Lunotriquetral coalitions are the most common form of carpal coalition wherein the cartilage between the lunate and triquetrum ossification centers failed to undergo apoptosis. This technical case report examines the arthrokinematics of bilateral lunotriquetral coalitions with dissimilar Minnaar types in one participant with one asymptomatic wrist and one wrist with suspected distal radioulnar joint injury. Static and dynamic (four-dimensional) CT images during pronosupination were captured using a photon-counting detector CT scanner. Interosseous proximity distributions were calculated between the lunotriquetral coalition and adjacent bones in both wrists to quantify arthrokinematics. Interosseous proximity distributions at joints adjacent to the lunotriquetral coalition demonstrate differences in median and minimum interosseous proximities between the asymptomatic and injured wrists during resisted pronosupination. Altered kinematics from lunotriquetral coalitions may be a source of ulnar-sided wrist pain and discomfort, limiting the functional range of motion. This case report highlights potential alterations to wrist arthrokinematics in the setting of lunotriquetral coalitions and possible associations with ulnar-sided wrist pain, highlighting anatomy to examine in radiographic follow-up. Furthermore, this case report demonstrates the technical feasibility of four-dimensional CT using photon-counting detector technology in assessing arthrokinematics in the setting of variant wrist anatomy.

OBJECTIVE: To evaluate the accuracy of four-dimensional computerized-tomography (4DCT) for localizing parathyroid adenomas (PTAs) in cases with discordant or non-localizing ultrasonography (US) and Technetium-99 sestamibi (MIBI) scans.
METHODS: Retrospective case series and systematic review.
METHODS: A case series and meta-analysis of patients diagnosed with primary hyperparathyroidism and discordant US and MIBI scans who underwent 4DCT prior to surgery. A comprehensive search for all relevant publications in the English literature between December 2006 and March 2022 was conducted for the meta-analysis. Patients undergoing parathyroidectomy between January 2015 and December 2021 were identified from the institutional electronic database for the case series. All studies were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 4DCT adenoma localization capabilities.
RESULTS: Thirteen retrospective studies that included 379 patients and one case series that included 37 patients were identified and analyzed. A per-patient analysis revealed sensitivity for lateralization to the correct side (n = 181) ranging from 80% to 100% with a fixed effects model of 89% (95%confidence interval [CI]: 82%-93%) and a PPV for lateralization ranging from 63%-95% with a random effects model of 87% (95% CI: 77%-95%). Sensitivity of localization to the correct quadrant (n = 172) ranged from 53% to 100% with a random effects model of 90.4% (95% CI: 76%-99%), and the PPV for localization ranged from 52% to 100% with a random effects model of 82% (95% CI: 73%-89%).
CONCLUSIONS: 4DCT enhances imaging capabilities of localizing PTAs in cases of discordant or non-localizing US and MIBI scans.
METHODS: NA Laryngoscope, 134:2198-2205, 2024.

OBJECTIVE: To compare the diagnostic performance of scapholunate gap (SLG) measurements acquired with dart throwing (DT), radio-ulnar deviation (RUD), and clenching fist (CF) maneuvers on 4D CT for the identification of scapholunate instability.
METHODS: In this prospective study, 47 patients with suspected scapholunate interosseous ligament (SLIL) tears were evaluated from March 2015 to March 2020 with semiautomatic quantitative analysis on 4D CT. Five parameters (median, maximal value, range, and coefficient of variation) for SLG, lunocapitate angle (LCA), and radioscaphoid angle (RSA) obtained during DT maneuver were evaluated in patients with and without SLIL tears. CT arthrography was used as the gold standard for the SLIL status. The SLG values obtained were also compared with those obtained during CF and RUD maneuvers.
RESULTS: Significant differences in all SLG- and LCA-derived parameters are found between patients with and without SLIL tears with DT (p < 0.003). The best diagnostic performance for the diagnosis of SLIL tears was obtained with median and maximal SLG values (sensitivity and specificity of 86-89% and 95%) and with maximal and range LCA values (sensitivity and specificity of 86% and 74%). No significant differences were observed for RSA values (p > 0.275). The SLG range obtained with DT maneuver was the only dynamic parameter statistically different between patients with partial and complete torn SLIL (p = 0.037).
CONCLUSIONS: 4D CT of the wrist during DT showed a similar performance than RUD and a better performance than CF for the differentiation between patients with and without SLIL tears.
CONCLUSIONS: • Four-dimensional computed tomography can dynamically assess scapholunate instability. • The best results for differentiating between patients with and without SLIL tears were obtained with SLG median and maximal values. • The dart throwing and radio-ulnar deviation maneuvers yielded the best results for the dynamic evaluation of scapholunate instability.

In primary hyperparathyroidism (PHPT) the diagnosis and treatment of ectopic parathyroid adenomas (EPTA) is a challenging process for head and neck surgeons. We present five patients with EPTA in different locations, along with an in-depth discussion of imaging modalities. We used sestamibi scintigraphy (MIBI) and ultrasound as first line imaging tools in asymptomatic hypercalcemia and PHPT. Single photon emission computed tomography (SPECT) was combined with MIBI or computed tomography (CT) if a parathyroid pathology was not localized initially. Four-dimensional parathyroid CT (4D-CT) was the last imaging modality preferred to localize the ectopic parathyroid gland. We performed focused unilateral neck exploration (FUNE) with intraoperative frozen section analysis as a routine procedure for imaging-detected lesions. Bilateral neck exploration was performed for re-exploration cases and imaging-negative cases. Histopathology confirmed EPTA and postoperative serum calcium normalized in all cases. 4D-CT is promising for ectopic parathyroid gland localization if all other imaging modalities fail. Despite the advancements in imaging, surgical experience continues to play the central role in the management of ectopic parathyroid pathologies.

BACKGROUND: Elongated mandibular coronoid process is a rare condition defined as enlargement of the coronoid process. The only useful way to treat the mouth-opening limitation is resection of the elongated coronoid process. Four-dimensional CT (4DCT; three spatial dimensions plus time axis) is a novel imaging technique. Its usefulness of for evaluation of dynamic movements such as joint motion has been reported. Here, we show the potential usefulness of 4DCT evaluation in a patient with elongated mandibular coronoid process.
METHODS: A 59-year-old female who suffered from mouth-opening difficulty and pressure during mouth opening was referred to our department. Elongation of the right coronoid process was evident in a panoramic X-ray image. The mandibular movement and temporal muscle motility before and after coronoidectomy in this patient on 4DCT could be evaluated.
CONCLUSIONS: 4DCT is useful in the diagnosis and surgical outcome of elongated coronoid process.

UNASSIGNED: Cardiac resynchronization therapy (CRT) could be an effective therapy for patients suffering from severe heart failure (HF) despite optimal medical therapy. However, it has been reported that about 30% of patients receive ineffective results even if CRT has been performed. In a recent study, four-dimensional computed tomography (4DCT) was shown to be useful for pre-operative planning in transcatheter aortic valve intervention. The 4DCT is reconstructed with 10% increments over the cardiac cycle so that the displacement of the myocardium can be evaluated over time. From the above, we considered that the most delayed site where we would implant the left ventricular (LV) lead could be recognized by 4DCT.
UNASSIGNED: A 55-year-old man with a recurrent admission for HF indicated for CRT was referred to our hospital. In this patient, the 12-lead electrocardiogram (ECG) showed a relatively narrow QRS complex with a left bundle branch block pattern. An echocardiography demonstrated severe LV dysfunction. Although no dyssynchrony was detected, the LV lead was inserted into the most delayed site based on the 4DCT. Three-month later, the ejection fraction increased and the cardiothoracic ratio obviously shortened.
UNASSIGNED: We experienced a case in which we could evaluate the effective implantation site for the LV lead based on the 4DCT even though the effective site was not detected by echocardiography, and we could implant the LV lead at that effective site. The 4DCT may be useful for implanting LV leads in effective sites.

A 49-year-old man with CTEPH (pre-procedural mean pulmonary artery pressure: 36 mmHg) underwent balloon pulmonary angioplasty. Chronic total occlusion of the left inferior pulmonary artery trunk was observed. To evaluate the collateral vessels of the chronic total occlusion, 4D-CTA was performed. The examination was performed using a 256-row detector CT system using the test bolus tracking method. 4D-CTA showed the bronchial artery-to-left inferior pulmonary artery collateral supply, which was confirmed by a selective bronchial artery angiography. The patient\'s symptoms improved with balloon pulmonary angioplasty of the other stenotic lesions. 4D-CTA can noninvasively evaluate the anatomy and hemodynamics of multiple systemic collaterals simultaneously. This technique can support interventions in systemic artery-to-pulmonary artery collaterals, such as embolization, and could be helpful in challenging balloon pulmonary angioplasty interventions for chronic total occlusion to identify vessel structures distal to the chronic total occlusion and collateral channels for a retrograde approach.

暂无摘要。

OBJECTIVE: Abdominal organ motion seriously compromises the targeting accuracy for particle therapy in patients with pancreatic adenocarcinoma. This study compares three different abdominal corsets regarding their ability to reduce pancreatic motion and their potential usability in particle therapy.
METHODS: A patient-individualized polyurethane (PU), a semi-individualized polyethylene (PE), and a patient-individualized three-dimensional-scan based polyethylene (3D-PE) corset were manufactured for one healthy volunteer. Time-resolved volumetric four-dimensional-magnetic resonance imaging (4D-MRI) and single-slice two-dimensional (2D) cine-MRI scans were acquired on two consecutive days to compare free-breathing motion patterns with and without corsets. The corset material properties, such as thickness variance, material homogeneity in Hounsfield units (HU) on computed tomography (CT) scans, and manufacturing features were compared. The water equivalent ratio (WER) of corset material samples was measured using a multi-layer ionization chamber for proton energies of 150 and 200 MeV.
RESULTS: All corsets reduced the pancreatic motion on average by 9.6 mm in inferior-superior and by 3.2 mm in anterior-posterior direction. With corset, the breathing frequency was approximately doubled and the day-to-day motion variations were reduced. The WER measurements showed an average value of 0.993 and 0.956 for the PE and 3DPE corset, respectively, and of 0.298 for the PU corset. The PE and 3DPE corsets showed a constant thickness of 2.8 ± 0.2 and 3.8 ± 0.2 mm, respectively and a homogeneous material composition with a standard deviation (SD) of 31 and 32 HU, respectively. The PU corset showed a variable thickness of 4.2 - 25.6 mm and a heterogeneous structure with air inclusions with an SD of 113 HU.
CONCLUSIONS: Abdominal corsets may be effective devices to reduce pancreatic motion. For particle therapy, PE-based corsets are preferred over PU-based corset due to their material homogeneity and constant thickness.

OBJECTIVE: In-house software is commonly employed to implement new imaging and therapy techniques before commercial solutions are available. Risk analysis methods, as detailed in the TG-100 report of the American Association of Physicists in Medicine, provide a framework for quality management of processes but offer little guidance on software design. In this work, we examine a novel model-based four-dimensional computed tomography (4DCT) protocol using the TG-100 approach and describe two additional methods for promoting safety of the associated in-house software.
METHODS: To implement a previously published model-based 4DCT protocol, in-house software was necessary for tasks such as synchronizing a respiratory signal to computed tomography images, deformable image registration (DIR), model parameter fitting, and interfacing with a treatment planning system. A process map was generated detailing the workflow. Failure modes and effects analysis (FMEA) was performed to identify critical steps and guide quality interventions. Software system safety was addressed through writing \"use cases,\" narratives that characterize the behavior of the software, for all major operations to elicit safety requirements. Safety requirements were codified using the easy approach to requirements syntax (EARS) to ensure testability and eliminate ambiguity.
RESULTS: Sixty-one failure modes were identified and assigned risk priority numbers using FMEA. Resultant quality management interventions include integration of a comprehensive reporting and logging system into the software, mandating daily and monthly equipment quality assurance procedures, and a checklist to be completed at image acquisition. Use cases and resulting safety requirements informed the design of needed in-house software as well as a suite of tests performed during the image generation process.
CONCLUSIONS: TG-100 methods were used to construct a process-level quality management program for a 4DCT imaging protocol. Two supplemental tools from the field of requirements engineering facilitated elicitation and codification of safety requirements that informed the design and testing of in-house software necessary to implement the protocol. These general tools can be applied to promote safety when in-house software is needed to bring new techniques to the clinic.