Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 9 de 9
Filter
1.
Clin Radiol ; 77(6): e425-e433, 2022 06.
Article in English | MEDLINE | ID: mdl-35351291

ABSTRACT

AIM: To evaluate the diagnostic value of spectral detector computed tomography (SDCT)-derived iodine overlay maps and low-energy virtual mono-energetic images (VMI) for the initial locoregional assessment of primary, therapy-naive head and neck cancer. MATERIALS AND METHODS: Fifty-six patients with histologically confirmed untreated squamous cell carcinoma of the head and neck who underwent SDCT of the neck for staging purposes were included in this retrospective study. Attenuation, image noise as well as signal- and contrast-to-noise ratios (S-/CNR) in VMI40-70keV were obtained from region of interest (ROI)-based measurements in the tumour and important anatomical landmarks (sternocleidomastoid muscle, subcutaneous fat, thyroid gland, submandibular gland, carotid artery, and jugular vein). Tumour conspicuity and delineation, as well as subjective image quality, were rated for conventional images, VMI40-70keV, and iodine overlay maps using five-point Likert scales. RESULTS: The CNR of the tumour versus the floor of the mouth and the CNR of the tumour versus the sternocleidomastoid muscle was significantly higher in VMI40keV in comparison to conventional images (10.0 ± 7.3 versus 3.8 ± 3.3 and 11.3 ± 7.6 versus 3.6 ± 2.8; p<0.05 each). This was supported by qualitative results, as tumour conspicuity and delineation received superior ratings in iodine overlay maps and VMI40keV compared to conventional images (5 [3-5] and 5 [4-5] versus 3 [2-5]; 5 [2-5] and 5 [3-5] versus 3 [2-4], respectively, all p<0.05). VMI40keV yielded the highest score among all included image reconstructions for overall image quality (p<0.05 all). CONCLUSION: Iodine overlay maps and low-energy VMI derived from SDCT improve initial assessment of primary squamous cell carcinoma of the head and neck compared to conventional images.


Subject(s)
Head and Neck Neoplasms , Iodine , Head and Neck Neoplasms/diagnostic imaging , Humans , Radiographic Image Interpretation, Computer-Assisted/methods , Retrospective Studies , Signal-To-Noise Ratio , Squamous Cell Carcinoma of Head and Neck/diagnostic imaging , Tomography, X-Ray Computed/methods
2.
Rofo ; 187(6): 445-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25877994

ABSTRACT

PURPOSE: To determine the frequency of histopathological underestimation of breast cancer after vacuum-assisted biopsy (VAB) in standardized assessment of breast calcifications compared to postsurgical diagnosis. MATERIALS AND METHODS: The retrospective study included acquired data of 506 consecutively examined women, who underwent VAB for the assessment of pure calcifications after standardized digital mammographic and sonographic imaging. 119/506 (24.5 %) women underwent further surgical procedures: 37 women had a surgical diagnostic excision biopsy, 82 women a surgical procedure based on a therapeutic concept. Presurgical results of VAB were compared with the postsurgical histopathological reports. RESULTS: In 91/119 women (76.5 %) the final histology was malignant. The rate of ductal carcinoma in situ (DCIS) was 79.1 % (72/91) and the rate of invasive carcinoma was 20.9 % (19/91). In 9/37 women with diagnostic excision biopsy, the presurgical status of benign or uncertain changed to a postsurgical diagnosis of malignant (24.3 %). In eight cases underestimation included DCIS (21.6 %) and in one case invasive cancer (2.7 %). Seven of the nine underestimated cases (77.8 %) resulted from excision biopsy of atypical epithelial proliferation of ductal type (AEPDT, positive predictive value 30.4 % (7/23)). After surgery due to DCIS in 7/71 women invasive breast cancer was diagnosed (9.9 %). In 11/82 women with oncological surgery, invasive cancer was already diagnosed by VAB. CONCLUSION: Underestimation of invasive cancer in terms of presurgical DCIS diagnosis can be minimized by the standardized assessment protocol to about 10 %. Underestimation of DCIS is mainly related to presurgical diagnosis of AEPDT. KEY POINTS: • The standardized use of digital mammographic and sonographic imaging prior to vacuum-assisted biopsy is suitable for minimizing underestimation of invasive breast cancer. AEPDT represents a high risk diagnosis for underestimation of DCIS.


Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/surgery , Calcinosis/diagnosis , Calcinosis/surgery , Mammography/statistics & numerical data , Mammography/standards , Adult , Aged , Breast Neoplasms/epidemiology , Calcinosis/epidemiology , False Negative Reactions , Female , Germany/epidemiology , Humans , Middle Aged , Postoperative Care/standards , Postoperative Care/statistics & numerical data , Preoperative Care/standards , Preoperative Care/statistics & numerical data , Prevalence , Reproducibility of Results , Retrospective Studies , Risk Factors , Sensitivity and Specificity
3.
Rofo ; 184(9): 795-804, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22618478

ABSTRACT

PURPOSE: Assignment of semi-automated lymph node analysis compared to manual measurements for therapy response classification of malignant lymphoma in MSCT. MATERIALS AND METHODS: MSCT scans of 63 malignant lymphoma patients before and after 2 cycles of chemotherapy (307 target lymph nodes) were evaluated. The long axis diameter (LAD), short axis diameter (SAD) and bi-dimensional WHO were determined manually and semi-automatically. The time for manual and semi-automatic segmentation was evaluated. The ref. standard response was defined as the mean relative change across all manual and semi-automatic measurements (mean manual/semi-automatic LAD, SAD, semi-automatic volume). Statistical analysis encompassed t-test and McNemar's test for clustered data. RESULTS: Response classification per lymph node revealed semi-automated volumetry and bi-dimensional WHO to be significantly more accurate than manual linear metric measurements. Response classification per patient based on RECIST revealed more patients to be correctly classified by semi-automatic measurements, e. g. 96.0 %/92.9 % (WHO bi-dimensional/volume) compared to 85.7/84.1 % for manual LAD and SAD, respectively (mean reduction in misclassified patients of 9.95 %). Considering the use of correction tools, the time expenditure for lymph node segmentation (29.7 ± 17.4 sec) was the same as with the manual approach (29.1 ± 14.5 sec). CONCLUSION: Semi-automatically derived "lymph node volume" and "bi-dimensional WHO" significantly reduce the number of misclassified patients in the CT follow-up of malignant lymphoma by at least 10 %. However, lymph node volumetry does not outperform bi-dimensional WHO.


Subject(s)
Algorithms , Lymph Nodes/diagnostic imaging , Lymphoma/diagnostic imaging , Pattern Recognition, Automated/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Observer Variation , Radiographic Image Enhancement/methods , Reproducibility of Results , Sensitivity and Specificity , Young Adult
4.
Rofo ; 183(4): 372-80, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21246480

ABSTRACT

PURPOSE: To evaluate the effect of slice thickness on semi-automated liver lesion segmentation. MATERIALS AND METHODS: In this retrospective study, liver MSCT scans from 60 patients were reconstructed at a slice thickness of 1.5 mm, 3 mm and 5 mm. 106 liver lesions (8 - 64 mm, mean size 25 ± 13 mm) were evaluated independently by two radiologists using semi-automated segmentation software (OncoTreat®). Lesions were classified as cystic, hypodense and hyperdense according to their contrast-to-noise ratio (CNR). The long axis diameter (LAD), short axis diameter (SAD) and volume were measured. The necessity for manual correction (NOC = relative difference between uncorrected and corrected volume) and the relative interobserver difference (RID) were determined. Precision was calculated in terms of relative measurement deviations (RMD) from the reference standard (mean of 1.5 mm data sets). Wilcoxon test, t-test and intraclass correlation coefficients (ICC) were employed for statistical analysis. All statistical analyses were intended to be exploratory. RESULTS: Regardless of the liver lesion subtype, the NOC was found to be significantly higher for 5 mm than for 3 mm (p = 0.035) and 1.5 mm (p = 0.0002). The RID was consistently low for metric and volumetric parameters with no difference in any of the slice thicknesses for all subtypes (ICC > 0.89). The RMD increased significantly for the LAD, SAD and volume at a slice thickness of 5 mm (p < 0.01), e. g. volume: 0.5 % at 1.5 mm, 5.5 % at 3.0 mm and 7.6 % at 5.0 mm. CONCLUSION: Since the deviations in measurements are significant, and manual corrections made during semi-automated assessment of the liver lesions are considerable, a slice thickness of 1.5 mm, and no more than 3.0 mm, should be used for reconstruction for inconsistently vascularized liver lesions.


Subject(s)
Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Liver Diseases/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Tomography, Spiral Computed/methods , Adult , Aged , Aged, 80 and over , Algorithms , Contrast Media , Female , Humans , Iohexol/analogs & derivatives , Liver/diagnostic imaging , Liver Diseases/classification , Liver Neoplasms/blood supply , Liver Neoplasms/classification , Liver Neoplasms/secondary , Male , Middle Aged , Observer Variation , Reference Values , Retrospective Studies , Software , Tumor Burden
5.
Clin Radiol ; 65(6): 440-6, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20451010

ABSTRACT

AIM: To evaluate the impact of bone subtraction computed tomography angiography (BS-CTA) for the assessment of transcranial arteries in comparison with standard CTA (S-CTA) without bone removal and time-of-flight magnetic resonance angiography (TOF-MRA). MATERIALS AND METHODS: Cranial unenhanced CT and S-CTA were performed in 53 patients with suspected cerebrovascular disease. BS-CTA datasets were reconstructed from the S-CTA and unenhanced CT source images. TOF-MRA was performed within 24h after CTA on a 1.5 T MRI system. Two radiologists, in consensus, evaluated the segments of the internal carotid artery (C2-C7), the vertebral artery (V4), and the basilar artery for the degree of stenosis. A five-step scale (0-49, 50-69, 70-89, 90-99% and occlusion) for the degree of stenosis was applied for all segments. Wilcoxon's signed rank test was used for statistical analysis. RESULTS: Seven hundred and fifty vessel segments (ICA:636, VA:106, BA:53) were analysed. The degree of stenosis on S-CTA was consistent with TOF-MRA in all segments. BS-CTA showed a trend towards higher stenosis scores in cases of calcified plaques compared to S-CTA (p=0.11) and TOF-MRA (p=0.09), which was not statistically significant. In transcranial segments, BS-CTA revealed equivalent scores compared to S-CTA and TOF-MRA (p=0.25; p=0.20). CONCLUSION: BS-CTA produced similar results to TOF-MRA and S-CTA and can be applied as a non-invasive imaging method for the transcranial arteries. However, BS-CTA shows a trend towards overestimation of the degree of stenosis.


Subject(s)
Angiography, Digital Subtraction/methods , Cerebral Arteries/diagnostic imaging , Cerebrovascular Disorders/diagnostic imaging , Magnetic Resonance Angiography/methods , Skull/diagnostic imaging , Cerebral Angiography/methods , Cerebral Arteries/pathology , Cerebrovascular Disorders/pathology , Female , Humans , Male , Middle Aged , Reproducibility of Results , Tomography, X-Ray Computed/methods
6.
Nuklearmedizin ; 49(1): 41-8; quiz N1, 2010.
Article in English | MEDLINE | ID: mdl-20087533

ABSTRACT

PURPOSE: To distinguish between benign and malignant mediastinal lymph nodes in patients with NSCLC by comparing 2D and semi-automated 3D measurements in FDG-PET-CT. PATIENTS, MATERIAL, METHODS: FDG-PET-CT was performed in 46 patients prior to therapy. 299 mediastinal lymph-nodes were evaluated independently by two radiologists, both manually and by semi-automatic segmentation software. Longest-axial-diameter (LAD), shortest-axial-diameter (SAD), maximal-3D-diameter, elongation and volume were obtained. FDG-PET-CT and clinical/FDG-PET-CT follow up examinations and/or histology served as the reference standard. Statistical analysis encompassed intra-class-correlation-coefficients and receiver-operator-characteristics-curves (ROC). RESULTS: The standard of reference revealed involvement in 87 (29%) of 299 lymph nodes. Manually and semi-automatically measured 2D parameters (LAD and SAD) showed a good correlation with mean intraclass coefficients of .80 and .72, respectively. Semi-automated prediction revealed the highest areas-under-the-ROC-curve for volume (.75, 95%CI: .69-81) and SAD (.75, 95%CI: .70-.81). AUC for LAD and maximal-3D diameter were about .68. Substantially lower accuracies were found for elongation (.57, 95%CI: .50-.64). CONCLUSION: Optimized semi-automated three dimensional parameters by CT cannot approximate reported data on FDG-PET-CT for lymph node assessment in NSCLC. SAD remains the most accurate and at the same time simple to achieve anatomical criterion for definition of NSCLC target lesions.


Subject(s)
Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Fluorodeoxyglucose F18 , Lymphatic Metastasis/diagnostic imaging , Aged , Automation , Carcinoma, Non-Small-Cell Lung/pathology , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/pathology , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis/pathology , Middle Aged , Neoplasm Staging , Positron-Emission Tomography , Predictive Value of Tests , ROC Curve , Radiography , Retrospective Studies , Sensitivity and Specificity
7.
Rofo ; 181(7): 683-90, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19241327

ABSTRACT

PURPOSE: Determination of an adequate scan delay for routine abdominal 64-slice CT examinations with body weight-adapted contrast application. MATERIALS AND METHODS: 57 patients underwent abdominal CT with a 64-slice scanner. The contrast material was adapted to patient body weight. All patients were randomized into five groups with varying scan delay and scan direction (group 1: delay 65 sec; group 2: 75 sec; group 3: 85 sec, craniocaudal; group 4: 85 sec, caudocranial; group 5: 95 sec). Two blinded radiologists evaluated the image quality. CT values (HU) were obtained in different segments of the aorta, inferior vena cava, iliac veins, portal vein, hepatic veins and liver, spleen and pancreas. Statistical analysis was performed using the independent sample t-test and ANOVA test. RESULTS: The diagnostic acceptability of protocols 3 and 4 were rated equally good and significantly/substantially superior to protocol 1 (p = 0.004/0.008) and protocol 5, respectively. Contrast enhancement in the aorta and portal vein peaked at 65 sec. Contrast enhancement in the hepatic and iliac veins peaked at 85 sec independently of the scan direction but was substantially lower at 75 sec. Liver parenchyma enhancement was lowest at 95 sec. CONCLUSION: This data suggests an optimal scan delay for routine abdominal 64-slice CT of 85 sec regardless of scan direction.


Subject(s)
Abdominal Neoplasms/diagnostic imaging , Abdominal Neoplasms/pathology , Body Weight , Contrast Media/administration & dosage , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Iopamidol/analogs & derivatives , Tomography, Spiral Computed/methods , Abdominal Neoplasms/blood supply , Adult , Aged , Aged, 80 and over , Aortography , Celiac Artery/diagnostic imaging , Celiac Artery/pathology , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Hepatic Veins/diagnostic imaging , Hepatic Veins/pathology , Humans , Injections, Intravenous , Iopamidol/administration & dosage , Iopamidol/pharmacokinetics , Liver/diagnostic imaging , Liver/pathology , Male , Middle Aged , Neoplasm Staging , Pancreas/diagnostic imaging , Pancreas/pathology , Portal Vein/diagnostic imaging , Portal Vein/pathology , Spleen/diagnostic imaging , Spleen/pathology , Time Factors , Young Adult
8.
Eur Radiol ; 19(7): 1645-52, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19238394

ABSTRACT

The aim of this study was to assess the performance of a motion-map algorithm that automatically determines optimal reconstruction windows for dual-source coronary CT angiography. In datasets from 50 consecutive patients, optimal systolic and diastolic reconstruction windows were determined using the motion-map algorithm. For manual determination of the optimal reconstruction window, datasets were reconstructed in 5% steps throughout the RR interval. Motion artifacts were rated for each major coronary vessel using a five-point scale. Mean motion scores using the motion-map algorithm were 2.4 +/- 0.8 for systolic reconstructions and 1.9 +/- 0.8 for diastolic reconstructions. Using the manual approach, overall motion scores were significantly better (1.9 +/- 0.5 and 1.7 +/- 0.6, p < 0.05), but diagnostic image quality was reached in >90% of cases using either approach. Using the automated approach, there was a negative correlation between heart rate and motion scores for systolic reconstructions (rho = -0.26, p < 0.05) and a positive correlation for diastolic reconstructions (rho = 0.46, p < 0.01). For the manual approach, no significant correlation was found for systolic reconstructions (rho = -0.1, p = 0.52), while there was a positive correlation for diastolic reconstructions (rho = 0.48, p < 0.01). Thus, the motion-map algorithm is a useful tool to save time in finding an appropriate reconstruction window in patients with heart rates <70 bpm (diastolic reconstruction) and >80 bpm (systolic reconstruction).


Subject(s)
Artifacts , Artificial Intelligence , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Pattern Recognition, Automated/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Algorithms , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Young Adult
9.
Rofo ; 181(1): 67-73, 2009 Jan.
Article in German | MEDLINE | ID: mdl-18975251

ABSTRACT

PURPOSE: To assess the accuracy of liver lesion measurement using automated measurement and segmentation software depending on the vascularization level. MATERIALS AND METHODS: Arterial and portal venous phase multislice CT (MSCT) was performed for 58 patients. 94 liver lesions were evaluated and classified according to vascularity (hypervascular: 13 hepatocellular carcinomas, 20 hemangiomas; hypovascular: 31 metastases, 3 lymphomas, 4 abscesses; liquid: 23 cysts). The RECIST diameter and volume were obtained using automated measurement and segmentation software and compared to corresponding measurements derived visually by two experienced radiologists as a reference standard. Statistical analysis was performed using the Wilcoxon test and concordance correlation coefficients. RESULTS: Automated measurements revealed no significant difference between the arterial and portal venous phase in hypovascular (mean RECIST diameter: 31.4 vs. 30.2 mm; p = 0.65; kappa = 0.875) and liquid lesions (20.4 vs. 20.1 mm; p = 0.1; kappa = 0.996). The RECIST diameter and volume of hypervascular lesions were significantly underestimated in the portal venous phase as compared to the arterial phase (30.3 vs. 26.9 mm, p = 0.007, kappa = 0.834; 10.7 vs. 7.9 ml, p = 0.0045, kappa = 0.752). Automated measurements for hypovascular and liquid lesions in the arterial and portal venous phase were concordant to the reference standard. Hypervascular lesion measurements were in line with the reference standard for the arterial phase (30.3 vs. 32.2 mm, p = 0.66, kappa = 0.754), but revealed a significant difference for the portal venous phase (26.9 vs. 32.1 mm; p = 0.041; kappa = 0.606). CONCLUSION: Automated measurement and segmentation software provides accurate and reliable determination of the RECIST diameter and volume in hypovascular and liquid liver lesions. Hypervascular lesions are prone to be underestimated with regard to size in the portal venous phase and therefore should preferentially be segmented in the arterial phase.


Subject(s)
Carcinoma, Hepatocellular/blood supply , Carcinoma, Hepatocellular/diagnostic imaging , Cysts/diagnostic imaging , Hemangioma/blood supply , Hemangioma/diagnostic imaging , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Liver Abscess/diagnostic imaging , Liver Diseases/diagnostic imaging , Liver Neoplasms/blood supply , Liver Neoplasms/diagnostic imaging , Lymphoma/diagnostic imaging , Software , Spiral Cone-Beam Computed Tomography/methods , Tomography, Spiral Computed/methods , Adult , Aged , Aged, 80 and over , Blood Flow Velocity/physiology , Diagnosis, Differential , Female , Hepatic Artery/diagnostic imaging , Humans , Liver/diagnostic imaging , Liver Neoplasms/secondary , Male , Middle Aged , Neovascularization, Pathologic/diagnostic imaging , Portal Vein/diagnostic imaging , Retrospective Studies , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...