High-resolution whole-body magnetic resonance image tumor staging with the use of parallel imaging versus dual-modality positron emission tomography-computed tomography: experience on a 32-channel system

Whole-body MRI in oncology: A comprehensive review

Whole-Body Magnetic Resonance Imaging (WB-MRI) has cemented its position as a pivotal tool in oncological diagnostics. It offers unparalleled soft tissue contrast resolution and the advantage of sidestepping ionizing radiation. This review explores the diverse applications of WB-MRI in oncology. We discuss its transformative role in detecting and diagnosing a spectrum of cancers, emphasizing conditions like multiple myeloma and cancers with a proclivity for bone metastases. WB-MRI's capability to encompass the entire body in a singular scan has ushered in novel paradigms in cancer screening, especially for individuals harboring hereditary cancer syndromes or at heightened risk for metastatic disease. Additionally, its contribution to the clinical landscape, aiding in the holistic management of multifocal and systemic malignancies, is explored. The article accentuates the technical strides achieved in WB-MRI, its myriad clinical utilities, and the challenges in integration into standard oncological care. In essence, this review underscores the transformative potential of WB-MRI, emphasizing its promise as a cornerstone modality in shaping the future trajectory of cancer diagnostics and treatment.

Comparison of whole-body 18F-FDG PET/CT and PET/MRI for distant metastases in patients with malignant tumors: a meta-analysis

BACKGROUND

As a first-line imaging modality, whole-body fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18F-FDG PET/magnetic resonance imaging (MRI) had been widely applied in clinical practice. However, 18F-FDG PET/MRI may be superior to PET/CT for the diagnosis of distant metastases in patients with advanced-stage. Therefore, it is timely and important to systematically determine the diagnostic accuracy of 18F-FDG PET/MRI compared with that of 18F-FDG PET/CT for the diagnosis of distant metastases.

METHODS

This study aimed to compare the diagnostic accuracy of 18F-FDG PET/CT and PET/MRI for the diagnosis of distant metastases in patients with malignant tumors. Relevant studies using both 18F-FDG PET/CT and PET/MRI for assessment of distant metastases in patients with malignant tumors were searched in PubMed, Embase, The Cochrane Library, and Scopus from January 2010 to November 2023. Two reviewers independently selected studies according to the inclusion and exclusion criteria. A reviewer extracted relevant data and assessed the quality of the eligible studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and area under the summary receiver operating characteristic curve (AUC) for 18F-FDG PET/CT and PET/MRI were analyzed. Subgroup analysis was performed.

RESULTS

Across 14 studies (1042 patients), 18F-FDG PET/MRI had a higher sensitivity (0.87 versus 0.81), AUC value (0.98 versus 0.95), and similar specificity (0.97 versus 0.97), than PET/CT for detecting distant metastases. In 3 studies of breast cancer (182 patients), 18F-FDG PET/MRI had a higher sensitivity (0.95 versus 0.87) and specificity (0.96 versus 0.94) than PET/CT. In 5 studies of lung cancer (429 patients), 18F-FDG PET/CT had a higher sensitivity (0.87 versus 0.84) and a lower specificity (0.95 versus 0.96) to PET/MRI.

CONCLUSIONS

18F-FDG PET/MRI and PET/CT both performed well as detectors of distant metastases in patients with malignant tumors, and the former has higher sensitivity. The subgroup analysis highlights that 18F-FDG PET/MRI and PET/CT hold different advantages for distant metastases staging in different tumors, PET/MRI has a higher accuracy in patients with breast cancer patients, while PET/CT has a higher accuracy in patients with lung cancer.

Combining CT Images and Clinical Features of Four Periods to Predict Whether Patients Have Rectal Cancer

In this paper, we mainly use random forest and broad learning system (BLS) to predict rectal cancer. A total of 246 participants with computed tomography (CT) image records were enrolled. The total model in the training set (combined with imaging and clinical indicators) has the best prediction result, with the area under the curve (AUC) of 0.999 (95% confidence internal (CI): 0.996-1.000) and the accuracy of 0.990 (95%CI: 0.976-1.000). Model 3, the general model in the test set, has the best prediction result, with the AUC of 0.962 (95%CI: 0.915-1.000) and the accuracy of 0.920 (95%CI: 0.845-0.995). The results of the model using random forest prediction are compared with those using BLS prediction. It can be found that there is no statistical difference between the two results. Our prediction model combined with image features has a good prediction result, and this image feature is the most important among all features. Consequently, we can successfully predict rectal cancer through a combination of the clinical indicators and the comprehensive indicators of CT image characteristics in four different periods (plain scan, vein, artery, and excretion).

Whole-body magnetic resonance imaging for the diagnosis of metastasis in children and adolescents: a systematic review and meta-analysis

Whole-body magnetic resonance imaging (WB-MRI) is a noninvasive imaging method that can be used to diagnose and stage tumors, as well as to assess therapeutic responses in oncology. The objective of this meta-analysis was to evaluate the accuracy of WB-MRI for the diagnosis of metastases in pediatric patients. The following electronic databases were searched: Medline, Embase, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin-American and Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and ClinicalTrials.gov. All of the selected studies included children and adolescents with histopathological confirmation of a primary tumor. Collectively, the studies included 118 patients ranging in age from 7 months to 19 years. The pooled sensitivity and specificity of WB-MRI were, respectively, 0.964 (95% CI: 0.944-0.978; I² = 0%) and 0.902 (95% CI: 0.882-0.919; I² = 98.4%), with an area under the curve (AUC) of 0.991. We found that WB-MRI had good accuracy for the diagnosis of metastases in pediatric patients and could therefore provide an alternative to complete the staging of tumors in such patients, being a safer option because it does not involve the use of ionizing radiation.

Whole-Body MRI in Rheumatology: Major Advances and Future Perspectives

Whole-body magnetic resonance imaging is constantly gaining more importance in rheumatology, particularly for what concerns the diagnosis, follow-up, and treatment response evaluation. Initially applied principally for the study of ankylosing spondylitis, in the last years, its use has been extended to several other rheumatic diseases. Particularly in the pediatric population, WB-MRI is rapidly becoming the gold-standard technique for the diagnosis and follow-up of both chronic recurrent multifocal osteomyelitis and juvenile spondyloarthritis. In this review, we analyze the benefits and limits of this technique as well as possible future applications.

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Diffusion-weighted whole-body imaging with background suppression (DWIBS) is effective and economical for detection of metastasis or recurrence of lung cancer

BACKGROUND

Diffusion-weighted whole-body imaging with background suppression (DWIBS) is used for the diagnosis and staging of cancers. The medical cost of an MR examination including DWIBS is $123, which is 80% less expensive than the cost ($798) of F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) examination.

METHODS

This study examined the efficacy of DWIBS for relapses after lung cancer resection. A total of 55 patients who had pulmonary resection of lung cancer, postoperative computed tomography (CT) every six months, and DWIBS and FDG-PET/CT (every year) were enrolled in this study. If a metastatic lesion was detected on CT scan, DWIBS and FDG-PET/CT were also used.

RESULTS

A total of 55 patients who underwent pulmonary resections for lung cancer, and had CT, DWIBS and FDG-PET/CT examination during follow-up after pulmonary resection were enrolled in this study. Lung cancer in 32 patients relapsed. Postoperative radiographic examinations revealed pulmonary metastases in 17 patients, bone metastases in seven, liver metastases in five, lymph node metastases in five, pleural metastases in four, metastases to the chest wall in two, brain metastases in two, adrenal gland metastasis in one, and renal metastasis in one. The mean apparent diffusion coefficient (ADC) value of the relapse was 0.9 to 1.70 × 10^-3 mm² /s. The accuracy 0.98 (54/55) of DWIBS for detecting multiple metastatic lesions was likely to be higher than 0.94 (52/55) of CT or 0.94 (52/55) of FDG-PET/CT, but there were no significant differences.

CONCLUSIONS

DWIBS can detect multiple metastatic lesions throughout the entire body and differentiate malignancy from benignity in only one examination. DWIBS has benefits of diagnostic accuracy and is less expensive in medical costs for the detection of a relapse. DWIBS could potentially replace FDG-PET/CT after lung cancer resection.

Whole-Body Functional MRI and PET/MRI in Multiple Myeloma

Simple Summary

Whole-body magnetic resonance imaging (MRI) is recognized as the most sensitive imaging technique for the detection of bone marrow infiltration, and was therefore, recently included in the new diagnostic myeloma criteria, as proposed by the International Myeloma Working Group. The use of diffusion-weighted MRI further improved the performances of whole-body MRI in the setting of multiple myeloma, and its systematic implementation in general clinical practice is now recommended. Whole-body, dynamic, contrast-enhanced MRI might provide further information on lesions vascularity and might help evaluate response to treatment. Hybrid PET/MRI might act as the optimal imaging modality, owing to the association of the best techniques for both detecting bone marrow involvement and evaluating treatment response, providing one-stop-shop imaging in a whole-body scale. This review provides an overview on the value of whole-body MRI, including diffusion-weighted and dynamic contrast-enhanced MRI and whole-body ¹⁸F-FDG PET/MRI in diagnosis, staging, and response evaluation in multiple myeloma.

Abstract

Bone disease is one of the major features of multiple myeloma (MM), and imaging has a pivotal role in both diagnosis and follow-up. Whole-body magnetic resonance imaging (MRI) is recognized as the gold standard for the detection of bone marrow involvement, owing to its high sensitivity. The use of functional MRI sequences further improved the performances of whole-body MRI in the setting of MM. Whole-body diffusion-weighted (DW) MRI is the most attractive functional technique and its systematic implementation in general clinical practice is now recommended by the International Myeloma Working Group. Whole-body dynamic contrast-enhanced (DCE) MRI might provide further information on lesions vascularity and help evaluate response to treatment. Whole Body PET/MRI is an emerging hybrid imaging technique that offers the opportunity to combine information on morphology, fat content of bone marrow, bone marrow cellularity and vascularization, and metabolic activity. Whole-body PET/MRI allows a one-stop-shop examination, including the most sensitive technique for detecting bone marrow involvement, and the most recognized technique for treatment response evaluation. This review aims at providing an overview on the value of whole-body MRI, including DW and DCE MRI, and combined whole-body ¹⁸F-FDG PET/MRI in diagnosis, staging, and response evaluation in patients with MM.

An initial experience with the use of whole body MRI for cancer screening and regular health checks

OBJECTIVES

We evaluated the utility of whole-body MRI (WB MRI) for cancer screening and other regular health evaluations.

METHODS

This retrospective study included 229 patients who underwent whole-body MRI as part of a routine health examination and cancer screening. The WB MRIs and radiologic reports were evaluated by a musculoskeletal radiologist, a neuroradiologist, and an abdominal radiologist. The consensus of their findings was characterized into three categories, as follows: suspicion of malignancy (category I); need for follow-up (category II); and no need for follow-up (category III). Any correlations between the abnormal findings and each study group were evaluated using the Mann-Whitney U test and chi-square test.

RESULTS

There were six category I lesions, among which two cases were found to involve malignancy. The most common category II findings were annular tears of the disc (14% of category II findings) and severe disc bulging or protrusion, followed by shoulder bursitis and uterine myoma. The most common category III finding was mild disc bulging or protrusion (47% of category III findings).

CONCLUSIONS

WB MRI can be used in cancer screening and for regular health evaluations. WB MRI not only provides information about potential malignancy, but also provides information regarding nonmalignant abnormalities that require further evaluation.

Whole-body magnetic resonance imaging (WB-MRI) in oncology: recommendations and key uses

The past decade has witnessed a growing role and increasing use of whole-body magnetic resonance imaging (WB-MRI). Driving these successes are developments in both hardware and software that have reduced overall examination times and significantly improved MR imaging quality. In addition, radiologists and clinicians have continued to find promising new applications of this innovative imaging technique that brings together morphologic and functional characterization of tissues. In oncology, the role of WB-MRI has expanded to the point of being recommended in international guidelines for the assessment of several cancer histotypes (multiple myeloma, melanoma, prostate cancer) and cancer-prone syndromes (Li-Fraumeni and hereditary paraganglioma-pheochromocytoma syndromes). The literature shows growing use of WB-MRI for the staging and follow-up of other cancer histotypes and cancer-related syndromes (including breast cancer, lymphoma, neurofibromatosis, and von Hippel-Lindau syndromes). The main aim of this review is to examine the current scientific evidence for the use of WB-MRI in oncology.

The added value of whole-body magnetic resonance imaging in the management of patients with advanced breast cancer

This study investigates the impact of whole-body MRI (WB-MRI) in addition to CT of chest-abdomen-pelvis (CT-CAP) and 18F-FDG PET/CT (PET/CT) on systemic treatment decisions in standard clinical practice for patients with advanced breast cancer (ABC). WB-MRI examinations in ABC patients were extracted from our WB-MRI registry (2009-2017). Patients under systemic treatment who underwent WB-MRI and a control examination (CT-CAP or PET/CT) were included. Data regarding progressive disease (PD) reported either on WB-MRI or on the control examinations were collected. Data regarding eventual change in treatment after the imaging evaluation were collected. It was finally evaluated whether the detection of PD by any of the two modalities had induced a change in treatment. Among 910 WB-MRI examinations in ABC patients, 58 had a paired control examination (16 CT-CAP and 42 PET/CT) and were analysed. In 23/58 paired examinations, additional sites of disease were reported only on WB-MRI and not on the control examination. In 17/28 paired examinations, PD was reported only on WB-MRI and not on the control examination. In 14 out of the 28 pairs of examinations that were followed by a change in treatment, PD had been reported only on WBMRI (14/28; 50%), while stable disease had been reported on the control examination. In conclusion, WB-MRI disclosed PD earlier than the control examination (CT-CAP or PET/CT), and it was responsible alone for 50% of all changes in treatment.

Whole-Body MR Imaging: The Novel, "Intrinsically Hybrid," Approach to Metastases, Myeloma, Lymphoma, in Bones and Beyond

Whole-body MR imaging (WB-MR imaging) has become a modality of choice for detecting bone metastases in multiple cancers, and bone marrow involvement by multiple myeloma or lymphoma. Combination of anatomic and functional sequences imparts an inherently hybrid dimension to this nonirradiating tool and extends the screening of malignancies outside the skeleton. WB-MR imaging outperforms bone scintigraphy and CT and offers an alternative to PET in many tumors by time of lesion detection and assessment of treatment response. Much work has been done to standardize procedures, optimize sequences, validate indications, confirm preliminary research into new applications, rendering clinical application more user-friendly.

Whole Body MRI and oncology: recent major advances

MRI is a very attractive approach for tumour detection and oncological staging with its absence of ionizing radiation, high soft tissue contrast and spatial resolution. Less than 10 years ago the use of Whole Body MRI (WB-MRI) protocols was uncommon due to many limitations, such as the forbidding acquisition times and limited availability. This decade has marked substantial progress in WB-MRI protocols. This very promising technique is rapidly arising from the research world and is becoming a commonly used examination for tumour detection due to recent technological developments and validation of WB-MRI by multiple studies and consensus papers. As a result, WB-MRI is progressively proposed by radiologists as an efficient examination for an expanding range of indications. As the spectrum of its uses becomes wider, radiologists will soon be confronted with the challenges of this technique and be urged to be trained in order to accurately read and report these examinations. The aim of this review is to summarize the validated indications of WB-MRI and present an overview of its most recent advances. This paper will briefly discuss how this examination is performed and which are the recommended sequences along with the future perspectives in the field.

Whole Body MRI and oncology: recent major advances

MRI is a very attractive approach for tumour detection and oncological staging with its absence of ionizing radiation, high soft tissue contrast and spatial resolution. Less than 10 years ago the use of Whole Body MRI (WB-MRI) protocols was uncommon due to many limitations, such as the forbidding acquisition times and limited availability. This decade has marked substantial progress in WB-MRI protocols. This very promising technique is rapidly arising from the research world and is becoming a commonly used examination for tumour detection due to recent technological developments and validation of WB-MRI by multiple studies and consensus papers. As a result, WB-MRI is progressively proposed by radiologists as an efficient examination for an expanding range of indications. As the spectrum of its uses becomes wider, radiologists will soon be confronted with the challenges of this technique and be urged to be trained in order to accurately read and report these examinations. The aim of this review is to summarize the validated indications of WB-MRI and present an overview of its most recent advances. This paper will briefly discuss how this examination is performed and which are the recommended sequences along with the future perspectives in the field.

Whole-body MRI in patients with lymphoma: collateral findings

PURPOSE

To assess the incidence of collateral findings detected on whole-body magnetic resonance (WB-MRI) scans performed on patients with lymphoma.

MATERIALS AND METHODS

114 patients (65 male; median age 45.2 years, range 15-86) with histologically confirmed lymphoma (47 Hodgkin, 67 Non-Hodgkin) underwent WB-MRI. The collateral findings were classified into three classes, according to their clinical significance, as follows: not or low significant (class 1), moderately or potentially significant (class 2), and significant (class 3). A Chi-square (χ (2)) test was performed to assess the statistical significance of differences in the incidence of collateral findings based on age (≤50 and >50 years old), gender and histology (Hodgkin and Non-Hodgkin Lymphoma).

RESULTS

Ninety-one of 114 patients (79.8 %) had one or more incidental findings on WB-MRI. Collateral findings were more frequent in class 1 (43 %); abnormalities found in 35 patients (30.7 %) were considered potentially significant, whereas seven patients (6.1 %) demonstrated significant collateral findings requiring immediate treatment or further diagnostic evaluation. Collateral findings were more frequent in subjects over 50 years old compared to those of 50 years old or younger; differences were statistical significant (χ (2) = 8.42, p < 0.05). There were not statistically significant differences related to gender (χ (2) = 0.17, p > 0.05) and histology (χ (2) = 0.24, p > 0.05).

CONCLUSION

WB-MRI is an attractive procedure that allows to detect incidental abnormalities of organs not involved by disease offering the opportunity to obtain an early diagnosis of asymptomatic life-threatening diseases.

The Diagnostic Value of MR Imaging in Determining the Lymph Node Status of Patients with Non-Small Cell Lung Cancer: A Meta-Analysis

Purpose To summarize existing evidence of thoracic magnetic resonance (MR) imaging in determining the nodal status of non-small cell lung cancer (NSCLC) with the aim of elucidating its diagnostic value on a per-patient basis (eg, in treatment decision making) and a per-node basis (eg, in target volume delineation for radiation therapy), with results of cytologic and/or histologic examination as the reference standard. Materials and Methods A systematic literature search for original diagnostic studies was performed in PubMed, Web of Science, Embase, and MEDLINE. The methodologic quality of each study was evaluated by using the Quality Assessment of Diagnostic Accuracy Studies 2, or QUADAS-2, tool. Hierarchic summary receiver operating characteristic curves were generated to estimate the diagnostic performance of MR imaging. Subgroup analyses, expressed as relative diagnostic odds ratios (DORs) (rDORs), were performed to evaluate whether publication year, methodologic quality, and/or method of evaluation (qualitative [ie, lesion size and/or morphology] vs quantitative [eg, apparent diffusion coefficients in diffusion-weighted images]) affected diagnostic performance. Results Twelve of 2551 initially identified studies were included in this meta-analysis (1122 patients; 4302 lymph nodes). On a per-patient basis, the pooled estimates of MR imaging for sensitivity, specificity, and DOR were 0.87 (95% confidence interval [CI]: 0.78, 0.92), 0.88 (95% CI: 0.77, 0.94), and 48.1 (95% CI: 23.4, 98.9), respectively. On a per-node basis, the respective measures were 0.88 (95% CI: 0.78, 0.94), 0.95 (95% CI: 0.87, 0.98), and 129.5 (95% CI: 49.3, 340.0). Subgroup analyses suggested greater diagnostic performance of quantitative evaluation on both a per-patient and per-node basis (rDOR = 2.76 [95% CI: 0.83, 9.10], P = .09 and rDOR = 7.25 [95% CI: 1.75, 30.09], P = .01, respectively). Conclusion This meta-analysis demonstrated high diagnostic performance of MR imaging in staging hilar and mediastinal lymph nodes in NSCLC on both a per-patient and per-node basis. (©) RSNA, 2016 Online supplemental material is available for this article.

[Whole-body staging of malignant melanoma: advantages, limitations and current importance of PET-CT, whole-body MRI and PET-MRI]

Cross-sectional imaging methods are currently the standard methods for staging of advanced melanoma. The former time-consuming and expensive multimodality approach is increasingly being replaced by novel whole-body (WB) staging methods, such as 18F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET-CT) and whole-body magnetic resonance imaging (WBMRI) because they offer a complete head-to-toe coverage of the patient in a single examination with an accurate and sensitive detection of tumor spread. Several studies in patients with advanced melanoma revealed that PET-CT is more sensitive and specific than conventional modalities, such as CT alone resulting in a change of management in up to 30 % of cases. Due to the limited sensitivity of PET for lesions smaller than 1 cm, PET-CT is not useful for the initial work-up of patients with stage I and II melanoma but has proven to be superior for detection of distant metastases, which is essential prior to surgical metastasectomy. If PET-CT is not available WB-CT or WB-MRI can alternatively be used and WB-MRI including diffusion-weighted imaging (DWI) has become a real alternative for staging of melanoma patients. So far, however, only few reports suffering from small numbers of cases and heterogeneous design have compared the diagnostic performance of WB-MRI and PET-CT. The preliminary results indicate a high overall diagnostic accuracy of both methods; however, these methods differ in organ-based detection rates: PET-CT was more accurate in N-staging and detection of lung and soft tissue metastases whereas WB-MRI was superior in detecting liver, bone and brain metastases. The value of PET-MRI for staging of advanced melanoma is the subject of ongoing clinical studies.

Continuously moving table MRI with golden angle radial sampling

PURPOSE

Continuously moving table (CMT) MRI is a high throughput technique that has multiple applications in whole-body imaging. In this work, CMT MRI based on golden angle (GA, 111.246° azimuthal step) radial sampling is developed at 3 Tesla (T), with the goal of increased flexibility in image reconstruction using arbitrary profile groupings.

THEORY AND METHODS

CMT MRI with GA and linear angle (LA) schemes were developed for whole-body imaging at 3T with a table speed of 20 mm/s. Imaging was performed in phantoms and a human volunteer with extended z fields of view of up to 1.8 meters. Four separate LA and a single GA scan were performed to enable slice reconstructions at four different thicknesses.

RESULTS

GA CMT MRI produced high image quality in phantoms and humans and allowed complete flexibility in reconstruction of slices with arbitrary slice thickness and position from a single data set. LA CMT MRI was constrained by predetermined parameters, required multiple scans and suffered from stair step artifacts that were not present in GA images.

CONCLUSION

GA sampling provides a robust flexible approach to CMT whole-body MRI with the ability to reconstruct slices at arbitrary positions and thicknesses from a single scan.

[Radiological diagnostics in CUP syndrome]

CLINICAL/METHODICAL ISSUE

Imaging plays an essential role in the therapeutic management of cancer of unknown primary (CUP) patients for localizing the primary tumor, for the identification of tumor entities for which a dedicated therapy regimen is available and for the characterization of clinicopathological subentities that direct the subsequent diagnostic and therapeutic strategy.

STANDARD RADIOLOGICAL METHODS

Modalities include conventional x-ray, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound as well as positron emission tomography (PET)-CT and MRI-PET.

PERFORMANCE

In whole body imaging CT has a high sensitivity for tumor entities which frequently present as a metastasized cancer illness. According to the current literature CT is diagnostic in 86% of patients with pancreatic carcinoma, in 36% of patients with colon carcinoma and in 74% of patients with lung carcinoma. Additionally a meta-analysis showed that for patients with squamous cell carcinoma and cervical lymph node metastases a positive diagnosis was possible in 22% of the cases using CT, in 36% using MRI and in 28-57% using 18F-fluorodeoxyglucose PET-CT ((18)F-FDG PET-CT). In addition, MRI plays an important role in the localization of primary occult tumors (e.g. breast and prostate) because of its high soft tissue contrast and options for functional imaging.

ACHIEVEMENTS

At the beginning of the diagnostic algorithm stands the search for a possible primary tumor and CT of the neck, thorax and abdomen is most frequently used for whole body staging. Subsequent organ-specific imaging examinations follow, e.g. mammography in women with axillary lymphadenopathy. For histological and immunohistochemical characterization of tumor tissue, imaging is also applied to identify the most accessible and representative tumor manifestation for biopsy. Tumor biopsy may be guided by CT, MRI or ultrasound and MRI also plays a central role in the localization of primary occult tumors because of superior soft tissue contrast and options for functional imaging (perfusion, diffusion), e.g. investigation of breast carcinoma or prostate carcinoma.

PRACTICAL RECOMMENDATIONS

Whole body staging stands at the beginning of the diagnostic algorithm in CUP syndrome to localize a potential primary tumor. Clinically, contrast-enhanced CT of the neck, thorax and abdomen is frequently applied; however, many studies have demonstrated augmented sensitivity of (18)F-FDG PET-CT for the detection of primary tumors and metastatic tumor manifestations.

Diagnostic accuracy of whole-body PET/MRI and whole-body PET/CT for TNM staging in oncology

PURPOSE

In various tumours PET/CT with [(18)F]FDG is widely accepted as the diagnostic standard of care. The purpose of this study was to compare a dedicated [(18)F]FDG PET/MRI protocol with [(18)F]FDG PET/CT for TNM staging in a cohort of oncological patients.

METHODS

A dedicated [(18)F]FDG PET/MRI protocol was performed in 73 consecutive patients (mean age of 59 years, range 21 - 85 years) with different histologically confirmed solid primary malignant tumours after a routine clinical FDG PET/CT scan (60 min after injection of 295 ± 45 MBq [(18)F]FDG). TNM staging according to the 7th edition of the AJCC Cancer Staging Manual was performed by two readers in separate sessions for PET/CT and PET/MRI images. Assessment of the primary tumour and nodal and distant metastases with FDG PET/CT and FDG PET/MRI was based on qualitative and quantitative analyses. Histopathology, and radiological and clinical follow-up served as the standards of reference. A McNemar test was performed to evaluate the differences in diagnostic performance between the imaging procedures.

RESULTS

From FDG PET/CT and FDG PET/MRI T stage was correctly determined in 22 (82 %) and 20 (74 %) of 27 patients, N stage in 55 (82 %) and 56 (84 %) of 67 patients, and M stage in 32 (76 %) and 35 (83 %) of 42 patients, respectively. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for lymph node metastases were 65 %, 94 %, 79 %, 89 % and 87 % for PET/CT, and 63 %, 94 %, 80 %, 87 % and 85 % for PET/MRI. The respective values for the detection of distant metastases were 50 %, 82 %, 40 %, 88 % and 76 % for PET/CT, and 50 %, 91 %, 57 %, 89 % and 83 % for PET/MRI. Differences between the two imaging modalities were not statistically significant (P > 0.05).

CONCLUSION

According to our results, FDG PET/CT and FDG PET/MRI are of equal diagnostic accuracy for TNM staging in patients with solid tumours.

Diagnostic value of whole-body diffusion-weighted magnetic resonance imaging for detection of primary and metastatic malignancies: a meta-analysis

PURPOSE

To perform a meta-analysis to evaluate the diagnostic performance of whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) technique in detection of primary and metastatic malignancies compared with that of whole-body positron emission tomography/computed tomography (WB-PET/CT).

MATERIALS AND METHODS

Search Pubmed, MEDLINE, EMBASE and Cochrane Library database from January 1984 to July 2013 for studies comparing WB-DWI with WB-PET/CT for detection of primary and metastatic malignancies. Methodological quality was assessed by the quality assessment of diagnostic studies (QUADAS) instrument. Sensitivities, specificities, predictive values, diagnostic odds ratio (DOR) and areas under the summary receiver operator characteristic curve (AUC) were calculated. Potential threshold effect, heterogeneity and publication bias were investigated.

RESULT

Thirteen eligible studies were included, with a total of 1067 patients. There was no significant threshold effect. WB-DWI had a similar AUC (0.966 (95% CI, 0.940-0.992) versus 0.984 (95% CI, 0.965-0.999)) with WB-PET/CT. No significant difference was detected between AUC of WB-DWI and WB-PET/CT. WB-DWI had a pooled sensitivity of 0.897 (95% CI, 0.876-0.916) and a pooled specificity of 0.954 (95% CI, 0.944-0.962). WB-PET/CT had a pooled sensitivity of 0.895 (95% CI, 0.865-0.920) and a pooled specificity of 0.975 (95% CI, 0.966-0.981). Heterogeneity was found to stem primarily from data type (per lesion versus per patient), MR sequence (DWIBS only and DWIBS with other sequence), and primary lesion type (single type and multiple type). The Deeks's funnel plots suggested the absence of publication bias.

CONCLUSION

WB-DWI has similar, good diagnostic performance for the detection of primary and metastatic malignancies compared with WB-PET/CT. DWIBS with other MR sequences could further improve the diagnostic performance. More high-quality studies regarding comparison of WB-DWI and WB-PET/CT and combination of them in detecting malignancies are still needed to be conducted.

Comparison of FDG PET/CT and gadolinium-enhanced MRI for the detection of bone metastases in patients with cancer: a meta-analysis

OBJECTIVE

At present, the differences in the efficacy between PET/CT and MRI for the detection of bone metastases in patients with cancer have not been clearly delineated. We performed a meta-analysis to compare the performance of FDG PET/CT with that of gadolinium-enhanced MRI for the detection of bone metastases in patients with cancer.

METHODS

Studies about PET/CT and MRI for the detection of bone metastases were systematically searched in the MEDLINE, EMBASE, and EBM Review databases. We calculated sensitivities, specificities, diagnostic odds ratios, positive likelihood ratios, negative likelihood ratios (NLR), and constructed summary receiver operating characteristic curves using bivariate regression models for PET/CT and MRI, respectively.

RESULTS

Across 9 studies (1116 patients), FDG PET/CT has similar patient-based sensitivity (0.803 vs 0.837), specificity (0.989 vs 0.977), diagnostic odds ratio (309.0 vs 221.9), positive likelihood ratio (61.7 vs 37.0), and negative likelihood ratio (0.200 vs 0.167) with gadolinium-enhanced MRI. Areas under the curve with 95% confidence interval for FDG PET/CT and gadolinium-enhanced MRI were 0.99 (0.98-0.99) and 0.98 (0.97-0.99), respectively.

CONCLUSIONS

FDG PET/CT and gadolinium-enhanced MRI have excellent diagnostic performance for the detection of bone metastases in patients with cancer.

Initial experience of MR/PET in a clinical cancer center

Magentic Resonance/positron emission tomography (PET) has been introduced recently for imaging of clinical patients. This hybrid imaging technology combines the inherent strengths of MRI with its high soft-tissue contrast and biological sequences with the inherent strengths of PET, enabling imaging of metabolism with a high sensitivity. In this article, we describe the initial experience of MR/PET in a clinical cancer center along with a review of the literature. For establishing MR/PET in a clinical setting, technical challenges, such as attenuation correction and organizational challenges, such as workflow and reimbursement, have to be overcome. The most promising initial results of MR/PET have been achieved in anatomical areas where high soft-tissue and contrast resolution is of benefit. Head and neck cancer and pelvic imaging are potential applications of this hybrid imaging technology. In the pediatric population, MR/PET can decrease the lifetime radiation dose. MR/PET protocols tailored to different types of malignancies need to be developed. After the initial exploration phase, large multicenter trials are warranted to determine clinical indications for this exciting hybrid imaging technology and thereby opening new horizons in molecular imaging.

Comparison between whole-body MRI and Fluorine-18-Fluorodeoxyglucose PET or PET/CT in oncology: a systematic review

BACKGROUND

The aim of the article is to systematically review published data about the comparison between positron emission tomography (PET) or PET/computed tomography (PET/CT) using Fluorine-18-Fluorodeoxyglucose (FDG) and whole-body magnetic resonance imaging (WB-MRI) in patients with different tumours.

METHODS

A comprehensive literature search of studies published in PubMed/MEDLINE, Scopus and Embase databases through April 2012 and regarding the comparison between FDG-PET or PET/CT and WB-MRI in patients with various tumours was carried out.

RESULTS

Forty-four articles comprising 2287 patients were retrieved in full-text version, included and discussed in this systematic review. Several articles evaluated mixed tumours with both diagnostic methods. Concerning the specific tumour types, more evidence exists for lymphomas, bone tumours, head and neck tumours and lung tumours, whereas there is less evidence for other tumour types.

CONCLUSIONS

Overall, based on the literature findings, WB-MRI seems to be a valid alternative method compared to PET/CT in oncology. Further larger prospective studies and in particular cost-effectiveness analysis comparing these two whole-body imaging techniques are needed to better assess the role of WB-MRI compared to FDG-PET or PET/CT in specific tumour types.

Potential Clinical Applications of PET/Magnetic Resonance Imaging

Hybrid PET/magnetic resonance (MR) imaging, which combines the excellent anatomic information and functional MR imaging parameters with the metabolic and molecular information obtained with PET, may be superior to PET/computed tomography or MR imaging alone for a wide range of disease conditions. This review highlights potential clinical applications in neurologic, cardiovascular, and musculoskeletal disease conditions, with special attention to applications in oncologic imaging.

Imaging techniques as predictive and prognostic biomarkers in renal cell carcinoma

A number of imaging modalities are showing promise as predictive and prognostic biomarkers in advanced renal cell carcinoma. This review discusses progress to date in this exciting area and identifies areas of future promise.

Postmortem whole-body MRI in traumatic causes of death

OBJECTIVE

The aim of this study was to determine the sensitivity and specificity of postmortem whole-body MRI for typical injuries resulting from traumatic causes of death.

MATERIALS AND METHODS

Forty cases of accidental death were evaluated with postmortem whole-body MRI. Imaging was conducted according to a standard protocol, and each examination had an average duration of 90 minutes. The imaging findings were correlated with the autopsy findings, which served as the reference standard.

RESULTS

MRI showed the main pathologic process leading to death in 39 of the 40 cases. The sensitivity of postmortem MRI ranged from 100% (pneumothorax) to 40% (fractures of the upper extremities). In general, MRI had a high level of performance for depicting soft-tissue lesions, such as subcutaneous hematoma (e.g., galeal hematoma with a sensitivity 95%). The sensitivity of MRI was remarkably lower for lesions of the upper abdominal organs (liver, 80%; spleen, 50%; pancreas, 60%; kidneys, 66%).

CONCLUSION

Postmortem whole-body MRI had overall good performance for depicting traumatic findings in corpses and therefore may serve an important role as an adjunct to classic autopsy for the forensic examination of cases of traumatic cause of death. However, the reduced sensitivity of postmortem MRI for lacerations of the upper abdominal organs and the observed superimposition of antemortem findings and postmortem findings (e.g., in the pulmonary tissue) in this retrospective study suggest that whole-body postmortem MRI not be recommended as a replacement for classic autopsy.

Current oncologic concepts and emerging techniques for imaging of head and neck squamous cell cancer

The incidence of head and neck squamous cell carcinoma (HNSCC) is increasing and currently they account for 5% of all malignancies worldwide. Inspite of ongoing developments in diagnostic imaging and new therapeutic options, HNSCC still represents a multidisciplinary challenge.One of the most important prognostic factors in HNSCC is the presence of lymph node metastases. Patients with confirmed nodal involvement have a considerable reduction of their 5-year overall survival rate. In the era of individually optimised surgery, chemotherapy and intensity modulated radiotherapy, the main role of pre- and posttherapeutic imaging remains cancer detection at an early stage and accurate follow-up. The combined effort of early diagnosis and close patient monitoring after surgery and/or radio-chemotherapy influences disease progression and outcome predicition in patients with HNSCC.This review article focuses on currrent oncologic concepts and emerging tools in imaging of head and neck squamous cell cancer. Besides the diagnostic spectrum of the individual imaging modalities, their limitations are also discussed. One main part of this article is dedicated to PET-CT which combines functional and morphological imaging. Furthermore latest developments in MRI are presented with regard to lymph node staging and response prediction. Last but not least, a clinical contribution in this review explains, which information the head and neck surgeon requires from the multimodality imaging and its impact on operation planning.

Optimal imaging protocols for lung cancer staging: CT, PET, MR imaging, and the role of imaging

Chest radiography, the most commonly performed imaging technique for the detection of lung disease, is limited in accurately detecting early lung cancer. The main imaging modality for the staging of lung cancer is computed tomography (CT), supplemented by positron emission tomography (PET), usually as a hybrid technique in conjunction with CT (PET/CT). Magnetic resonance (MR) imaging is a useful diagnostic tool for specific indications and has the advantage of not using ionizing radiation. This article discusses the optimal imaging protocols for lung cancer staging using CT, PET (PET/CT), and MR imaging, and the role of imaging in patient management.

[Importance of whole body MRI for staging of colorectal cancer]

CLINICAL/METHODICAL ISSUE

Staging and follow-up of colorectal cancer are usually performed with multimodal imaging strategies. These can be time-intensive and potentially lead to examiner-dependent bias. Alternatively, whole body magnetic resonance imaging (WB-MRI) provides oncologic imaging with a systemic approach.

STANDARD RADIOLOGICAL METHODS

Ultrasound, multislice computed tomography (MSCT), dedicated MRI and positron emission tomography/CT (PET/CT).

METHODICAL INNOVATIONS

High-resolution WB-MRI with focused examination of various organs, such as the pelvis and abdomen, lungs, brain and skeletal system, using different sequence and contrast techniques.

PERFORMANCE

Detection of colorectal tumor recurrence with WB-MRI provides 83% accuracy (lymph node metastases 80%, organ metastases 86%).

ACHIEVEMENTS

Potential cost reduction through decreased examination time and personnel costs.

PRACTICAL RECOMMENDATIONS

Whole body MRI is a radiation-free alternative to standard sequential algorithms of staging and follow-up of colorectal cancer.

Performance of whole-body PET/CT for the detection of distant malignancies in various cancers: a systematic review and meta-analysis

At present, there is no ideal imaging modality for the diagnosis of distant metastases and second primary cancers in cancer patients. We aimed to assess the accuracy of whole-body PET/CT for the overall assessment of distant malignancies in patients with various cancers.

METHODS

Studies about whole-body PET/CT for the detection of distant malignancies in cancer patients were systematically searched in MEDLINE and EMBASE. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios, and constructed summary receiver operating characteristic curves using hierarchical regression models for whole-body PET/CT.

RESULTS

Across 41 studies (4,305 patients), the sensitivity and specificity of whole-body PET/CT were 0.93 (95% confidence interval [CI], 0.88-0.96) and 0.96 (95% CI, 0.95-0.96), respectively. Subgroup analysis showed that the sensitivity and specificity of whole-body PET/CT for various cancers, respectively, were as follows: head and neck cancer, 0.90 (95% CI, 0.83-0.95) and 0.95 (95% CI, 0.94-0.96); lung cancer, 0.91 (95% CI, 0.76-0.97) and 0.96 (95% CI, 0.94-0.98); breast cancer, 0.97 (95% CI, 0.93-0.99) and 0.95 (95% CI, 0.90-0.97); and cancer of digestive system, 0.92 (95% CI, 0.68-0.98) and 0.97 (95% CI, 0.91-0.99).

CONCLUSION

Whole-body PET/CT has excellent diagnostic performance for the overall assessment of distant malignancies in patients with various cancers, especially head and neck cancer, breast cancer, and lung cancer.

Magnetic resonance of the lung: a step forward in the study of lung disease

Magnetic resonance imaging (MRI) of the lung has progressed tremendously in recent years. Because of improvements in speed and image quality, MRI is now ready for routine clinical use. The main advantage of MRI of the lung is its unique combination of structural and functional assessment in a single imaging session. We review the three major clinical indications for MRI of the lung: staging of lung tumors; evaluation of pulmonary vascular disease; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation.

The method and efficacy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography for diagnosing the lymphatic metastasis of colorectal carcinoma

RATIONALE AND OBJECTIVES

The aim of this study was to analyze the morphologic and functional features of metastatic lymph nodes of colorectal carcinoma on (18)F-fluorodeoxyglucose positron emission tomographic (PET)/computed tomographic (CT) images and correlate these with pathologic results to explore the best diagnostic performance.

METHODS

Sixty-eight patients without any previous treatment underwent (18)F-fluorodeoxyglucose PET/CT examinations and subsequent operations. All lymph nodes were evaluated by recording short diameter and maximum standardized uptake value (SUVmax) on axial images and were carefully verified on the surgically resected specimens. The radiologic diagnostic efficacies on the basis of different diagnostic criteria were compared and evaluated with pathologic results.

RESULTS

There was a significant difference for SUVmax between metastatic and benign juxtaintestinal lymph nodes (F = 96.836, P = .000) and a correlation between size and SUVmax in metastatic juxtaintestinal lymph nodes (r = 0.352, P = .038). Diagnosing according to short diameter ≥ 10 mm and SUVmax ≥ 2.5, the sensitivity, specificity, positivity prediction value (PPV), and negative prediction value (NPV) were 10.00%, 98.26%, 66.67%, and 75.84% and 82.50%, 90.43%, 75.00%, and 93.69%, respectively. Considered together, the sensitivity, specificity, PPV, and NPV were 10.00%, 99.13%, 80.00%, and 76.00%, respectively. Receiver-operating characteristic curves showed that the best cutoff values for SUVmax and short diameter were 2.0 and 4.85 mm, respectively; the corresponding sensitivity, specificity, PPV, and NPV, were 91.43%, 87.83%, 69.57%, and 97.12% and 85.71%, 60.87%, 40.00%, and 98.2%, respectively. Considered together, the sensitivity, specificity, PPV, and NPV were 95.00%, 86.96%, 71.70%, and 98.04%, respectively.

CONCLUSIONS

Fluorine-18-fluorodeoxyglucose uptake was a more reliable indicator in diagnosing malignant juxtaintestinal lymph node of colorectal carcinoma. The optimal diagnostic efficacy could be reached by considering morphologic and functional features together.