedure for establishing final histopathological diagnosis. However, microbiological yield is low regardless of technical issues and antibiotic therapy. Other than CRP values, laboratory investigations added little useful information to diagnose infection in our study group. CRP values significantly correlated with bacterial growth and with histopathological signs of active spondylitis.

Cumulative Effective Dose Associated With Radiography and CT of Adolescents With Spinal Injuries

OBJECTIVE The purpose of this study was to analyze the quantity and distribution of cumulative effective doses in diagnostic imaging of adolescents with spinal injuries. MATERIAL AND METHODS At a level 1 trauma center from July 2003 through June 2009, imaging procedures during initial evaluation and hospitalization and after discharge of all patients 10-20 years old with spinal fractures were retrospectively analyzed. The cumulative effective doses for all imaging studies were calculated, and the doses to patients with spinal injuries who had multiple traumatic injuries were compared with the doses to patients with spinal injuries but without multiple injuries. The significance level was set at 5%. RESULTS Imaging studies of 72 patients (32 with multiple injuries; average age, 17.5 years) entailed a median cumulative effective dose of 18.89 mSv. Patients with multiple injuries had a significantly higher total cumulative effective dose (29.70 versus 10.86 mSv, p < 0.001) mainly owing to the significantly higher CT-related cumulative effective dose to multiple injury patients during the initial evaluation (18.39 versus 2.83 mSv, p < 0.001). Overall, CT accounted for 86% of the total cumulative effective dose. CONCLUSION Adolescents with spinal injuries receive a cumulative effective dose equal to that of adult trauma patients and nearly three times that of pediatric trauma patients. Areas of focus in lowering cumulative effective dose should be appropriate initial estimation of trauma severity and careful selection of CT scan parameters.

Transbronchial Biopsy Guided by Low-Dose MDCT: A New Approach for Assessment of Solitary Pulmonary Nodules

OBJECTIVE The objective of our study was to determine whether transbronchial bronchoscopic biopsy of solitary pulmonary nodules under CT guidance using a low-dose protocol can increase diagnostic yield in patients who had undergone unsuccessful conventional bronchoscopic biopsy. SUBJECTS AND METHODS We included 33 consecutive patients (25 men; mean age +/- SD, 64 +/- 9.6 years) with solitary pulmonary nodules at different sites and with a lesion-to-pleura distance of at least 2 cm who previously underwent conventional bronchoscopy that did not result in histologic diagnosis. All patients were prospectively investigated with transbronchial bronchoscopic biopsy under MDCT guidance. Examinations were performed with the patient in conscious sedation using a low-dose protocol (80 kV, 20 mAs, 5-mm collimation, 10-mm slices). The position of the tip of the biopsy device was confirmed and documented before biopsies were performed. All specimens were examined by standard histopathologic techniques. The effective radiation dose was calculated for every patient. RESULTS The diagnostic yield was 24 in 33 selected patients (overall accuracy, 72.7%): 13 (54%) had primary lung cancer and 11 (46%) had benign diagnoses. The formal operative characteristics were sensitivity, 59%; specificity, 100%; positive predictive value, 100%; and negative predictive value, 55%. The final diagnoses of the remaining nine patients in whom transbronchial bronchoscopic biopsy was not diagnostic were non-small cell lung cancer (n = 3); small cell lung cancer (n = 3); and alveolar carcinoma, carcinoid tumor, and hemorrhaged bulla (n = 1 each). All nonmalignant diagnoses were confirmed by 6 months radiographic and clinical follow-up. The mean duration of the procedure was 39 +/- 15 minutes, and the average effective dose was 0.7 mSv (range, 0.5-1.1 mSv). One case of pulmonary hemorrhage (3%) occurred after the procedure. CONCLUSION MDCT-guided transbronchial bronchoscopic biopsy is a promising and safe tool for the diagnostic pathway of solitary pulmonary nodules in previously undiagnosed patients. Image quality was sufficient with low-dose protocols, which resulted in low radiation exposure for patients and personnel.

Renal perforation and retroperitoneal hematoma: an unusual complication following cardiac catheterization

Retroperitoneal hematoma (RPH) is a well-recognised, albeit rare complication of percutaneous transfemoral cardiac catheterization. We describe an unusual case of renal perforation and RPH following transfemoral cardiac catheterization for endomyocardial biopsy. Diagnosis was made based on multidetector computed tomography (MDCT) which clearly depicted active renal hemorrhage in short acquisition time. The case expands the spectrum of possible complications of percutaneous transfemoral cardiac catheterization and illustrates the usefulness MDCT in quickly and adequately detecting RPH.

Association between clinical signs assessed by manual segmental examination and findings of the lumbar facet joints on magnetic resonance scans in subjects with and without current low back pain: A prospective, single-blind study ☆

Summary Only the combination of the clinical sign pain and certain MRI findings seems to be adequate to identify patients with true facet joint arthropathy. ABSTRACT The relevance of magnetic resonance imaging (MRI) findings such as facet joint (FJ) effusion and edema in low back pain (LBP) is still unknown. Therefore, we prospectively evaluated the presence of these MRI findings in the lumbar spine (Th12‐S1) and their association with pain evoked by manual segmental FJ provocation tests (spinal percussion, springing, and segmental rotation tests) in 75 subjects with current LBP (≥30 days in the past 3 months) compared with 75 sex‐ and age‐matched control subjects. FJs were considered painful, if ≥1 provocation test triggered LBP. FJs were classified as true positives, if the same FJ was painful and showed effusion and/or edema. FJs with effusion and/or edema and painful FJs were present significantly more frequently in subjects with LBP, but these conditions were also common in control subjects (27% vs 21% and 50% vs 12%, respectively). Effusion and/or edema were present in 65 subjects with LBP (87%) and in 56 control subjects (75%, not significant); painful FJs were present in 68 (91%) and 29 (39%) (P < 0.01) LBP and control subjects, respectively. True‐positive findings occurred in 16% of LBP FJs and in 2% of control FJs (P < 0.01); 46 LBP subjects (61%) and 9 control subjects (12%, P < 0.01) had true‐positive findings. Pain on provocation and FJ effusion and/or edema were significantly correlated only in patients with LBP. In conclusion, only true‐positive findings (ie, concurrent effusion and/or edema and positive provocation test results in the same FJ) discriminate well enough between control subjects and subjects with current LBP, whereas neither effusion and/or edema nor FJ provocations tests alone are suitable to detect suspected FJ arthropathy.

Paediatric radiology and scientific contributions to radiation dose at the meeting of the German Radiological Society--an analysis of an 11-year period.

AIM Evaluation of the emphasis on themes pertaining to paediatric radiology and radiation dose at the Meeting of the German Radiological Society from 1998 to 2008 in comparison to international data. MATERIALS AND METHODS Retrospective analysis of 9440 abstracts with documentation of type of contribution, imaging modality, and examined body region. Abstracts primarily dealing with paediatric radiology and those stating radiation dose were documented. Results were compared with a Pubmed query. RESULTS 448 contributions in paediatric radiology were presented corresponding to 5% of all abstracts with an increase from 5 (1998) to 7% (2008). The proportion of prospective studies of all congress contributions was 10%, whereas in paediatric radiology, the share of prospective studies was 6%. From 1998 to 2008, the share of MRI fell from 48 to 38%, while CT contributions rose from 30 to 34%. Within paediatric radiology, the proportion of CT rose from 23 to 29%, while MRI and ultrasound fell from 63 to 48% and 35 to 19%, respectively. The share of abstracts dealing with radiation dose rose from 7 to 10% while that primarily pertaining to dose reduction grew from 2 to 4%. Of all abstracts concerning CT, 15% touched on radiation dose, whereas 6% primarily dealt with dose reduction. Among all abstracts dealing with paediatric radiology, 20 and 6% mentioned radiation dose and dose reduction, respectively. In the subgroup of paediatric radiology CT abstracts, radiation dose and dose reduction were mentioned in 34 and 16%, respectively. An online query produced 137,791 publications on CT, of whose abstracts 3% mentioned radiation dose and 0.5% mentioned dose reduction. 11% of all CT publications dealt with paediatric populations and 2% of these publications examined questions of radiation dose. CONCLUSIONS In the last 11 years the Meeting of the German Radiological Society has presented a growing number of contributions pertaining to paediatric radiology. CT has shown the most pronounced growth of all contributions. Paediatric radiology has significantly more often dealt with questions of radiation exposure than those from general radiology. However, contributions with definite reference to radiation dose, both pertaining to all publications and specifically to those dealing with CT, remain a minority, albeit with a higher proportion when compared to international data.

Interventional radiology at the meetings of the German Radiological Society from 1998 to 2008: evaluation of structural changes and radiation issues

AbstractObjectivesEvaluation of structural changes and the weight given to radiation exposure of interventional radiology (IR) contributions at the Congress of the German Radiological Association from 1998 to 2008.MethodsAll IR abstracts were evaluated for type of contribution, design, imaging modality, and anatomic region. Weight given to radiation exposure was recorded as general statement, main topic and/or dose reduction. Statistical analysis included calculation of absolute/relative proportions of subgroups and ANOVA regression analyses.ResultsOut of 9,436 abstracts, 1,728 (18%) were IR-related. IR abstracts significantly rose to a maximum of 200 (20%) in 2005 (P = 0.048). While absolute numbers of scientific contributions declined, educational contributions significantly increased (P = 0.003). Computed tomography (CT) and magnetic resonance imaging (MRI) were the main IR imaging modalities, with growing use of CT (P = 0.021). The main body regions were vessels (45%) and abdomen (31%). Radiation exposure was addressed as a general statement in 3% of abstracts, as a main topic in 2%, and for dose reduction in 1%, respectively. During the study interval a significant growth of dose reduction abstracts was observed (P = 0.016).ConclusionsIR emerged as a growing specialty of radiology, with a significant increase in educational contributions. Radiation exposure was rarely in the focus of interest but contributions relating to dose reduction demonstrated a significant growth during the study period. Main MessagesInterventional radiology emerged as a growing specialty at the German radiological congress.Significant increments of educational and prospective research contributions could be observed.Despite a significant trend towards computed tomography, radiation exposure of IR was rarely in the focus of interest.Contributions related to dose reduction demonstrated a significant growth during the study period.