Unfavorable switching of skewed X chromosome inactivation leads to Menkes disease in a female infant.

Menkes disease is an X-linked disorder of copper metabolism caused by mutations in the ATP7A gene, and female carriers are usually asymptomatic. We describe a 7-month-old female patient with severe intellectual disability, epilepsy, and low levels of serum copper and ceruloplasmin. While heterozygous deletion of exons 16 and 17 of the ATP7A gene was detected in the proband, her mother, and her grandmother, only the proband suffered from Menkes disease clinically. Intriguingly, X chromosome inactivation (XCI) analysis demonstrated that the grandmother and the mother showed skewing of XCI toward the allele with the ATP7A deletion and that the proband had extremely skewed XCI toward the normal allele, resulting in exclusive expression of the pathogenic ATP7A mRNA transcripts. Expression bias analysis and recombination mapping of the X chromosome by the combination of whole genome and RNA sequencing demonstrated that meiotic recombination occurred at Xp21-p22 and Xq26-q28. Assuming that a genetic factor on the X chromosome enhanced or suppressed XCI of its allele, the factor must be on either of the two distal regions derived from her grandfather. Although we were unable to fully uncover the molecular mechanism, we concluded that unfavorable switching of skewed XCI caused Menkes disease in the proband.

Massive true thymic hyperplasia with osseous metaplasia.

True thymic hyperplasia is defined as an increase in both the size and weight of the gland, while maintaining a normal microscopic architecture. Massive true thymic hyperplasia is a rare type of hyperplasia that compresses adjacent structures and causes various symptoms. Limited reports address the imaging findings of massive true thymic hyperplasia. Herein, we report a case of massive true thymic hyperplasia in a 3-year-old girl with no remarkable medical history. Contrast-enhanced CT revealed an anterior mediastinal mass with a bilobed configuration containing punctate and linear calcifications in curvilinear septa, which corresponded to lamellar bone deposits in the interlobular septa. To our knowledge, this is the first report of massive true thymic hyperplasia with osseous metaplasia. We also discuss the imaging features and etiology of massive true thymic hyperplasia with osseous metaplasia.

A case of germinoma located in the fornix inducing transsynaptic atrophy of the Papez circuit.

Germinoma is a rare CNS germ cell tumor preferentially affecting children and young adults. Intracranial germinomas arise typically in the neurohypophysis and pineal region and occasionally in the basal ganglia and thalamus. Germinomas in the basal ganglia and thalamus are characterized by the ipsilateral cerebral and brainstem hemiatrophy with slowly progressive neurological deficits, which is due to tumor infiltration into the thalamocortical and corticospinal tract and induction of anterograde and retrograde Wallerian degeneration. We report an 11-year-old boy with a mass located in the fornix incidentally discovered on the first work-up of his minor head injury. Imaging findings revealed the ipsilateral atrophy of the mammillary body and the fornix. Stereotactic brain biopsy was performed and the final diagnosis was germinoma. The ipsilateral atrophy of the mammillary body and the fornix implied the transsynaptic degeneration via the Papez circuit. We discuss the unique nature of germinomas and underlying pathological mechanisms.

Imaging of extrapontine myelinolysis preceding central pontine myelinolysis in a case of ornithine transcarbamylase deficiency with hyperammonaemia and hypokalaemia.

Background: Patients with ornithine transcarbamylase deficiency (OTCD) often present with severe hyperammonaemia. We report a case of osmotic demyelination syndrome (ODS) secondary to the treatment of hyperammonaemia due to OTCD, a disease requiring early diagnosis, as it can have a severe prognosis. Case: A girl toddler was brought to the hospital with a complaint of somnolence, presenting with hyperammonaemia and liver failure, and was diagnosed with OTCD. Treatment was started immediately, and the ammonia level returned to the normal range within 24 hours. On days 13-20, another treatment was commenced for re-elevated ammonia levels, which subsequently returned to within the reference range; however, mildly impaired consciousness persisted. Hypokalaemia coincided with temporary intravenous treatment and continuous haemodialysis. T2-weighted magnetic resonance images revealed lesions as high-signal areas in the bilateral putamen on day 11 (extrapontine myelinolysis (EPM)) and in the pons on day 51 (central pontine myelinolysis (CPM)). Consequently, ODS was diagnosed. Conclusion: When interpreting magnetic resonance images of patients under acute treatment for hyperammonaemia due to OTCD, a condition that may be complicated by hypokalaemia, paying attention to findings suggesting EPM may help detect ODS before CPM appears and may improve patient prognosis.

Effects of menstrual cycle on background parenchymal enhancement and detectability of breast cancer on dynamic contrast-enhanced breast MRI: A multicenter study of an Asian population.

PURPOSE: To evaluate the effect of the menstrual cycle on BPE and cancer detectability in an Asian population. MATERIAL AND METHODS: 266 premenopausal patients with regular menstrual cycles from 24 centers were included, and 176 of them were diagnosed by pathology as having breast cancer. Thirty-five patients were examined in the menstrual phase (days 1-4), 105 in the proliferative phase (days 5-14), and 126 in the secretory phase (days 15-30). Measurement of the following signal intensities (SIs) were obtained: breast tissue on the unaffected side on a pre-contrast image (SI1) and an early-phase image (SI2); the SIs of breast tissue on the affected side on a pre-contrast image (SI3) and an early-phase image (SI4); and the SIs of breast cancer on a pre-contrast image (SI5) and an early-phase image (SI6). We calculated the BPE ratio, i.e., (SI2- SI1)/SI1 and the cancer/background enhancement ratio (C/B) ratio, i.e., (SI6- SI5) / (SI4- SI3). The BPE was classified as minimal, mild, moderate, or marked, and the cancer detectability was classified as excellent, good, or poor independently by two radiologists. RESULTS: The average C/B ratio was 20.1, 15.7, and 9.1 at the menstrual, proliferative, and secretory phases (p < 0.001). BPE was determined as moderate or marked in 0% and 5.4% at the menstrual phase, 10.3% and 11.0% at the proliferative phase, and 17.5% and 21.7% at the secretory phase by the two observers, respectively (p = 0.01, p = 0.01). The detectability of breast cancer was classified as poor in 0% and 0%, 1.4% and 13.0%, and 8.0% and 22.1% at the menstrual, proliferative, and secretory phases by the two observers, respectively (p = 0.07, p = 0.02). CONCLUSION: The menstrual phase and the proliferative phase seem to be suitable for breast MRI of Asian women.

New radiographic standards for age at appearance of the ossification center of the femoral head in Japanese: Appearance at ≤12 months of age is normal in Japanese infants.

BACKGROUND: The ossification center of the femoral head reportedly appears at 7-8 months in 95% infants in the radiographs, but its appearance often delays in Japanese normal infants. The purpose of this study was to survey the age at appearance of the femoral head in the radiographs, evaluate the normal standards of its appearance in Japanese infants, and determine whether the acetabular state affects the time of its appearance. MATERIALS AND METHODS: The patients comprised 436 infants consulted with our institution because of a limitation of abduction in flexion (LA), acetabular dysplasia, or suspected developmental dysplasia of the hip (DDH). Among these patients, 111 infants (222 hips) without radiographic appearance of the femoral head at the first visit were reviewed. The 222 hips were classified into three groups: α angle ≥30° (DDH + group), <30° with LA (DDH-/LA + group), or < 30° without LA (DDH-/LA-group). The age at appearance of the femoral head was investigated in the radiograph in each group. RESULTS: The 50th percentile of the age at appearance of the femoral head was 6 months in the DDH-/LA- and DDH-/LA + groups and 8 months in the DDH + group. The femoral head significantly appeared earlier in the DDH-/LA- and DDH-/LA + groups than in the DDH + group (P < 0.01). The 95th percentile was 12 months in all groups. CONCLUSIONS: Radiographic appearance of the ossification center of the femoral head by 12 months of age is normal in Japanese infants. When the α angle is ≥ 30°, the age at appearance of the femoral head is sometimes delayed.

Non-enhanced magnetic resonance imaging versus renal scintigraphy in acute pyelonephritis.

The utility of non-enhanced magnetic resonance imaging (MRI) has not been examined extensively for diagnosing acute pyelonephritis (APN) in children. The aims of this study were to compare non-enhanced MRI with technetium-99 m dimercaptosuccinic acid (99m Tc-DMSA) renal scintigraphy in detecting APN. Six boys and one girl with temperature ≥38°C and positive urine culture received both non-enhanced MRI with whole body diffusion-weighted imaging (DWI) and 99m Tc-DMSA scintigraphy ≤7 days from the fever onset. The sensitivity and specificity of MRI in detecting APN lesions diagnosed on 99m Tc-DMSA scintigraphy were 80% and 100%, respectively. Non-enhanced MRI in children with suspected APN ≤7 days from fever onset might be a suitable replacement for 99m Tc-DMSA scintigraphy for the detection of APN.

Spinal magnetic resonance imaging manifestations at neurological onset in Japanese patients with spinal cord sarcoidosis.

OBJECTIVE: We retrospectively investigated spinal magnetic resonance imaging (MRI) manifestations at neurological onset in Japanese patients with spinal cord sarcoidosis. METHODS: Between July 2000 and April 2012, we reviewed our database and recruited patients with spinal cord sarcoidosis. On spinal MRI performed at neurological onset, the following items were evaluated: the vertebral-segment distribution and length of intramedullay T2-elongated lesions, abnormal enhancement patterns and distributions and the concomitant presence of spondylosis and associated extraspinal lesions. If available, brain MRI scans were concomitantly assessed. RESULTS: Nine patients were enrolled (four men and five women; median, 49 years). Reflecting Japanese epidemiological backgrounds, a predilection for occurrence was observed in young men and middle-aged women. Intramedullary T2-elongated lesions were present in eight patients, peaking at the C5 level, with a mean length of 3.7 ± 2.6 vertebral segments. Spondylosis coexisted in the middle-aged patients. Abnormal intramedullary enhancement with concomitantly involved the nerve roots was observed in six patients, comprised of two types reflecting the disease progression: linear- and/or nodular enhancement along the surface of the spinal cord and intramedullary enhancement consisting of patchy, broad-based enhancement adjacent to the cord surface. Five patients had associated extraspinal lesions, including lymphadenopathy in four patients and brain involvement in four patients. CONCLUSION: Spinal cord sarcoidosis exhibits a predilection for young men and middle-aged women among Japanese individuals and is characterized by intramedullary T2-elongated lesions spreading more than three vertebral segments peaking at the C5 level, two types of abnormal intramedullary enhancement reflecting disease progression, frequent nerve root involvement and lymphadenopathy.

Percutaneous retrograde sclerotherapy for refractory bleeding of jejunal varices: direct injection via superficial epigastric vein.

Small-bowel varices are rare and almost always occur in cases with portal hypertension. We encountered a patient with bleeding jejunal varices due to liver cirrhosis. Percutaneous retrograde sclerotherapy was performed via the superficial epigastric vein. Melena disappeared immediately after treatment. Disappearance of jejunal varices was confirmed by contrast-enhanced computed tomography. After 24 months of follow-up, no recurrent melena was observed.

Biceps pulley: normal anatomy and associated lesions at MR arthrography.

The biceps pulley or "sling" is a capsuloligamentous complex that acts to stabilize the long head of the biceps tendon in the bicipital groove. The pulley complex is composed of the superior glenohumeral ligament, the coracohumeral ligament, and the distal attachment of the subscapularis tendon, and is located within the rotator interval between the anterior edge of the supraspinatus tendon and the superior edge of the subscapularis tendon. Because of its superior depiction of the capsular components, direct magnetic resonance arthrography is the imaging modality of choice for demonstrating both the normal anatomy and associated lesions of the biceps pulley. Oblique sagittal images and axial images obtained with a high image matrix are valuable for identifying individual components of the pulley system. Various pathologic processes occur in the biceps pulley as well as the rotator interval. These processes can be traumatic, degenerative, congenital, or secondary to injuries to the surrounding structures. The term hidden lesion refers to an injury of the biceps pulley mechanism and is derived from the difficulty in making clinical and arthroscopic identification. Pathologic conditions associated with pulley lesions include anterosuperior impingement, instability of the biceps tendon, biceps tendinopathy or tendinosis, superior labrum anterior and posterior lesions, and adhesive capsulitis. It is important to be familiar with the normal appearance of the biceps pulley so that abnormalities can be correctly assessed and effectively managed.