Utility of quantitative FDG-PET/CT for the detection of bone marrow involvement in follicular lymphoma: a histopathological correlation study

Objective

To determine the value of visual and quantitative ¹⁸?F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) for the detection of bone marrow involvement in follicular lymphoma, using direct histopathological examination at the right posterior iliac crest as reference standard.

Materials and methods

This retrospective study included 22 patients with newly diagnosed follicular lymphoma who had undergone FDG-PET/CT before BMB of the right posterior iliac crest. FDG-PET/CT images were visually evaluated for bone marrow involvement in the right posterior iliac crest. Volumes of interest were placed in the right posterior iliac crest to calculate the 3D partial volume corrected mean standardized uptake value (cSUV_mean), maximum standardized uptake value (SUV_max) and peak standardized uptake value (SUV_peak).

Results

Sensitivity and specificity of visual FDG-PET/CT analysis for the detection of bone marrow involvement in the right posterior iliac crest were 0.0 % (95 % confidence interval (CI): 0–32.4 %) and 100 % (95 % CI: 78.5–100 %), respectively. Areas under the receiver-operating characteristic curve of cSUV_mean, SUV_max and SUV_peak for the detection of bone marrow involvement in the right posterior iliac crest were 0.85 (95 % CI: 0.63–0.96), 0.89 (95 % CI: 0.68–0.98) and 0.87 (95 % CI: 0.65–0.97), respectively. Optimal cutoff values for cSUV_mean, SUV_max and SUV_peak were 1.3, 2.1 and 1.7, and yielded sensitivity and specificity combinations of 75.0 % and 85.7 %, 87.5 % and 85.7 % and 87.5 % and 85.7 %, respectively.

Conclusion

This histopathological correlation study shows that, unlike visual interpretation of FDG-PET/CT images, quantitative FDG-PET/CT analysis may be beneficial in diagnosing bone marrow involvement by follicular lymphoma.     

Whole-body MRI for initial staging of paediatric lymphoma: prospective comparison to an FDG-PET/CT-based reference standard

Objective

To compare whole-body MRI, including diffusion-weighted imaging (whole-body MRI-DWI), with FDG-PET/CT for staging newly diagnosed paediatric lymphoma.

Methods

A total of 36 children with newly diagnosed lymphoma prospectively underwent both whole-body MRI-DWI and FDG-PET/CT. Whole-body MRI-DWI was successfully performed in 33 patients (mean age 13.9 years). Whole-body MRI-DWI was independently evaluated by two blinded observers. After consensus reading, an unblinded expert panel evaluated the discrepant findings between whole-body MRI-DWI and FDG-PET/CT and used bone marrow biopsy, other imaging data and clinical information to derive an FDG-PET/CT-based reference standard.

Results

Interobserver agreement of whole-body MRI-DWI was good [all nodal sites together (κ = 0.79); all extranodal sites together (κ = 0.69)]. There was very good agreement between the consensus whole-body MRI-DWI- and FDG-PET/CT-based reference standard for nodal (κ = 0.91) and extranodal (κ = 0.94) staging. The sensitivity and specificity of consensus whole-body MRI-DWI were 93 % and 98 % for nodal staging and 89 % and 100 % for extranodal staging, respectively. Following removal of MRI reader errors, the disease stage according to whole-body MRI-DWI agreed with the reference standard in 28 of 33 patients.

Conclusions

Our results indicate that whole-body MRI-DWI is feasible for staging paediatric lymphoma and could potentially serve as a good radiation-free alternative to FDG-PET/CT.

Keypoints

? Accurate staging is important for treatment planning and assessing prognosis ? Whole-body MRI-DWI could be a good radiation-free alternative to FDG-PET/CT ? Interobserver agreement of whole-body MRI-DWI is good ? Agreement between whole-body MRI and the FDG-PET/CT reference standard is good ? Most discrepancies were caused by suboptimal accuracy of size measurements on MRI     

FDG PET/CT for the detection of bone marrow involvement in diffuse large B-cell lymphoma: systematic review and meta-analysis

Purpose

To systematically review and meta-analyse published data on the diagnostic performance of ¹⁸F-FDG PET/CT in detecting bone marrow involvement in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL).

Methods

PubMed/MEDLINE and Embase were systematically searched for relevant studies. The methodological quality of each study was assessed. Sensitivities and specificities of FDG PET/CT in individual studies were calculated and meta-analysed with a random effects model. A summary receiver operating characteristic curve (sROC) was constructed with the Moses-Shapiro-Littenberg method. Weighted summary proportions of discrepancies between the FDG PET/CT and (blind) bone marrow biopsy (BMB) results among all patients were calculated.

Results

Seven studies, with a total of 654 patients with newly diagnosed DLBCL, were included. Overall, the quality of the included studies was moderate. The sensitivity and specificity of FDG PET/CT for detecting bone marrow involvement ranged from 70.8 % to 95.8 % and from 99.0 % to 100 %, with pooled estimates of 88.7 % (95 % confidence interval, CI, 82.5 – 93.3 %) and 99.8 % (95 % CI 98.8 – 100 %), respectively. The area under the sROC curve was 0.9983. The weighted summary proportion of FDG PET/CT-negative patients with positive BMB findings among all patients was 3.1 % (95 % CI 1.8 – 5.0 %) and the weighted summary proportion of FDG PET/CT-positive patients with negative BMB findings among all patients was 12.5 % (95 % CI 8.4 – 17.3 %).

Conclusion

FDG PET/CT is accurate and complementary to BMB for detecting bone marrow involvement in patients with newly diagnosed DLBCL. A negative FDG PET/CT scan cannot rule out the presence of bone marrow involvement, but positive FDG PET/CT findings obviate the need for BMB for the detection of bone marrow involvement in these patients.     

Whole body MRI with qualitative and quantitative analysis of DWI for assessment of bone marrow involvement in lymphoma

Aim

Our study aimed to investigate the role of qualitative and quantitative whole body MRI with DWI for assessment of bone marrow involvement (BMI) in newly diagnosed lymphoma using FDG PET–CT and bone marrow biopsy (BMB) as reference standard.

Materials and methods

We retrospectively evaluated 56 patients with newly diagnosed lymphoma (21 Hodgkin’s lymphoma and 35 non-Hodgkin’s lymphoma) who underwent random unilateral BMB, FDG PET–CT and Wb-MRI-DWI for initial staging. In a patient-based analysis, results of Wb-MRI-DWI were compared with FDG PET–CT and BMB. For quantitative analysis, mean ADC values of posterior iliac crest were correlated with BMI and bone marrow cellularity.

Results

WB-MR-DWI obtained excellent concordance with FDG PET–CT both in HL (k = 1.000; 95% CI 1.000–1.000) and in DLBCL (k = 1.000; 95% CI 1.000–1.000). In other NHL, WB-MRI-DWI obtained a good correlation with BMB (k = 0.611; 95% CI 0.295–0.927) while FDG PET–CT had poor concordance (k = 0.067; 95% CI 0.372–0.505). WB-MR-DWI has no false negative errors but 4 false positive results consisting in focal lesions consensually reported by FDG PET–CT and resolved after therapy. No significant correlation between ADC mean value and BMI was found (p = 0.0586).

Conclusion

Our data suggest that Wb-MRI-DWI is a valid technique for BMI assessment in lymphoma patients, thanks to its excellent concordance with FDG PET–CT and good concordance with BMB (superior than FDG PET–CT). If further investigations will confirm our results on larger patient groups, it could become a useful tool in the clinical workup.

     

Role of F-18 FDG PET/CT in assessing bone marrow involvement in pediatric Hodgkin’s lymphoma

Objectives

The aim of the current study was to assess the utility of F-18-fluoro-2-deoxy-d-glucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) in assessing bone marrow involvement (BMI) compared to bone marrow biopsy (BMB) in initial staging of Hodgkin’s lymphoma (HL) in pediatric patients.

Methods

Data of 38 pediatric patients (mean age 9.8 years, range 3–18 years) with HL were analyzed for the involvement of bone marrow. All patients underwent non-contrast F-18 FDG PET/CT study. BMB was done in 31 patients from the bilateral iliac crests. Scans were interpreted by two nuclear medicine physicians blinded to the details of BMB.

Results

Of the 31 patients who underwent BMB, 5 patients had lymphomatous involvement on BMB. PET/CT was positive in four of these five patients. In 26 patients negative on BMB, PET was negative in 23 patients and positive in 3 patients for BMI. The sensitivity and negative predictive value of F-18 FDG PET/CT was 87.5 and 96 %, respectively, for BMI.

Conclusions

F-18 FDG PET/CT can predict BMB results with high accuracy. F-18 FDG PET/CT may be used at initial staging of pediatric Hodgkin’s lymphoma as it uncovers unsuspected BMI and BMB may be omitted in patients with PET-positive BMI.     

Whole-body MRI with diffusion-weighted sequence for staging of patients with suspected ovarian cancer: a clinical feasibility study in comparison to CT and FDG-PET/CT

Objectives

To evaluate whole-body MRI with diffusion-weighted sequence (WB-DWI/MRI) for staging and assessing operability compared with CT and FDG-PET/CT in patients with suspected ovarian cancer.

Methods

Thirty-two patients underwent 3-T WB-DWI/MRI, ¹⁸?F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and CT before diagnostic open laparoscopy (DOL). Imaging findings for tumour characterisation, peritoneal and retroperitoneal staging were correlated with histopathology after DOL and/or open surgery. For distant metastases, FDG-PET/CT or image-guided biopsies were the reference standards. For tumour characterisation and peritoneal staging, WB-DWI/MRI was compared with CT and FDG-PET/CT. Interobserver agreement for WB-DWI/MRI was determined.

Results

WB-DWI/MRI showed 94 % accuracy for primary tumour characterisation compared with 88 % for CT and 94 % for FDG-PET/CT. WB-DWI/MRI showed higher accuracy of 91 % for peritoneal staging compared with CT (75 %) and FDG-PET/CT (71 %). WB-DWI/MRI and FDG-PET/CT showed higher accuracy of 87 % for detecting retroperitoneal lymphadenopathies compared with CT (71 %). WB-DWI/MRI showed excellent correlation with FDG-PET/CT (κ?=?1.00) for detecting distant metastases compared with CT (κ?=?0.34). Interobserver agreement was moderate to almost perfect (κ?=?0.58–0.91).

Conclusions

WB-DWI/MRI shows high accuracy for characterising primary tumours, peritoneal and distant staging compared with CT and FDG-PET/CT and may be valuable for assessing operability in ovarian cancer patients.

Key Points

? Whole-body MRI with diffusion weighting (WB-DWI/MRI) helps to assess the operability of suspected ovarian cancer. ? Interobserver agreement is good for primary tumour characterisation, peritoneal and distant staging. ? WB-DWI/MRI improves mesenteric/serosal metastatic spread assessment compared with CT and FDG-PET/CT. ? Retroperitoneal/cervical-thoracic nodal staging using qualitative DWI criteria was reasonably accurate. ? WB-DWI/MRI and FDG-PET/CT showed the highest diagnostic impact for detecting thoracic metastases.     

Suspected invasive placenta: evaluation with magnetic resonance imaging

Purpose

To determine the utility of magnetic resonance imaging (MRI) in diagnosing invasive placenta (IP).

Materials and methods

MRI findings in 32 women with suspected IP were evaluated independently by four readers. Interobserver agreement was calculated with kappa (κ) statistics. Associations between MRI findings and IP were assessed by univariate and multivariate analyses. Sensitivity, specificity and accuracy of MRI for the diagnosis of IP were estimated.

Results

Sixteen women (16/32; 50 %) had confirmed IP. Interobserver correlation for the diagnosis of IP was fair (κ?=?0.40). Univariate analysis revealed that thinning or focal defect of the uteroplacental interface (P?P?=?0.0006; OR?=?64.99).

Conclusion

MR imaging has 84 % sensitivity [95 % CI: 75–94 %] and 80 % specificity [95 % CI: 66–93 %] for the diagnosis of IP. Thinning or focal defect of the uteroplacental interface is the most discriminating independent MR variable in differentiating between normal placenta and IP.

Key points

? MR imaging has acceptable degrees of accuracy to diagnose invasive placenta. ? Focal uteroplacental interface defect is the best finding to diagnose invasive placenta. ? Focal uteroplacental interface defect is the single independent predictor of invasive placenta.     

Diffusion-weighted MR imaging for the diagnosis of abscess complicating fistula-in-ano: preliminary experience

Objective

To investigate the role of diffusion-weighted magnetic resonance imaging (DWMRI) in the diagnosis of abscess-complicating fistula-in-ano.

Methods

This retrospective study was approved by our Institutional Review Board and informed consent was waived. MRI examinations, including fat-suppressed T2-weighted turbo spin-echo (T2-TSE) MRI and DWMRI, of 24 patients with a fistula-in-ano, were reviewed by two independent readers for the presence and number of visible fistulas, conspicuity and apparent diffusion coefficient (ADC) measurement of suspected fistula tracks and pelvic collections. The reference standard was surgical with follow-up findings.

Results

Sensitivity was 91.2 % [95 % CI: 76 %-98 %] for T2-weighted TSE MRI and 100 % [95 % CI: 90 %-100 %] for DWMRI detecting fistulas. ADC values were lower in abscesses than in inflammatory masses (P?=?0.714.10^-6). The area under the ROC curve was 0.971 and the optimal cut-off ADC value was 1.186?×?10^-3 mm²/s, yielding a sensitivity of 100 % [95 % CI: 77 %-100 %], a specificity of 90 % [95 % CI: 66 %-100 %], a positive predictive value of 93 % [95 % CI: 82.8 %-100 %] and a negative predictive value of 90 % [95 % CI: 78 %-100 %] for an abscess diagnosis. Fistula conspicuity was greater with DWMRI than with T2-TSE MRI for the two observers (P?=?0.0034 and P?=?0.0007).

Conclusion

DWMRI shows high sensitivity and specificity for the diagnosis of perianal abscesses and helps discriminate between an abscess and inflammatory mass. Conspicuity of fistulas-in-ano is greater with DWMRI than with T2-weighted TSE MRI.

Key Points

? DWMRI can differentiate between pelvic abscess and inflammatory mass. ? DWMRI helps avoid gadolinium-chelate administration in patients with a suspected fistula-in-ano. ? DWMRI provides high degrees of conspicuity for fistula-in-ano. ? Conspicuity of fistulas is better with DWMRI imaging than with T2-TSE-weighted MRI.     

Apparent diffusion coefficient of the vertebral bone marrow in children with Gaucher's disease type I and III

Purpose

To assess apparent diffusion coefficient (ADC) as a quantitative parameter for detection of vertebral bone marrow infiltration in children with Gaucher’s disease type I and III.

Material and methods

Prospective study was conducted on 20 infants and children (14 M, 6 F; aged 31–61 months; mean age 46 months) with Gaucher’s disease type I (n?=?13) and III (n?=?7), and 20 age and sex matched controls. They underwent routine and diffusion-weighted MR imaging of the lumbar spine using echo planar imaging with b value of 0, 500 and 1000 sec/mm2. The ADC value of the lumbar vertebral bone marrow was compared in different phenotypes and genotypes; and correlated with bone marrow burden score (BMB), chitotriosidase level, hemoglobin and platelet count.

Results

The mean ADC value of marrow infiltration in patients with Gaucher’s disease (0.39?±?0.06?×?10^?3 mm²/s) was significantly lower (P?=?0.001) than that of vertebral bone marrow in controls (0.54?±?0.05?×?10^?3 mm²/s). The cut-off ADC value used to differentiate patients with Gaucher’s disease from controls was (0.47?×?10^?3 mm²/s); with sensitivity of 95 %; specificity of 95 % and area under the curve of 0.986. The L444P/L444P mutation had significantly lower ADC value compared to other mutations (P?=?0.001). The mean ADC value of the bone marrow negatively correlated with BMB (r?=??0.831; P?=?0.001), and biomarkers of disease activity including chitotriosidase (r?=??0.542; P?=?0.014), hemoglobin (r?=??0.727; P?=?0.001) and platelets (r?=??0.698; P?=?0.001).

Conclusion

We concluded that there is significant difference in the ADC value of vertebral bone marrow between children with Gaucher’s disease and controls, and the ADC value correlated well with genotyping and some biomarkers of disease activity.     

Bone involvement in patients with lymphoma: the role of FDG-PET/CT

Purpose To evaluate the diagnostic impact and clinical significance of FDG-avid bone lesions detected by FDG-PET/CT in patients with lymphoma. Methods The study population comprised 50 consecutive patients (mean age 41.7±15.5 years; 27 female, 23 male; 41 staging, 9 restaging) with Hodgkin’s disease (n=22) or aggressive non-Hodgkin’s lymphoma (n=28) in whom FDG-avid bone lesions were detected by FDG-PET/CT. All patients had either direct biopsy of the FDG-avid bone lesion (n=18), standard bone marrow biopsy at the iliac crest (BMB; n=43) or both procedures (n=11). In 15 patients, additional MRI of the bone lesions was performed. All patients underwent FDG-PET/CT after the end of treatment. All CT images of FDG-PET/CT scans were analysed independently regarding morphological osseous changes and compared with FDG-PET results. Results In the 50 patients, 193 FDG-avid lesions were found by PET/CT. The mean standardised uptake value was 6.26 (±3.22). All direct bone biopsies (n=18) of the FDG-avid lesions proved the presence of lymphomatous infiltration. BMB (n=43) was positive in 12 patients (27.9%). In CT, 32 of 193 (16.6%) lesions were detected without the PET information. No additional morphological bone infiltration was detected on CT compared with FDG-PET. All morphological bone alterations on CT scans persisted after the end of therapy. Additional PET/CT information regarding uni- or multifocal bone involvement resulted in lymphoma upstaging in 21 (42%) patients compared with the combined information provided by CT and BMB. Conclusion In patients with FDG-avid bone lesions, FDG-PET is superior to CT alone or in combination with unilateral BMB in detecting bone marrow involvement, leading to upstaging in a relevant proportion of patients.     

Clinical examination versus magnetic resonance imaging in the pretreatment staging of cervical carcinoma: systematic review and meta-analysis

Objectives

To review the literature on the diagnostic performance of clinical examination and magnetic resonance imaging (MRI) in detecting parametrial invasion and advanced stage disease (FIGO stage ≥ IIB) in patients with cervical carcinoma.

Methods

Reports of studies were searched using the MEDLINE, EMBASE and Cochrane databases. Two observers reported on data relevant for analysis and methodological quality using the QUADAS scoring system. Publication bias was analysed using Deeks funnel plots. Covariates were added to the model to study the influence on the summary results of the technical and methodological aspects of the clinical examination and MRI.

Results

In total, 3,254 patients were included. Partial verification bias was often encountered. Pooled sensitivity was 40 % (95 % CI 25–58) for the evaluation of parametrial invasion with clinical examination and 84 % (95 % CI 76–90) with MRI, 53 % (95 % CI 41–66) for the evaluation of advanced disease with clinical examination, and 79 % (95 % CI 64–89) with MRI. Pooled specificities were comparable between clinical examination and MRI. Different technical aspects of MRI influenced the summary results.

Conclusions

MRI is significantly better than clinical examination in ruling out parametrial invasion and advanced disease in patients with cervical carcinoma.

Key Points

? MRI has a higher sensitivity than clinical examination for staging cervical carcinoma. ? Clinical examination and MRI have comparably high specificity for staging cervical carcinoma. ? Quality of clinical examination studies was lower than that of MRI studies. ? The use of newer MRI techniques positively influences the summary results. ? Anaesthesia during clinical examination positively influences the summary results.     

Grading of Cerebral Glioma with Multiparametric MR Imaging and 18F-FDG-PET: Concordance and Accuracy

Objectives

To retrospectively evaluate concordance rates and predictive values in concordant cases among multiparametric MR techniques and FDG-PET to grade cerebral gliomas.

Methods

Multiparametric MR imaging and FDG-PET were performed in 60 consecutive patients with cerebral gliomas (12 low-grade and 48 high-grade gliomas). As the dichotomic variables, conventional MRI, minimum apparent diffusion coefficient in diffusion-weighted imaging, maximum relative cerebral blood volume ratio in perfusion-weighted imaging, choline/creatine ratio and (lipid and lactate)/creatine ratio in MR spectroscopy, and maximum standardised uptake value ratio in FDG-PET in low- and high-grade gliomas were compared. Their concordance rates and positive/negative predictive values (PPV/NPV) in concordant cases were obtained for the various combinations of multiparametric MR techniques and FDG-PET.

Results

There were significant differences between low- and high-grade gliomas in all techniques. Combinations of two, three, four, and five out of the five techniques showed concordance rates of 77.0?±?4.8 %, 65.5?±?4.0 %, 58.3?±?2.6 % and 53.3 %, PPV in high-grade concordant cases of 97.3?±?1.7 %, 99.1?±?1.4 %, 100.0?±?0 % and 100.0 % and NPV in low-grade concordant cases of 70.2?±?7.5 %, 78.0?±?6.0 %, 80.3?±?3.4 % and 80.0 %, respectively.

Conclusion

Multiparametric MR techniques and FDG-PET have a concordant tendency in a two-tiered classification for the grading of cerebral glioma. If at least two examinations concordantly indicated high-grade gliomas, the PPV was about 95 %.

Key Points

? Modern imaging techniques can help predict the aggressiveness of cerebral gliomas. ? Multiparametric MRI and FDG-PET have a concordant tendency to grade cerebral gliomas. ? Their high-grade concordant cases revealed at least 95 % positive predictive values. ? Their low-grade concordant cases revealed about 70–80 % negative predictive values.     

Characterizing bone marrow involvement in Hodgkin’s lymphoma by FDG-PET/CT

Purpose

Fluoro-deoxyglucose positron emmission tomography combined with computed tomography (FDG-PET/CT) is superior to iliac bone marrow biopsy (iBMB) for detection of bone marrow involvement (BMI) in staging of Hodgkin’s lymphoma (HL). The present study aims to characterize the patterns and distribution of BMI in HL as determined by FDG-PET/CT.

Methods

Reports of FDG-PET/CT studies performed for staging of HL were reviewed. BMI was defined as positive iBMB and/or foci of pathological FDG uptake in the skeleton that behaved in concordance with other sites of lymphoma in studies following chemotherapy. Number of FDG uptake foci, their specific location in the skeleton and the presence of corresponding lesions in the CT component of the study, and stage according to the Ann Arbor staging system, were recorded.

Results

The study included 473 patients. iBMB was performed in 336 patients. Nine patients had positive iBMB (9/336, 3 %). Seventy-three patients (73/473, 15 %) had FDG-PET/CT-defined BMI. The BM was the only extranodal site of HL in 52/473 patients (11 %). Forty-five patients had three or more foci of pathological skeletal FDG uptake (45/73, 62 %). Sixty-four patients (64/73, 88 %) had at least one uptake focus in the pelvis or vertebrae. In 60 patients (60/73, 82 %), the number of skeletal FDG uptake foci without corresponding CT lesions was equal to or higher than the number of foci with morphological abnormalities.

Conclusion

FDG-PET/CT demonstrated BMI in 15 % of patients with newly diagnosed HL. Diagnosis of BMI in HL by FDG-PET/CT was more sensitive than iBMB with potential upstage in 11 % of patients. The most common pattern of FDG-PET/CT BMI was multifocal (at least three foci) skeletal FDG uptake, with at least one focus in the pelvis or vertebrae and no corresponding CT lesions.     

3-T breast magnetic resonance imaging in patients with suspicious microcalcifications on mammography

Objective

To investigate the diagnostic value of 3-Tesla (T) breast MRI in patients presenting with microcalcifications on mammography.

Methods

Between January 2006 and May 2009, 123 patients with mammographically detected BI-RADS 3–5 microcalcifications underwent 3-T breast MRI before undergoing breast biopsy. All MRIs of the histopathologically confirmed index lesions were reviewed by two breast radiologists. The detection rate of invasive carcinoma and ductal carcinoma in situ (DCIS) was evaluated, as well as the added diagnostic value of MRI over mammography and breast ultrasound.

Results

At pathology, 40/123 (33 %) lesions proved malignant; 28 (70 %) DCIS and 12 (30 %) invasive carcinoma. Both observers detected all invasive malignancies at MRI, as well as 79 % (observer 1) and 86 % (observer 2) of in situ lesions. MRI in addition to conventional imaging led to a significant increase in area under the receiver operating characteristic (ROC) curve from 0.67 (95 % CI 0.56–0.79) to 0.79 (95 % CI 0.70–0.88, observer 1) and to 0.80 (95 % CI 0.71–0.89, observer 2), respectively.

Conclusions

3-T breast MRI was shown to add significant value to conventional imaging in patients presenting with suspicious microcalcifications on mammography.

Key points

? 3-T MRI is increasingly used for breast imaging in clinical practice. ? On 3-T breast MRI up to 86 % of DCIS lesions are detected. ? 3-T MRI increases the diagnostic value in patients with mammographically detected microcalcifications.     

The evaluation of FDG-PET imaging for epileptogenic focus localization in patients with MRI positive and MRI negative temporal lobe epilepsy

Introduction

We studied the contribution of interictal FDG-PET ([18 F] fluorodeoxyglucose-positron emission tomography) in epileptic focus identification in temporal lobe epilepsy patients with positive, equivocal and negative magnetic resonance imaging (MRI).

Methods

Ninety-eight patients who underwent surgical treatment for drug resistant temporal lobe epilepsy after neuropsychological evaluation, scalp video EEG monitoring, FDG-PET, MRI and/or long-term intracranial EEG and with >12 months clinical follow-up were included in this study. FDG-PET findings were compared to MRI, histopathology, scalp video EEG and long-term intracranial EEG monitoring.

Results

FDG-PET lateralized the seizure focus in 95 % of MRI positive, 69 % of MRI equivocal and 84 % of MRI negative patients. There was no statistically significant difference between the surgical outcomes among the groups with Engel class I and II outcomes achieved in 86 %, 86 %, 84 % of MRI positive, equivocal and negative temporal lobe epilepsy patients, respectively. The patients with positive unilateral FDG-PET demonstrated excellent postsurgical outcomes, with 96 % Engel class I and II. Histopathology revealed focal lesions in 75 % of MRI equivocal, 84 % of MRI positive, and 23 % of MRI negative temporal lobe epilepsy cases.

Conclusion

FDG-PET is an accurate noninvasive method in lateralizing the epileptogenic focus in temporal lobe epilepsy, especially in patients with normal or equivocal MRIs, or non-lateralized EEG monitoring. Very subtle findings in MRI are often associated with histopathological lesions and should be described in MRI reports. The patients with negative or equivocal MRI temporal lobe epilepsy are good surgical candidates with comparable postsurgical outcomes to patients with MRI positive temporal lobe epilepsy.     

Metabolic information on staging FDG-PET–CT as a prognostic tool in the evaluation of 97 patients with gastric cancer

Background and objective

Gastric cancer remains a leading cause of malignancy-related mortality. Many patients with locally advanced disease succumb despite peri-operative chemotherapy and the survival benefit of chemotherapy for advanced disease is modest, suggesting that current staging is imperfect. The role of fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in the staging of gastric cancer remains to be determined. This study aimed to determine, and compare with computerized tomography (CT), the association between FDG-PET uptake in the primary tumour and regional lymph nodes, and overall survival in patients with all stage gastric cancer.

Methods

Patients with histologically confirmed gastric cancer (any stage) who, at diagnosis, had received a staging FDG-PET–CT at our institution between 2006 and 2011 were included. Records were retrospectively analysed. Patients with >50 % of tumour above the gastro-oesophageal junction or an active second malignancy were excluded.

Results

97 patients were included in the analysis. Surgery with curative intent was performed in 68 patients. In univariate analysis, an association with overall survival was seen in patients who had FDG-PET-positive primary tumours (hazard ratio (HR) for death 3.33, 95 % confidence interval (95 % CI) 1.63–6.80, p?=?0.001). FDG-PET lymph node positive (vs node negativity) was associated with inferior overall survival (HR 8.66, 95 % CI 4.59–16.37, p < 0.0001), and remained an independent predictor in the multivariate analysis. In contrast, positive lymphadenopathy identified on CT was not associated with overall survival (HR 1.34, 95 % CI 0.79–2.29, p = 0.82).

Conclusion

FDG-PET-positive tumours are associated with an inferior overall survival. In contrast to CT, FDG-PET-positive lymphadenopathy is associated with a decreased overall survival.     

Radiofrequency ablation of renal tumours: diagnostic accuracy of contrast-enhanced ultrasound for early detection of residual tumour

Objective

To evaluate the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in the early detection of residual tumour after radiofrequency ablation (RFA) of renal tumours.

Methods

Patients referred to our institution for RFA of renal tumours prospectively underwent CEUS and computed tomography (CT) or magnetic resonance imaging (MRI) before, within 1 day and 6 weeks after treatment. Identification of residual tumour was assessed by three blinded radiologists. Reference standard was CT/MRI performed at least 1 year after RFA.

Results

A total of 66 renal tumours in 43 patients (median age 62 years; range 44–71.5) were studied. Inter-reader agreement (κ value) was 0.84 for CEUS. Prevalence of residual disease was 19%. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), respectively, were as follows: 64% [confidence interval (CI) 39–84], 98% [CI 91–100], 82% [CI 52–95] and 92% [CI 83–97] on 24-h CEUS; 79% [CI 52–92], 100% [CI 94–100], 100% [CI 74–100] and 95% [CI 87–100] on 6-week CEUS; 79% [CI 52–92], 95% [CI 86–98], 79% [CI 52–92] and 95% [CI 86–98] on 24-h CT/MRI; and 100% [CI 72–100], 98% [CI 90–100], 91% [CI 62–98] and 100% [CI 93–100] on 6-week CT/MRI.

Conclusion

CEUS has high specificity for the early diagnosis of residual tumour after renal RFA.     

Whole-body FSE STIR MR imaging of lymphoma

Purpose

To evaluate the role of FSE STIR whole body MRI in diagnosis and initial staging of malignant lymphoma, and can FSE STIR whole body MRI replace conventional staging procedures including computed tomography and bone marrow biopsy in initial staging of lymphoma.

Materials and methods

Twenty one newly diagnosed histologically proven lymphoma patients underwent whole body MR imaging and conventional staging procedures including computed tomography and bone marrow biopsy for initial staging of lymphoma using Modified Ann Arbor staging system. Both methods evaluated positive involvement by lymphoma to the nodal and extra-nodal sites including parenchymal organs, serosal cavities and bone marrow. The numbers of involved nodal and extra-nodal sites detected by both methods were compared, then agreement and disagreement between whole-body MRI and conventional procedures regarding lesions detection and staging according to the Ann Arbor staging system were calculated, along with binomial exact 95% confidence intervals (CIs).

Results

Twenty one patients had a total of 145 abnormalities. One hundred and twenty four were correctly diagnosed by conventional staging procedures, however, FSE STIR whole body MRI correctly diagnosed all the 144 abnormalities with 1 false negative and 3 false positive abnormalities with a total of detected abnormalities of 147 lesions. FSE STIR whole body MRI was significantly more accurate than conventional staging procedures in the diagnosis of positive lymphoma lesions [(99.3%; 95% CI: 95.6-100.0%) versus (85.5%; 95% CI: 78.5-90.6%)]. FSE STIR whole body MRI correctly staged 20 out of 21 patients, Kappa test 0.93 (P < 0.001) while conventional staging procedures correctly staged 17 and incorrectly staged 4 cases, Kappa test 0.74 (P < 0.001).

Conclusion

Whole body MR imaging can replace conventional staging procedures in the diagnosis and initial staging of malignant lymphoma as it offers a whole body overview of the lymphoma infiltration through the lymph node stations, parenchymal organs, serosal cavities and bone marrow.     

Current clinical use of 18FDG-PET/CT in patients with thoracic and systemic sarcoidosis

Purpose

This study assessed the role of whole-body ¹⁸fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸FDG PET/CT) in the restaging and follow-up of patients with sarcoidosis previously studied by multidetector computed tomography (MDCT).

Materials and methods

This retrospective study enroled 21 patients to evaluate the sensitivity, specificity and accuracy of ¹⁸FDG-PET/CT and MDCT. The results of the two techniques were compared with the Mc Nemar test. Cohen’s K was used to compare concordance at the different lesion sites.

Results

The sensitivity, specificity and accuracy of ¹⁸FDG-PET/CT were 80, 66.67, and 76.19 %, respectively. The sensitivity, specificity and accuracy of MDCT were 93.33, 33.33, and 76.19 %, respectively. In 16 patients who underwent whole-body MDCT, the sensitivity, specificity and accuracy values were 91.67, 81.25, and 50 % (MDCT) and 100, 50, and 87.5 % (¹⁸FDG-PET/CT).

Conclusions

¹⁸FDG-PET/CT is useful in evaluating the extent of sarcoidosis and recognising lesions at different sites, including lymph nodes, lungs, liver, spleen and bone. It also improves the interpretation of the morphological lesions seen on MDCT and depicts a larger number of lesions. Therefore, ¹⁸FDG-PET/CT could be used to complement other more traditional techniques for the restaging and follow-up in patients with sarcoidosis.     

Contrast-enhanced MRI compared with the physical examination in the evaluation of disease activity in juvenile idiopathic arthritis

Objectives

To assess the value of magnetic resonance imaging (MRI) in discriminating between active and inactive juvenile idiopathic arthritis (JIA) patients and to compare physical examination outcomes with MRI outcomes in the assessment of disease status in JIA patients.

Methods

Consecutive JIA patients with knee involvement were prospectively studied using an open-bore MRI. Imaging findings from 146 JIA patients were analysed (59.6 % female; mean age, 12.9 years). Patients were classified as clinically active or inactive. MRI features were evaluated using the JAMRIS system, comprising validated scores for synovial hypertrophy, bone marrow oedema, cartilage lesions and bone erosions.

Results

Inter-reader reliability was good for all MRI features (intra-class correlation coefficient [ICC]?=?0.87–0.94). No differences were found between the two groups regarding MRI scores of bone marrow oedema, cartilage lesions or bone erosions. Synovial hypertrophy scores differed significantly between groups (P?=?0.016). Nonetheless, synovial hypertrophy was also present in 14 JIA patients (35.9 %) with clinically inactive disease. Of JIA patients considered clinically active, 48.6 % showed no signs of MRI-based synovitis.

Conclusions

MRI can discriminate between clinically active and inactive JIA patients. However, physical examination is neither very sensitive nor specific in evaluating JIA disease activity compared with MRI. Subclinical synovitis was present in >35 % of presumed clinically inactive patients.

Key points

? MRI is sensitive for evaluating juvenile idiopathic arthritis (JIA) disease activity. ? Contrast-enhanced MRI can distinguish clinically active and inactive JIA patients. ? Subclinical synovitis is present in 35.9?% of presumed clinically inactive patients. ? Physical examination is neither sensitive nor specific in evaluating JIA disease activity.