MRI identification of pseudolesions in the distal tibia articular surface: Frequency and diagnostic criteria.

OBJECTIVE: Pseudolesions of joints are known as focal irregularities of chondral or subchondral bone in typical joint areas and occur frequent but without clinical relevance. This study aims to report the prevalence and describe MRI findings of a previously unreported chondral, mostly posterior located pseudolesion of the distal tibia, and to define criteria to distinguish it from pathologic osteochondral lesions, as well as from another known pseudolesion of this area - the so called "Notch of Harty". MATERIAL AND METHODS: A tri-centric retrospective case-control study included a total of 2,428 patients with ankle MRI examinations performed over a period of 6 years. MRI scans were evaluated by three radiologists in consensus for any cartilage irregularity of the distal tibial articular surface. For this purpose, the tibial articular surface was divided into 9 topographic regions. Proton-density weighted, fat-suppressed sequences in sagittal and coronal acquisition were used to assess the postero-medial articular surface of the tibia. Imaging features such as size and localization of cartilage irregularity and/or a cortical mould as well as presence of associated edema and/or subchondral cysts were reported. Demographic data (sex, age, and weight) was also recorded. Clinical data comprised presence of pain, movement impairment, and concomitant pathologies. RESULTS: A total of 68 patients (34 male, 34 female) with a lesion of the distal tibia were identified that had a new pseudolesion (prevalence of 3%). These lesions occurred most frequently (50 out of 68, 74%) in the postero-medial distal tibia plafond and were more commonly detected in the age group of 9-30 years (47%). In 13 of these 68 cases, the cartilage irregularity was the sole lesion without subchondral abnormalities. By defining these cases as definite pseudolesions, the prevalence was 1% and their age distribution was similar to that of the 55 other lesions with subchondral changes. Here with 11 of the 13 cases the majority (85%) were seen in the posterior part, especially in the postero-medial part (55%) of the distal tibia. The size of the cartilage defect ranged from 1 to 7 mm, and the majority (69%) sized from 2 to 3 mm. In 36 of 68 patients, we have seen subchondral alterations such as edema and/or cysts in addition to cartilage irregularity. 66% (n = 45) of these changes were edema and 37% (n = 25) were cysts. None of these 68 new pseudolesions with or without subchondral changes needed surgical or arthroscopic intervention. In the radiological and orthopaedic reports, clinical symptoms such as pain or instability were never associated with our observed lesions and there was no significant correlation between the presence of motion-related pain and imaging findings of cartilage irregularity, subchondral edema, and subchondral cysts. Thirteen patients had MRI follow-up examinations. Here the lesions did not show any MR morphological changes or clinical deterioration. Besides the new pseudolesion, which occured mainly in the posterior part of the tibia surface, we observed the "Notch of Harty" with a higher prevalence (25%) in our patient cohort. The typical localization was in the antero-medial tibial articular surface, without any edema or cysts. There were no coincidences of patients with both a new pseudolesion and the "Notch of Harty" CONCLUSION: A new pseudolesion is typically seen in the postero-central and postero-medial tibial articular surface with a prevalence of 3% and may be associated with only a small cartilage irregularity. In many cases, however, additional findings such as bone edema and/or an adjacent bone cysts were found, which impairs differentiation of these lesions from pathologic osteochondral lesions. The latter are obviously often associated with a larger cartilage defect and clinical symptoms. Due to the balanced age distribution between those pseudolesions with and without subchondral changes and the lack of clinical symptoms, we conclude that the here reported pseudolesions are not a predilection for a clinically manifest osteochondral lesion (OCL). At the very least, the apparent lack of clinical relevance increases the likelihood that we are dealing with a new true pseudolesion.

Fast, High-Fidelity Addressed Single-Qubit Gates Using Efficient Composite Pulse Sequences.

We use electronic microwave control methods to implement addressed single-qubit gates with high speed and fidelity, for ^{43}Ca^{+} hyperfine "atomic clock" qubits in a cryogenic (100 K) surface trap. For a single qubit, we benchmark an error of 1.5×10^{-6} per Clifford gate (implemented using 600 ns π/2 pulses). For 2 qubits in the same trap zone (ion separation 5 µm), we use a spatial microwave field gradient, combined with an efficient four-pulse scheme, to implement independent addressed gates. Parallel randomized benchmarking on both qubits yields an average error 3.4×10^{-5} per addressed π/2 gate. The scheme scales theoretically to larger numbers of qubits in a single register.

Robust Quantum Memory in a Trapped-Ion Quantum Network Node.

We integrate a long-lived memory qubit into a mixed-species trapped-ion quantum network node. Ion-photon entanglement first generated with a network qubit in ^{88}Sr^{+} is transferred to ^{43}Ca^{+} with 0.977(7) fidelity, and mapped to a robust memory qubit. We then entangle the network qubit with a second photon, without affecting the memory qubit. We perform quantum state tomography to show that the fidelity of ion-photon entanglement decays ∼70 times slower on the memory qubit. Dynamical decoupling further extends the storage duration; we measure an ion-photon entanglement fidelity of 0.81(4) after 10 s.

[Clinical radiological evaluation of teeth-part 2 : Caries, inflammatory dental changes and important differential diagnoses]. / Klinisch-radiologische Beurteilung der Zähne ­ Teil 2 : Karies, entzündliche Zahnveränderungen und wichtige Differenzialdiagnosen.

Inflammatory diseases of the teeth and periodontium are widespread and are frequent secondary diagnoses in head and neck examinations. Periapical inflammation can be the cause of sinusitis or abscess formation in the oral and maxillofacial region. Early detection is important for the patient's course of treatment. For further diagnostics, a dental presentation should be carried out. Dental radiological examinations, such as panoramic radiographs and dental films are used for specific diagnostics. This article is intended to provide an overview of the different stages of caries, the most important inflammatory dental changes and their most frequent differential diagnoses.

[Clinical radiological evaluation of teeth-part 1 : Anatomy and anomalies]. / Klinisch-radiologische Beurteilung der Zähne ­Teil 1 : Anatomie und Anomalien.

Radiological assessment of the teeth and periodontium is often left to the dentist. Nevertheless, it is useful to know the anatomy and possible anomalies of the teeth in order to correctly assess pathological processes in both projection radiographic and slice imaging. Dental radiological examinations, such as panoramic slice imaging (PSA) and dental film are used for targeted diagnostics. In the case of incidental findings, a dental presentation should be made for further clarification. This article first provides an overview of the anatomy and anomalies of teeth.

[Imaging of chronic inflammatory bowel diseases in childhood and adolescence : Repetitorium]. / Bildgebung chronisch-entzündlicher Darmerkrankungen im Kindes- und Jugendalter : Repetitorium.

Chronic inflammatory bowel diseases can already occur in childhood and in contrast to affected adults, are more frequently manifested as unspecific symptoms. Therefore, at the time of diagnosis the gastrointestinal tract may already be severely affected. Both the diagnostic methods and the treatment concept, which is ideally carried out by pediatric gastroenterologists, differ from those used in adults. The primary diagnostics mainly include sonography and hydro-magnetic resonance imaging (MRI), whereby each modality offers certain advantages depending on the patient and the examiner but is also subject to limitations in terms of feasibility and evaluation. Imaging diagnostics contribute not only to finding the diagnosis but also to assessing the extent of the disease. They also serve to monitor the course of the disease in terms of treatment response or failure, to assess the activity and to detect and quantify possible complications, such as fistulas or abscesses.

[Chronic nonbacterial osteomyelitis : Imaging and differential diagnoses]. / Chronische nichtbakterielle Osteomyelitis : Bildgebung und Differenzialdiagnosen.

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease in childhood and adolescence with a preference for the female gender. It is manifested with multiple osseous lesions, with a predilection for the metaphyseal end zones of the long bones of the lower extremities. These bone lesions usually occur multifocally, can recur and develop a different appearance depending on the bone structure affected. Patients present with a longer disease history, changing clinical symptoms and unspecific paraclinical signs. Magnetic resonance imaging (MRI) is the imaging of choice and particularly as a whole body examination can speed up the diagnosis and is an important component of follow-up controls. Differential diagnoses include numerous inflammatory, benign and malignant bone diseases. Therefore, it is essential to know the diagnosis of CNO and to take it into consideration in cases of an unclear inflammatory bone process in young patients.

[Fracture classification-part 1 : Modern low-dose radiation imaging in pediatric traumatology]. / Frakturklassifikation ­ Teil 1 : Moderne strahlensparende Diagnostik in der Kindertraumatologie.

BACKGROUND: Fractures in children are significantly more common than bone fractures in adults. Overall, they have a good prognosis regarding spontaneous correction and a restitutio ad integrum. The aim of this study is to provide an overview of established modern (low-dose radiation) imaging techniques in pediatric fractures. MATERIALS AND METHODS: Knowledge of typical fractures for different ages, of the individual bone nuclei of the growth plate, and epiphyseal injuries are important for the correct radiological diagnosis. This review also focuses on fractures of the elbow because misinterpretation may result in delays of consolidation with subsequent growth disturbances, joint dysfunctions, and malpositions. RESULTS AND CONCLUSIONS: In addition to conventional x­rays, fracture sonography is becoming increasingly important for the detection of fractures in children. In the upper extremity, a sensitivity of 96% and specificity of 97% can be achieved for some fracture entities, e.g., at the distal forearm. Computed tomography is used restrictively but plays an important role in a few special indications for polytraumatized children and preoperative assessment, e.g., in the case of transitional fractures.

Correction to: Perfusion MRI in CNS disease: current concepts.

The above article was published with one author name being incorrect. The published paper states "H. von Tengg", whereas it should be "H. von Tengg-Kobligk". The author name has been corrected above.