7,120 research outputs found
A glance at imaging bladder cancer.
Purpose: Early and accurate diagnosis of Bladder cancer (BCa) will contribute extensively to the management of the disease. The purpose of this review was to briefly describe the conventional imaging methods and other novel imaging modalities used for early detection of BCa and outline their pros and cons.
Methods: Literature search was performed on Pubmed, PMC, and Google scholar for the period of January 2014 to February 2018 and using such words as bladder cancer, bladder tumor, bladder cancer detection, diagnosis and imaging .
Results: A total of 81 published papers were retrieved and are included in the review. For patients with hematuria and suspected of BCa, cystoscopy and CT are most commonly recommended. Ultrasonography, MRI, PET/CT using 18F-FDG or 11C-choline and recently PET/MRI using 18F-FDG also play a prominent role in detection of BCa.
Conclusion: For initial diagnosis of BCa, cystoscopy is generally performed. However, cystoscopy can not accurately detect carcinoma insitu (CIS) and can not distinguish benign masses from malignant lesions. CT is used in two modes, CT and computed tomographic urography (CTU), both for dignosis and staging of BCa. However, they cannot differentiate T1 and T2 BCa. MRI is performed to diagnose invasive BCa and can differentiate muscle invasive bladder carcinoma (MIBC) from non-muscle invasive bladder carcinoma (NMIBC). However, CT and MRI have low sensitivity for nodal staging. For nodal staging PET/CT is preferred. PET/MRI provides better differentiation of normal and pathologic structures as compared with PET/CT. Nonetheless none of the approaches can address all issues related for the management of BCa. Novel imaging methods that target specific biomarkers, image BCa early and accurately, and stage the disease are warranted
Magnetic resonance imaging for localization of prostate cancer in the setting of biochemical recurrence
The clinical suspicion of local recurrence of prostate cancer after radical treatment is based on the onset of biochemical failure. The use of multiparametric magnetic resonance imaging (MRI) for prostate cancer has increased over recent years, mainly for detection, staging, and active surveillance. However, suspicion of recurrence in the set of biochemical failure is becoming a significant reason for clinicians to request multiparametric MRI. Radiologists should be able to recognize the normal posttreatment MRI findings. Fibrosis and atrophic remnant seminal vesicles (SV) after radical prostatectomy are often found and must be differentiated from local relapse. Moreover, brachytherapy, external beam radiotherapy, and focal therapies tend to diffusely decrease the signal intensity of the peripheral zone on T2-weighted images due to the loss of water content, consequently mimicking tumor and hemorrhage. The combination of T2-weighted images and functional studies like diffusion-weighted imaging and dynamic contrast-enhanced imaging improves the identification of local relapse. Tumor recurrence tends to restrict on diffusion images and avidly enhances after contrast administration. The authors provide a review of the normal findings and the signs of local tumor relapse after radical prostatectomy, external beam radiotherapy, brachytherapy and focal therapies
Pancreatic tumors imaging: an update
Currently, ultrasound (US), computed tomography (CT) and Magnetic Resonance imaging (MRI) represent the mainstay in the evaluation of pancreatic solid and cystic tumors affecting pancreas in 80-85% and 10-15% of the cases respectively. Integration of US, CT or MR imaging is essential for an accurate assessment of pancreatic parenchyma, ducts and adjacent soft tissues in order to detect and to stage the tumor, to differentiate solid from cystic lesions and to establish an appropriate treatment. The purpose of this review is to provide an overview of pancreatic tumors and the role of imaging in their diagnosis and management. In order to a prompt and accurate diagnosis and appropriate management of pancreatic lesions, it is crucial for radiologists to know the key findings of the most frequent tumors of the pancreas and the current role of imaging modalities. A multimodality approach is often helpful. If multidetector-row CT (MDCT) is the preferred initial imaging modality in patients with clinical suspicion for pancreatic cancer, multiparametric MRI provides essential information for the detection and characterization of a wide variety of pancreatic lesions and can be used as a problem-solving tool at diagnosis and during follow-up
Methods of anatomical and metabolic imaging in head and neck region tumors
The incidence of head and neck cancer (HNC) ranges from 5.5% to 6.2% of general cancer incidence in Poland as well as in other European countries and in the US. Precise evaluation of the clinical stage in this group of patients allows for personalized treatment, inter alia, to choose proper surgery technique, to plan and verify radiation therapy. It is a result of availability of wide spectrum of imaging methods currently used in oncology. These methods are also used in the suitable assessment of antineoplastic therapy effects, which gives the chance of early detection of cancer progression.
Methods of imaging diagnostics â anatomical and metabolic â differ in terms of sensitivity, specificity and diagnostic accuracy. Each of them has advantages and disadvantages in imaging of HNC, hence, choice of treatment method should not be made based on single imaging modality. Increasingly, information obtained from alternative imaging studies support optimal decision in everyday clinical practice.
This review describes clinical usefulness of currently available morphological and metabolic imaging methods in HNC patients, with particular emphasis on innovative technologies, like PET/MR hybrid
Imaging follow-up after liver transplantation
Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures
Carcinoma of the uterine cervix: aspects on preoperative staging and assessment of treatment effect using magnetic resonance imaging
Background Uterine CC mainly affects young women as it is caused by persistent HPV
infection most often acquired during adolescence. Early-stage disease is treated with surgery,
and locally advanced disease with chemoradiotherapy. Both treatment methods are associated
with infertility and morbidity. Combined treatment modalities (both surgery and CRT) should
be avoided as this has negative impact on morbidity. The choice of treatment depends on the
tumour stage at diagnosis, and accurate initial staging is therefore essential. MRI has been an
integral part of the routine diagnostic work-up for CC patients at Karolinska since 2003. MRI
is also an important tool in the evaluation of treatment, which traditionally is performed after
the treatment is completed. However, identification of imaging parameters for prediction of
the treatment effect early during the therapy, would provide more individualized treatment.
This would enable early change of the treatment strategy for those predicted to experience
treatment failure and may contribute to less morbidity in others.
Aim The overall aim of this thesis was to identify an optimal examination protocol for MRI of
the pelvis in patients with biopsy verified CC scheduled for surgery, improve identification of
risk factors for recurrence, and identify MRI standards for therapy monitoring, in particular
the timing of MRI in relation to treatment.
In Study I 57 patients with early-stage disease treated with surgery were evaluated with three
different sets of MR protocols. We found that magnetic resonance tumour (mrT), magnetic
resonance lymph node (mrN) and magnetic resonance distant metastases (mrM) stages were
the same for a basic standard protocol including transaxial and sagittal T2-weighted images,
and transaxial T1-weighted sequences, as for protocols with the addition of oblique and/or
contrast-enhanced sequences. The inter-observer agreement was âgoodâ between readers for
all three protocols. The agreement among readers was negatively affected by prior conization
of the patient.
Study II included 102 patients comprising the patients in study I with the addition of patients
receiving brachytherapy prior to surgery. Two main groups were compared regarding 10-year
outcome, those with visible and non-visible tumours on pre-treatment MRI. Tumour
recurrence was seen in 17.9% of patients with visible tumour, and in 17.6% of patients with
non-visible tumours. Recurrence free survival (RFS) was longer for patients having
undergone conization prior to MRI than for those who had not.
Study III The inter-observer agreement among experienced and less experienced observers of
MRI and TVS was investigated in 60 patients with all stages of CC for this study. For all
MRI observers, the inter-observer agreement was âgoodâ for assessment of stromal- and
parametrial invasion (PMI). Only for tumour detection was inter-observer agreement lower
for the less experienced observers. For TVS observers, the agreement was âmoderateâ for
assessment of tumour detection, stromal- and parametrial invasion. The agreement was
significantly higher among experienced TVS observers regarding PMI.
Study IV was designed as a pilot-study including 15 patients with stage IB2-IIIB scheduled
for concomitant chemoradiotherapy (CRT). MRI was performed at baseline, 3 weeks, 5
weeks, and 12 weeks after treatment start. During follow-up, 7 patients relapsed, (âpoor
prognosis groupâ, PP), 8 patients did not relapse (âgood prognosis groupâ, GP). We
compared tumour size, change in size (Îsize), ADC and change in ADC (ÎADC), and
tumour visibility on MRI at all four time points between the PP and GP group. By combining
tumour size at baseline with tumour visibility on DWI at 5 weeks, the area under the curve
(AUC) in receiver operating characteristics (ROC) analysis reached 0.83.
The findings of this thesis confirm the value of MRI for CC staging and therapy follow-up. In
early-stage disease, unequivocally without parametrial invasion, evaluation consisting of a
basic standard protocol including transaxial and sagittal T2-weighted images, and transaxial
T1-weighted sequences is not improved by addition of oblique and contrast-enhanced
sequences. Interpretation of the images is affected by prior conization but the clinical
importance of detecting small tumours on MRI can be questioned as tumour visibility in
early-stage disease does not affect long term outcome. Interobserver agreement is higher for
MR than for TVS. A reasonable level of inter-observer agreement can be achieved for both
experienced and less experienced observers of MRI and TVS, after attending a short basic
training session on evaluation of cervical tumours. Prediction of disease recurrence seems
feasible by combining visibility on high b-value diffusion-weighted imaging (DWI) at 5
weeks after treatment start with tumour size at baseline MRI. For all four studies in this
thesis, the limited number of patients must be considered, and results need to be confirmed in
larger cohorts
Non-invasive diagnostic imaging of colorectal liver metastases
Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases (CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liver- directed therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs
Contrast-enhanced imaging in the biological and functional assessment of breast cancer
Contrast-enhanced MRI and ultrasound have emerged as additional imaging modalities in the management of breast cancer. This thesis examines the role these modalities currently play in the surgical management of breast cancer. Ways in which MRI may contribute to staging, diagnosis, treatment and prognosis are investigated.
It was demonstrated that small additional enhancing foci on MRI, away from the primary tumour, represent in-situ or invasive cancer foci. Although their resection may result in extended wide local excisions or even unnecessary mastectomies, it was demonstrated that MRI findings do not currently influence the amount of tissue removed during breast conservation surgery. Volumetric analysis of breast MRI was proposed as an accurate objective assessment of the extent of surgery required for a particular tumour. Breast MRI was shown to be useful in the assessment of extent of residual disease during primary medical therapy but not in the detection of axillary lymph node metastases.
In the second section of this thesis, the clinical application of pre-operative MRI in providing prognostic as well as diagnostic information was evaluated. Contrast- enhancement with both MRI and ultrasound is believed to depend on tumour angiogenesis but only a weak correlation was demonstrated between contrast- enhancement intensity and tumour angiogenesis. The detection of angiogenesis was applied to Doppler ultrasound using a novel microbubble ultrasound contrast agent (Levovist). Within a multicentre prospective study, Doppler ultrasound was shown to be a powerful discriminator of malignancy in suspected local recurrence. A strong correlation was found between MRI and histological assessment of tumour size but there was no correlation between enhancement intensity and other pathological prognostic variables.
This thesis has shown that breast MRI is useful in pre-operative planning of surgery and provides diagnostic as well as limited prognostic information. Future proposed studies to determine the effect of MRI on patient management and patient outcome in breast cancer are considered
AI-basierte volumetrische Analyse der Lebermetastasenlast bei Patienten mit neuroendokrinen Neoplasmen (NEN)
Background: Quantification of liver tumor load in patients with liver metastases from neuroendocrine neoplasms is essential for therapeutic management. However, accurate measurement of three-dimensional (3D) volumes is time-consuming and difficult to achieve. Even though the common criteria for assessing treatment response have simplified the measurement of liver metastases, the workload of following up patients with neuroendocrine liver metastases (NELMs) remains heavy for radiologists due to their increased morbidity and prolonged survival. Among the many imaging methods, gadoxetic acid (Gd-EOB)-enhanced magnetic resonance imaging (MRI) has shown the highest accuracy.
Methods: 3D-volumetric segmentation of NELM and livers were manually performed in 278 Gd-EOB MRI scans from 118 patients. Eighty percent (222 scans) of them were randomly divided into training datasets and the other 20% (56 scans) were internal validation datasets. An additional 33 patients from a different time period, who underwent Gd-EOB MRI at both baseline and 12-month follow-up examinations, were collected for external and clinical validation (n = 66). Model measurement results (NELM volume; hepatic tumor load (HTL)) and the respective absolute (ÎabsNELM; ÎabsHTL) and relative changes (ÎrelNELM; ÎrelHTL) for baseline and follow-up-imaging were used and correlated with multidisciplinary cancer conferences (MCC) decisions (treatment success/failure). Three readers manually segmented MRI images of each slice, blinded to clinical data and independently. All images were reviewed by another senior radiologist.
Results: The modelâs performance showed high accuracy between NELM and liver in both internal and external validation (Matthewâs correlation coefficient (Ï): 0.76/0.95, 0.80/0.96, respectively). And in internal validation dataset, the group with higher NELM volume (> 16.17 cm3) showed higher Ï than the group with lower NELM volume (Ï = 0.80 vs. 0.71; p = 0.0025). In the external validation dataset, all response variables (âabsNELM; âabsHTL; ârelNELM; ârelHTL) reflected significant differences across MCC decision groups (all p < 0.001). The AI model correctly detected the response trend based on ârelNELM and ârelHTL in all the 33 MCC patients and showed the optimal discrimination between treatment success and failure at +56.88% and +57.73%, respectively (AUC: 1.000; P < 0.001).
Conclusions: The created AI-based segmentation model performed well in the three-dimensional quantification of NELMs and HTL in Gd-EOB-MRI. Moreover, the model showed good agreement with the evaluation of treatment response of the MCCâs decision.Hintergrund: Die Quantifizierung der Lebertumorlast bei Patienten mit Lebermetastasen von neuroendokrinen Neoplasien ist fĂŒr die Behandlung unerlĂ€sslich. Eine genaue Messung des dreidimensionalen (3D) Volumens ist jedoch zeitaufwĂ€ndig und schwer zu erreichen. Obwohl standardisierte Kriterien fĂŒr die Beurteilung des Ansprechens auf die Behandlung die Messung von Lebermetastasen vereinfacht haben, bleibt die Arbeitsbelastung fĂŒr Radiologen bei der Nachbeobachtung von Patienten mit neuroendokrinen Lebermetastasen (NELMs) aufgrund der höheren Fallzahlen durch erhöhte MorbiditĂ€t und verlĂ€ngerter Ăberlebenszeit hoch. Unter den zahlreichen bildgebenden Verfahren hat die GadoxetsĂ€ure (Gd-EOB)-verstĂ€rkte Magnetresonanztomographie (MRT) die höchste Genauigkeit gezeigt.
Methoden: Manuelle 3D-Segmentierungen von NELM und Lebern wurden in 278 Gd-EOB-MRT-Scans von 118 Patienten durchgefĂŒhrt. 80% (222 Scans) davon wurden nach dem Zufallsprinzip in den Trainingsdatensatz eingeteilt, die ĂŒbrigen 20% (56 Scans) waren interne ValidierungsdatensĂ€tze. Zur externen und klinischen Validierung (n = 66) wurden weitere 33 Patienten aus einer spĂ€teren Zeitspanne des MultidisziplinĂ€re Krebskonferenzen (MCC) erfasst, welche sich sowohl bei der Erstuntersuchung als auch bei der Nachuntersuchung nach 12 Monaten einer Gd-EOB-MRT unterzogen hatten. Die Messergebnisse des Modells (NELM-Volumen; hepatische Tumorlast (HTL)) mit den entsprechenden absoluten (ÎabsNELM; ÎabsHTL) und relativen VerĂ€nderungen (ÎrelNELM; ÎrelHTL) bei der Erstuntersuchung und der Nachuntersuchung wurden zum Vergleich mit MCC-Entscheidungen (Behandlungserfolg/-versagen) herangezogen. Drei Leser segmentierten die MRT-Bilder jeder Schicht manuell, geblindet und unabhĂ€ngig. Alle Bilder wurden von einem weiteren Radiologen ĂŒberprĂŒft.
Ergebnisse: Die Leistung des Modells zeigte sowohl bei der internen als auch bei der externen Validierung eine hohe Genauigkeit zwischen NELM und Leber (Matthew's Korrelationskoeffizient (Ï): 0,76/0,95 bzw. 0,80/0,96). Und im internen Validierungsdatensatz zeigte die Gruppe mit höherem NELM-Volumen (> 16,17 cm3) einen höheren Ï als die Gruppe mit geringerem NELM-Volumen (Ï = 0,80 vs. 0,71; p = 0,0025). Im externen Validierungsdatensatz wiesen alle Antwortvariablen (âabsNELM; âabsHTL; ârelNELM; ârelHTL) signifikante Unterschiede zwischen den MCC-Entscheidungsgruppen auf (alle p < 0,001). Das KI-Modell erkannte das Therapieansprechen auf der Grundlage von ârelNELM und ârelHTL bei allen 33 MCC-Patienten korrekt und zeigte bei +56,88% bzw. +57,73% eine optimale Unterscheidung zwischen Behandlungserfolg und -versagen (AUC: 1,000; P < 0,001).
Schlussfolgerungen: Das Modell zeigte eine hohe Genauigkeit bei der dreidimensionalen Quantifizierung des NELMs-Volumens und der HTL in der Gd-EOB-MRT. DarĂŒber hinaus zeigte das Modell eine gute Ăbereinstimmung bei der Bewertung des Ansprechens auf die Behandlung mit der Entscheidung des Tumorboards
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