Experience enhances mammographic interpretation, doesn't it? Yes, it does!
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Breast Neoplasms↗
Biomedical subjects
R Groell
Publications and source records attributed to R Groell.
Medical audit after 26,711 breast imaging studies: improved rate of detection of small breast carcinomas (classified as Tis or T1a,b)
BACKGROUND: Patients with breast carcinomas 1 cm or smaller are known to have the highest long term survival rates. This pathologic measurement was used as a quality indicator of the performance of different reporting radiologists. METHODS: A total of 26,711 diagnostic breast imaging studies were performed over a period of 5 years. Within the first 18 months, several general radiologists reported mammograms, whereas during the rest of the evaluated period only 1 radiologist was responsible for all mammography reporting. Radiologic findings leading to open biopsy were correlated with the histologic results. The cancer sizes from the histologic reports were recorded, and the number of Tis, T1a, and T1b cancers were correlated with all cancers found at open biopsy. The change in the relative percentage of small cancers was evaluated, along with the positive predictive value (PPV). RESULTS: Between 1991 and 1995, 26,711 breast imaging studies were performed. This resulted in 2698 open biopsies with 620 breast carcinomas detected. In the first 2 years, the percentages of small cancers detected (Tis or T1a,b) were 27.2% and 25.7%, respectively. In the third, fourth, and fifth years, the percentages increased to 38.8%, 34.5%, and 38.8%, respectively. At the same time, the PPV increased slightly, from 0.23 in 1991 to 0.27 in 1995. CONCLUSIONS: The detection of curable early stage breast carcinomas requires the dedication and commitment of a small group of radiologists who are willing to spend most of their time on this single subject. This will increase considerably the number of early stage cancers found and reduce the number of false-positive diagnoses. [See editorial counterpoint on pages 2430-1 and reply to counterpoint on pages 2432-3.]
Breast Neoplasms↗
Value of echo-enhanced Doppler sonography in evaluation of transjugular intrahepatic portosystemic shunts.
OBJECTIVE: The value of echo-enhanced color and power Doppler sonography in the evaluation of transjugular intrahepatic portosystemic shunts (TIPS) was assessed and compared with that of unenhanced Doppler sonography and portal angiography. SUBJECTS AND METHODS: In a prospective randomized trial, 31 shunts in 30 patients underwent unenhanced conventional color and power Doppler sonography and portal venography including pressure measurements. The patients were allocated to either echo-enhanced conventional color Doppler sonography or echo-enhanced power Doppler sonography. For echo enhancement, a galactose-based suspension was administered IV. Shunt stenoses, if present, were quantified by percentage of stenosis and correlated with angiography, which was the gold standard. The diagnostic confidence of unenhanced and echo-enhanced Doppler sonography was assessed using a visual analog scale. RESULTS: In the diagnosis of shunt occlusion, echo-enhanced Doppler sonography yielded a sensitivity and a specificity of 100% and 100%, respectively, compared with 100% and 89%, respectively, for unenhanced Doppler sonography. Our evaluation of hemodynamically significant stenoses (portosystemic gradient > or = 15 mm Hg) found echo-enhanced Doppler sonography to be superior to unenhanced Doppler sonography (sensitivity and specificity of 82% and 83%, respectively, compared with 64% and 80%, respectively). In the detection of a shunt stenosis based on morphologic criteria only, echo-enhanced Doppler sonography yielded a sensitivity and a specificity of 78% and 100%, respectively, compared with 47% and 50%, respectively, for unenhanced Doppler sonography. Power Doppler imaging did not improve diagnostic accuracy but did increase diagnostic confidence for unenhanced Doppler sonography compared with conventional color Doppler sonography. The diagnostic confidence for sonographic evaluation of TIPS was significantly (p < .001) increased and the variability of hemodynamic measurements was markedly decreased with echo-enhanced sonography. CONCLUSION: Echo-enhanced Doppler sonography provides images of TIPS like those of angiography and allows morphologic assessment of the shunts, complementary to the essential pulsed Doppler waveform analysis that would be performed in a more guided manner. Also, echo-enhanced Doppler sonography significantly increases the sensitivity and specificity in the diagnosis of shunt dysfunction. The high diagnostic confidence and the diminished variability of spectral Doppler measurements may improve acceptance of sonographic evaluation of TIPS. Echo-enhanced Doppler sonography is safe and effective and may reduce the instances in which TIPS sonographic surveillance is nondiagnostic, in which case angiographic assessment is required.
Adult↗
CT-anatomy of the nasolacrimal sac and duct.
Recent developments in ophthalmology such as balloon dilatation, stent implantation, laser therapy and endoscopy of the lacrimal drainage system raise the need for a detailed anatomical knowledge of this system. In this study morphometric measurements of the lacrimal drainage system were performed with thin-section axial computed tomography (CT) examinations in 147 patients with no signs of pathology related to the lacrimal drainage system. The mean length of the nasolacrimal duct measured 11.2 +/- 2.6 mm (range: 6-21 mm), the narrowest diameter was 3.7 +/- 0.7 mm (range: 2-7 mm). The mean length of the nasolacrimal sac was 11.8 +/- 2.5 mm (range: 6-18 mm). The width of the nasolacrimal sac did not exceed 4 mm unless filled with air. In 43 (29.3%) of the subjects air was visible within the nasolacrimal sac or duct. The knowledge of the morphometry of the lacrimal drainage system enables the ophthalmologist to plan intervention on the lacrimal drainage system precisely and avoid unnecessary manipulations.
Female↗
Morphometric measurement of abdominal organs. Comparison of ultrasound and spiral CT.
PURPOSE: To determine interobserver variability in the morphometric measurement of abdominal organs with US and spiral CT, and to compare the results obtained with these two modalities. MATERIAL AND METHODS: US and spiral CT examinations of the abdomen were performed in 25 patients. In each patient, 13 defined distances were measured in the liver, spleen and both kidneys with US and spiral CT by two pairs of radiologists in a blinded manner. The interobserver variations of these measurements were evaluated for the US and CT examinations, and the data of both modalities were compared with one another. RESULTS: The measurement of distances in the abdomen with US and spiral CT is subject to considerable interobserver variability in both modalities. The relative interobserver variations showed marked differences, according to which distance was measured. The average interobserver variations were higher in US than in CT. A direct comparison of US and spiral CT revealed that distances obtained with CT frequently exceeded those obtained with US. CONCLUSION: Morphometric measurements of abdominal organs with US and with spiral CT showed considerable differences. The follow-up examinations should therefore be performed with the same imaging modality as used in the original examination.
Abdomen↗
The peripheral intravenous cannula: a cause of venous air embolism.
Venous air embolism has been reported as a complication of invasive diagnostic and therapeutic procedures or accidental trauma. Little is known about the incidence of air embolism after minimal intravenous manipulations, such as the insertion of a peripheral intravenous cannula. Small air emboli in the central veins, central arteries, and cardiac chambers can be detected during electron-beam computed tomography studies of the chest. Electron-beam computed tomography of the chest was performed on 208 patients after the insertion of a peripheral intravenous cannula. The images were analyzed using a digital workstation. Small air embolism was visible in 10 of 208 (4.8%) patients in the following locations: the pulmonary trunk in 6 patients, the right ventricle in 2, the right atrium in 1, and the left brachiocephalic vein in 1. The embolism was asymptomatic in each patient. Although the potential risks in patients with septal defects and shunts remain unclear, caution should be taken with minimal intravenous manipulations.
Catheterization, Peripheral↗
Vascular air embolism: location, frequency, and cause on electron-beam CT studies of the chest.
PURPOSE: To determine the frequency and location of venous air emboli that occur with the use of electron-beam computed tomographic (CT) studies of the chest. MATERIALS AND METHODS: Findings from 677 patients who underwent chest electron-beam CT with intravenous administration of contrast material were reviewed. Unenhanced CT studies were performed in 127 (18.8%) of these patients while the intravenous cannula was in place but before injection of contrast material. RESULTS: Air emboli were observed on CT studies in 79 (11.7%) of 677 patients. Emboli were small (up to three air bubbles less than 1 cm in diameter) in 70 (10.3%) patients and were moderate (more than three air bubbles or bubbles 1-2 cm in diameter) in nine (1.3%) patients. Air emboli were located in the main pulmonary artery (n = 54 [8.0%]), superior vena cava (n = 12 [1.8%]), right ventricle (n = 10 [1.5%]), subclavian or brachiocephalic vein (n = 6 [0.9%]), and right atrium (n = 5 [0.7%]). Seven patients (1.0%) had emboli in more than one location. Air emboli were depicted on unenhanced CT scans of seven (5.5%) of 127 patients. No association was found between the frequency of air embolism and injection flow, injection site, or amount or type of contrast agent. CONCLUSION: Intravenous administration of contrast material may cause small to moderate-sized air emboli. Knowledge of the common locations of emboli can help radiologists distinguish them from image artifacts or paravasal air collections.
Brachiocephalic Veins↗
[Hydrocalicosis caused by a large renal artery aneurysm].
Rupture and development of hypertension represent frequent complications of renal artery aneurysms. We report the case of a 27-year-old patient with pain in the region of the right kidney due to a large renal artery aneurysm. This aneurysm induced partial, obstructive hydrocalicosis. The aneurysm was clearly differentiated from the dilated calices by color Doppler sonography and contrast-enhanced spiral CT.
Adult↗
Ultrafast computed tomography and three-dimensional image processing of CT sialography in patients with parotid masses poorly defined by magnetic resonance imaging.
The purpose of this study was to determine the efficacy of ultrafast computed tomography (UF CT) in patients with parotid masses poorly defined by magnetic resonance imaging (MRI) and to evaluate the diagnostic potential of three-dimensional (3-D) UF CT sialography when compared with conventional CT sialograms. Thirteen patients with clinical suspicion of a parotid mass, in whom MRI was degraded by motion, underwent UF CT of the parotid region. Two radiologists independently assessed the CT and MR with respect to tumor localization, intraglandular tumor location, tumor margin characteristics, and infiltration of surrounding tissue. In 9 patients, CT sialography was performed using 3-D image processing. Anatomical details and pathologic findings were assessed by three readers using a numerical grad and compared with the findings derived from conventional CT sialography. Histopathologic specimens were obtained in all cases and correlated with the radiographic findings in a consensus manner following the blinded interpretations. UF CT and (suboptimal) MRI provided the same diagnostic information for the evaluation of tumor localization, and intraglandular location. UF CT was superior to MRI in the detection of tumor infiltration, and definition of tumor margins in 2 cases (15%), resulting in a substantial difference in treatment. Three-dimensional CT sialography offered significant improvement in demonstration of anatomic detail (2.5 +/- 0.2 vs 1.5 +/- 0.1, respectively) and pathologic findings (2.6 +/- 0.1 vs 1.3 +/- 0.2, respectively) when compared with conventional CT sialography. UF CT is a viable alternative in uncooperative patients with parotid masses. UF CT 3-D sialography has the potential to allow more precise pre-surgical planning and contributes to the diagnosis and therapy planning of parotid masses.
Adult↗
Quantitative perfusion parameters of focal nodular hyperplasia and normal liver parenchyma as determined by electron beam tomography.
Eight patients with known focal nodular hyperplasia (FNH) were studied by electron beam tomography (EBT) in a multisection flow mode at defined time intervals after intravenous contrast agent injection. Various regions of interest (ROIs) were defined in the areas of FNH, normal liver parenchyma, aorta and portal vein. In each ROI density changes were measured and plotted against time. In those time-density curves (TDCs) the slope, the time of maximal enhancement and the absolute density value of peak enhancement were determined. Arterial tissue perfusion was calculated for normal liver parenchyma and FNH. In all eight patients significant differences in peak density (123.88 +/- 18.92 HU vs 102.5 +/- 15.49 HU, p = 0.012), in the rate of arterial contrast enhancement (252.63 +/- 28.05 HU min-1 vs 38.88 +/- 4.19 HU min-1, p = 0.012) and in the arterial tissue perfusion (1.36 +/- 0.19 ml min-1 cm-3 vs 0.21 +/- 0.03 ml min-1 cm-3, p = 0.012) between FNH and normal liver parenchyma were found. Perfusion values of normal liver parenchyma correspond to those determined by inert gas clearance. Further studies will determine the practicability of this quantitative method in the evaluation of global and other focal liver diseases.
Adolescent↗
Three-dimensional processing of ultrafast CT sialography for parotid masses.
PURPOSE: To evaluate the diagnostic potential of three-dimensional image processing of ultrafast CT sialography in comparison with conventional CT sialography in patients with parotid masses. METHODS: In nine patients, CT sialography was done with three-dimensional image processing. The visibility of anatomic details and pathologic findings, derived from three-dimensional images, were graded numerically by three observers and compared with the findings obtained from conventional CT sialograms. Histopathologic specimens were obtained in all cases. RESULTS: Ultrafast CT images showed no motion artifact. Three-dimensional CT sialography offered significant improvement in demonstration of ductal anatomy (2.5 +/- 0.2 versus 1.5 +/- 0.1, respectively) and ductal pathology (2.6 +/- 0.1 versus 1.1 +/- 0.2, respectively) over conventional CT sialography. In two cases, the therapeutic regimen was altered substantially. CONCLUSION: Ultrafast CT three-dimensional sialography has the potential to allow more precise presurgical planning and contributes to the diagnosis and therapy planning of parotid masses, especially in patients in whom MR image quality is degraded by motion artifact.
Adult↗
Extended infusion of rtPA lysis of pulmonary emboli: influence of time after onset of symptoms on outcome.
PURPOSE: Evaluate efficacy and safety of short-term thrombolysis with recombinant human-tissue plasminogen activator (rtPA). METHODS: Thrombolysis with rtPA was performed in 29 patients with angiographically documented severe acute pulmonary embolism (Miller score of 20/34 or more). All patients received 100 mg rtPA through peripheral veins within the first 2 hr, followed by a continuous infusion of rtPA (0.05 mg/kg/hr) over a 4-hr period. Concomitant intravenous heparin 1000 U/hr infusion was applicated for the first 6 hr. RESULTS: Using this treatment, 83% of our patients showed clinical improvement objectified by the Miller score, by the clinical stage (Grosser), and by the pulmonary artery mean pressure (PAPm). The treatment regimen was unsuccessful if the clinical history lasted more than 3 days. Complications occurred in 10 patients (34%), and 3 patients (10%) died of acute right heart failure. CONCLUSION: The success of rtPA treatment appears to depend on the interval between onset of symptoms and start of thrombolytic therapy. Otherwise the technique leads to objectifiable improvement within 6 hr with an acceptable bleeding risk.
Adult↗
Anterior and upward displacement of the inferior mesenteric vein:a new diagnostic clue to left paraduodenal hernias?
A 26-year-old man with acute deterioration of recurrent abdominal pain was admitted to the hospital. Plain film (abdominal radiographs), spiral computed tomography (CT), and barium contrast studies were performed. A left paraduodenal hernia causing acute jejunal obstruction was identified on upper gastrointestinal barium studies and spiral CT. Pre- and postsurgery examinations were compared, and relevant radiological findings were identified. Spiral CT provided excellent visualization of the pathognomonic displacement of the inferior mesenteric vein.
Adult↗
CT number variations due to different image acquisition and reconstruction parameters: a thorax phantom study.
A humanoid thorax phantom containing six compartments was scanned with two different computed tomography (CT) scanners using various image acquisition and reconstruction parameters. The differences of CT numbers were statistically significant between the two CT scanners for each compartment (p<0.001) except for the "air" compartment. The variabilities of the CT numbers are described for the different parameters. The mean CT numbers of the "water" compartment, for instance, ranged from 1 to 15HU (Hounsfield Units), those of the "air" compartment varied from -962 to -990HU. Knowledge of these CT number variabilities is necessary when CT numbers are used for tissue characterization.
Air↗
Digital image fusion of CT and PET data sets--clinical value in abdominal/pelvic malignancies.
PURPOSE: We investigated the clinical relevance of digital image fusion of CT and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) studies in patients with suspected abdominal and/or pelvic metastasis. METHOD: Nineteen patients with suspected residual/recurrent malignancies underwent CT and [18F]FDG PET studies of the abdomen and/or pelvis. The data sets of both modalities were fused on a digital workstation by automatic adaptation of the pixel size and the slice thickness. Different body positions were corrected by semiautomatic adaptation of the body axes. The fused images were reconstructed in sagittal, coronal, and axial planes. RESULTS: Good spatial correlation between both modalities was achieved in all patients. Image fusion improved the spatial allocation of pathologically increased [18F]FDG uptake in 7 of 35 lesions (20%). CONCLUSION: This work suggests that digital image fusion of CT and [18F]FDG PET data sets improves the anatomical localization of foci with increased [18F]FDG enhancement of the retroperitoneum and the abdominal/pelvic wall, respectively.
Abdominal Neoplasms↗
Helical CT angiography of stent-grafts in abdominal aortic aneurysms: morphologic changes and complications.
Transfemoral placement of an endovascular stent-graft is increasingly be-ing used as an alternative to surgical repair in the treatment of abdominal aortic aneurysm, especially in high-risk patients. However, complications frequently occur after stent-graft placement. Helical computed tomographic (CT) angiography is a fast, minimally invasive procedure that is quickly becoming the imaging modality of choice for assessment of these complications. Thirty-nine patients who were treated for abdominal aortic aneurysm with stent-graft placement underwent helical CT angiography at routinely scheduled follow-up intervals or whenever complications were suspected. The resulting images were evaluated for the presence, extent, and origin of endovascular leaks. In addition, the position, shape, and patency of the stent-grafts were assessed. Findings included both graft-related (n = 4) and non-graft-related (n = 3) leaks, thrombosis of a graft limb (n = 3), distal migration of the stent-graft (n = 5), angulation of bifurcated stent-grafts distal to the main graft (n = 6), shrinkage of the abdominal aortic aneurysm (n = 7), enlargement of the aneurysm with secondary graft-related leaks (n = 2), and an aortoduodenal fistula (n = 1). Helical CT angiography can depict complications that develop after treatment of abdominal aortic aneurysms with endovascular stent-grafts. Long-term follow-up is required to determine the full spectrum and frequency of complications that may develop after initially successful repair.
Aged↗