Role of perforator flaps in leg and foot reconstruction.

INTRODUCTION: Lower extremity wounds have always been a challenge for the reconstructive surgeons. Free perforator flaps are considered to be the best option for this problem but require the complexity of microsurgery. So, pedicled perforator flaps have emerged as an alternative option. PATIENTS AND METHODS: Prospective study was conducted in 40 patients with traumatic soft tissue defects in the leg and foot. The free flaps included the anterolateral thigh flap (ALT) and medial sural artery perforator flap (MSAP). In pedicled perforator flaps group, 10 cases were designed as propeller flaps while the other 10 flaps were designed as perforator plus flaps. RESULTS: Free flaps were mainly used for large-sized defects; we had one case of partial flap loss and one case of complete flap necrosis.  MSAP flap was the first option for coverage of large-sized defects on foot and ankle as it is a thin and pliable flap, while ALT flap was used for coverage of larger defects on the leg. Pedicled perforator flaps were used mainly for small to medium-sized defects, especially in the lower third of the leg; we had three cases of flap loss in propeller flap design while we had no cases of flap loss in perforator plus flap. CONCLUSION: Perforator flaps have become a reasonable solution for soft tissue defects of the lower extremity. Careful assessment of the dimensions, location, patient comorbidities, availability of surrounding soft tissue and presence of adequate perforators are mandatory for proper perforator flap selection.

Which MR imaging sequences are necessary in determining the need for radiation therapy for cord compression? A prospective study.

BACKGROUND AND PURPOSE: To determine which MR imaging sequences are necessary to assess for spinal metastases. METHODS: Hypothetical MR imaging interpretations and management plans were made prospectively for consecutive adult cases acquired retrospectively. Standardized MR imaging protocols were independently interpreted by 2 neuroradiologists. MR imaging protocol types varied: 1) T1-weighted images only; 2) T1-weighted and T2-weighted images; 3) T1-weighted and postcontrast T1-weighted images; and 4) T1- and T2-weighted images and postcontrast T1-weighted images. Hypothetical management plans were created by 2 radiation oncologists. Logit model was used to investigate the effect of MR imaging protocol type on the probability of recommending radiation therapy (RT). Mixed effect models were used to investigate whether median spinal level or total number of spinal levels of planned RT was associated with MR imaging protocol type. RESULTS: Thirty-one subjects were evaluated, each with multiple scan interpretations. Logit model showed that neither MR imaging protocol type nor neuroradiologist reader affected the probability that the oncologist would recommend RT (all P > .50). Mixed models showed that neither ML nor NL was affected by MR imaging protocol type or by neuroradiologist reader (all P > .12). CONCLUSION: Although MR imaging is known to be the most useful diagnostic test in suspected spinal cord compression, which particular MR images are necessary remain unclear. Compared with T1-weighted images alone, the additional use of T2-weighted and/or postcontrast T1-weighted sequences did not significantly affect the probability that RT would be recommended or the levels that would be chosen for RT in our study. Our data suggest that unenhanced T1-weighted images may be sufficient for evaluation of possible cord compression.

Correlates of brain edema in uncontrolled IDDM.

Blood glucose, plasma sodium, bicarbonate (HCO3-), vasopressin, and hematocrit were monitored before and during treatment in patients with uncontrolled insulin-dependent diabetes mellitus (IDDM). These parameters were correlated with simultaneous serial cranial computed tomography readings of brain edema. Six of seven patients had positive computed tomography readings for brain edema on admission. Initial brain edema correlated directly with blood glucose (r = 0.79, P = 0.033) and inversely with HCO3- (r = -0.76, P = 0.047). At 6 h, brain edema still correlated with acidosis (HCO3-; r = -0.79, P = 0.033) but no longer with blood glucose. At that time, however, brain edema correlated with the rate of change in blood glucose (r = 0.915, P = 0.005). Results of interactive stepwise regression analysis suggest that the change in the calculated effective plasma osmolality plays a predominant role in the progression of brain edema during therapy (r = 0.995, P less than 0.001). Thus, although hyperglycemia and acidosis probably predispose to diabetic brain edema, osmotic factors may be major predictors of its evolution. No relationships were detected between brain edema and initiation of insulin therapy, plasma vasopressin, or changes in hematocrit. The factors responsible for initial brain edema and its progression, statistically identified in this study, require reassessment of common theories that attribute brain edema exclusively to therapy.

Periventricular low attenuations: a normal finding in computerized tomographic scans of neonates?

Twenty-five of the initial computerized tomographic (CT) scans of 63 neonates had "definite" abnormalities. These abnormalities included dilated ventricles, advanced hypodensities extending beyond the periventricular areas, and varieties of hemorrhage. Thirty-six, with otherwise normal intracranial structures, were found to have localized periventricular frontal or frontooccipital areas of low attenuation. These areas were confined to the white matter of the periventricular area and have been identified by others as indicating "periventricular leukomalacia." In follow-up clinical studies on 26 of this latter groups, only two showed neurological abnormalities. Seven CT scans were repeated; only one was abnormal. In this case, the attenuations had disappeared, but were replaced by mild deep and cortical atrophy. The patient then showed findings suggesting a mild spastic diparesis and psychomotor delay. Our findings suggest that periventricular low attenuations in an otherwise normal CT scan are usually due to incomplete myelination or, at least, a transient abnormality. Periventricular low attenuation cannot be used as a diagnostic sign of periventricular leukomalacia, nor does it necessarily suggest an unfavorable prognosis.

Intrathoracic meningoceles and neurofibromatosis.

We describe here four additional cases of intrathoracic meningoceles associated with neurofibromatosis, bringing the total number of reported cases of thoracic meningoceles to 88. Seventy-five (85%) have been associated with neurofibromatosis. Possibly, both dural and regional vertebral dysplasia are intrinsic to neurofibromatosis and contribute to the development of the meningocele.

Dural sarcoidosis presenting with transient neurologic symptoms.

Despite the propensity of sarcoid granulomas to be clustered around blood vessels, transient ischemic attacks and strokes are rare. A 43-year-old man had recurrent transient dysarthria and right hemiparesis; a biopsy specimen showed neurosarcoidosis. There was complete resolution of both symptomatology and the subdural sarcoid mass lesion with the administration of corticosteroid therapy.

Irreversible neurologic complications of metrizamide myelography.

Metrizamide, a major contrast agent for myelographic procedures, has rarely been reported to cause irreversible neurologic complications. The major transient neurologic alterations include neuropsychological reactions, generalized tonic-clonic seizures, and headaches. Two cases of irreversible spinal neurologic deficits resulting from metrizamide myelography are reported, and the factors that may increase the risks of complications in metrizamide myelographic studies are discussed, including preexisting dehydration, patient positioning, and the concentration of contrast agent.

Cerebellar atrophy in epilepsy and headache: lack of relationship to phenytoin.

CT scans of 70 patients with seizures and 48 patients with headaches were studied. Using accepted CT criteria for the diagnosis of cerebellar atrophy, the films were analyzed in a blind, unbiased fashion to evaluate possible relationship between cerebellar atrophy and phenytoin use or epilepsy itself. We found no evidence that either phenytoin or epilepsy caused cerebellar atrophy.

The value, limitations, and applications of nuclear dacryocystography.

Nuclear dacryocystography is simple, relatively harmless method of evaluating patients suspected of having abnormalities of the nasolacrimal drainage system. A group of normal saline containing approximately 100 muCi of 99mTc-pertechnetate is placed on the conjunctiva near the lateral canthus, and serial scintigrams are obtained as the pertechnetate flows along the tear strips, through the nasolacrimal drainage system, into the nasal fossa. By using a pinhole collimator with a very small aperture (1mm), the canaliculi, the nasolacrimal sac, and the nasolacrimal duct are readily visualized. When flow is impaired, the site of obstruction can often be identified. Contrast dacryocystography provides similar information but requires the injection of contrast material directly into a canaliculus. Nuclear dacryocystography provides good functional assessment of nasolacrimal drainage but has serious shortcomings in defining pathologic anatomy. Contrast dacryocystography outlines the anatomy well but often misses minor obstructions. The two studies are complementary and together provide an effective means of evaluating the nasolacrimal drainage system.

Intrasellar subarachnoid herniation or empty sella associated with galactorrhea.

Eight of 115 patients with empty sella had concurrent galactorrhea. All 8 patients had abnormal sellae, and the diagnosis of empty sella was made by polytome pneumoencephalography. There were no obvious endocrine dysfunctions, but 2 patients had elevated prolactin levels. One mechanism for production of galactorrhea may involve compression of the hypothalamus and/or pituitary stalk; this was suggested by most of our observations. There may be a coincidental association of empty sella with galactorrhea, and this association is probably more common than previously noted. Evaluation of patients with galactorrhea and abnormal sellae by polytome pneumoencephalography is emphasized.

Paragangliomas of the neck.

Between 1967 and 1990 inclusive, 28 patients with paragangliomas of the neck were diagnosed at the University of Alabama at Birmingham Affiliated Hospitals. There were 11 men and 17 women, whose ages ranged from 12 to 76 years (mean, 47 years). Tumor locations included the carotid bodies (19 cases), the vagus nerves (three), supraglottic larynx (two), the left lateral pharyngeal wall (one), posterior to the right jugular vein (not otherwise defined) (one), subcutaneous neck tissue (one), and a cervical lymph node with unknown primary (one). Diagnostic workup included angiography (23 cases) with preoperative embolization (three), computed tomography (one), magnetic resonance imaging (two), and urinary catecholamine assay (four). All 28 patients underwent resection of the lesions. Cranial nerve damage occurred in 11 patients (39%). There were no perioperative deaths or cerebrovascular accidents, although one of two saphenous vein grafts became thrombotic after carotid body tumor resection.

Computed tomography of orbital medial wall fractures.

Increasing experience with computed tomographic evaluation of head trauma reveals this radiologic modality to be superior to conventional polytomography in the assessment of certain areas of maxillofacial injury. A comparison of hypocycloidal polytomography and computed tomography in nine patients with fractures of the medial wall of the orbit reveals CT to be superior in localization of the fracture site, delineation of displaced bone fragments, and recognition of herniation of intraorbital contents into the ethmoid labyrinth. Information regarding damage to the nasolacrimal duct and associated intraorbital abnormalities such as the presence and location of hemorrhage and foreign bodies is also available from the CT scan.

MR cisternography: initial experience in 41 cases.

PURPOSE: To present our initial experience with MR cisternography, an application of fast spin-echo MR with fat suppression, and compare it with routine MR cranial studies in the evaluation of the subarachnoid cisterns and their contents. METHODS: MR cisternography is a heavily T2-weighted fast spin-echo technique with high spatial resolution; it uses fat suppression and video reversal of the images. A small number of individual sections (two to four) are compressed into a composite image by a maximum-intensity projection algorithm, providing better depiction of anatomy in three dimensions. MR cisternography enhances the signal intensity of the cerebrospinal fluid (CSF) with suppression and subtraction of the background. A total of 41 patients were examined during a period of 6 months. MR cisternography was performed as an additional one (n = 31) or two (n = 10) sequences after conventional MR study. RESULTS: Twenty-one cases of disease were examined by MR cisternography, including 8 neoplasms, 4 CSF fistulas, and 3 large intracranial aneurysms. MR cisternography provided information unavailable by conventional MR studies in 17 cases. These included visualization of fistulous tracks in patients with CSF rhinorrhea, origin of a large suprasellar aneurysm, an additional loculus of a posterior fossa aneurysm and its relation to surrounding structures, and proper location of three tumors (intraaxial versus extraaxial). Clear depiction of the pituitary gland separate from the cavernous sinus was noted in 60% of the cases, and a new observation of a CSF sleeve around the third nerve in the posterior cavernous sinus was made in 85% of the cases. CONCLUSION: MR cisternography is superior to conventional MR studies in depicting anatomic structures within the subarachnoid spaces. This technique is recommended in the evaluation of cranial CSF fistulas and suprasellar and posterior fossa masses and in diagnosis of intraaxial versus extraaxial location of intracranial tumors.

Serial biplane magnification and subtraction myelocisternography: normal and pathologic findings.

A modified technique for performing Amipaque myelocisternography is described and results obtained in the first 100 patients are analyzed. Diagnostic quality examinations were obtained in 90% of patients in whom the technique was employed. The complication rate was comparable to studies using C1-C2 puncture and to other reports using Amipaque contrast medium. This examination is valuable for high cervical and craniocervical junction lesions, cervical cord atrophy or enlargement, cerebellar ectopia, lower cranial nerve neuropathies, and cerebellopontine angle problems, especially the early detection of small acoustic neurinomas.

Syringomyelia associated with intradural extramedullary masses of the spinal canal.

Three cases of syringomyelia associated with intradural extramedullary tumors of the spinal canal are reported to demonstrate their radiographic feature, to postulate a mechanism for their formation, and to describe the clinical deterioration occurring in two patients immediately after metrizamide myelography. It is believed that the mechanism by which these syrinx cavities formed was similar to the mechanism of syrinx formation within chronically injured spinal cords. The cystic cavities may extend for considerable distances away from the extramedullary mass and may be present above and/or below the mass. The development of a syringomyelia in the face of an intradural extramedullary tumor may not be rare, and it is suspected that with the more frequent use of delayed metrizamide CT and now magnetic resonance imaging, syringomyelia will be found as an occasional consequence of this type of mass.

Myelography of sacral agenesis.

In the past, neurologic deficits found in association with sacral agenesis were thought to be unamenable to surgical therapy. Recent experience and a careful review of autopsy and case reports form the literature have demonstrated that this assumption is unwarranted. Four cases of sacral agenesis are reported with description of the myelographic findings of each case. Surgical confirmation was obtained in three of these patients. Dural sac stenosis treated with duraplasty resulted in striking improvement in the neurologic status of two patients, while in the third, a 2-month-old infant, adhesive arachnoidal bands in the distal thecal sac were found at surgery and a taut and thickened filum terminale was transected. The fourth patient has a low-lying spinal cord and a posterior meningocele. The myelographic findings appear to be divisible into two categories. One group of patients may have high termination of the subarachnoid space with a dural sac stenosis and will benefit from duraplasty, while in the other, findings may include a widened or normal subarachnoid space and low-lying tethered spinal cord. It is emphasized that treatment of dural sac stenosis, tethered cord, and intrathecal or extrathecal masses that occur in some of these patients may afford significant improvement in their neurologic condition. These children deserve careful baseline neurologic evaluation and follow-up and a more aggressive approach toward adequate myelographic assessment.

MR imaging of the ectopic bright signal of posterior pituitary regeneration.

High-field-strength MR studies of 13 patients with sellar and/or parasellar tumors revealed an aberrant location of the posterior pituitary bright signal in the hypothalamus in seven cases and in relation to the pituitary infundibulum in six cases. Five of the MR studies were obtained in patients who had not had surgery and had pituitary adenomas producing compression and/or destruction of the posterior lobe. In the other eight cases, the aberrant bright signal occurred after hypophysectomy in seven patients and after removal of a craniopharyngioma in the eighth. Accumulation of neurosecretory material and regeneration of pituitary tissue in these ectopic locations have been documented previously in animal experiments and in a few reports in humans after hypophysectomy. MR imaging now provides further corroborative evidence in vivo of this process in which a "miniature posterior lobe" is formed.

C1-C2 myelography with iohexol and metrizamide: comparative study.

Comparison of metrizamide and iohexol contrast media for myelography performed via lateral C1-C2 puncture in a total of 64 patients demonstrated superiority of iohexol with respect to the incidence of postprocedure adverse reactions. There was no significant difference between the two media in quality of radiographic demonstration in the cervical region. Patients in whom posterior fossa positive-contrast radiographic examinations were performed at the same time as myelography, using either water-soluble agent, did not demonstrate any increased incidence of side effects over those having myelography alone.

Modified CT techniques in the evaluation of temporal lobe epilepsy prior to lobectomy.

The outcome of temporal lobectomy performed for seizure control is improved by preoperative identification of structural lesions. We used cranial CT, modified to improve visualization of mesial temporal structures, as a means of preoperative evaluation in 48 patients with partial complex seizures. The axial views, parallel to the temporal fossa, improved visualization of five lesions, including two that were not diagnosed by routine cranial CT. In 12 patients, intrathecal metrizamide was used; the rest received intravenous contrast. These modified techniques could not reliably predict mesial temporal herniation; however, modified axial CT with intravenous contrast is recommended for evaluation of suspected temporal lobe pathology.

Frequency and variation of the posterior pituitary bright signal on MR images.

Sagittal T1-weighted series with 3-mm sections have routinely been used for all cranial MR studies at our institution. It was apparent from examining these studies that the rate of occurrence of a normal posterior pituitary bright signal was lower than has been previously reported, particularly in older patients. This prompted both a retrospective and a prospective review and analysis of the posterior lobe bright signal in three patient categories. The overall frequency of posterior pituitary bright signal and the influence of sex and age were evaluated in one category. An age-related statistically significant decline in the frequency of posterior pituitary bright signal was found, with a decline rate of approximately 1% per year. An evaluation of the occurrence of anatomic variation in the location of posterior lobe bright signal was made in a second group of 1500 patients. Aberrant location of the posterior lobe was found to be uncommon and was seen most frequently in patients with a sellar fossula. Temporal variation in the presence or absence and size of the posterior lobe bright signal was evaluated in a third group of 36 patients who had at least two MR examinations available for review. Follow-up MR study showed an obvious posterior lobe bright signal in 8% of these patients for whom no bright signal was apparent at the time of initial examination. Loss of the posterior lobe bright signal was apparent in another 25% of patients. A significant change in size of the bright signal was apparent in 19% of patients within this category. Our results indicate that variation in the bright signal of the posterior pituitary lobe should be expected as a normal physiological occurrence.