Jon-Kway Huang

Congenital pyriform aperture stenosis: Surgery and evaluation with three-dimensional computed tomography

Objective We described the surgical efficacy of congenital pyriform aperture stenosis by measuring the width of the nasal pyriform aperture with three‐dimensional computed tomography.

Age-Related Changes in Resting-State Networks of A Large Sample Size of Healthy Elderly

Population aging is burdening the society globally, and the evaluation of functional networks is the key toward understanding cognitive changes in normal aging. However, the effect of age on default mode subnetworks has not been documented well, and age‐related changes in many resting‐state networks remain debatable. The purpose of this study was to propose more precise results for these issues using a large sample size.

Prenatal diagnosis of otocephaly with microphthalmia/anophthalmia using ultrasound and magnetic resonance imaging

A 30-year-old primigravid woman was referred to hospital at 29 weeks’ gestation because of polyhydramnios and regular uterine contractions. She and her husband were non-consanguineous and healthy. There was no family history of congenital malformations, nor any history of teratogenic medication, recent infection, diabetes mellitus, or hypertension during this pregnancy. A level II, twodimensional (2D) ultrasound examination revealed a single live fetus with a biparietal diameter of 7.99 cm (appropriate for 29 weeks’ gestation), a femur length of 5.4 cm (29 weeks), an abdominal circumference of 24 cm (29 weeks), polyhydramnios with an amniotic fluid index of 45 cm, absence of the mandible, hypotelorism, lowset ventromedially displaced ears, left microphthalmia with an ocular diameter of 1.29 cm (< 5th centile), and right anophthalmia with absence of the right lens (Figure 1). A tentative diagnosis of otocephaly was made. Magnetic resonance imaging (MRI) demonstrated agnathia and right anophthalmia (Figure 2). The other internal organs were unremarkable. A 1404-g female baby (Figure 3) was delivered 1 day later because of premature rupture of the membranes and preterm labor. The proband died shortly after birth. Autopsy confirmed the diagnosis of otocephaly, which was characterized by the isolated agnathia, aglossia, microstomia, and synotia without central nervous system and other organ defects except for the ocular abnormalities of left microphthalmia and absence of the right lens. The karyotype of the proband was 46,XX. Computed tomography (CT) scans following three-dimensional (3D) reconstruction showed a characteristic otocephalic skull (Figure 4). Prenatal diagnosis of otocephaly using 2D and 3D ultrasound has been well described in the literature1–5. To the best of our knowledge, this

Extraosseous chordoma of the retropharyngeal space.

Chordomas are uncommon malignant tumors of notocordal origin that arise along the craniococcygeal axis. They account for at most 5% of all malignant neoplasms of bone. Generally, a total of 50% arise from the sacrococcygeal area of the axial skeleton, 35% in the sphenooccipital region, and 15% along true vertebrae. The vast majority of chordomas have axial osseous involvement. Extraosseous chordomas are rare tumors, with 18 cases reported in the literature. Most of the extraosseous chordomas are located in the intradural space. As evidenced by computed tomography (CT) scanning and surgical findings, we report an extremely rare case of extraosseous retropharyngeal chordoma. To our knowledge, this is the first case of extraosseous chordoma located in the retropharyngeal space.

Two- and three-dimensional ultrasound demonstration of a giant epignathus

A 41-year-old woman, gravida 6 para 3, was referred to hospital in the second trimester for genetic amniocentesis. She and her husband were non-consanguineous and healthy. There was no family history of congenital malformations. She did not have teratogenic medication, recent infection, diabetes mellitus, or hypertension during this pregnancy. Her previous pregnancies resulted in two miscarriages and uneventful deliveries of three healthy children. Amniocentesis revealed a 46,XY karyotype in this pregnancy. A detailed two-dimensional (2D) ultrasound examination at 17 weeks’ gestation revealed a single live fetus with a biparietal diameter of 3.4 cm (equivalent to 16 weeks’ gestation), an abdominal circumference of 13.1 cm (equivalent to 18 weeks’ gestation), a femur length of 2.1 cm (equivalent to 16 weeks’ gestation), a normal amniotic fluid index of 16.8 cm, and a giant mixed echogenic mass measuring 8.1 × 4.8 × 7.1 cm in the left face in continuation with the skull. The intracranial structures were intact. Doppler flow study showed a high-volume and high-velocity flow within the tumor. Echocardiography was normal. The left orbit was absent. The nose and mouth were difficult to identify. There was no fetal head movement. Three-dimensional (3D) ultrasound displayed a giant left facial mass (Figure 1a). 3D color power angiography showed that the large facial tumor parasitized blood supply from the fetal circulation. A tentative diagnosis of epignathus was made. The woman opted for termination of the pregnancy. A 372-g male fetus with epignathus was delivered (Figures 1b and 2a). Autopsy revealed a teratoma arising from the palate without involving the skull and brain. Cytogenetic analysis of the teratoma revealed a 46,XY karyotype. Multiple transectional skull computed tomography scans showed intralesional calcification and an intact skull. Magnetic resonance imaging scans showed a giant facial mass distorting the skull and brain structures (Figure 2b). An epignathus is a rare teratoma of the oropharynx with an incidence between 1 in 35 000 and 1 in 200 000 live births1. The majority of epignathi originate from the base of the skull in the posterior nasopharynx and usually involve the hard palate or sphenoid bone2. Cleft palate and bifid tongue or nose may be present3. A few epignathus teratomas have been associated with chromosome aberrations, such as 45,X/46,X,r(X) mosaicism3, trisomy 134, duplication of 1q and 19p5, and inverted proximal 1q duplication3. Prenatal diagnosis of epignathi by 2D ultrasound has been well documented1–16. However, to our knowledge, 3D ultrasound demonstration of an epignathus has not yet been described. The 2D ultrasound features of epignathi include a mass projecting from the oral cavity, a mass adjacent to the face with or without intracranial extension, polyhydramnios, and hydrops fetalis. Fetal prognosis depends on the extent of the neighboring tissue involvement and the size of the tumor. Fetuses with a bidirectional epignathus invading the intracranial structures usually have a poor outcome. We have presented the 2D and 3D ultrasound findings of a second-trimester fetus with a giant epignathus distorting the face and skull but without an intracranial extension. 2D ultrasound demonstrated a large complex facial mass and intact intracranial structures. 3D ultrasound displayed comprehensive images and the vasculature of the tumor. The effect of the craniofacial teratoma on the fetal circulation can be documented by Doppler flow study and echocardiography. Doppler flow study may demonstrate high-volume and high-velocity flow of the tumor and echocardiography may reveal dilated ventricles in association with high-output cardiac failure due to massive tumor arteriovenous shunting17. 3D color power angiography further provides a perfusion display of the vasculature, thus allowing visualization of the blood flow between the tumor and fetal circulation and an understanding of the hemodynamic pathophysiology. We believe that both 2D and 3D ultrasound scans are very useful in the prenatal investigation of fetal epignathi for which detailed assessments of the craniofacial structural abnormalities of the fetus and the vasculature of the tumor are required.

Computed tomography of spontaneous intracranial haemorrhage due to haemostatic disorders in children

Intracranial haemorrhage is a serious problem in haemostatic disorders in children. Intracranial bleeding is sometimes more marked than suspected clinically. Computed tomography (CT) permits accurate, sensitive diagnosis of intracranial haemorrhage. We report 13 patients; 3 patients with hypoprothrombinaemia, 4 patients with thrombocytopenia or platelet dysfunction and 6 with haemophilia A, B or Von-Willebrands disease. One patient with hypoprothrombinaemia had a subarachnoid hemorrhage (SAH), one a subdural haematoma (SDH) and the third a combination of SAH, SDH and intracerebral haematoma (ICH). One patient with thrombocytopenia or platelet dysfunction had a SDH, while the others had ICH. In the six patients with haemophilia A, B or Von-Willebrands disease, there were four examples of ICH, five of SAH and six of SDH. A neurosurgical procedure was performed in only one patient. Three children died of serious intracranial complications with uncal herniation.

Early second-trimester diagnosis of fetal otocephaly.

In a recent issue of this journal, Cannie et al.1 reported the role of magnetic resonance imaging (MRI) in the field of fetal medicine and suggested that the true advantage of fetal MRI is the functional evaluation of the fetus. Here, we present the earliest application of MRI in the assessment of fetal otocephaly. A 41-year-old gravida 4, para 2 woman was referred to our hospital because of abnormal findings on an earlier scan. Ultrasound examination at 12 weeks’ gestation and MRI at 15 weeks revealed an abnormal fetal face, synotia and agnathia (Figures 1 and 2). The fetal brain, heart and internal organs were normal. At 16 weeks’ gestation, termination of pregnancy was performed and a

99mTc-Ethyl Cysteinate Dimer Cranial Single-Photon Emission Computed Tomography and Serial Cranial Magnetic Resonance Imaging in a Girl With Isolated Sulfite Oxidase Deficiency

Isolated sulfite oxidase deficiency, a rare autosomal recessive inherited disorder, is easily misdiagnosed as the more common hypoxic-ischemic encephalopathy. A female term infant was diagnosed with isolated sulfite oxidase deficiency. Magnetic resonance imaging at ages 13 days, 2 months, and 10 months indicated diffuse edema with posterior predominance, followed by progressive multicystic encephalomalacia and brain atrophy with relatively sparing of the thalami. Single-photon emission computed tomography using (99m)Tc-ethyl cysteinate dimer at 2 months revealed decreased uptake in the frontal lobes. The characteristic neuroimaging findings in isolated sulfite oxidase deficiency help differentiate it from hypoxic insult. The correct diagnosis is helpful in genetic counseling for parents.

Congenital Nasal Pyriform Aperture Stenosis and Single Central Maxillary Incisor: Preoperative Evaluation with Three-Dimensional Computed Tomography

BACKGROUND AND PURPOSE Congenital nasal pyriform aperture stenosis (CNPAS) is an uncommon cause of nasal airway obstruction in neonates and infants. It is frequently associated with a single central maxillary incisor (SCMI). The purpose of this study was to assess whether 3-dimensional spiral computed tomography (3D spiral CT) could be used for the diagnosis of CNPAS and for detecting SCMI in CNPAS patients before tooth eruption. METHODS From January 1996 to December 2001, 16 patients (mean age, 2 +/- 3 months) with clinically suspected CNPAS and 13 normal control subjects (mean age, 28 +/- 32 months) were studied prospectively by 3D spiral CT. On the 3D CT image of each subject, the middle pyriform aperture width (MPAW), upper 1/4 PA width (UPAW), and middle internasal process width (MINPW) were measured. In addition, the ratios of MINPW to MPAW and of MINPW to UPAW were calculated. SCMI was identified as a bigger tooth with singular convexity. RESULTS SCMI was diagnosed in 11 of the 16 CNPAS patients. In the CNPAS patient group, the mean MINPW (5 +/- 1 mm) was significantly shorter than the mean MPAW (9 +/- 1 mm) and the mean UPAW (8 +/- 1 mm) [p < 0.001]. However, in the normal control group, the mean UPAW (13 +/- 2 mm) was significantly shorter than the mean MPAW (16 +/- 3 mm) and the mean MINPW (16 +/- 3 mm) [p < 0.01]. In the CNPAS patients, the mean ratios of both MINPW to MPAW (0.5 +/- 0.1) and of MINPW to UPAW (0.6 +/- 0.1) were significantly lower than the corresponding mean ratios in the normal control subjects (1.0 +/- 0.1 and 1.3 +/- 0.2, respectively; both p < 0.001). CONCLUSION Our results indicate that CNPAS is frequently associated with a SCMI and CNPAS patients have a significant reduction in the MINPW and in the ratios of MINPW to MPAW and of MINPW to UPAW. We conclude that 3D spiral CT can be used for diagnosis of CNPAS and for detecting SCMI in CNPAS patients before tooth eruption.

Mandibular condyle and tympanic plate fracture causing external auditory canal stenosis.

Severe fractures of the mandibular condyle and tympanic plate resulting from trauma (1,2) can lead to external auditory canal (EAC) stenosis. If this stenosis hinders epithelial migration, complications such as EAC cholesteatoma can occur. As the cholesteatoma develops and grows, it can penetrate the canal bony wall and invade the mastoid. However, with the stenosis of the ear canal, it may be easy to overlook the pathology within the deeper canal as well as tissues surrounding the stenosis on otoscopic examination, leading to misdiagnosis. High-resolution computed tomographic (HRCT) scan can help localize the fracture and any associated complications. Patient 1 was a 35-year-old woman who sustained mandibular trauma 3 months before presentation. The