[Focal lesions in whole-body MRI in multiple myeloma : Quantification of tumor mass and correlation with disease-related parameters and prognosis]

BACKGROUND AND OBJECTIVES

In this study, we evaluated methods of quantification of tumor mass in whole-body MRI (wb-MRI) in multiple myeloma and correlated these with disease-related parameters in serum and bone marrow.

MATERIALS AND METHODS

We retrospectively evaluated wb-MRIs of 52 patients with focal infiltration pattern and a total of 700 focal lesions (subsequently called lesions). We determined the longest diameter (LD), the segmented volume (SV), and the morphology (spherical or non-spherical). We correlated total number/volume of the lesions with clinical parameters and prognosis and furthermore LD with SV. After that we analyzed the agreement of SV and estimated volume (EV) using the volume formula of a sphere based on LD.

RESULTS

Results showed no significant correlations of total number/volume with prognosis or clinical parameters. The latter were situated predominantly in the normal range. Furthermore, 10% of lesions were spherical. SV and LD correlated significantly in single lesions and on patient level. SV was in lesions <6 cm³ systematically larger and in lesions ≥6 cm³ smaller than EV. In 95%, we found in small lesions a deviation of EV versus SV from +0.9 cm³ to -4.6 cm³ and in large lesions from +160 cm³ to -111 cm³ (EV-SV).

CONCLUSIONS

Quantification of tumor mass in the focal infiltration pattern is performed more accurately by volumetry than LD due to the predominant existence of non-spherical lesions. The patient cohort with clinical parameters predominantly in the normal range is distributed to ISS stage I and partly pretreated, a fact that makes interpretation of absent correlations more difficult. Consider also a variation in activitiy of lesions and a diffuse infiltration not detectable by MRI.

CT-Guided Percutaneous Spine Biopsy in Suspected Infection or Malignancy: A Study of 214 Patients

Purpose: To retrospectively determine the effectiveness and accuracy of CT-guided percutaneous biopsy of malignant and inflammatory bone lesions of the spine and to assess the reliability of pre-biopsy CT and MRI. Materials and Methods: 214 patients with lesions of the spine, which were suspicious either for being malignant or inflammatory, underwent CT-guided biopsy for pathological and/or microbiological detection. Biopsy samples were sent for histological examination in 128/214 patients, for microbiological analysis in 17/214 patients and for both analyses in 69/214 patients. Retrospectively, the diagnostic accuracy and sensitivity/specificity of the pre-interventional imaging (CT and MRI) were determined. In addition, the influence of the biopsy on subsequent patient management was assessed. Results: The accuracy was 94.4 % for histopathological analysis and 97.7 % for microbiological analysis. In 25 % of cases the microbiological analysis revealed an underlying pathogen that was not significantly affected by pre-biopsy antibiotic therapy. The sensitivity/specificity of the pre-biopsy cross-sectional imaging concerning suspected malignancy was 69 %/78 %. For suspected infection, the sensitivity/specificity of pre-biopsy imaging was 81 %/44 %. In 52 % of all cases, the biopsy result changed subsequent patient management. Conclusion: Percutaneous CT-guided spine biopsy is a useful and reliable diagnostic procedure to establish a definitive diagnosis but with a relatively low yield of microorganisms in the case of infection. Key Points: • CT-guided spine biopsy is an accurate and reliable procedure in case of infection and tumour.• The results of the CT-guided spine biopsy have a significant influence on the subsequent patient management.• Pathogen recovery-rate in case of infection is moderate but not significantly affected by prebiopsy antibiotic therapy. Citation Format: • Rehm J, Veith S, Akbar M et al. CT-Guided Percutaneous Spine Biopsy in Suspected Infection or Malignancy: A Study of 214 Patients. Fortschr Röntgenstr 2016; 188: 1156 - 1162.

Modern Radiological Imaging of Osteoarthritis of The Hip Joint With Consideration of Predisposing Conditions

Osteoarthritis is the most common disease of the hip joint in adults and has a high socioeconomic impact. This review article discusses the value of three imaging modalities in the diagnosis of osteoarthritis of the hip joint: projection radiography, computed tomography, and magnetic resonance imaging (MRI). Besides established imaging diagnostics of osteoarthritis, this review also outlines new MRI techniques that enable the biochemical analysis of hip joint cartilage and discusses predisposing deformities of the hip joint including femoroacetabular impingement (FAI) with labral pathologies, hip joint dysplasia, malrotation, and, finally, femoral head necrosis, for which early detection and an exact description of the extent and localization of the necrotic area are extremely important. Conventional X-rays remain indispensable for the diagnosis of osteoarthritis, while MRI is able to depict additional early symptoms and signs of activity of the disease. With the increasing number of joint-preserving interventions such as surgical hip luxation and hip joint arthroscopy for treating FAI, high-resolution imaging is gaining further importance for both pre- and postoperative diagnostics because it can accurately recognize early stages of joint damage. With high-resolution MR sequences and MR arthrography, the detailed depiction of the thin cartilaginous coating of the hip joint has become quite possible.

KEY POINTS

• Projection radiography is the method of choice for the diagnostic work-up of osteoarthritis of the hip joint.• Using computed tomography, the amount of acetabular bone stock prior to total hip arthroplasty is assessed in selected patients.• Magnetic resonance imaging can substantiate the indication of surgery in case of discrepancy between clinical symptoms and radiological findings of the hip joint.• If distinct and left untreated, predisposing conditions (such as femoroacetabular impingement) may lead to early development of osteoarthritis of the hip joint.• Functional cartilage imaging can verify changes in the biochemical composition of the cartilage before they become morphologically evident. Citation Format: • Weber MA, Merle C, Rehnitz C et al. Modern Radiological Imaging of Osteoarthritis of The Hip Joint With Consideration of Predisposing Conditions. Fortschr Röntgenstr 2016; 188: 635 - 651.

Comparison of Modern 3D and 2D MR Imaging Sequences of the Wrist at 3 Tesla

PURPOSE

To compare the image quality of modern 3 D and 2 D sequences for dedicated wrist imaging at 3 Tesla (T) MRI.

MATERIALS AND METHODS

At 3 T MRI, 18 patients (mean age: 36.2 years) with wrist pain and 16 healthy volunteers (mean age: 26.4 years) were examined using 2 D proton density-weighted fat-saturated (PDfs), isotropic 3 D TrueFISP, 3 D MEDIC, and 3 D PDfs SPACE sequences. Image quality was rated on a five-point scale (0 - 4) including overall image quality (OIQ), visibility of important structures (cartilage, ligaments, TFCC) and degree of artifacts. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) of cartilage/bone/muscle/fluid as well as the mean overall SNR/CNR were calculated using region-of-interest analysis. ANOVA, paired t-, and Wilcoxon-signed-rank tests were applied.

RESULTS

The image quality of all tested sequences was superior to 3 D PDfs SPACE (p < 0.01). 3 D TrueFISP had the highest combined cartilage score (mean: 3.4) and performed better in cartilage comparisons against 3 D PDfs SPACE in both groups and 2 D PDfs in volunteers (p < 0.05). 3 D MEDIC performed better in 7 of 8 comparisons (p < 0.05) regarding ligaments and TFCC. 2 D PDfs provided constantly high scores. The mean overall SNR/CNR for 2 D PDfs, 3 D PDfs SPACE, 3 D TrueFISP, and 3 D MEDIC were 68/65, 32/27, 45/47, and 57/45, respectively. 2 D PDfs performed best in most SNR/CNR comparisons (p < 0.05) and 3 D MEDIC performed best within the 3 D sequences (p < 0.05).

CONCLUSION

Except 3 D PDfs SPACE, all tested 3 D and 2 D sequences provided high image quality. 3 D TrueFISP was best for cartilage imaging, 3 D MEDIC for ligaments and TFCC and 2 D PDfs for general wrist imaging.

KEY POINTS

• 3 D TrueFISP is recommended for cartilage imaging of the wrist at 3 T.• 3 D MEDIC is recommended for ligaments and TFCC.• Robust 2 D PDfs should be used in routine protocols. 3 D sequences may be added depending on the clinical question.• 3 D PDfs SPACE is currently inferior. Citation Format: • Rehnitz C, Klaan B, von Stillfried F et al. Comparison of Modern 3D and 2D MR Imaging Sequences of the Wrist at 3 Tesla. Fortschr Röntgenstr 2016; 188: 753 - 762.

[Osteoidosteoma. From diagnosis to treatment]

An osteoid osteoma is a benign bone-forming tumor which usually presents in childhood and adolescence and is characterized by extensive nocturnal pain. Computed tomography (CT) is used to reveal the typical radiolucent nidus surrounded by a sclerotic reaction and in magnetic resonance imaging (MRI) a nidal enhancement and perifocal edema can confirm the diagnosis. Having shown excellent success rates radiofrequency ablation has become the treatment of choice which allows minimally invasive and precise destruction of nidal tumor tissue. By using thermal protection techniques and multiple ablation positions successful therapy of perineural tumors and niduses with diameters of more than 2 cm are possible.

[Clinical or radiological diagnosis of impingement]

CLINICAL/METHODICAL ISSUE

Shoulder impingement syndrome is a clinically common entity involving trapping of tendons or bursa with typical clinical findings.

STANDARD RADIOLOGICAL METHODS

Important radiological procedures are ultrasound, magnetic resonance imaging (MRI) and MR arthrography. Projection radiography and computed tomography (CT) are ideal to identify bony changes and CT arthrography also serves as an alternative method in cases of contraindications for MRI. These modalities support the clinically suspected diagnosis of impingement syndrome and may identify its cause in primary diagnosis. In addition, effects of impingement are determined by imaging. Therapy decisions are based on a synopsis of radiological and clinical findings.

PERFORMANCE

The sensitivity and specificity of these imaging modalities with regard to the diagnostics of a clinically evident impingement syndrome are given in this review article.

PRACTICAL RECOMMENDATIONS

Orthopedic and trauma surgeons express the suspicion of an impingement syndrome based on patient history and physical examination and radiologists confirm structural changes and damage of intra-articular structures using dedicated imaging techniques.

Modern Radiological Postoperative Diagnostics of the Hip Joint in Children and Adults

The assessment of bone healing and loosening of endoprosthesis material was long the primary indication for postoperative projection radiography and CT imaging of the hip joint following trauma and endoprosthesis implantation. With the increasing number of joint-preserving surgery, e. g. of surgical hip luxation and hip arthroscopy for the treatment of femoroacetabular impingement (FAI), high-resolution imaging of intra-articular pathologies before and after surgery has become increasingly important. In this review article, diagnostic imaging of the hip joint is presented following common trauma surgery and orthopedic surgery interventions. The imaging modalities of projection radiography, CT and MRI including direct MR-arthrography are discussed with regard to their diagnostic capability in the postoperative assessment of the hip joint. Among others topics, imaging is discussed following hip arthroplasty, following surgical hip luxation and arthroscopic interventions for the treatment of FAI, as well as following core decompression for avascular necrosis of the femoral head. Moreover, orthopedic interventions of the hip joint in children and adolescents are presented and the dedicated reporting of postoperative imaging is outlined.

KEY POINTS

• Consolidation of osteotomies and position of implants should be assessed in postoperative imaging. • MRI is useful for confirming correct articulation after treatment of congenital hip dislocation. • Radiologically assessable complications after total hip replacement are inlay wear, loosening, dislocation, periarticular ossifications and infection. • MRI can detect and classify pseudotumours in cases of metal-metal pairing after total hip replacement.

[Imaging of the elbow joint with focused MRI. Part 1: examination techniques and sequences for bone and ligaments]

Imaging of the elbow joint places high demands on the quality of imaging due to the challenging anatomy and the sometimes subtle findings. For the diagnosis of periarticular soft tissues, ligamentous structures and in individual cases for fracture and tumor diagnosis, magnetic resonance imaging (MRI) is mostly groundbreaking and allows a reliable diagnosis in most cases. This review article discusses the complex imaging anatomy and anatomical variants of this joint and the most common osseous and ligamentous injuries of the elbow joint are presented. The typical MRI findings and indications are illustrated and discussed and possible pitfalls are pointed out. The various examination techniques and MRI sequences are also addressed.

[Aseptic osteonecrosis in children and adolescents]

BACKGROUND

Aseptic osteonecrosis (AO) in children and adolescents has been described in all parts of the skeleton. The disease is presumed to be caused by local blood circulation disorders, the reasons for which are multifactorial and occur more often in times of stronger growth intensity.

DISEASE SEQUELAE

The disease leads to bone catabolism which can affect the epiphyses, metaphyses, apophyses, carpal and tarsal bones of the hands and feet. The more stretched the form alteration of the bone at the end of the diseases is, the earlier arthritic alterations occur due to the incongruence of the corresponding joint partner. If a growth plate is affected, a growth disorder can be the result.

DIAGNOSTICS AND THERAPY

The diagnostics and therapeutic measures are oriented to the site and extent of the disease and the age of the child. For early forms of AO magnetic resonance imaging (MRI) is the imaging method of choice. In recent years the medicinal therapy of AO has been described as an additional option. The disease lasts at least several months up to years and more commonly affects boys than girls with the exception of necrosis of the foot tarsals.

CONCLUSION

The early diagnosis and immediate initiation of adequate therapy which must take the age and stage of the disease into consideration, can reduce a possible joint destruction. Prostaglandin therapy, as an off label use, leads to a reduction of pain and improvement in mobility.

Prevalence of carpal tunnel syndrome and wrist osteoarthritis in long-term paraplegic patients compared with controls

We compared functional and structural changes in the hands, in particular the prevalence of carpal tunnel syndrome, in 56 paraplegic patients who had been wheelchair dependent for over 25 years with a group of able-bodied volunteers (with matching criteria for gender and age). The hands were assessed by clinical examination, electrophysiology, disabilities of the arm shoulder and hand score and magnetic resonance imaging. Hand function was worse and wrist pain was experienced more often in the paraplegic patients, and they also had a significantly higher prevalence of carpal tunnel syndrome both clinically and electrophysiologically. The prevalence of wrist and trapeziometacarpal osteoarthritis was significantly higher in the right hand.