Right-to-left shunting via persistent left superior vena cava identified by perfusion lung scintigraphy

A right-to-left shunt was demonstrated following a left antecubital injection of [99mTc]MAA but was not seen after a right antecubital injection. This was because of the presence of a persistent left superior vena cava draining into the left atrium. Recognition of the presence of this anatomic variant is of importance in perfusion imaging, in patients with otherwise unexplained systemic embolization.     

Discrepant sulfur colloid and radioparticle liver uptake in superior vena cava obstruction: case report

The presence of collateral venous channels connecting the upper extremity veins and portal vein via the paraumbilical veins is considered the probable explanation for the observed scintigraphic hepatic "hot spot". This is seen in [99mTc]sulfur colloid liver imaging and perfusion lung imaging with 99mTc radiolabeled particles injected into an antecubital vein in the presence of superior vena caval (SVC) obstruction. The typical distribution is one of focal uptake centrally, anteriorly, and inferiorly. An unusual pattern is described in this report and mechanisms proposed for the "diffuse homogeneous" hepatic uptake also observed in a patient with SVC obstruction undergoing a perfusion lung scan.     

Bilateral lipoma arborescens of the bicipitoradial bursa

A 37-year-old military mechanic presented to our institution with a chronic history of a slowly enlarging left elbow antecubital fossa mass. There was no history of other chronic illness or trauma. Magnetic resonance imaging (MRI) and excisional biopsy revealed fatty villi and synovial inflammation within the left bicipitoradial bursa, consistent with lipoma arborescens. Four years later the patient presented with a 6-month history of swelling at the antecubital fossa of the opposite elbow. Diagnostic computed tomography and MRI examinations were performed. The surgical and pathologic findings confirmed the imaging diagnosis of lipoma arborescens at the right bicipitoradial bursa.     

Statistical assessment of regional time-density measurement of myocardial perfusion

RATIONALE AND OBJECTIVES: The measurement of time-density relationships of the myocardium in studies of magnetic resonance perfusion images is a clinical technique used in assessing myocardial perfusion. This article presents a new technique, allowing regional time-density measurement and display of myocardial perfusion with improved accuracy compared with traditional manual trace techniques. Moreover, a method using statistical methods to discriminate relative decreased perfusion regions that differ significantly from the normally perfused myocardial tissue is introduced. MATERIALS AND METHODS: Human datasets were obtained using a 1.5 T Signa Echospeed system (GE Medical Systems, Milwaukee, WI). The perfusion sequence was a 2D cardiac-gated fast gradient echo sequence with echo train readout, generating an in-plane pixel size of 1.46 mm2. Seven 10-mm-thick contiguous short axis tomographic slice images were obtained during a prolonged single breathhold. Data was collected at 30 time phases per slice image level during passage of 20 cc gadolinium contrast injected at a rate of 4-5 cc/sec into an antecubital vein. RESULTS: Dilution properties can be determined and displayed as color-encoded regions superimposed on the myocardial slice according to the area of interest. Time-density curves throughout the perfusion study can be generated. Moreover, displays of normal and decreased perfusion areas can be used as statistically enhanced diagnosis guides. CONCLUSION: This measurement, display, and diagnosis technique adds diagnostically important information to previous measurement and visualization techniques, providing enhanced detection and quantitative evaluation of regional deficits in myocardial contractility and perfusion, providing improved reliability and reproducibility of clinical diagnoses from MR-perfusion data.     

Multislice MR first-pass myocardial perfusion imaging: impact of the receiver coil array

PURPOSE: To compare a new 12-element body phased-array coil with a conventional four-element surface receiver coil array to provide increased signal-to-noise ratios (SNRs) for cardiac steady state free precession (SSFP) perfusion imaging. MATERIALS AND METHODS: Thirteen consecutive patients were included in the study. Patients were examined both with a four-element surface coil array and a 12-element body coil array. First-pass myocardial perfusion imaging using saturation recovery SSFP was acquired during antecubital injection of Gd-DTPA. Imaging parameters: TR 2.8 msec/TE 1.3 msec, flip angle 50 degrees , bandwidth 960 Hz/pixel and half-Fourier acquisition. SNR was calculated using six regions of interest (ROI) for the myocardial perfusion scans. Calculations of corresponding ROIs using the two different coil setups were compared using analysis of variance (ANOVA). Semiquantitative perfusion parameters were calculated for both groups. RESULTS: The mean SNR in myocardial perfusion imaging increased by 21% using the 12-element coil setup (P < 0.001) when compared to the four-element coil. ROI comparisons revealed an increased signal inhomogeneity with the 12-element coil when compared to four-element coil experiments. Absolute normal range values of semiquantitative perfusion parameters were consistently higher using the 12-element coil setup (P < 0.001). CONCLUSION: The 12-element coil array provides higher SNR, but these improvements come with trade-offs in image homogeneity. Increased SNR translates into higher semiquantitative perfusion values and offers the potential for improved detection of perfusion defects.     

Radionuclide studies in postoperative evaluation of the Fontan procedure

Radionuclide studies were performed on 12 patients who had had a Fontan operation for cyanotic congenital heart disease, six of whom had undergone a prior palliative Glenn procedure. The patients without prior Glenn anastomoses were studied by radionuclide first-pass angiocardiography, using a right antecubital vein injection of 99mTc pertechnetate. The patients with Glenn anastomoses required two injections, one by femoral vein to study the Fontan procedure, using bolus injection of 99mTc pertechnetate or microspheres, and the second by right antecubital vein to study the Glenn anastomosis and right lung, using a bolus of microspheres. Gated cardiac blood-pool scintigraphy was used to measure right atrial and left ventricular ejection fraction in three patients. In nine patients, contrast angiography confirmed that these techniques allowed recognition of residual right-to-left shunts, right atrial stasis, right atrial outflow obstructions, left ventricular dysfunction, and right lung arteriovenous fistulas. Noninvasive radionuclide methods seem to be dependable in the postoperative evaluation of patients after the Fontan procedure. First-pass angiocardiography is most helpful in evaluating the dynamics and distribution of blood flow, especially the right atrial output, and gated blood-pool scintigraphy offers a better evaluation of right atrial and left ventricular contraction, so both supply complementary information.     

Extravasation from venous catheter: a serious complication potentially missed by lung imaging

Three patients were referred for lung ventilation and perfusion (V/Q) imaging with symptoms strongly suggestive of pulmonary embolus (PE). Chest roentgenograms and xenon ventilation studies on all three were normal, save for prominent mediastinal silhouettes and effusions. Technetium-99m macroaggregated albumin (Tc-99m MAA), when injected through the central venous catheter (CVP), revealed mediastinal localization, whereas antecubital injections showed normal pulmonary perfusion. Contrast fluoroscopy introduced through the venous catheter in the first patient defined the extravasation. For patients under strong suspicion of PE, with a venous catheter whose distal tip is seen about the level of the heart on chest radiograph, we recommend administering the perfusion agent slowly through the central catheter to exclude catheter-induced complications. When extravasation is detected, injection of Tc-99m MAA by peripheral vein should be used to exclude PE.     

T2* effects in the dual-sequence method for high-dose first-pass myocardial perfusion

PURPOSE: To examine whether T2* effects reduce the accuracy of arterial input function (AIF) measurement by the dual-sequence method. MATERIALS AND METHODS: The dual-sequence method obtains a low-resolution AIF image and high-resolution myocardial images in each cycle, with suitable T1 weightings. It was modified to assess T2* effects in the low-resolution AIF image (4.8x4.8x10 mm voxels, TE=0.58 msec) by minimizing T1 weighting in that sequence, while the myocardial sequence remained T1-weighted. In 10 patients who underwent perfusion MRI scans (0.5 M Magnevist, 0.1 mmol/kg, 15-ml flush, 7 mL/second right antecubital) the blood signal in the left ventricle (LV) was measured at the bolus peak and compared with the first cycle's fresh magnetization signal. RESULTS: The bolus peak measured 98%+/-4% (mean+/-SD, N=20) of the value before contrast agent arrival. CONCLUSION: T2* causes insignificant error in the dual-sequence method at the stated parameters.     

Prolonged cholinergic crisis and compartment syndrome following subcutaneous injection of an organophosphate compound for suicide attempt

A case of poisoning with highly lipid soluble organophosphate compound, fenthion is reported in which cholinergic crisis recurred upto 25 days following a suicide attempt. Subcutaneous injection of fenthion in the antecubital fossa by the patient produced massive swelling, cellulitis and compartment syndrome of the left arm. Emergency fasciotomy helped in restoration of circulation and saved the limb from being amputated.     

Quantitation of the critically ischemic zone at risk during acute coronary occlusion using PET

Critical myocardial ischemia has been defined experimentally during acute coronary occlusion as flow reduction of 50% or more since cellular ATP depletion begins to occur beyond this flow reduction threshold, placing tissue at risk of cellular injury. To test the hypothesis that critically ischemic fractional left ventricular mass can be measured noninvasively with PET, nine dogs were imaged in a multi-slice positron camera using the perfusion tracer 13N-ammonia, while radiolabeled microspheres were injected into the left atrium during acute coronary occlusion. Images were processed using a 50% threshold and the size of the resulting perfusion defect was expressed as a fraction of total left ventricular image volume. The critically ischemic left ventricular fraction determined in vitro from the microsphere perfusion data, ranged from 5% to 30% of the total left ventricular weight and correlated closely with that determined noninvasively by PET with r = 0.94 (y = 1.05X - 2.0%). We conclude that the fraction of left ventricular myocardium rendered critically ischemic during acute coronary occlusion can be measured accurately and noninvasively in vivo using perfusion imaging with positron emission tomography.     

An anomalous median nerve avoiding injury in a gunshot wound to the antecubital fossa

We report the case of a 19 year old man who received a gunshot wound to the soft tissues of his left elbow. He presented with an ischaemic hand due to transection of the brachial artery bifurcation anterior to the elbow joint. He was spared an associated median nerve injury by an anomalous course of the nerve through the antecubital fossa.     

Shunt between right subclavian vein and the left heart in superior vena cava obstruction due to lung cancer

A case in which there was a shunt between systemic veins and the left heart in superior vena cava syndrome due to lung cancer is reported. Superior vena cava syndrome developed one and a half years after right upper lobectomy with combined resection of thoracic wall. Radionuclide venography from the right antecubital vein showed immediate visualization of the left ventricle and aorta, before the right atrium and right ventricle were seen. In the superior vena cava syndrome due to a malignant tumor, this rare pathway as well as usual collaterals should be considered.     

肘前穿支皮瓣的解剖与临床应用

目的 探讨肘前穿支皮瓣解剖、供区的设计和临床应用. 方法通过10侧尸体解剖,应用红、黄、蓝三色乳胶灌注研究皮瓣的血管、神经的起源、走行、分支、外径、分布及其吻合情况,一侧新鲜尸体标本行墨汁注射测量皮瓣面积,根据肘前穿支皮瓣血供来源及其与前臂筋膜皮肤血供的相互关系,设计肘前穿支皮瓣.利用近端蒂肘前穿支皮瓣转位修复肘部各方位的皮肤软组织缺损、远端蒂肘前穿支皮瓣修复前臂中下段掌背侧皮肤软组织缺损共7例. 结果术后皮瓣完全成活,创面Ⅰ期愈合.经3～15个月随访,皮瓣质地优良,色泽接近正常,外形美观.结论 肘前穿支皮瓣解剖位置恒定,血液供应良好,手术方法简单、安全,为修复肘部、前臂中下段皮肤软组织的缺损提供一种新的术式,可供临床选择.     

Pulmonary perfusion "without ventilation"

An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a "reversed ventilation/perfusion mismatch."     

Arm vein uptake of thallium-201 during exercise: incidence and clinical significance

We prospectively analyzed several clinical and technical variables that might be associated with arm vein uptake of 201Tl during stress thallium scintigraphy in 63 patients. The influence of site (medial antecubital vs. other vein) and technique (with or without a 15-cc saline flush) were examined. Arm vein uptake was not seen after medial antecubital injections except in one case injected through a 24-hr-old indwelling catheter. Arm vein uptake was seen in 24/45 (53%) of cases injected into veins other than the medial antecubital. A saline flush did not reduce the incidence of arm uptake. In patients with normal myocardial studies, those with positive arm uptake had 33% lower net myocardial counts on the postexercise images (p = 0.00008) and 20% lower net myocardial counts on the delayed images (p = 0.04). Myocardial washout of thallium was significantly (p = 0.009) slower in those with arm uptake.     

Organ hyperthermia: experimental selective perfusion

The technical feasibility of selectively changing internal organ temperatures using balloon catheter perfusion was investigated. The liver or kidney temperatures were measured during the perfusion of cold or heated saline or preheated blood into the afferent vessels. Hyperthermic perfusion of the renal artery distal to an occlusion balloon catheter raised the kidney temperature to 43 degrees C. The hepatic arterial perfusion caused small changes in the liver temperature, whereas, with portal venous perfusion, the liver could be heated to 43 degrees C. Selective heating of the left hepatic lobe could be achieved by selective perfusion of the left portal vein. The potential therapeutic application of this technique is described.     

经肘下腔静脉滤器置入术六例

目的 探讨经肘下腔静脉滤器置入的方法及并发症的防治.方法 2004年10月至2006年5月我科收治的下肢深静脉血栓形成(DVT)患者中,有6例采取经肘静脉穿刺下腔静脉滤器置入.6例均经右肘正中静脉或贵要静脉穿刺,将SNF(Simon nitinol filter,Bard)沿90 cm长鞘置人下腔静脉.结果 6例手术均1次成功,用时平均25 rain.除1例肘部穿刺点有轻度红肿外,其余均愈合良好,无出血或血肿,无静脉炎.滤器位置准确,无偏斜.患者均无肺栓塞发生.结论 经肘下腔静脉滤器置人术穿刺容易,创伤小,术后患者无需卧床制动,有利丁DVT的治疗.同时,对于经股静脉穿刺有禁忌的DVT患者,经肘下腔静脉滤器置入更不失为较好的替换选择.     

Effect of diatrizoate on renal extraction of PAH in man

The effect of diatrizoate on the renal extraction of para-amino hippurate (EPAH) was studied in 8 healthy male volunteers. The contrast medium was injected into an antecubital vein and into a renal vein in each individual. A single-injection technique for the determination of EPAH was used and EPAH was measured before and over a period of 30 min after each contrast medium injection. In addition, the renal extraction of diatrizoate was measured simultaneously. Small but significant and similar decreases in EPAH were observed after both antecubital and renal venous administrations of the contrast medium, with a duration of less than 30 min after the injection. The renal extraction ratio for the diatrizoate was 0.20. It is concluded that diatrizoate should not be used before the determination of EPAH, at least not until 30 min after the administration of the contrast medium. The decrease in EPAH caused by diatrizoate seems to be due to a direct tubular depressant effect.     

Double nuclide myocardial scintigraphy with thallium 201 and iodine 123-heptadecanoic acid--the possibilities in cardiological diagnosis

We studied in 11 patients the individual variable pattern of coronary blood supply after the end of diagnostic coronary catheterisation by intracoronary injection of T1201 into the left and J 123-heptadeconic acid into the right coronary artery. In 4 static views computer aided quantitative analysis of circumferential profiles was performed. Based on Schlesinger's criteria three types of coronary arterial patterns were defined (right, left preponderant, balanced) after the presentation in the angiographic projections. Conclusions: Sharp boders between different perfusion areas could be detected by the gamma camera. If patients with right preponderant circulation are compared with balanced circulation, the perfusion areas of the left coronary artery are greater in all cases with balanced circulation than expected. More important for the indication of coronary artery surgery is that a considerable area of the left ventricular myocardium is perfused by the right coronary artery independent of the anatomical perfusion pattern with the exception of the left preponderant type.     

Radionuclide angiocardiography in tricuspid atresia

In two cases of tricuspid atresia and one of severe tricuspid stenosis the Glenn and Fontan operation was performed. These patients were evaluated post-operatively by studying the distribution of the ventilation with Xe-133 on a gamma camera; the pulmonary circulation was evaluated by injection through antecubital and pedal veins of TC^99m MAA and angiography was performed by in vivo tagging of red blood cells with TC^99m04 preceded by the administration of stannous pyrophosphate.The scintigraphic findings in two cases consisted of decreased ventilation of the left lung and grossly normal perfusion of both lungs. In one case there was abundant collateral because of partial occlusion of the anastomosis between the superior vena cava and right pulmonary artery.The patients also had angiocardiography with constrast medium; the correlation between the scintigraphic and angiocardiographic findings was excellent.Presented in part in The 2nd International Congress of Nuclear Medicine. Washington, D.C. September 1978