[Autoimmune pancreatitis versus pancreatic cancer]. / Autoimmunpankreatitis versus Pankreaskarzinom.

CLINICAL ISSUE: Autoimmune pancreatitis (AIP) is classified as a distinct form of pancreatitis according to the guidelines. It is characterized by imaging morphologic and histologic features and is associated with extrapancreatic manifestations in type 1 IgG 4-associated disease. Symptoms and findings almost always improve with administration of steroids. Differentiation from pancreatic ductal adenocarcinoma is required, particularly in the presence of AIP with focal parenchymal involvement. STANDARD RADIOLOGIC PROCEDURES: If AIP is suspected, abdominal ultrasound and/or endosonography, computed tomography (CT), and preferably magnetic resonance imaging (MRI) are indicated. A distinction is made between parenchymal and ductal changes that specifically indicate the presence of AIP. METHODOLOGICAL INNOVATIONS AND EVALUATION: The diagnosis of autoimmune pancreatitis should be made based on the International Consensus Criteria (ICDC), in which the five main features (imaging, serology, histology, other organ involvement, response to steroid medication) are assessed. In type 1 AIP, typical imaging changes are sufficient to establish the diagnosis even with negative histology, whereas for type 2 AIP, histologic evidence is required. Imaging changes help in the differential diagnosis from pancreatic cancer. PRACTICAL RECOMMENDATIONS: The following article addresses and evaluates crucial imaging diagnostic CT and MRI criteria for correct classification of findings, description of results, and differentiation of autoimmune pancreatitis from pancreatic cancer.

[Incidental and leave me alone findings of abdominal organs-part 2 : Spleen, kidneys and adrenal glands and efferent urinary tracts]. / Inzidentelle und Leave-me-alone-Befunde der abdominellen Organe ­ Teil 2 : Milz, Niere und Nebennieren sowie ableitende Harnwege.

For masses of the spleen, which are mostly benign, accessory spleens, cysts and hemangiomas should be radiologically described; however, if confirmed further follow-up control is unnecessary. In the case of disseminated small masses, chronic inflammation and granulomatous diseases, such as tuberculosis and sarcoidosis should be considered in the differential diagnostics. Solid masses in the kidneys should always be further clarified, with the exception of a fat-rich angiomyolipoma. For cystic masses of the kidneys, the modified Bosniak classification for computed tomography or magnetic resonance imaging should be used. Masses of the adrenal glands greater than 10mm in size should be clarified further as well as those where fat is not detected, independent of the size and evidence of malignancy.

[Diagnostic Imaging of pancreatic carcinoma-Update of the new guideline]. / Diagnostik beim Pankreaskarzinom ­ Update in der neuen Leitlinie.

The new German S3 guidelines on ductal pancreatic adenocarcinoma were published for the first time on the homepage of the Association of the Scientific Medical Societies in Germany (AWMF) in December 2021 as a new update and thus the second update (first update 2013) and contain a large number of innovations in terms of diagnostics and treatment. The guidelines were organized and led by the German Society for Digestive and Metabolic Diseases (DGVS). In this article we would like to present the central content and innovations related to the radiological diagnostics of ductal pancreatic adenocarcinoma. The most important innovations are the highest recommendation strength in favor of computed tomography (CT) when assessing tumor spread as well as the adaptation of the European guidelines for cystic tumors by magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) as the method of first choice. A further innovation is the implementation of a structured reporting of CT findings for describing the anatomical tumor resectability on the basis of the publication presented by the Abdominal Imaging Working Group and the Oncological Imaging Working Group of the German Radiological Society. There is no evidence for the implementation of radiological imaging in the field of aftercare or in the field of screening.

[Incidental and "leave me alone" findings of abdominal organs-part 1 : Liver, gall ducts and pancreas]. / Inzidentelle und Leave-me-alone-Befunde der abdominellen Organe ­ Teil 1 : Leber, Gallenwege und Pankreas.

Incidentalomas of the parenchymal organs of the abdomen, i.e. radiological findings in these organs that are not the primary focus of the clinical question, are frequent in this region of the body. In particular, findings presumed to be unimportant, such as cystic masses in the liver, the bile duct system or the pancreas, initially appear to be irrelevant in the diagnosis. For the liver we define the mostly clearly diagnosable simple cysts and hemangiomas as leave me alone lesions. Otherwise, we recommend a classification of incidentalomas into the three major categories (<0.5 cm, 0.5-1.5 cm and >1.5 cm) as well as an assessment with respect to clearly benign and suspect imaging characteristics in the context of a classification of patients into three different risk groups.

[Incidental and "leave me alone" findings of the GI tract-part 2 : Intestinal wall and mesentery]. / Inzidentelle und Leave-me-alone-Befunde des GI-Trakts ­ Teil 2 : Darmwand und Mesenterium.

Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) asymptomatic incidental findings of the gastrointestinal (GI) tract are increasingly being recognized. Incidental findings are frequently not part of the primary inquiry from referring physicians but it is obligatory to make a diagnosis and to stipulate the need for further clarification. A multitude of incidental findings in the intestinal lumen, in the intestinal wall and in the adjacent mesentery or subperitoneal space are shown in CT and MRI of the GI tract. The last part of the two-part review addresses the gastrointestinal incidental findings in the intestinal wall and the adjacent sections. Extramural incidental findings occur as mesenteric inflammation, tumors and cysts. Many of the findings can be classified as benign and as "leave me alone lesions" do not necessitate any further clarification but in contrast others need a definitive clarification. The most important incidental findings in the GI tract are systematically classified, illustrated and evaluated with respect to the clinical relevance, depending on the localization (e.g. stomach, small and large intestines).

[Incidental and "leave me alone" findings in the GI tract-part 1 : Intestinal lumen and intestinal wall]. / Inzidentelle und Leave-me-alone-Befunde des GI-Trakts ­ Teil 1 : Darmlumen und Darmwand.

CLINICAL PROBLEM: Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) asymptomatic incidental findings of the gastrointestinal tract (GI) are increasingly being recognized. Incidental findings are frequently not part of the primary inquiry from referring physicians but it is obligatory to make a diagnosis and to stipulate the need for further clarification. RADIOLOGICAL STANDARD PROCEDURES: A multitude of incidental findings in the intestinal lumen, in the intestinal wall and in the adjacent mesenterium or subperitoneal space are shown in CT and MRI. METHODOLOGICAL INNOVATIONS AND ASSESSMENT: The first part of the two-part overview addresses the intestinal incidental findings in the lumen, such as coproliths, invaginations, mucoceles and chronic dilatations. In the intestinal wall, thickenings of neoplastic and nonneoplastic origins are discussed. Many of the findings can be classified as benign and as "leave me alone lesions" do not necessitate any further clarification but in contrast others need a definitive clarification. The most important incidental findings in the GI tract are systematically classified, illustrated and evaluated with respect to the clinical relevance, depending on the localization (e.g. stomach, small and large intestines).

[Rational staging and follow-up of colorectal cancer : Do guidelines provide further help?] / Rationales Staging und Follow-up beim kolorektalen Karzinom : Helfen Leitlinien weiter?

CLINICAL/METHODICAL ISSUE: Colorectal cancer is one of the most common malignant tumors. Preoperative imaging is crucial in rectal cancer as patients can only receive optimal treatment when accurate staging is performed. The N­staging is often difficult with the available options and must be called into question as a staging parameter. STANDARD RADIOLOGICAL METHODS: Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) are particularly suitable for local staging. Multiparametric MRI with diffusion imaging is indispensable for tumor follow-up. METHODICAL INNOVATIONS: The assessment of infiltration of the mesorectal fascia is best accomplished using high-resolution MRI. In addition, extramural vascular infiltration (EMVI) has become established as another important prognostic factor. After neoadjuvant therapy and restaging of locally advanced rectal cancer, the identification and validation of prognostically relevant image parameters are prioritized. Multiparametric MRI of the rectum including diffusion imaging as well as the application of radiological and pathological scores (MR-TRG) are becoming increasingly more important in this context. ASSESSMENT: For the radiologist it is important to become familiar with indicators of the resectability of rectal cancer and to be able to reliably read prognostically relevant imaging parameters in the tumor follow-up. PRACTICAL RECOMMENDATIONS: For the practical application, the establishment of a fixed MRI protocol is essential. In addition to a guideline-compliant TNM classification, the radiologist must provide the clinician with information on infiltration of the mesorectal fascia and extramural vascular infiltration. The MR-TRGs are becoming increasingly more important in tumor follow-up.

[Radiological imaging of acute infectious and non-infectious enterocolitis]. / Radiologische Bildgebung akuter infektiöser und nichtinfektiöser Enterokolitiden.

BACKGROUND: Computed tomography (CT) is often used as the initial diagnostic test in patients with inflammatory and infectious types of enterocolitis. The differential diagnosis is broad, including infectious, non-infectious and vascular causes, which have substantially different management strategies. Although a definitive diagnosis often relies on endoscopic biopsy results, stool culture results or other clinical features, radiologists often help to guide the diagnosis. OBJECTIVES: This article reviews the CT appearance of different infectious and inflammatory forms of enterocolitis. General and specific intramural and extramural CT findings in the small bowel and colon are discussed. Added focus is placed on distribution patterns and medication side effects that can act as important diagnostic clues. RESULTS: Infectious enterocolitis is due to bowel inflammation caused by bacteria, viruses, or parasites, which show a preferential localization. Pancolitis can be seen with Clostridium difficile with the relatively specific CT finding of the "giraffe coat" sign. Inflammatory enterocolitis can be primary (inflammatory bowel disease, vasculitis) or secondary (radiation therapy, graft versus host disease etc.). Ischemic colitis and enteritis can result from arterial compromise, low flow states that globally reduce perfusion or venous insufficiency. The CT appearance varies depending on the cause, the time of onset and grade of reperfusion. CONCLUSION: Knowledge of characteristic mural and extramural CT of MRI findings, geographic distributions and therapy effects help to guide the differential diagnostics in inflammatory and infectious types of enterocolitis.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany--Part 2: Abdominal Parenchymal Organs.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract as well as the parenchymal abdominal organs. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. The working group experts cover the most recent relevant studies concerning liver-specific contrast media with an emphasis on a new classification system for liver adenomas. Additionally studies regarding selective internal radiotherapy (SIRT) are reviewed. For the pancreas the most important tumors are described followed by an introduction to the most recently introduced functional imaging techniques. The manuscript concludes with some remarks on recent studies and concerning chronic pancreatitis as well as autoimmune pancreatitis. KEY POINTS: • Different subtypes of liver adenomas with different therapeutic consequences can be differentiated by MRI • Most recently published studies focus on liver imaging with extracellular liver specific contrast media as well as diffusion weighted imaging. They consider this new method having a high diagnostic potential. • For pancreatic neoplasm diagnosis diffusion--as well as perfusion--imaging is considered as a highly promising method.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany - Part 1: Gastrointestinal Tract.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract with all parenchymatous abdominal organs. In addition to the clinical and scientific further development of abdominal radiology, the education of radiologists within this core discipline of radiology is one of the major aims. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. This manuscript focuses on the most recent literature on the diagnosis of the stomach, small bowel, colon and rectum. The review with a focus on the most recent studies published by German radiologists concludes with a synopsis of mesenterial bleeding and ischemia followed by a critical appraisal of the current literature on conventional abdominal radiography. KEY POINTS: Based on recent literature and guidelines there is a change of paradigms regarding the diagnosis of esophagus and gastric cancer towards CT, which is considered equally to endosonography. For small bowel imaging in Crohn's disease ultrasound as well as MRI with a new focus on DWI are the most important imaging modalities scientifically. For colonic diagnosis virtual colonoscopy has replaced the conventional radiological methods. For staging of rectal carcinoma as well as for therapeutic stratification a high resolution MRI of the pelvis is of paramount interest. Multislice CT is considered the most important modality to assess mesenteric ischemia or bleeding.

Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study.

PURPOSE: Evaluation of diagnostic accuracy of abdominal CT depending on the type of enteric contrast agent. METHODS AND MATERIALS: Multislice CTs of 2,008 patients with different types of oral preparation (positive with barium, n = 576; neutral with water, n = 716; and no enteric contrast, n = 716) were retrospectively evaluated by two radiologists including delineation of intestinal segments and influence on diagnosis and diagnostic reliability exerted by the enteric contrast, using a three-point scale. Furthermore, diagnostic reliability of the delineation of selected enteric pathologies was noted. CT data were assigned into groups: oncology, inflammation, vascular, pathology, trauma and gastrointestinal pathology. RESULTS: Delineation of the bowel was clearly practicable across all segments irrespective of the type of enteric contrast, though a slight impairment was observed without enteric contrast. Although delineation of intestinal pathologies was mostly classified "clearly delimitable" more difficulties occurred without oral contrast (neutral/positive/no contrast, 0.8 %/3.8 %/6.5 %). Compared to examinations without enteric contrast, there was a significant improvement in diagnosis that was even increased regarding the reader's diagnostic reliability. Positive opacification impaired detection of mucosal enhancement or intestinal bleeding. CONCLUSION: Water can replace positive enteric contrast agents in abdominal CTs. However, selected clinical questions require individual enteric contrast preparations. Pathology detection is noticeably impaired without any enteric contrast.

Comparison of manual and semi-automatic measuring techniques in MSCT scans of patients with lymphoma: a multicentre study.

OBJECTIVES: Multicentre evaluation of the precision of semi-automatic 2D/3D measurements in comparison to manual, linear measurements of lymph nodes regarding their inter-observer variability in multi-slice CT (MSCT) of patients with lymphoma. METHODS: MSCT data of 63 patients were interpreted before and after chemotherapy by one/two radiologists in five university hospitals. In 307 lymph nodes, short (SAD)/long (LAD) axis diameter and WHO area were determined manually and semi-automatically. Volume was solely calculated semi-automatically. To determine the precision of the individual parameters, a mean was calculated for every lymph node/parameter. Deviation of the measured parameters from this mean was evaluated separately. Statistical analysis entailed intraclass correlation coefficients (ICC) and Kruskal-Wallis tests. RESULTS: Median relative deviations of semi-automatic parameters were smaller than deviations of manually assessed parameters, e.g. semi-automatic SAD 5.3 vs. manual 6.5 %. Median variations among different study sites were smaller if the measurement was conducted semi-automatically, e. g. manual LAD 5.7/4.2 % vs. semi-automatic 3.4/3.4 %. Semi-automatic volumetry was superior to the other parameters (2.8 %). CONCLUSIONS: Semi-automatic determination of different lymph node parameters is (compared to manually assessed parameters) associated with a slightly greater precision and a marginally lower inter-observer variability. These results are with regard to the increasing mobility of patients among different medical centres and in relation to the quality management of multicentre trials of importance. KEY POINTS: • In a multicentre setting, semi-automatic measurements are more accurate than manual assessments. • Lymph node volumetry outperforms all other semi-automatically and manually performed measurements. • Use of semi-automatic lymph node analyses can reduce the inter-observer variability.

Therapy response evaluation of malignant lymphoma in a multicenter study: comparison of manual and semiautomatic measurements in CT.

PURPOSE: Comparison of manual one-/bi-dimensional measurements versus semi-automatically derived one-/bi-dimensional and volumetric measurements for therapy response evaluation of malignant lymphoma during CT follow-up examinations in a multicenter setting. MATERIALS AND METHODS: MSCT data sets of patients with malignant lymphoma were evaluated before (baseline) and after two cycles of chemotherapy (follow-up) at radiological centers of five university hospitals. The long axis diameter (LAD), the short axis diameter (SAD) and the bi-dimensional WHO of 307 target lymph nodes were measured manually and semi-automatically using dedicated software. Lymph node volumetry was performed semi-automatically only. The therapeutic response was evaluated according to lymphoma-adapted RECIST. RESULTS: Based on a single lymph node, semi-automatically derived multidimensional parameters allowed for significantly more accurate therapy response classification than the manual or the semi-automatic unidimensional parameters. Incorrect classifications were reduced by up to 9.6%. Compared to the manual approach, the influence of the study center on correct therapy classification is significantly less relevant when using semi-automatic measurements. CONCLUSION: Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients by approximately 9.6% in the multicenter setting in comparison to linear parameters. Semi-automatic quantitative software tools may help to significantly reduce wrong classifications that are associated with the manual assessment approach. KEY POINTS: ► Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients ► Manual lymph node evaluation with uni-dimensional parameters is inferior to semi-automatic analysis in a multicenter setting ► Semi-automatic quantitative software tools should be introduced in clinical study evaluation.

MSCT follow-up in malignant lymphoma: comparison of manual linear measurements with semi-automated lymph node analysis for therapy response classification.

PURPOSE: Assignment of semi-automated lymph node analysis compared to manual measurements for therapy response classification of malignant lymphoma in MSCT. MATERIALS AND METHODS: MSCT scans of 63 malignant lymphoma patients before and after 2 cycles of chemotherapy (307 target lymph nodes) were evaluated. The long axis diameter (LAD), short axis diameter (SAD) and bi-dimensional WHO were determined manually and semi-automatically. The time for manual and semi-automatic segmentation was evaluated. The ref. standard response was defined as the mean relative change across all manual and semi-automatic measurements (mean manual/semi-automatic LAD, SAD, semi-automatic volume). Statistical analysis encompassed t-test and McNemar's test for clustered data. RESULTS: Response classification per lymph node revealed semi-automated volumetry and bi-dimensional WHO to be significantly more accurate than manual linear metric measurements. Response classification per patient based on RECIST revealed more patients to be correctly classified by semi-automatic measurements, e. g. 96.0 %/92.9 % (WHO bi-dimensional/volume) compared to 85.7/84.1 % for manual LAD and SAD, respectively (mean reduction in misclassified patients of 9.95 %). Considering the use of correction tools, the time expenditure for lymph node segmentation (29.7 ± 17.4 sec) was the same as with the manual approach (29.1 ± 14.5 sec). CONCLUSION: Semi-automatically derived "lymph node volume" and "bi-dimensional WHO" significantly reduce the number of misclassified patients in the CT follow-up of malignant lymphoma by at least 10 %. However, lymph node volumetry does not outperform bi-dimensional WHO.

Diagnostic and radiological management of cystic pancreatic lesions: important features for radiologists.

Cystic pancreatic neoplasms are often an incidental finding, the frequency of which is increasing. The understanding of such lesions has increased in recent years, but the numerous types of lesions involved can hinder differential diagnosis. They include, in particular, intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN), and mucinous cystic neoplasms (MCN). Knowledge of their histological and radiological structure, as well as distribution in terms of localization, age, and sex, helps to differentiate such tumours from common pancreatic pseudocysts. Several types of cystic pancreatic neoplasms can undergo malignant transformation and, therefore, require differentiated radiological management. This review aims to develop a broader understanding of the pathological and radiological characteristics of cystic pancreatic neoplasms, and provide a guideline for everyday practice based on current concepts in the radiological management of the given lesions.

Incidentally detected splenic lesions in ultrasound: does contrast-enhanced ultrasonography improve the differentiation of benign hemangioma/hamartoma from malignant lesions?

PURPOSE: The aim of the study was to identify and validate enhancing features for differentiating benign vascular neoplasms of the hemangioma/hamartoma type from malignant splenic lesions on contrast-enhanced ultrasonography (CEUS). MATERIALS AND METHODS: 136 splenic lesions (58 benign vascular neoplasms, 78 malignant) in 136 patients underwent baseline US and pulse-inversion CEUS after sulfur hexafluoride-filled microbubble injection. Two on-site readers assessed lesion enhancement features during arterial and parenchymal phase in consensus. Best predicting CEUS features for lesion diagnosis were identified through univariate and multivariate analyses. Two blinded off-site readers independently issued a confidence rating for lesion diagnosis in baseline US and CEUS using extracted diagnostic CEUS features. Diagnostic performance, receiver operating curves (Az-value), and interreader agreement were calculated. The reference standards were histopathology or CT and/or MR imaging with clinical follow-up.  RESULTS: Multivariate analysis outlined arterial hyperenhancement or isoenhancement to be an independent CEUS predictor of benign vascular neoplasms (odds ratio, 3.558; p < 0.0017). Within the subgroup of isoechoic or hypoechoic lesions, arterial hyperenhancement was virtually diagnostic for benign vascular neoplasm (odds ratio, 21.333; p < 0.001). The diagnostic accuracy and confidence (Az-value) of the two readers was 63.2 % and 70.6 % (0.785 and 0.818) for baseline US, which improved significantly to 87.5 % and 88.2 % (0.915 and 0.908) for CEUS (p < 0.001). Interreader agreement also increased with CEUS (қ = 0.88) compared to baseline US (қ = 0.52). CONCLUSION: Sulfur hexafluoride-enhanced CEUS improves differentiation between benign vascular and malignant splenic tumors and may be especially useful in clinical scenarios in which the incidental hypoechoic splenic lesion is unclear on conventional US.

Liver lesion segmentation in MSCT: effect of slice thickness on segmentation quality, measurement precision and interobserver variability.

PURPOSE: To evaluate the effect of slice thickness on semi-automated liver lesion segmentation. MATERIALS AND METHODS: In this retrospective study, liver MSCT scans from 60 patients were reconstructed at a slice thickness of 1.5 mm, 3 mm and 5 mm. 106 liver lesions (8 - 64 mm, mean size 25 ± 13 mm) were evaluated independently by two radiologists using semi-automated segmentation software (OncoTreat®). Lesions were classified as cystic, hypodense and hyperdense according to their contrast-to-noise ratio (CNR). The long axis diameter (LAD), short axis diameter (SAD) and volume were measured. The necessity for manual correction (NOC = relative difference between uncorrected and corrected volume) and the relative interobserver difference (RID) were determined. Precision was calculated in terms of relative measurement deviations (RMD) from the reference standard (mean of 1.5 mm data sets). Wilcoxon test, t-test and intraclass correlation coefficients (ICC) were employed for statistical analysis. All statistical analyses were intended to be exploratory. RESULTS: Regardless of the liver lesion subtype, the NOC was found to be significantly higher for 5 mm than for 3 mm (p = 0.035) and 1.5 mm (p = 0.0002). The RID was consistently low for metric and volumetric parameters with no difference in any of the slice thicknesses for all subtypes (ICC > 0.89). The RMD increased significantly for the LAD, SAD and volume at a slice thickness of 5 mm (p < 0.01), e. g. volume: 0.5 % at 1.5 mm, 5.5 % at 3.0 mm and 7.6 % at 5.0 mm. CONCLUSION: Since the deviations in measurements are significant, and manual corrections made during semi-automated assessment of the liver lesions are considerable, a slice thickness of 1.5 mm, and no more than 3.0 mm, should be used for reconstruction for inconsistently vascularized liver lesions.

PET surveillance of patients with Ewing sarcomas of the trunk: Must the lower legs be included?

AIM: FDG-PET(/CT) is frequently used in surveillance of Ewing sarcoma (ES) patients. Since ES and PNET (primitive neuroectodermal tumours) may cause peripheral metastases some centers routinely recommend whole body PET acquisition from head to toe what may necessitate repositioning of the patient and thus extending examination time. It is not clear yet whether inclusion of lower leg adds to the diagnostic accuracy of PET scanning, especially in primary tumors of the trunk. PATIENTS, METHOD: 40 patients with ES and PNET of the trunk who were referred for surveillance after primary therapy with complete remission, were evaluated retrospectively: 27 men, 13 women; mean age at diagnosis 16.3 (3-35) years. At the time of diagnosis 28 patients had localized and 12 metastatic disease. Almost all of the patients had undergone a combined chemotherapy with surgery or/and radiotherapy. 156 follow-up PET scans of the legs of these patients were evaluated retrospectively. RESULTS: only in three (1.9%) of 156 scans a pathologic FDG accumulation was attributed to metastatic disease of the lower extremities. In these cases the observation of metastatic disease in the legs did not alter therapy, since in all three cases a multifocal disease progression was observed. CONCLUSION: scanning of the lower legs may be omitted during follow-up in patients in whom the primary tumor was located in the trunk and in whom no clinical signs pointing to metastases in the lower legs are present. This provides a sufficient diagnostic power and a shorter examination time, thus increasing patient comfort and scanner availability.