A functional MRI study of language networks in left medial temporal lobe epilepsy

Purpose

The purpose of this study was to investigate the abnormality of language networks in left medial temporal lobe epilepsy (MTLE) using fMRI.

Materials and methods

Eight patients with left MTLE and 15 healthy subjects were evaluated. An auditory semantic judgment (AJ) paradigm was used. The fMRI data were collected on a 3T MR system and analyzed by AFNI (analysis of functional neuroimages) to generate the activation map.

Results

Behavioral data showed that the reaction time of the left MTLE patients was significantly longer than that of controls on the AJ task (t = −3.396, P < 0.05). The left MTLE patients also exhibited diffusively decreased activation in the AJ task. Right hemisphere dominance of Broca's and Wernicke's areas was demonstrated in left MTLE patients.

Conclusions

Long-term activation of spikes in left MTLE patients results in language impairment, which is associated with an abnormality of the brain neural network.     

Parenchymal lymphoma of the brain on initial MR imaging: A comparative study between primary and secondary brain lymphoma

Background and purpose

Parenchymal lymphomatous brain masses have not been investigated considering if they are primary or as a part of systemic lymphoma (secondary) on imaging studies previously. We aimed to determine characteristics of the secondary parenchymal lymphomatous involvement of the brain and to find if there is any radiologic feature to help discrimination of untreated primary and secondary central nervous system lymphoma on patients’ initial magnetic resonance imaging.

Materials and methods

We evaluated MR images of 18 patients with the diagnosis of primary (n = 12) and secondary central nervous system lymphoma (n = 6). We considered the number, localization, enhancement pattern, signal characteristics, diffusion properties, presence of hemorrhage and presence of butterfly pattern on MR imaging at initial presentation.

Results

Secondary central nervous system lymphomas predominantly presented as multiple (n = 4, 66.7%) lesions. Homogenous nodular enhancement and supratentorial white matter involvement were present in all patients with butterfly pattern and infiltrative/perivenular enhancement in half (n = 3) of the patients. Deep gray matter (n = 1, 16.7%) and infratentorial involvement (n = 1, 16.7%) were scarce and no ring enhancement was observed. There was no statistically significant difference in any of the investigated MR features between the two groups.

Conclusion

Statistical analyses revealed no significant distinctive radiologic characteristics between primary and secondary lymphoma of the brain parenchyma.     

Iron deposition in the precentral grey matter in patients with multiple sclerosis: A quantitative study using susceptibility-weighted imaging

Purpose

Several studies suggest that iron deposition may play a role in multiple sclerosis (MS) pathology. Three-dimensional (3D) enhanced T2*-weighted angiography (ESWAN) at 3T was used to quantify iron deposition in the precentral grey matter in MS and its relationship with disease duration, atrophy and Expanded Disability Status Scale (EDSS) scores.

Methods

We recruited 33 patients with diagnosis of clinically definite MS and 31 age- and sex-matched healthy controls who underwent conventional brain MRI, 3D-ESWAN and 3D T1sequences. We obtained the mean phase values (MPVs) of the precentral grey matter on ESWAN-filtered phase images and volume of the precentral gyrus on 3D T1 images. We investigated the correlation between precentral grey matter MPVs, precentral gyrus volume, disease duration and EDSS scores of MS patients and healthy controls.

Results

The precentral grey matter MPVs in MS patients and controls were 1870.83 ± 56.61 and 1899.22 ± 51.73 respectively and had significant difference in the MS group vs. the control group (t = −2.09, P = 0.04). There was significant negative correlation between precentral grey matter MPVs and disease duration (r = −0.365, P = 0.03). No correlation was found between MPVs and EDSS scores. Mean precentral gyrus volume in MS patients was 4368.55 ± 867.78 whereas in controls was 5701.00 ± 1184.03 with significant difference between volume of the precentral gyrus in MS patients compared to healthy controls (t = −5.167, P < 0.001). There was a positive correlation between MPVs and precentral gyrus volume (r = 0.291, P = 0.020).

Conclusions

Our study demonstrated that quantitative assessment of abnormal iron deposition in the precentral grey matter in MS patients can be measured using 3D-ESWAN.     

Abdominal aspergillosis: CT findings

Objective

In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients.

Materials and methods

CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome.

Results

All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum.

Conclusion

Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.     

Previous imaging findings of breast cancers that occurred in combined screening negatives

Purpose

To retrospectively evaluate previous imaging findings of breast cancers that occurred in women whose combined screening using both mammography and ultrasonography was negative.

Materials and methods

A search of the institutional database identified 65 patients with breast cancers who had comparable previous negative screening mammography and ultrasonography (BI-RADS category 1 or 2) within 2 years. We classified each case as true or false negative. The previous imaging findings and the final outcome were analyzed.

Results

Among 65 cases, 42 (65%) were true negatives, 23 (35%) were false negatives. The abnormalities of false negatives were underestimated in 16 (70%) and unrecognized in 7 (30%). The findings were calcifications (n = 8) or a mass (n = 6) on mammography, a mass (n = 5) or a non-mass (n = 3) on ultrasonography and a density on mammography correlated with non-mass on ultrasonography (n = 1). Ductal carcinoma in situ among false and true negatives accounted for 5 (22%) and 7 (17%), respectively. Symptomatic cancers among false and true negatives were 6 (26%) and 13 (31%), respectively.

Conclusion

Breast cancers that rarely occurred in combined screening negatives are often retrospectively seen as minimal abnormalities on previous imaging studies.     

T2-enhanced tensor diffusion trace-weighted image in the detection of hyper-acute cerebral infarction: Comparison with isotropic diffusion-weighted image

Background and purpose

Although isotropic diffusion-weighted imaging (isoDWI) is very sensitive to the detection of acute ischemic stroke, it may occasionally show diffusion negative result in hyper-acute stroke. We hypothesize that high diffusion contrast diffusion trace-weighted image with enhanced T2 may improve stroke lesion conspicuity.

Methods

Five hyper acute stroke patients (M:F = 0:5, average age = 61.8 ± 20.5 y/o) and 16 acute stroke patients (M:F = 11:5, average age = 67.7 ± 12 y/o) were examined six-direction tensor DWIs at b = 707 s/mm². Three different diffusion-weighted images, including isotropic (isoDWI), diffusion trace-weighted image (trDWI) and T2-enhanced diffusion trace-weighted image (T2E_trDWI), were generated. Normalized lesion-to-normal ratio (nLNR) and contrast-to-noise ratio (CNR) of three diffusion images were calculated from each patient and statistically compared.

Results

The trDWI shows better nLNR than isoDWI on both hyper-acute and acute stroke lesions, whereas no significant improvement in CNR. Nevertheless, the T2E_trDWI has statistically superior CNR and nLNR than those of isoDWI and trDWI in both hyper-acute and acute stroke.

Conclusions

We concluded that tensor diffusion trace-weighted image with T2 enhancement is more sensitive to stroke lesion detection, and can provide higher lesion conspicuity than the conventional isotropic DWI for early stroke lesion delineation without the need of high-b-value technique.     

A qualitative approach to combined magnetic resonance imaging and spectroscopy in the diagnosis of prostate cancer

Purpose

To investigate the feasibility and diagnostic value of a whole prostate qualitative approach to combined magnetic resonance imaging and spectroscopy (MRI + MRS) in the detection of prostate cancer in patients with elevated PSA.

Materials and methods

Three hundred and fifty six subjects (mean serum PSA 11.47 ng/ml, range 0.40-133 ng/ml) were examined with fast-T2-weighted images (MRI) and 3D-magnetic resonance spectroscopy (MRS). Both modalities were qualitatively analyzed on a whole prostate basis by a single radiologist using a 4-point diagnostic scale. Prostate cancer was histopathologically proven in 220 patients and non-evidence of cancer was determined after at least 12 months clinical follow-up in 136 subjects.

Results

Receiver operating curve analysis revealed a significantly better diagnostic performance of MRI + MRS (A_z = 0.857) than MRI alone (A_z = 0.801) and MRS alone (A_z = 0.810). The sensitivity, specificity and accuracy of MRI + MRS for detection of prostate cancer were 72.3%, 92.6%, and 80.1%, respectively.

Conclusions

Spectral evaluation with a whole prostate qualitative approach is feasible in routine clinical practice. The combination of MRI and MRS yields superior diagnostic results than either modality alone.     

Evaluation of anterior knee laxity on MRI

Purpose

Evaluation of the ACL and anterior knee laxity on MR during anterior tibial translation.

Patients and methods

Three groups were identified based on clinical and arthrometric (KT-1000) data: normal ACL (n = 12), complete tear (n = 10) and partial tear (n = 20). MRI was performed without and with anterior tibial translation (pneumatic device) with morphological and laximetric analysis: drawer tests and dynamic evaluation of ligamentous tension.

Results

Intra- and inter-observer reproducibility was excellent, correlated to arthrometric data and clinical tests (Lachman, pivot shift). The difference between the drawer signs of normal subjects and patients with ACL tear was significant for a threshold value of 1,1 mm for the anterior drawer (sensitivity: 93,33%, specificity: 91,7%) and 2,8 mm for the posterior drawer (sensitivity: 86,7%, specificity: 100%). Dynamic evaluation of ligamentous tension was also reproducible, statistically correlated to the MR drawer tests and reliable for the diagnosis of ACL lesions. In this preliminary study, the distinction between complete and partial ACL tears could not be detected.

Conclusion

Anterior cruciate ligament function can be demonstrated on MR. The predictive value of this morphological and functional association should be determined in the management of patients with partial tears.     

Tumorsize dependent detection rate of endorectal MRI of prostate cancer—A histopathologic correlation with whole-mount sections in 70 patients with prostate cancer

Purpose

To evaluate the value of T2w endorectal MRI (eMRI) for correct detection of tumor foci within the prostate regarding tumor size.

Materials and Methods

70 patients with histologically proven prostate cancer were examined with T2w eMRI before radical prostatectomy at a 1.5 T scanner. For evaluation of eMRI, two radiologists evaluated each tumor focus within the gland. After radical prostatectomy, the prostates were prepared as whole-mount sections, according to transversal T2w eMRI. For each slice, tumor surroundings were marked and compared with eMRI. Based on whole-mount section, 315 slices were evaluated and 533 tumor lesions were documented.

Results

Based on the T2w eMRI, 213 tumor lesions were described. In 137/213, histology could prove these lesions. EMRI was able to visualize 0/56 lesions with a maximum size of <0.3 cm (detection rate 0%), between 0.3 and 0.5 cm 4/116 (3%), between 1 and 0.5 cm 22/169 (13%), between 2 and 1 cm 61/136 (45%) and for >2 cm 50/56 (89%). False positive eMRI findings were: <0.3 cm n = 0, 0.5-0.3 cm n = 12, 0.5-1 cm n = 34, 1-2 cm n = 28 and >2 cm n = 2.

Conclusion

T2w eMRI cannot exclude prostate cancer with lesions smaller 10 mm and 0.4 cm³ respectively. The detection rate for lesions more than 20 mm (1.6 cm³) is to be considered as high.     

Diagnosis and quantification of hepatic fibrosis in children with diffusion weighted MR imaging

Purpose

To evaluate the accuracy of diffusion weighted MR imaging in diagnosis and quantification of hepatic fibrosis in children with chronic hepatitis.

Materials and methods

Sixty-three consecutive children (40 boys, 23 girls, median age 9.3 years), with chronic hepatitis and thirty age matched volunteers underwent diffusion weighted MR imaging of the liver using a single shot echoplanar imaging with b-value = 0, 250, and 500 s/mm². Liver biopsy was obtained with calculation of METAVIR score. The ADC value of the liver was correlated with METAVIR score. Receiver operating characteristic curve was done for diagnosis and grading of hepatic fibrosis.

Results

There was statistical difference in the mean ADC value between volunteers and patients with hepatic fibrosis (P = 0.001) and in patients with different grades of METAVIR scores (P = 0.002). There was correlation between the mean ADC value and METAVIR score (r = 0.807, P = 0.001). The cut off point to predict fibrosis (1.7 × 10⁻³ mm²/s) revealed 83% accuracy, 85% sensitivity, 82% specificity, 83% PPV, and 85% NPV. The area under the curve was 0.91 for F1, 0.85 for F2, 0.86 for F3 and 0.90 for F4.

Conclusion

The apparent diffusion coefficient value is a promising quantitative parameter used for diagnosis and quantification of hepatic fibrosis in children with chronic hepatitis.     

US-guided interventional joint procedures in patients with rheumatic diseases—When and how we do it?

Objective

To describe the main indications and the technical steps to perform ultrasound guided procedures in patients with rheumatic diseases. To access procedures accuracy, safety and effectiveness.

Materials and methods

27 patients with pain related to articular complications of rheumatic diseases and according to previous radiographic or US exam were submitted to several US-guided procedures. 42% of patients (n = 11) had rheumatoid arthritis, 11% (n = 3) spondyloarthropathies, 18% (n = 5) psoriatic arthritis, 15% (n = 4) undifferentiated arthritis, 3% (n = 1) Sjögren syndrome and 11% (n = 3) had gout.Described procedures are synovial biopsies, intra-articular injections of corticosteroids, radiation synovectomy and synovial cysts drainage procedures. When a therapeutical procedure was made, patients were evaluated by 2 rheumatologists.Corticosteroids used were Prednisolone and Triamcinolone. Yttrium-90 was used for synovectomy.

Results

In all cases success was achieved with correct needle placement inside the joint. After injection/aspiration symptoms successfully solved with all patients improving their health status. No complications were recorded during follow-up period.

Conclusions

US-guidance is very reliable to afford a safety procedure always checking the injection, biopsy or aspiration. Guided-biopsy has high success rates obtaining several samples. Thus is also possible to use more powerful/long acting therapeutic drugs aggressive to extra-articular structures avoiding complications.     

Quantitative diffusion tensor deterministic and probabilistic fiber tractography in relapsing-remitting multiple sclerosis

Purpose

Our aim was to study the quantitative fiber tractography variations and patterns in patients with relapsing-remitting multiple sclerosis (RRMS) and to assess the correlation between quantitative fiber tractography and Expanded Disability Status Scale (EDSS).

Material and methods

Twenty-eight patients with RRMS and 28 age-matched healthy volunteers underwent a diffusion tensor MR imaging study. Quantitative deterministic and probabilistic fiber tractography were generated in all subjects. And mean numbers of tracked lines and fiber density were counted. Paired-samples t tests were used to compare tracked lines and fiber density in RRMS patients with those in controls. Bivariate linear regression model was used to determine the relationship between quantitative fiber tractography and EDSS in RRMS.

Results

Both deterministic and probabilistic tractography's tracked lines and fiber density in RRMS patients were less than those in controls (P < .001). Both deterministic and probabilistic tractography's tracked lines and fiber density were found negative correlations with EDSS in RRMS (P < .001). The fiber tract disruptions and reductions in RRMS were directly visualized on fiber tractography.

Conclusion

Changes of white matter tracts can be detected by quantitative diffusion tensor fiber tractography, and correlate with clinical impairment in RRMS.     

Susceptibility-weighted imaging in grading brain astrocytomas

Objective

To evaluate the value of intratumoral vessels and micro-hemorrhage shown in susceptibility weighted imaging (SWI) for grading brain astrocytomas and to analyze the difference between SWI and conventional imaging techniques.

Methods

22 patients with astrocytomas were diagnosed with surgical specimens, 9 of which were grades I-II, and 13 were grades III-IV. All examinations were performed on Signa DEx 3.0 T MRI scanner. Conventional imaging techniques (T1WI, T2WI, T2FLAIR, CE-T1WI) and SWI sequence were used. The parameters of SWI sequence were the following: TR = 35 ms, TE = 20 ms, FA = 15°, slice thickness = 2 mm. The small vessels and blood products of the tumors in SW images were analyzed. The differences between the two groups in SW images were analyzed statistically.

Results

The findings in SW images of brain astrocytomas were correlated strongly with pathology. SWI was more sensitive compared to conventional imaging techniques for showing small vessels and micro-hemorrhage in brain astrocytomas. Statistical comparison showed that the small vessels and micro-hemorrhage of two groups of brain astrocytomas in SW images differed significantly.

Conclusion

SWI is superior to conventional imaging techniques at showing the small vessels and micro-hemorrhage in brain astrocytomas, which plays an important role in the tumor grading.     

Effect of different saline chaser volumes and flow rates on intravascular contrast enhancement in CT using a circulation phantom

Purpose

To evaluate the influence of different saline chaser volumes and different saline chaser flow rates on the intravascular contrast enhancement in MDCT.

Materials and methods

In a physiological flow phantom contrast medium (120 ml, 300 mgI/ml, Ultravist 300) was administered at a flow rate of 6 ml/s followed by different saline chaser volumes (0, 30, 60 and 90 ml) at the same injection rate or followed by a 30-ml saline chaser at different injection rates (2, 4, 6 and 8 ml/s). Serial CT-scans at a level covering the pulmonary artery, the ascending and the descending aorta replica were obtained. Time-enhancement curves were computed and both pulmonary and aortic peak enhancement and peak time were determined.

Results

Compared to contrast medium injection without a saline chaser the pushing with a saline chaser (30, 60, and 90 ml) resulted in a statistically significant increased pulmonary peak enhancement (all p = 0.008) and prolonged peak time (p = 0.032, p = 0.024 and p = 0.008, respectively). Highest aortic peak enhancement values were detected for a saline chaser volume of 30 ml. A saline chaser flow rate of 8 ml/s resulted in the highest pulmonary peak enhancement values compared to flow rates of 2, 4 and 6 ml/s (all p = 0.008). Aortic peak enhancement showed the highest values for a flow rate of 6 ml/s.

Conclusion

A saline chaser volume of 30 ml and an injection rate of 6 ml/s are sufficient to best improve vascular contrast enhancement in the pulmonary artery and the aorta in MDCT.     

Correlation between high-resolution computed tomography and galactomannan antigenemia in adult hematologic patients at risk for invasive aspergillosis

Objectives

To analyse the predominant radiological pattern of pulmonary lesions in adult hematologic patients at risk for invasive aspergillosis (IA) together with the results of serial serum Aspergillus galactomannan antigen testing (GM).

Material and methods

In a prospective study for patients at high risk of aspergillus pulmonary infection, serum GM were performed 2-3 times per week during the periods of high risk for IA and high-resolution CT (HRCT) was performed in case of abnormal chest X-ray (CXR) and/or persistent fever after 5 days of antibiotic treatment. Changes on HRCT scan were classified as airway IA and angioinvasive IA. IA was classified as proven or probable in accordance with the definitions stated by the European Organization for Research and Treatment of Cancer/Mycosis Study Group (EORTC-MS). Positive GM testing was not considered as microbiological criterion.

Results

38 hematological patients were diagnosed of probable (n = 28) or proven (n = 10) IA. 55% patients had a neutrophil count less than 500 mm⁻³ (n = 21), and 37% patients ≥2 risk factors for IA. All probable IA were diagnosed by bronchoalveolar lavage (BAL). Proven IA was reached by positive histopathologic and culture results of samples obtained by autopsy (n = 4), percutaneous (n = 3) or transbronchial biopsy (n = 3). 18 patients had airway IA, and 60% had a GM level ≥1.5. 20 patients were diagnosed of angioinvasive IA from which 80% had a GM level ≥1.5.

Conclusion

Serum GM levels may be lower in patients with airway IA than in those with an angioinvasive form. HRCT and serum GM are complementary tests in the diagnosis of IA.     

CT characteristics of resolving ground-glass opacities in a lung cancer screening programme

Purpose

This study aimed at evaluating the computed tomography (CT) characteristics of resolving localized ground-glass opacities (GGOs) in a screening programme for lung cancer.

Material and methods

280 patients at high-risk for lung cancer (221 men, 59 women; mean age, 58.6 years), divided into four groups (lung cancer history (n = 83), head and neck cancer history (n = 63), symptomatic (n = 88) and asymptomatic (n = 46) cigarette smokers), were included in a prospective trial with annual low-dose CT for lung cancer screening. We retrospectively reviewed all localized GGOs, analyzed the CT characteristics on initial CT scans and changes during follow-up (median 29.1 months). Variables associated with resolution of GGOs were tested using chi-square or Mann-Whitney tests.

Results

A total of 75 GGOs were detected in 37 patients; 54.7% were present at baseline and 45.3% appeared on annual CT. During follow-up, 56.2% persisted and 43.8% disappeared. The resolving localized GGOs were significantly more often lobular GGOs (p = 0.006), polygonal in shape (p = 0.02), mixed (p = 0.003) and larger (p < 0.0001) than non-resolving localized GGOs.

Conclusion

Localized GGOs are frequent and many disappeared on follow-up. CT characteristics of resolving GGOs show significant differences compared to persistent ones. This study emphasizes the importance of short-term CT follow-up in subjects with localized GGOs.     

The additional value of three time point color coding in dynamic contrast-enhanced MRI of the breast for inexperienced and experienced readers

Purpose

To evaluate the additional value of the color coding of dynamic data using the 3TP method in the evaluation of contrast-enhanced breast MRI for readers with different levels of experience.

Materials and methods

A total of 52 lesions were included in this study, 25 malignant and 27 benign. All lesions were evaluated by four readers on two different workstations for the evaluation of dynamic breast MRI; one displaying the subtracted images and relative enhancement versus time curves and one displaying the subtracted images together with the 3TP color coding projected onto pre-contrast T1 images. Readers with different levels of experience were used. The diagnostic performance of both workstations was evaluated using ROC curve analyses. Interobserver variations were evaluated using kappa statistics.

Results

All lesions were detected by all four readers on both workstations. The diagnostic performance found in the inexperienced readers improved significantly when using the 3TP evaluations (p = 0.04 and p = 0.03). No significant difference was found for the more experienced readers (p = 0.94 and p = 0.54). The level of agreement between the readers improved significantly when using the 3TP evaluation method (p = 0.01).

Conclusion

Even though the 3TP color coding did not improve the diagnostic performance of the more experienced readers, this study clearly shows its value for inexperienced readers. The use of 3TP color coding is therefore recommended for inexperienced readers.     

Perfusion maps of the whole liver based on high temporal and spatial resolution contrast-enhanced MRI (4D THRIVE): Feasibility and initial results in focal liver lesions

Purpose

To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated.

Materials and methods

Fifteen patients suspected for colorectal liver metastases (LMs) were included. Parametric maps were evaluated qualitatively (ring-enhancement and lesion heterogeneity) and compared to three-phased contrast-enhanced MRI. Quantitative analysis was based on average perfusion values of entire FLLs. Reference standard comprised surgery with histopathology or follow-up imaging. Fisher's exact test was used for qualitative and Kruskal-Wallis test for quantitative analysis.

Results

In total 29 LMs, 17 hemangiomas and 4 focal nodular hyperplasias were evaluated. FLLs could be differentiated by qualitative assessment of parametric maps respectively three-phased contrast-enhanced MRI (Fisher's p < 0.001 for comparisons between LMs and hemangiomas and LMs and FNHs for both ring-enhancement and lesion heterogeneity) rather than by quantitative analysis of parametric maps (Chi-square for Kep = 0.33 (p = 0.847) and Chi-square for Kel = 1.35 (p = 0.509)).

Conclusion

This preliminary study shows potential of 4D THRIVE for whole liver imaging enabling calculation of parametric maps. Qualitative rather than quantitative analysis was accurate for differentiating malignant and benign FLLs.     

Evaluation of liver hemangiomas using three different b values on diffusion MR

Purpose

To determine which diffusion-weighted MR technique (i.e., b-100, b-600, b-1000 s/mm²) is most useful in depicting liver hemangiomas. We also aimed to assess the effect of lesion size on apparent diffusion coefficient (ADC) values.

Materials and methods

Diffusion-weighed MR (DWMR) was performed for 61 hemangiomas in 32 patients. DWMR images were obtained before contrast administration using three different b values of 100, 600, and 1000 s/mm². ADCs were measured for each lesions and compared with normal liver parenchymal ADCs on different b values. Hemangiomas were subdivided according to lesion size (less than 3 cm and 3 cm or greater). Data were analyzed using SPSS software by analysis of variances (ANOVA) and post hoc values were tested using HSD Tukey test.

Results

There was no significant relation between lesion size and ADC values on different b values. Lower ADC values were obtained for higher b values in normal liver tissue and hemangiomas. Although there is significant difference between normal liver tissue and hemangiomas; this is more apparent on b-1000 images (p = 0.022 on b-100, p = 0.003 on b-600, and p = 0.000 on b-1000 images). Variance analysis revealed hemangiomas had higher ADC values than normal liver tissue on b-1000 images.

Conclusion

Mean values for ADCs of hemangiomas were lower than ADCs of the normal liver except for b-1000 value. Higher b values are useful for the differentiation between normal liver tissue and hemangiomas. Lesion size does not affect ADC measurement on different b values.     

Renal cortical volume measured using automatic contouring software for computed tomography and its relationship with BMI, age and renal function

Purpose

To evaluate the relationship between renal cortical volume, measured by an automatic contouring software, with body mass index (BMI), age and renal function.

Materials and methods

The study was performed in accordance to the institutional guidelines at our hospital. Sixty-four patients (34 men, 30 women), aged 19 to 79 years had their CT scans for diagnosis or follow-up of hepatocellular carcinoma retrospectively examined by a computer workstation using a software that automatically contours the renal cortex and the renal parenchyma. Body mass index and estimated glomerular filtration rate (eGFR) were calculated based on data collected. Statistical analysis was done using the Student t-test, multiple regression analysis, and intraclass correlation coefficient (ICC).

Results

The ICC for total renal and renal cortical volumes were 0.98 and 0.99, respectively. Renal volume measurements yielded a mean cortical volume of 105.8 cm³ ± 28.4 SD, mean total volume of 153 cm³ ± 39 SD and mean medullary volume of 47.8 cm³ ± 19.5 SD. The correlation between body weight/height/BMI and both total renal and cortical volumes presented r = 0.6, 0.6 and 0.4, respectively, p < 0.05, while the correlation between renal cortex and age was r = −0.3, p < 0.05. eGFR showed correlation with renal cortical volume r = 0.6, p < 0.05.

Conclusion

This study demonstrated that renal cortical volume had a moderate positive relationship with BMI, moderate negative relationship with age, and a strong positive relationship with the renal function, and provided a new method to routinely produce volumetric assessment of the kidney.