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Biomedical subjects

Robert F Dondelinger

Publications and source records attributed to Robert F Dondelinger.

15 recordsLinked to original sources
PubMed2006

Does multi-detector row CT pulmonary angiography reduce the incremental value of indirect CT venography compared with single-detector row CT pulmonary angiography?

PURPOSE: To compare retrospectively the incremental value of indirect computed tomographic (CT) venography performed after multi-detector row CT pulmonary angiography and single-detector row CT pulmonary angiography for the diagnosis of venous thromboembolism (VTE). MATERIALS AND METHODS: The institutional ethics committee approved this study; informed consent was not required. The authors retrospectively reviewed results of 1100 combined single-detector row CT pulmonary angiographic and indirect CT venographic examinations (542 men, 558 women; mean age, 61 years +/- 17 [standard deviation]) (group 1) and 308 combined multi-detector row CT pulmonary angiographic and indirect CT venographic examinations (150 men, 158 women; mean age, 62 years +/- 18) (group 2), performed in 1408 patients suspected of having pulmonary embolism (PE). Frequency of deep venous thrombosis (DVT), PE, and VTE, and the incremental value of indirect CT venography were recorded in both groups. Data were compared by means of the Student t test for continuous data and z statistics for independent proportions. RESULTS: VTE, PE, and DVT were found in 23.3% (n = 256), 19.9% (n = 219), and 18.3% (n = 201) of the 1100 patients in group 1, respectively, and in 23.7% (n = 73), 17.2% (n = 53), and 18.8% (n = 58) of the 308 patients in group 2, respectively (P values ranging from .273 to .876). The incremental value of indirect CT venography was 14.4% (37 of 256 patients) in group 1 and 27.4% (20 of 73 patients) in group 2. CONCLUSION: Despite potential improved accuracy of multi-detector row CT pulmonary angiography for the diagnosis of PE, the addition of indirect CT venography increased the diagnosis of VTE in 27.4% of patients.

Adolescent↗
PubMed2006

Severe pulmonary embolism:pulmonary artery clot load scores and cardiovascular parameters as predictors of mortality.

PURPOSE: To retrospectively evaluate pulmonary artery (PA) clot load scores and computed tomographic (CT) cardiovascular parameters as predictors of mortality in patients with severe pulmonary embolism (PE). MATERIALS AND METHODS: Institutional review board approval was obtained with waiver of informed consent. A total of 82 consecutive patients (42 women, 40 men; mean age+/-standard deviation, 61 years+/-15) were admitted to the intensive care unit for PE-related conditions and were evaluated by using CT pulmonary angiography. Two independent readers who were blinded to clinical outcome quantified PA clot load by using four scoring systems. Cardiovascular measurements included right ventricular (RV) and left ventricular (LV) short-axis measurements; RV short axis to LV short axis (RV/LV) ratios; main PA, ascending aorta, azygos vein, and superior vena cava diameters; and main PA diameter to aorta diameter ratios. Reflux of contrast medium into the inferior vena cava, leftward bowing of the interventricular septum, pleural or pericardial effusion, pulmonary consolidation, infarct, platelike atelectasis, and mosaic ground-glass opacity were also recorded. Results were correlated with patient outcome during hospital stay by using the Wilcoxon rank sum and chi2 tests. RESULTS: Twelve patients died within 1-14 days. RV and LV short axis; RV/LV ratio; azygos vein, superior vena cava, and aorta diameters; and contrast medium reflux into the inferior vena cava were significantly different between survivors and nonsurvivors (P<.05). No significant relationship was found between PA clot load and mortality rate. RV/LV ratio and azygos vein diameter allowed correct prediction of survival in 89% of patients (P<.001). CONCLUSION: RV/LV ratio and azygos vein diameter are predictors of mortality in patients with severe PE.

Adult↗
PubMed2005

Helical CT of blunt diaphragmatic rupture.

OBJECTIVE: This study evaluated CT findings for signs of blunt diaphragmatic rupture. MATERIALS AND METHODS: CT examinations of 179 blunt trauma patients, including 11 with left-sided and five with right-sided blunt diaphragmatic rupture, were reviewed by two staff radiologists who first decided by consensus on the presence or absence of 11 published signs of blunt diaphragmatic rupture and then formulated the diagnosis in terms of absence of, presence of, or suggestion of blunt diaphragmatic rupture. The significance of the findings was assessed by multivariate logistic regression. Four other reviewers interpreted the CT findings independently. They were asked first to formulate a diagnosis in terms of absence of, presence of, or suggestion of blunt diaphragmatic rupture and then to enumerate the findings supporting a diagnosis or suggestion of blunt diaphragmatic rupture. These findings were compared with those of the staff radiologists. RESULTS: Diaphragmatic discontinuity, diaphragmatic thickening, segmental nonrecognition of the diaphragm, intrathoracic herniation of abdominal viscera, elevation of the diaphragm, and both hemothorax and hemoperitoneum were strong predictors of blunt diaphragmatic rupture (p < 0.001). The combination of the first three findings was 100% sensitive (16/16). The staff radiologists' sensitivity for diagnosing blunt diaphragmatic rupture was 100% (16/16). The four reviewers' sensitivities were 56.2% (9/16), 81.2% (13/16), 62.5% (10/16), and 87.5% (14/16). CONCLUSION: Six of 11 signs were good predictors of blunt diaphragmatic rupture. Despite diaphragmatic thickening, focal defect and segmental nonrecognition had 100% cumulative sensitivity; the reviewers formulating the diagnosis before analyzing CT signs overlooked blunt diaphragmatic rupture on CT in 12.5-43.8% of the patients.

Adolescent↗
PubMed2003

Percutaneous ablation for atrial fibrillation: the role of cross-sectional imaging.

Percutaneous ablation is a well-established technique for treating cardiac arrhythmia by removing or isolating tissue at the site of the abnormal impulse formation. Various forms of energy for ablation procedures may be delivered via a catheter with fluoroscopic guidance. The procedures most commonly performed are radiofrequency ablation and cryotherapy. Atrial fibrillation, the most frequently occurring supraventricular tachyarrhythmia, may be initiated by ectopic beats that originate in the ostia of the pulmonary veins. The clinical efficacy of isolation (or focal ablation) of the pulmonary veins for treatment of atrial fibrillation has been well demonstrated. Pre- and postprocedural examinations with computed tomography (CT) or magnetic resonance (MR) imaging are frequently performed to depict the anatomy and to obtain baseline measurements of the pulmonary veins to enable early detection of complications from ablation. Venous stenosis or thrombosis and pulmonary hypertension may occur after radio-frequency ablation. Familiarity with the appearance of normal anatomic variants at CT and MR imaging and with the normal range of pulmonary vein diameters is essential for preoperative management and early detection of procedure-related complications.

Adult↗
PubMed2002

Non-traumatic thoracic emergencies: CT venography in an integrated diagnostic strategy of acute pulmonary embolism and venous thrombosis.

Deep venous thrombosis and pulmonary embolism are the two aspects of venous thrombo-embolism. Investigation of lower limb veins has been part of various diagnostic algorithms in the past 15 years. Recently, the combination of CT venography (CTV) of lower limbs and abdominal veins together with CT angiography of the pulmonary arteries has allowed a complete examination of venous thrombo-embolism in one session. The technical aspects, imaging findings, venous anatomy on CT, interpretative pitfalls, results and advantages of CT venography are reviewed.

Acute Disease↗
PubMed2002

Stereotactic breast biopsy with an 8-gauge, directional, vacuum-assisted probe: initial experience.

This study was prospectively conducted to assess the feasibility, safety and accuracy of an 8-G directional vacuum-assisted biopsy (DVAB) probe in the diagnostic management of nonpalpable breast lesions (NPBL). Of 170 planned procedures which were indicated for investigation of BI-RADS category-3 to category-5 lesions, 153 were performed in 138 consecutive patients. The probe was targeted by the stereotactic unit of a prone table (United States Surgical Corporation, Norwalk, Conn.; and Lorad, Danbury, Conn.). Four to 18 (mean 8) core specimens were obtained for each lesion. In case of complete removal of the lesion, a localizing clip was deployed at the biopsy site. Adequate material for histopathologic examination was obtained in all cases (100%). Four of 138 (3%) patients experienced mild hematomas. We observed 15 of 39 failures (38%) to place the localizing clips. Thirteen of 153 (8%) procedures were inconclusive and required reintervention. Following DVAB, 42 of 138 (30%) patients underwent surgery. Subject to incomplete follow-up of the entire cohort, we observed no false-positive and one false-negative diagnosis. These preliminary results suggest that DVAB using an 8-G probe are feasible, safe and accurate. In our experience, clip placement was problematic. It is probable that increasing the dimensions of DVAB will only be relevant in a limited number of clinical situations, primarily the desire to obtain complete radiologic resections of the target abnormality.

Biopsy↗
PubMedDate not supplied

Computed tomographic findings in 35 dogs with nasal aspergillosis.

The purpose of this study was to describe the computed tomographic (CT) features of nasal aspergillosis in dogs. Initial (n = 35) and follow-up (n = 12) CT images were available from 35 dogs. The most commonly encountered CT findings were (1) moderate to severe cavitary destruction of the turbinates with presence of a variable amount of abnormal soft tissue in the nasal passages, (2) non-specific thickening of the mucosa adjacent to the inner surface of bones of the frontal sinus, maxillary recess and nasal cavity and, (3) thickened reactive bone. The findings were consistent with a disease initially affecting one nasal cavity then progressing into the ipsilateral frontal sinus, the contralateral nasal cavity and the contralateral frontal sinus. Two dogs with associated nasal foreign body had a more localized invasion of the nasal cavity. Attenuation values and contrast enhancement were not specific. With follow-up examinations, a reduction in the amount of abnormal soft tissue was observed in all dogs except one, but this reduction could not be quantified.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging of the palmar aspect of the equine podotrochlear apparatus: normal appearance.

The purpose of this study was to describe the normal magnetic resonance (MR) imaging characteristics of the palmar structures of the equine podotrochlear apparatus by means of retrospective evaluation of MR imaging studies of 16 cadaver limbs. The articular aspect of the distal sesamoid bone was not evaluated in this study. Equine digits were imaged with a human knee radiofrequency coil in a 1.5 T magnetic field, using spin echo (SE) T1-weighted, turbo spin echo proton density (TSE PD)-weighted with and without fat saturation (FS), and FS TSE T2-weighted sequences. The limbs were dissected after imaging to validate the absence of gross abnormalities of the flexor aspect of the distal sesamoid bone, of the deep digital flexor tendon, and the distal impar sesamoidean ligament. Seven deep digital flexor tendons were subjected to histologic examination to exclude any microscopic tendon pathology. The anatomic structures of the podotrochlear apparatus were easily identified on MR images. Compact bone of the flexor cortex of the distal sesamoid bone had low intensity signal on all sequences. In 11 digits an increased signal was seen within the thickness of the sagittal eminence of the flexor cortex in SE T1-weighted images and in TSE PD-weighted images without FS. Trabecular bone had a granular appearance and high signal in SE T1-weighted sequences and TSE images without FS. The deep digital flexor tendon had low signal on FS T2-weighted images, while on short echo time sequences (T1- and PD-weighted sequences), the tendon signal varied depending on the relative orientation between its fibers and the static magnetic field. Seven tendons had stippled appearance due to small intratendonous foci of slightly increased signal on transverse T1-weighted images. MR imaging provides a thorough evaluation of the anatomical structure of the podotrochlear apparatus: A good knowledge of the MR imaging appearance and anatomy and an awareness of potential pitfalls will improve diagnostic specificity for the detection of pathologic changes.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging findings in the equine deep digital flexor tendon and distal sesamoid bone in advanced navicular disease--an ex vivo study.

We describe the abnormal magnetic resonance (MR) imaging findings in the deep digital flexor tendon (DDFT) and distal sesamoid bone in horses with radiographic changes compatible with navicular syndrome. Thirteen postmortem specimens were examined using a 1.5-T magnetic field, with spin echo (SE) T1-weighted, turbo SE (TSE) proton density-weighted (with and without fat saturation), and fat saturation TSE T2-weighted sequences. The limbs were then dissected to compare the MR findings with the gross assessment and histologic examination of the DDFT and distal sesamoid bones. Tendonous abnormalities were detected by MR imaging in 12 DDFTs and confirmed at necropsy. Most tendon lesions were located at the level of the distal sesamoid bone and the proximal recess of the podotrochlear bursa. Tendon lesions were classified based on their MR imaging features as core lesions, dorsal lesions, dorsal abrasions, and parasagittal splits. Areas of increased MR signal in the DDFTs were characterized by tendon fiber disturbance and lack of continuity of the collagen fibers, foci of edema, hemorrhages, and formation of lakes containing eosinophilic plasma-like material or amphophilic material of low density. Bone marrow signal alterations in the distal sesamoid bone were seen in all digits. Two main phenomena were responsible for the abnormal signal, respectively, in T1-weighted (decreased signal) and in T2-weighted fat-suppressed images (increased signal): a decrease in the fat marrow content in the trabecular spaces and an increase in the fluid content. Histologic examination revealed foci of bone marrow edema, hemorrhage, necrosis, and fibrosis. Cyst formation and trabecular abnormalities (disorganization, thinning, remodelling) were also observed in areas of abnormal signal intensity. Increased bone density because of trabecular thickening induced a decrease in signal in all sequences.

Animals↗
PubMedDate not supplied

Can CT pulmonary angiography allow assessment of severity and prognosis in patients presenting with pulmonary embolism? What the radiologist needs to know.

Computed tomographic (CT) pulmonary angiography has been established as a first-line diagnostic technique in patients suspected of having pulmonary embolism. Risk stratification is important in patients with pulmonary embolism because optimal management, monitoring, and therapeutic strategies depend on the prognosis. Acute right-sided heart failure is known to be responsible for circulatory collapse and death in patients with severe pulmonary embolism. Acute right-sided heart failure can be assessed at CT pulmonary angiography by measuring the dimensions of right-sided heart cavities or upstream venous structures, such as the superior vena cava or azygos vein. The magnitude of pulmonary embolism can be calculated at CT pulmonary angiography by applying angiographic scores adapted for CT (Miller and Walsh scores) or dedicated CT scores (Qanadli and Mastora scores). The advent of CT pulmonary angiography performed with electrocardiographic gating permits new advances in assessment of acute right-sided heart failure, such as measurement of the ventricular ejection fraction. Although such findings may be useful for assessment of treatment effectiveness, their effect on prognosis in patients with severe pulmonary embolism is debated in the literature.

Angiography↗