Effects of combining multiple dose reduction techniques on coronary computed tomography angiography.

BACKGROUND: Coronary computed tomography angiography (CCTA) is the preferred non-invasive examination method for coronary heart disease. However, the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase. AIM: To explore the value of multiple dose reduction techniques for CCTA. METHODS: Consecutive normal and overweight patients were prospectively divided into two groups: Group A1, patients who received multiple dose reduction scans (n = 82); and group A2, patients who received conventional scans (n = 39). The scan parameters for group A1 were as follows: Isocentric scan, tube voltage = 80 kV, and tube current control using 80% smart milliampere. The scan parameters for group A2 were as follows: Normal position, tube voltage = 100 kV, and smart milliampere. RESULTS: The average effective doses (EDs) for groups A1 and A2 were 1.13 ± 0.35 and 3.36 ± 1.30 mSv, respectively. There was a statistically significant difference in ED between the two groups (P < 0.01). Furthermore, noise was significantly lower, and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1 (P < 0.01). Moreover, the subjective image quality (IQ) scores were excellent in both groups, in which there was no significant difference in subjective IQ score between the two groups (P = 0.12). CONCLUSION: Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.

Magnetic Resonance Imaging Features and Misdiagnosis of Spinal Epidural Cavernous Hemangioma.

OBJECTIVE: Spinal epidural cavernous hemangiomas (SECHs) are rare, and merely a few have previously been described in case reports. The present study aims to explore the magnetic resonance imaging (MRI) features of SECHs and analyze the causes of their preoperative misdiagnosis. METHODS: The present retrospective study included 11 patients (three male and eight female patients, mean age ± standard deviation: 47.55±17.39 years old) with histopathologically confirmed SECH between January 2015 and April 2021. The MRI features of SECH were analyzed by two radiologists. RESULTS: The cervical, thoracic and thoracolumbar segments were involved in 2, 7 and 2 patients, respectively. All lesions grew along the long axis of the spine. The tumors were shuttle-shaped in six patients, oval in two patients, pseudopodia-shaped in one patient, clamp-shaped in one patient, and growing outward along the intervertebral foramen in one patient. Nine SECHs had relatively uniform isointense or hypointense T1-weighted imaging (T1WI) and hyperintense T2-weighted imaging (T2WI) signals. On the T2WI, filamentary low-signal shadows (i.e., the hairline or grid sign) with significant contrast enhancement and asymptotic strengthening were observed. Two SECHs had mixed high and low signals on T1WI and T2WI, with significant heterogeneous enhancement, hemorrhage, and hemosiderin deposition. The SECH was misdiagnosed as meningioma, neurofibromatosis and schwannoma in 1, 1 and 4 patients, respectively, while this was not diagnosed in one patient. The preoperative diagnosis was correct in merely approximately 36% of patients. Among the four patients with a correct preoperative diagnosis, hemosiderin deposition was found in three patients and small tortuous vascular shadows were found in one patient. CONCLUSION: SECH presents as a long spindle-shaped mass, and the "'pen cap sign" is common at the lesion edges. SECH also exhibits a hairline or grid sign on T2WI. Furthermore, some lesions present with hemorrhage and hemosiderin deposition. Therefore, the hairline, grid sign and hemosiderin deposition are valuable diagnostic features of SECH.

[CT imaging features and misdiagnosis analysis of occult anterior calcaneal process fracture].

OBJECTIVE: To explore CT imaging features and reason for missed diagnosis of clinical practice of occult anterior calcaneal process fracture. METHODS: From July 2013 to November 2018, the clinical data of 13 patients with occult an anterior calcaneal process fracture were retrospectively analyzed, including 2 males and 11 females, aged from 22 to 54 years old. Classification of fracture, displacement of fracture, direction of fracture line, size of fracture, with or without tarsal coalition, other fractures and misdiagnosis, the time from injury to diagnosis, condition of treatment and fracture healing were observed according to case history, data of X-ray and CT. RESULTS: Thirteen patients were diagnosed as occult anterior calcaneal process fracture after CT examination. According to Degan classification, 9 patients were type I, 4 patients were typeII; 4 patients were occurred displacement, and 9 patients did not occurred displacement. On the horizontally CT, fracture line of 12 patients showed transverse, 1 patient oblique, and the size of fracture ranged from 0.40 to 1.72 cm; while on the sagittal view, fracture line of 12 patients showed vertical, 1 patient oblique, and the size of fracture ranged from 0.10 to 0.59 cm. No patients combined with talocalcaneal and scaphoid bridge. Six patients were simple anterior calcaneal process fracture, 7 patients combined with other fractures. Eight patients were misdiagnosed. The time from injury to diagnose ranged from 0 to 21 days. Nine patients with type Iwere performed conservative treatment, 6 patients healed well and 3 patients with fracture line less than 1 cm on horizontally view occurred fracture nonunion. Four patients with type II did not perform operation, and fracture were not union, regardless of fracture size. CONCLUSIONS: Occult anterior calcaneal process fracture have high rate of missed diagnosis in clinical practice. CT imaging features of fracture showed that most fracture line were transverse on CT horizontal plane while vertical on CT sagittal plane, as well as small side of fragment on CT sagittal plane with differernt sizes of fragment on CT horizontal plane; type Ifracture with fragment less than 1 cm on CT horizontal plane and type II both have high rate of nonunion while treated with conservative treatment.