Mirror-image right aortic arch: A proposed mechanism in symptomatic vascular ring

We describe a rare case of right aortic arch with mirror-image branching and a left ductus arteriosus that form an anomalous vascular ring. The unusual feature of this symptomatic vascular ring is presence of a left (posterior) circumflex descending aorta in lieu of an aortic diverticulum which usually represents the posterior element of the vascular ring associated with right aortic arch and mirror-image branching. This we believe is the seventh reported case of Type 1 right aortic arch and only the third such case with a left circumflex descending aorta. Accurate diagnosis was made by barium esophagogram and angiocardiogram and was confirmed surgically. We propose a new theory as to why some vascular rings formed by the right aortic arch are symptomatic while others are not.     

Incomplete double aortic arch with atresia of the distal left arch: distinctive imaging appearance

OBJECTIVE: We present 10 patients with double aortic arch with atresia of the distal left arch segment, a form of incomplete double aortic arch, and describe the distinct MRI and CT findings for this potentially symptomatic vascular ring. CONCLUSION: Knowledge of the distinctive imaging appearance of this congenital arch anomaly can direct the radiologist to the correct preoperative diagnosis.     

MDCT of variations and anomalies of the neural arch and its processes: part 2--articular processes, transverse processes, and high cervical spine

OBJECTIVE: The purpose of this pictorial essay is to review the variations and anomalies of the neural arch and its processes with a focus on the articular and transverse processes. We also discuss variations and anomalies of the neural arch at the high cervical spine. CONCLUSION: Variations and anomalies of the neural arch and its processes may be identified on MDCT studies. Familiarity with their MDCT appearances is required for characterization and may help evaluate their potential clinical relevance.     

Fractures of the neural arch and odontoid process of the axis: A study of their causation

Summary The anatomical findings in 43 cases with fractures of the neural arch or odontoid process of the axis have been correlated to the reconstructions of the course of events in the accidents. Bilateral fractures of the neural arch anterior to the inferior apophyseal joints were the result of a violent anteroflexion of the head. Simultaneous traction or compression of the cervical spine were possibly of contributing importance. Considerable non symmetrical fractures of the neural arch were due to oblique anteroflexion of the head combined with traction of the cervical spine. Trauma against the posterior part of the neck resulted in fractures of the neural arch posterior to the inferior apophyseal joints. The fractures of the odontoid process were the result of a violent anteroflexion or retroflexion of the head. Simultaneous compression of the cervical spine and rotation of the head were possibly of contributing importance in some cases.     

Painful spondylolysis or spondylolisthesis studied by radiography and single-photon emission computed tomography

Planar bone scintigraphy (PBS) and single-photon emission computed tomography (SPECT) were compared in 19 adults with radiographic evidence of spondylolysis and/or spondylolisthesis. SPECT was more sensitive than PBS when used to identify symptomatic patients and sites of "painful" defects in the pars interarticularis. In addition, SPECT allowed more accurate localization than PBS. In 6 patients, spondylolysis or spondylolisthesis was unrelated to low back pain, and SPECT images of the posterior neural arch were normal. The authors conclude that when spondylolysis or spondylolisthesis is the cause of low back pain, pars defects are frequently heralded by increased scintigraphic activity which is best detected and localized by SPECT.     

Sagittal movement of the medial longitudinal arch is unchanged in plantar fasciitis

BACKGROUND: Although a lowered medial longitudinal arch has been cited as a causal factor in plantar fasciitis, there is little experimental evidence linking arch motion to the pathogenesis of the condition. This study investigated the sagittal movement of the arch in subjects with and without plantar fasciitis during gait. METHODS: Digital fluoroscopy was used to acquire dynamic lateral radiographs from 10 subjects with unilateral plantar fasciitis and 10 matched control subjects. The arch angle and the first metatarsophalangeal joint angle were digitized and their respective maxima recorded. Sagittal movement of the arch was defined as the angular change between heel strike and the maximum arch angle observed during the stance phase of gait. The thickness of the proximal plantar fascia was determined from sagittal sonograms of both feet. ANOVA models were used to identify differences between limbs with respect to each dependent variable. Relationships between arch movement and fascial thickness were investigated using correlations. RESULTS: There was no significant difference in either the movement or maximum arch angle between limbs. However, subjects with plantar fasciitis were found to have a larger metatarsophalangeal joint angle than controls (P < 0.05). Whereas the symptomatic and asymptomatic plantar fascia were thicker than those of control feet (P < 0.05), significant correlations were noted between fascial thickness and peak arch and metatarsophalangeal joint angles (P < 0.05) in the symptomatic limb only. CONCLUSIONS: Neither abnormal shape nor movement of the arch are associated with chronic plantar fasciitis. However, arch mechanics may influence the severity of plantar fasciitis, once the condition is present. Digital flexion, in contrast, has a protective role in what might be a bilateral disease process.     

Ossicles of lumbar articular facets: normal variant or spondylolytic variant?

Purpose

The objective of this study was to establish the prevalence and significance of ossicles of lumbar articular facets (OLAF) in young athletes with backache diagnosed by multi-detector computed tomography (MDCT).

Materials and methods

The MDCT examinations of the lumbar spine carried out for suspected spondylolysis on 46 consecutive symptomatic young athletes presenting to a sports injury clinic over a 1-year period were retrospectively reviewed. OLAF study included detailed correlation with the structural and morphological stress features of the posterior neural arches. This was then compared with a control group composed of 39 patients.

Results

Twenty-three OLAF were identified in 15 patients. Eleven of the 15 patients with ossicles had posterior element stress changes (PEST)/pars defects. In the control group, two OLAF were identified in two patients, one demonstrating PEST changes.

Conclusion

The high prevalence of OLAF in young symptomatic athletes compared with the asymptomatic control group is indicative of stress fractures. The non-united articular process fractures should be regarded as part of the spectrum of stress-induced changes in the posterior neural arch in the same way as spondylolysis. MDCT with volumetric acquisition and multi-planar reformation is the most reliable investigation in the diagnosis of OLAF.

Key Points

1) This CT study supports a traumatic aetiology for lumbar articular facets ossicles. 2) OLAF represent part of a spectrum of stress-induced changes in the posterior neural arch. 3) OLAF are associated with typical spondylolysis. 4) OLAF can be overlooked on reverse gantry angle computed tomography (RG-CT). 5) OLAF may account for some of the discrepancy between radionuclide and RG-CT studies.     

Vertebral hemangiomas: radiologic evaluation

Radiologic studies of 57 solitary vertebral hemangiomas (VHs) were reviewed to find radiographic and computed tomographic (CT) criteria by which to distinguish asymptomatic lesions from those compressing the spinal cord. Six features were seen significantly more often in those compressing the cord: location between T-3 and T-9, involvement of the entire vertebral body, extension to the neural arch, an expanded cortex with indistinct margins, an irregular honeycomb pattern, and soft-tissue mass. Contrast material-enhanced CT scans and selective spinal angiograms demonstrated extension into the spinal canal. In patients with a VH and back pain of uncertain origin, the presence of three or more of these signs may indicate a potentially symptomatic VH. In such patients, spinal angiography and, in some cases, embolization, are indicated.     

Congenital midline cleft of the posterior arch of atlas: a rare cause of symptomatic cervical canal stenosis

Developmental symptomatic C1 canal stenosis is very rare. We describe the computed tomography (CT) and magnetic resonance imaging (MRI) appearances in a 8-year-old child who presented with progressive upper and lower limb neurological symptoms and in whom imaging revealed the medial posterior hemiarches of a bifid C1 to be inturned and compressing the cervical cord. This particular configuration of the posterior arch of atlas is frequently associated with other craniocervical bony anomalies and presents with neurological symptoms early in life. Early CT or MRI examination of patients with symptomatic posterior arch of C1 defects is necessary, in order to detect such an appearance, since surgical treatment may prevent neurological deterioration.     

Partial aplasia of the posterior arch of the atlas with an isolated posterior arch remnant: findings in three cases

We report the imaging findings in three symptomatic cases of partial aplasia of the posterior arch of the atlas with an isolated posterior remnant of the arch. These cases are instructive in illustrating the mechanism of cord impingement produced by the posterior arch remnant during extension of the cervical spine. Additionally, focal increased T2 signal was observed within the cord at the level of the anomaly in two of the patients.     

MR imaging of hindbrain deformity in Chiari II patients with and without symptoms of brainstem compression

We examined the MR appearance of the hindbrain deformity, including the upper cervical spinal canal and craniovertebral junction, in 33 patients with Chiari II malformation. In this disorder, there is impaction at birth of the medulla and cerebellar vermis into the upper cervical spine, resulting in obliteration of the subarachnoid space and scalloping of the dens. Spinal canal enlargement during the child's growth, combined with dorsal displacement of neural tissue, eventually causes marked widening of the precervical subarachnoid space. This enlargement may simulate an intradural mass. Our series documents the changes seen at birth and the progression of the widened precervical space through the first and second decades. Twelve (36%) of the 33 patients studied were symptomatic, with brainstem or longtract symptomatology, and 11 of these required surgery. This group was compared with the remaining 21 asymptomatic Chiari II patients to identify MR features associated with clinical deterioration. The level of descent of the hindbrain hernia was critical; eight of 12 symptomatic patients had a cervicomedullary kink at C4 or lower, while no asymptomatic patients had a fourth ventricle, medulla, or kink below C3-C4. The precervical cord subarachnoid space was slightly wider in asymptomatic patients, although there was great overlap. In five patients with follow-up scans, this space was seen to increase in width after laminectomy. A CSF flow void was present in the precervical space in about 25% of patients in both groups. In nine of 12 symptomatic patients, C1 arch indentation of the dura (causing significant compression) was confirmed surgically. However, seven (33%) of the 21 asymptomatic patients also had this appearance. Absolute measurement of the anteroposterior diameter of the canal at C1 ranged from 11 to 25 mm in both groups. Retrocollis, which persisted despite sedation for MR, was seen in two patients, both symptomatic. Recognition of the vermis, medullary kink, cervical cord, C1 arch, fourth ventricle, and precervical space in Chiari II patients is fundamental to the analysis of symptoms in     

Ankylosing spondylitis complicated by trauma: MR findings correlated with plain radiographs and CT

Four patients with ankylosing spondylitis sustained a traumatic spinal injury. In three cases, pseudoarthrosis developed at the discovertebral junction, while involvement of the neural arch occurred in the fourth. Although the diagnosis of ankylosing spondylitis was readily estabished on plain radiographs, magnetic resonance more effectively identified the complicating injury and in two cases demonstrated the presence of cord compression. Computed tomography was also contributory in delineating bony and ligamentous abnormalities of the neural arch.     

Myelography in severe lumbosacral spondylolisthesis

The radiological and myelographic appearances of 14 patients with severe lumbosacral spondylolisthesis have been reviewed in relation to compression of the cauda equina and their clinical symptomatology. Patients could be separated into two groups as defined by the position of the L5 neural canal. In Group 1, the arch was displaced downwards and the cauda equina compression was due to pressure from the L5/S1 disc and was related to the degree of listhesis. L5 root sheath abnormalities predominated in this group. In Group 2 the neural arch maintained a more normal position and the compression, which was unrelated to the degree of slip, occurred between the arch and the posterior aspect of the sacrum. S1 root lesions occurred in these patients due to pressure from the arch. Clinical symptoms and signs were also more prominent in this group.     

Atypical vertebral Paget’s disease

A 40-year-old Mauritanian man consulted for back pain. A computed tomography of the spine showed patchy sclerosis of the fifth and seventh thoracic vertebral bodies with normal neural arch of T5 and sclerosis and hypertrophy of the neural arch of T7, as well as diffuse sclerosis of the T11 vertebral body with a normal neural arch. At MRI, low signal-intensity on T1-weighted images and high signal-intensity on T2-weighted images involved the whole T5 and T7 vertebrae and the vertebral body of T11. Working diagnoses included metastatic disease and lymphoma, and a biopsy of T7 and then T11 was carried out. Both showed pathological findings very suggestive of Paget’s disease. Since CT is usually the more specific radiological examination in vertebral Paget’s disease, we thought it could be useful to report this atypical CT presentation (patchy sclerosis of the vertebral body without diffuse bone texture changes and isolated involvement of the vertebral body) of vertebral Paget’s disease.     

Right aortic arch with aberrant left innominate artery: MR imaging findings

A rare case of a 60-year-old man with a right aortic arch and aberrant left innominate artery is presented. This case had an unusual clinical presentation. The dysphagia appeared suddenly in adulthood, whereas vascular rings, when symptomatic, usually manifest early in childhood.To our knowledge, MR imaging findings of this anomaly have never been reported. The diagnosis was made by MR imaging and confirmed by surgery. Magnetic resonance imaging can replace angiography in the assessment of the aortic arch anomalies. Received: 4 April 1997; Revision received: 11 July 1997; Accepted: 3 May 1998     

症状性椎体血管瘤应用经皮椎体成形术治疗的疗效评估

目的探讨经皮椎体成形术(PVP)治疗症状性椎体血管瘤的疗效。资料与方法回顾性分析35例(44个椎体)PVP治疗的症状性椎体血管瘤患者临床资料及影像学资料。29例(82.9%)患者表现为不同程度的颈、胸、腰背部疼痛。6例(17.1%)患者合并病理性骨折,除患处疼痛外,还表现为不同程度的神经功能受损。所有患者均在术前及术后1周采用视觉模拟评分(visual ananlog scale,VAS)评价患者的疼痛程度。术后第3～6个月行门诊随访,术后6个月以后行门诊或电话随访。结果 35例患者44个病变椎体,骨水泥用量1.5～11.0 ml,平均5.5 ml。其中5个(11.3%)椎体发生椎旁渗漏,2个(4.5%)椎体发生椎间盘渗漏。所有患者均未出现肺栓塞或者其他较严重的并发症。术前VAS评分平均为6.8±1.1,术后VAS评分平均为2.6±0.7,两者比较P<0.05,术后疼痛缓解明显,差异有统计学意义。结论 PVP是治疗椎体血管瘤的一种安全、有效、微创的方法,并发症少,长期随访效果明确。     

Single-session alcohol sclerotherapy in symptomatic benign hepatic cysts performed with a time of exposure to alcohol of 10 min: initial results

The aim of this study was to evaluate the 1-year results of single-session sclerotherapy of symptomatic benign non-parasitic liver cysts performed with maximum 10 min time of ethanol exposure. During the period 1995–1999, 15 symptomatic liver cysts in nine patients — eight women and one man — were treated with 10 min time of exposure to ethanol. Ultrasound-guided puncture combined with fluoroscopy was used for catheter placement. Alcohol sclerotherapy was performed with a maximum volume of ethanol 96% of 10% of the cyst volume, never exceeding 100 ml. At follow-up the patients were examined with liver function tests, ultrasound or CT examination, clinical examination, and interview by a gastrointestinal surgeon. Ten cysts in seven patients (six women and one man; age range 44–61 years, median age 58 years), who had a follow-up of at least 1 year, were included. The original cyst volumes were 30–4110 ml (median 392 ml). After a follow-up period of 12–47 months (median 23 months), cyst volumes were 0–523 ml (median 21.5 ml) with a reduction of the median cyst volume by 95% (p<0,005). All patients experienced relief of their clinical symptoms. Except for pain, no complications were observed. Sclerotherapy using only one session and maximum 10 min time of exposure to ethanol represents an effective treatment of symptomatic liver cysts.     

The relationship of acromial architecture to rotator cuff disease

Variations in the architecture of the coracoacromial arch can lead to a clinically symptomatic rotator cuff lesion. Differences in the development and morphology of the acromion, and the presence of anterior acromial spurs and inferior acromioclavicular osteophytes decrease the volume of the subacromial space, leading to impingement. Recent anatomic, radiographic, biomechanical, and SPG studies have confirmed these architectural variations and their effects on the contents of the subacromial space. Abnormal contact between the acromion and these soft tissues can lead to pathologic lesions. Surgical procedures should be directed at increasing the space beneath the coracoacromial arch to reduce wear on the rotator cuff.     

MDCT of right aortic arch with aberrant left subclavian artery associated with kommerell diverticulum and calcified ligamentum arteriosum

We present a case of the right aortic arch with kommerell diverticulum (KD) and aberrant left subclavian artery in a symptomatic 50-year-old patient with a calcification in the presumed attachment site of the ligamentum arteriosum (LA) to the KD. In another 30-year-old male patient, the entire course of a calcified LA was demonstrated using multidetector row computed tomography.     

Aberrant subclavian arteries: cross-sectional imaging findings in infants and children referred for evaluation of extrinsic airway compression

OBJECTIVE: The purpose of our study was to describe patterns of airway compression identified on cross-sectional imaging in infants and children with either right aortic arch and aberrant left subclavian artery or left aortic arch with aberrant right subclavian artery. MATERIALS AND METHODS: Data from MR imaging and CT performed to evaluate pediatric patients for extrinsic airway compression were reviewed for cases that revealed an aberrant right or left subclavian artery. Clinical, endoscopic, and imaging findings in identified cases were reviewed. Recurrent patterns of extrinsic compression were reviewed among cases. RESULTS: Twelve patients with right aortic arch with aberrant left subclavian artery and nine patients with left aortic arch and aberrant right subclavian artery were identified. All 12 with right aortic arch with aberrant left subclavian artery had airway compression shown, with multiple sites or diffuse compression in six. Of these 12 patients, nine had compression at the level of the arch and aberrant subclavian artery (10 had Kommerell's diverticulum), and nine had compression of the distal airway in association with a midline descending aorta. Five of the nine patients with left aortic arch and aberrant right subclavian artery had airway compression shown, all at the level of the arch and aberrant subclavian artery. None of these compressions was associated with either Kommerell's diverticulum or midline descending aorta. CONCLUSION: Both right and left aberrant subclavian arteries can be associated with symptomatic airway compression, but the patterns of compression are different. The airway compression in right aortic arch with aberrant left subclavian artery is often associated with either Kommerell's diverticulum or midline descending aorta, whereas compression associated with left aortic arch and aberrant right subclavian artery is not.