Diffusion-weighted MR imaging in comparison to integrated [¹8F]-FDG PET/CT for N-staging in patients with lung cancer.

PURPOSE: The purpose of this study was to prospectively determine the diagnostic accuracy of diffusion-weighted imaging (DWI) using MRI in the staging of thoracic lymph nodes in patients with lung cancer, and to compare the performance to that of PET/CT. PATIENTS AND METHOD: 20 consecutive patients (pts) with histologically proven lung cancer were included in this study. In all pts FDG-PET/CT was routinely performed to stage lung carcinoma. Additionally, MRI (1.5T) was performed including native T1w, T1w post contrast medium, T2w, and DWI sequences. Regarding the N stage based on the results of the PET/CT there were 5 patients with N0, 3 patients with N1, 5 patients with N2 and 7 patients with N3. Image analysis was performed by two radiologists (R1 and R2), respectively. The reviewers had to chose between 1 (at least one lymph node within a station is malignant) or 0 (no lymph nodes suspicious for malignancy). First the T1 post contrast sequence was analyzed. In a second step the DWI sequence (b=800) was analyzed. Both steps were performed in a blinded fashion. RESULTS: MR imaging with or without DWI only agreed with the results of the PET/CT regarding the N stage in 80% of the patients-15% were understaged and 5% overstaged. There was excellent interobserver agreement; the N-staging result only differed in 1 patient for DWI, resulting in correlation coefficients of 0.98 for DWI and 1.0 for MRI. Compared to PET-CT MRI overstaged one and understaged 4 patients, while DWI overstaged one and understaged 3 patients. This resulted in correlation coefficients of 0.814 (R1 and R2) for MRI and 0.815 (R1) and 0.804 (R2) for DWI. Regarding the ADC values there were no significant differences between ipsilateral hilar (1.03 mm(2)/s ± 0.13), subcarinal (0.96 mm(2)/s±0.24), ipsilateral mediastinal (1.0mm(2)/s ± 0.18), contralateral mediastinal (0.93 mm(2)/s ± 0.23) and supraclavicular (0.9 mm(2)/s ± 0.23) lymph nodes. CONCLUSION: Diffusion-weighted imaging does not show a clear advantage over conventional MR protocols in the N-staging of lung cancer. MRI with or without DWI shows a moderately correlation with PET/CT with a tendency for understaging.

Use of magnetic resonance imaging to detect neoplastic meningitis: limited use in leukemia and lymphoma but convincing results in solid tumors.

BACKGROUND: An early diagnosis of meningitis is important to improve patients' survival. Data about a direct comparison of cerebrospinal fluid cytology (CSF-cytology) and MRI are very limited. Therefore, the aim of this study was to compare these two diagnostic modalities in diagnosing meningitis in patients with hematopoietic and solid malignancies. METHODS: In 68 patients suspicious for neoplastic meningitis, cytology and MRI (1.5 T) was performed. The meningeal, pial or intraparenchymal hyperintense signal or contrast enhancement was correlated to the final CNS diagnosis and to cytology. RESULTS: 44 patients (64.7%) had neoplastic meningitis, 21 patients (30.9%) had non-neoplastic meningitis. The sensitivity to diagnose meningeal disease was 49.2% for MRI and 95.4% for cytology (p<0.001). In patients with neoplastic meningitis, sensitivity was 45.5% for MRI and 93.2% for cytology (p<0.001). In patients with infectious meningitis, sensitivity was 57.1% for MRI and 100% for cytology (p=0.0013). In patients with solid tumors, the sensitivity was 84.6% for both diagnostic methods. The sensitivity for MRI was low in patients with leukemia (20.0%) and lymphoma (37.5%). The positive predictive value (PPV) for MRI to differentiate infectious from neoplastic meningitis was high in patients with infectious meningitis (75.0%), in patients with lymphoma (83.3%), and in patients with solid tumors (72.7%). Ppv was low in patients with leukemia (33.3%). CONCLUSION: Diagnostic value of MRI for diagnosing meningitis is especially limited in patients with hematopoietic malignancies. MRI better detected leptomeningeal involvement caused by solid tumors than by leukemia or lymphoma. The ppv to specify neoplastic meningitis depends on tumor subtype.

Screening for liver metastases in women with mammary carcinoma: comparison of contrast-enhanced ultrasound and magnetic resonance imaging.

OBJECTIVE: The objective of the present study was to compare conventional B-mode ultrasound (BMU), contrast-enhanced ultrasound (CEUS), and magnetic resonance imaging (MRI) in the detection of liver metastases at the primary staging and follow-up of women with histologically confirmed mammary carcinoma. PATIENTS AND METHODS: Included in the study were 55 women (aged 57.5 ± 11.0 years, range 27-75 years; mean disease duration 57.5 months, range 5-168 months); of these, 17 women were examined as part of primary staging (staging group) and 38 women at follow-up (follow-up group). All patients underwent BMU (Philips HDI 5000), CEUS (Philips HDI 5000; 4.8 ml SonoVue), and MRI (Siemens Avanto 1.5 T) of the liver. RESULTS: In the staging group (n = 17), a mass was detected by BMU in 24% (n = 4), by CEUS in 29% (n = 5), and by MRI in 47% (n = 8); masses suspicious for malignancy were identified in 6% of patients with BMU and in 12% each by CEUS and MRI. Malignancy was not confirmed in any case by cytology or surgery. In the follow-up group (n = 38), masses were identified by MRI in 53% of patients with suspicion of malignancy in 18%. Malignancy was confirmed in 16% of cases identified at MRI, in 13% of cases identified with CEUS, and in 11% of cases identified with BMU. The Pearson coefficients of correlation were r = .29 (P = .03) for MRI vs. BMU; r = .42 (P = .002) for MRI vs. CEUS; and r = .75 (P ≤ .001) for BMU vs. CEUS. With respect to malignancy, the Pearson coefficients of correlation were r = .40 (P = .099) for BMU vs. MRI and r = .71 (P = .0009) for CEUS vs. MRI. CONCLUSIONS: Beginning in tumor stage III, the use of CEUS and MRI is associated with a significantly greater benefit in the detection of malignant tumors of the liver compared with conventional BMU. BMU appears to be adequate for primary staging and the follow-up of lower tumor stages.

The role of dynamic, contrast-enhanced MRI in differentiating lung tumor subtypes.

The aim was to correlate dynamic magnetic resonance imaging perfusion parameters of pulmonary tumors with histological tumor classification. Eighty-six patients with lung cancer were examined. A differentiation of non-small cell lung cancer vs. small cell lung cancer was possible with the parameters tumor necrosis, maximum contrast upslope, and the time until the maximum contrast upslope was reached. The beginning of a relevant contrast uptake, the mean time to peak and the time until the maximum contrast upslope was reached allowed a differentiation between squamous cell carcinoma and adenocarcinoma.

Variations of the aortic arch - a study on the most common branching patterns.

BACKGROUND: Anatomical variants of the aortic arch and its branching patterns often appear as an incidental finding during routine computed tomography (CT) scanning. These variations can be of relevance when performing angiography or endovascular interventions and may cause symptoms such as dysphagia. PURPOSE: To analyze common anatomical variations found within the arteries originating from the aortic arch in patients using contrast CT imaging techniques. MATERIAL AND METHODS: A total of 2033 contrast CT scans were analyzed. To obtain a truly representative sample, cases were chosen from different hospital departments without previous knowledge of the patient history. RESULTS: The total percentage of variations within the analyzed patients was 13.3%. In 8.0% a truncus bicaroticus was found. 4.2% of the patients showed a left vertebral artery originating directly from the aortic arch, mostly proximal, and in 1 case distal to the left subclavian artery. In 1.0% we found an aberrant right subclavian artery. We also found a single case of a right descending aortic arch. CONCLUSION: Variations of the aortic arch and its branching are frequently found, mostly as an incidental finding during routine diagnostic scanning. A contrast-enhanced CT scan is a good method with which to study the aortic arch and its associated branching pattern.

Cerebrospinal fluid pleocytosis: pitfalls and benefits of combined analysis using cytomorphology and flow cytometry.

BACKGROUND: Cerebrospinal fluid samples with doubtful morphologic interpretation are a common problem in the workup of patients with clinical signs for leptomeningeal disease. The authors report on the combination of morphology and flow cytometry in the diagnosis of leptomeningeal disease in patients with radiological, clinical, or cytological findings suspicious for leukemia or lymphoma with spread into the cerebrospinal fluid. METHODS: The authors defined a set of antibodies for flow cytometric analysis, which is capable of distinguishing between malignant and nonmalignant hematopoietic cells. One hundred twenty-seven cases were analyzed with both methods. RESULTS: The additional application of flow cytometry resulted in an improvement of diagnostic reliability in 29 of 127 cases. Diagnostic sensitivity was raised from 73% (cytology) to 96% (flow cytometry), specificity from 94% to 97%, the positive predictive value from 88% to 96%, and the negative predictive value from 76% to 97%. CONCLUSIONS: Because the appropriate selection of markers is crucial to successful analysis, the authors suggested a highly selected panel of antibodies for flow cytometry analysis of cerebrospinal fluid samples. The authors were able to demonstrate that leptomeningeal disease caused by leukemia or lymphoma can be diagnosed by flow cytometry and discriminated from reactive pleocytosis in most cases of doubtful morphology.

Cisterna chyli in patients with malignancy--influence of cardiovascular disease on the prevalence of the cisterna.

UNLABELLED: The purpose of this study was to investigate the potential correlation between the presence and size of the cisterna chyli (CC) on computed tomography (CT) and the presence of cardiovascular disease. MATERIALS AND METHODS: Out of a 3000-patient cohort 2599 patients who received a CT examination of the chest and/or abdomen with measurable inferior vena cava and azygos vein were included in this retrospective study. To assess the presence of cardiovascular disease the following parameters were recorded from the PACS or clinical information system: diameter of vena cava and azygos vein, presence of ascitis, serum creatinine, history of congestive heart failure, coronary artery disease or arterial hypertension and medication (diuretics, beta-blocker). In addition the volume of the CC and the presence or absence of malignant disease were recorded. Mean values (vessel diameters, creatinine) or percentages were calculated and compared for the groups with (n=416) and without (n=2183) a cisterna. Multivariate logistic regression analysis was performed for all parameters to identify the potential association with the presence and size of a cisterna. In addition the simultaneous influence of the parameter malignancy, cardiovascular disease and age on presence and size of the CC was analyzed in a logistic regression model. RESULTS: The presence or absence of a CC was not associated with any of the measured parameter. Regarding the size of the CC, there was a positive correlation with the diameter of the azygos vein, the presence of ascitis and diuretic medication. The influences of malignancy, elevated central venous pressure and age on the development of a CC proved to be highly significant but could not be separated or quantified. CONCLUSION: The volume of the cisterna chyli is influenced by pathologic states with an increased central venous pressure, while the presence or absence of the cisterna seems to be independent of those factors.

Clinical value of 18-fluorine-fluorodihydroxyphenylalanine positron emission tomography/computed tomography in the follow-up of medullary thyroid carcinoma.

BACKGROUND: 18-Fluorine-fluorodihydroxyphenylalanine positron emission tomography ((18)F-DOPA PET) is a sensitive method for detecting medullary thyroid carcinoma (MTC). The advent of PET/computed tomography (CT) has enabled more sensitive and specific lesion identification using various tracers in many other tumors. The aim of this study was therefore to test the hypothesis that combined (18)F-DOPA PET/CT more accurately detects MTC lesions than each modality does alone. METHODS: Twenty-eight consecutive (18)F-DOPA PET, CT, and (18)F-DOPA PET/CT scans of patients followed up for sporadic MTC or multiple endocrine neoplasia 2 syndrome-associated MTC were reviewed retrospectively in randomized sequence by two blinded readers, one a nuclear medicine physician and the other a radiologist, with extensive experience interpreting such images. RESULTS: Of 18 lesions detected concurrently by the three modalities, PET identified all as positive for MTC, but was unable to definitively localize 4 (22%) lesions. CT could definitively localize all 18 lesions, but could not definitively diagnose or exclude MTC in 6 (33%) lesions. Further, CT falsely identified as MTC-negative one lesion that was judged to be MTC-positive by both PET and PET/CT. Only PET/CT scans accurately characterized and localized all 18 lesions. On a per patient basis, the sensitivity of (18)F-DOPA PET/CT for MTC was 74% and the specificity, 100%. In the present series, no truly MTC-positive (18)F-DOPA PET/CT case was found in patients with basal human calcitonin (hCt) levels under 60 pg/mL, and conversely, no truly MTC-negative PET/CT case was found in patients with basal hCt over 120 pg/mL. Between hCt concentrations of 60 and 150 pg/mL true-negative, false-negative, and true-positive scans all were obtained. (18)F-DOPA PET/CT had 100% sensitivity and specificity when hCt at the time of scanning was over 150 pg/mL, the threshold at which the 2009 American Thyroid Association guidelines recommend performing additional imaging including (18)F-DOPA PET/CT. CONCLUSIONS: (18)F-DOPA PET/CT allows for a more accurate diagnosis and localization of MTC lesions than do (18)F-DOPA PET or CT alone. Supporting the recent American Thyroid Association recommendations on additional imaging in MTC, (18)F-DOPA PET/CT appears to have 100% sensitivity in patients with hCt over 150 pg/mL.

Assessment of COPD severity by computed tomography: correlation with lung functional testing.

CT scans of 474 patients with suspected chronic obstructive pulmonary disease (COPD) were retrospectively evaluated by automated software. There was a correlation between the total lung capacity (TLC) and the total lung volume (TLV) (r=.675, P<.001), between the TLC and the total emphysema volume (r=.571, P<.001), as well as between the TLC and the emphysema index (r=.532, P<.001), respectively. The correlation between the TLC and the TLV was dependent on the COPD severity according to the Global Initiative for Chronic Obstructive Lung Disease classification (chi(2)=6.3079, P=.043). The TLC allows a prediction of clinical illness severity.

Clinical value of 18F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography (18F-DOPA PET/CT) for detecting pheochromocytoma.

PURPOSE: In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor (18)F-fluorodihydroxyphenylalanine ((18)F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined (18)F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone. METHODS: (18)F-DOPA PET, CT and (18)F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology. RESULTS: Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of (18)F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value. CONCLUSION: (18)F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do (18)F-DOPA PET or CT alone.

Cisterna chyli in patients with malignancy--is there a correlation between changes in cisterna volume and progression or regression of the tumor?

UNLABELLED: The purpose of this study was to investigate the potential correlation between the size of the cisterna chyli (CC) and the tumor size in patients with malignancies on computed tomography (CT). MATERIALS AND METHODS: Out of a 3000 patient cohort 138 patients with histologically confirmed malignant disease, a detectable CC on CT and at least two CT scans within a 6 month period were included in this retrospective study. Out of 525 scans a total of 711 lesion intervals were evaluated. The volume of the CC and all target lesions (up to three per scan) were recorded. The Pearson correlation coefficient for the two parameters of changes in lesion size and CC size was calculated for the whole cohort and for a 33 patient subgroup that included only patients with tumors that showed the closest association with large CC in a previous study. RESULTS: The mean difference in lesion size for all 711 intervals was -1165µl. The mean difference in CC size for all 711 intervals was -46.6µl. The respective Pearson correlation coefficient was .05 with a non-significant p-value of .1823 (subgroup: r=.04, p=.6358). CONCLUSION: No significant correlation between the progression or regression of malignant disease and the size of the cisterna chyli could be found.

Integrated FDG-PET-CT: its role in the assessment of bone and soft tissue tumors.

PURPOSE: The purpose of this study was to evaluate prospectively, whether integrated 2-deoxy-2-[(18)F]fluoro-D: -glucose positron emission tomography-computed tomography (FDG-PET-CT) is more accurate for determination musculoskeletal tumors compared with separate interpretation of CT and FDG-PET, because most of the current clinical data come from patients studied with PET. METHODS: Eighty patients with newly diagnosed musculoskeletal tumors underwent FDG-PET-CT. CT, FDG-PET, and FDG-PET-CT were interpreted separately to determine the performance of each imaging modality. RESULTS: Assuming that equivocal lesions are benign, performance of diagnostic tests was as follows: sensitivity, specificity and accuracy for CT alone was 81, 84, 83%, for PET 71, 82, 76, and for PET-CT 80, 83 and 86%. Assuming that equivocal lesions are malignant, sensitivity, specificity, and accuracy for CT was 61, 100, 70%, for PET 69, 100, 79, and for PET-CT 69, 100 and 79%. CONCLUSIONS: Combined FDG-PET-CT reliably differentiates soft tissue and bone tumors from benign lesions. The value of the information provided by FDG-PET-CT for planning surgical procedures must be evaluated in further studies.

Lymphangioleiomyomatosis: solitary abdominal manifestation (2009: 9b).

Lymphangioleiomyomatosis (LAM) is a rare disease that usually affects premenopausal woman and is characterized by cystic lung lesions and lymphatic disorders. We report a case of a 23-year-old woman who presented with diffuse, but increasing abdominal pain. Transabdominal ultrasound showed multiple cystic formations. Due to the patient's uncharacteristic symptoms, an exploratory laparotomy with tissue sampling was performed, and the diagnosis of LAM was confirmed by two independent pathologists. With computed tomography a broad abdominal, but no pulmonary, manifestation could be established. During sirolimus therapy the patient showed clinical benefit, but only slight progress in computed tomography.

Pitfalls in abdominal diffusion-weighted imaging: how predictive is restricted water diffusion for malignancy.

OBJECTIVE: As diffusion-weighted imaging is increasingly implemented into routine protocols of abdominal MRI, abnormal findings in expected and unexpected locations become more common. The aim of our retrospective study was to investigate the specificity of restricted diffusion in differentiation of benign from malignant abdominal disease. MATERIALS AND METHODS: Two hundred thirty consecutively registered patients underwent abdominal MRI including diffusion-weighted imaging (single-shot spin-echo echo-planar sequence) with b values of 0, 150, 500, and 1,000 s/mm(2). Lesions were detected by two blinded readers using only the images with a b value of 1,000 s/mm(2), and representative apparent diffusion coefficients were measured. Lymph nodes were not documented. RESULTS: Fifty-two of the 230 patients had a total of 55 lesions with restricted diffusion (23.9%). The mean apparent diffusion coefficient was 809 mm(2)/s. Forty-three lesions (78.2%) were malignant. The 12 benign lesions were liver hemangioma, liver adenoma, autoimmune pancreatitis, pancreatic teratoma, two abscesses, three cases of inflammatory bowel wall thickening due to Crohn's disease, Bartholin cyst, hemorrhagic ovarian cyst, and renal Rosai-Dorfman disease. CONCLUSION: Restricted diffusion is generally considered to be associated with malignant tumors because of the high cellularity of these tumors. However, in interpretation of diffusion-weighted images, it should be kept in mind that a number of benign lesions, as many as 22% in our cohort, can exhibit restricted diffusion on images with high b values, thus mimicking malignant lesions.

Challenging complications of treatment--human herpes virus 6 encephalitis and pneumonitis in a patient undergoing autologous stem cell transplantation for relapsed Hodgkin's disease: a case report.

BACKGROUND: Reactivation of human herpesvirus 6 (HHV-6) occurs frequently in patients after allogeneic stem cell transplantation and is associated with bone-marrow suppression, enteritis, pneumonitis, pericarditis and also encephalitis. After autologous stem cell transplantation or intensive polychemotherapy HHV-6 reactivation is rarely reported. CASE REPORT: This case demonstrates a severe symptomatic HHV-6 infection with encephalitis and pneumonitis after autologous stem cell transplantation of a patient with relapsed Hodgkin's disease. CONCLUSION: Careful diagnostic work up in patients with severe complications after autologous stem cell transplantation is mandatory to identify uncommon infections.

Detection of bone metastases in patients with lung cancer: 99mTc-MDP planar bone scintigraphy, 18F-fluoride PET or 18F-FDG PET/CT.

PURPOSE: The aim of the study was to compare the diagnostic accuracy of (18)F-fluorodeoxyglucose (FDG) PET/CT versus standard planar bone scintigraphy (BS) and (18)F-labelled NaF ((18)F) PET for the detection of bone metastases (BM) in non-small cell lung cancer (NSCLC). METHODS: (18)F-FDG PET/CT was performed in 126 patients with NSCLC. Within 7 days BS (n = 58) or (18)F PET (n = 68) was performed. (18)F-FDG PET/CT, BS and (18)F PET were evaluated by two experienced readers. Lesions were graded on a scale from 1 (definite BM) to 5 (degenerative lesion), and equivocal lesions were determined as indifferent (grade 3). RESULTS: A total of 92 patients showed degenerative lesions (grade 4/5) on PET/CT, BS or (18)F PET. In 34 patients (27%) BM lesions were diagnosed (grades 1 and 2). In 13 of 18 patients BM were concordantly diagnosed with PET/CT and (18)F PET. PET/CT showed more BM compared to (18)F PET (53 vs 40). In one patient one osteolytic BM was false-negative on (18)F PET. However, (18)F PET identified four patients with BM compared to negative findings on PET/CT. Of 16 patients, 11 had concordant findings of BM on PET/CT and BS. In three patients BS was false-negative and in two patients BM were diagnosed as indifferent. CONCLUSION: Integrated (18)F-FDG PET/CT is superior to BS in the detection of osteolytic BM in NSCLC. Thus, PET/CT may obviate the need to perform additional BS or (18)F PET in the staging of NSCLC, which significantly reduces costs.

Influence of the turbinate volumes as measured by magnetic resonance imaging on nasal air conditioning.

BACKGROUND: Changes in nasal airflow caused by varying intranasal volumes and cross-sectional areas affect the contact between air and surrounding mucosa entailing alterations in nasal air conditioning. This study evaluates the correlation between nasal air conditioning and the volumes of the inferior and middle turbinates as measured by magnetic resonance imaging (MRI). METHODS: Fourteen healthy volunteers were enrolled. Each volunteer had been examined by rhinomanometry, acoustic rhinometry, intranasal air temperature, and humidity measurements at defined intranasal sites as well as MRI of the nasal cavity and the paranasal sinuses. The volumetric data of the turbinates was based on the volumetric software Amira. RESULTS: Comparable results were obtained regarding absolute humidity values and temperature values within the nasal valve area and middle turbinate area for both the right and the left side of the nasal cavity. No statistically significant differences were found in the rhinomanometric values and the acoustic rhinometry results of both sides (p > 0.05). No statistical correlations were found between the volumes of the inferior (mean, 6.1 cm3) and middle turbinate (mean, 1.8 cm3) and the corresponding humidity and temperature values. Additionally, the air temperature and humidity values did not correlate with the rhinometrical endonasal volumes (0-20 mm and 20-50 mm from the nasal entrance). CONCLUSION: The normal range of volumes of the inferior and middle turbinate does not seem to have a significant impact on intranasal air conditioning in healthy subjects. The exact limits where alterations of the turbinate volume negatively affect nasal air conditioning are still unknown.

Liver perfusion with dynamic multidetector-row computed tomography as an objective method to evaluate the efficacy of chemotherapy in patients with colorectal cancer.

A total of 24 liver metastases of colorectal cancer were evaluated by dynamic multiphasic CT. Under chemotherapy, follow-up examinations were performed every 3 months. The tumor marker CEA before vs. after chemotherapy correlated with the mean contrast enhancement within the margin of metastases. The total size of metastases correlated with the size of central necrosis as well as with the size of marginal contrast enhancement. CT is able to quantify perfusion and local activity of liver metastases to determine the efficacy of chemotherapy.

The cisterna chyli: prevalence, characteristics and predisposing factors.

The purpose of this study was to determine the prevalence and characteristics of the cisterna chyli (CC) in a large 3,000-patient cohort and to identify potential predisposing factors for the development of a CC. Three thousand consecutive contrast-enhanced CT examinations (1,261 women, 1,739 men, mean age 61.0 years) of the chest and/or abdomen were included in this retrospective study. Imaging characteristics of the CC (size, attenuation, location) were documented as well as clinical information (malignant disease, pattern of metastasis). A CC was found in 16.1% of the patients with an average volume of 302 microl. The mean attenuation was 4.8 Hounsfield units (HU). Twenty percent of the CC showed CT densities of 15 HU and higher. Patients with malignancies showed a significantly (p < 0.001) higher prevalence of CC (340/1,757, 19.4%) than patients with benign conditions (144/1,243, 11.6%). Especially the finding of a large CC (>1,000 microl) represents an elevated relative risk for malignancy of 1.7 (p = 0.0017). We found a significant association between malignant disease and the presence and size of a cisterna chyli. Identifying the continuity between the CC and the thoracic duct is a safer method to distinguish a CC from retrocrural lymph nodes than near-water CT attenuation alone.

Assessment of pneumonia severity: multidetector-row CT in comparison to clinical score CRB-65.

This study involved 92 patients with clinically diagnosed pneumonia. Differences in the frequency of typical pattern were calculated for patients with mild pneumonia and for patients with severe pneumonia (confusion, respiratory rate, blood pressure, 65 years of age and older). The frequency of singular morphologic changes did not differ significantly between the two groups. Empyema and pleural effusion, as well as an atelectasis in combination with patchy infiltrates and a positive bronchogram/multisegmental infiltrates, seem to have an influence on severity of pneumonia.