case_images: PMC11079374_01
case_images: Horseshoe lung in a 2-year-old male associated with left lung hypoplasia. (a) Chest radiograph demonstrates a small, opaque left hemithorax with ipsilateral mediastinal shift and compensatory hyperinflation of the right lung. (b) Minimum intensity projection (MinIp) coronal image of the CT chest shows a hypoplastic left main stem bronchus (white arrow) with an absent left upper lobe branch. (c and d) Axial CT chest (lung window) demonstrates fusion of both lungs (red star) without any intervening fissure, with the isthmus of the midline lung parenchymal tissue (red arrows) extending up to the level of the tracheal bifurcation.
case_images: SAJR-28-2766-g001.jpg
case_images: PMC11079374_01_SAJR-28-2766-g001.jpg
case_images: F0001
case_images: On imaging workup, the chest radiograph demonstrated an opaque left hemithorax with volume loss (Figure 1a). The left upper lobe bronchus was absent, suggesting left upper lobe agenesis (Figure 1b). No isthmic fissure was visible, suggesting true HL (Figure 1c). Superiorly, the isthmus of the midline lung parenchymal tissue extended to the level of the tracheal bifurcation (Figure 1d).
case_images: Contrast enhanced CT chest (a) lung window, (b) mediastinal window) images reveal that the fusion of the lung parenchyma lies posterior to the heart and the oesophagus (blue arrow) and anterior to the aorta (yellow arrow). Axial maximum intensity projection (MIP) images (c and d) demonstrate a hypoplastic left pulmonary artery at its origin (red arrow), and a single pulmonary vein (white arrows) draining the hypoplastic left lung, traversing through the isthmus of the true horseshoe lung and joining the right inferior pulmonary vein.
case_images: SAJR-28-2766-g002.jpg
case_images: PMC11079374_01_SAJR-28-2766-g002.jpg
case_images: F0002
case_images: The isthmus was located posterior to the oesophagus and anterior to the aorta (Figure 2a, 2b). The left pulmonary artery was also hypoplastic, and coursed anterior and lateral to the hypoplastic left bronchus (Figure 2c). A single left pulmonary vein was seen traversing through the parenchymal isthmus of the HL and subsequently draining into the right inferior pulmonary vein (Figure 2d).
case_images: PMC11079374_02
case_images: Pseudo-horseshoe lung in a 7-day-old male with left lung hypoplasia, total anomalous pulmonary venous return and multiple cardiovascular anomalies. (a) Coronal (minimum intensity projection [MinIP]) image of the contrast enhanced CT chest (lung window) demonstrates the rudimentary blind ending left upper lobe bronchus (arrow), absence of left upper lobe parenchyma and relatively narrow calibre of the left main bronchus in comparison with the right. (b) Axial maximum intensity projection (MIP) image shows the hypoplastic left pulmonary artery (arrow) arising from the main pulmonary artery. (c) Axial CT chest (lung window) demonstrates an isthmus of lung parenchyma joining the basal segments of both lungs posterior to the heart, with a thin intervening isthmic fissure (arrows). (d) Coronal oblique MIP image shows total anomalous pulmonary venous return with the right common anomalous pulmonary vein (white arrows) and the left single pulmonary vein (red arrows) both draining into the supra-hepatic inferior vena cava (star).
case_images: SAJR-28-2766-g003.jpg
case_images: PMC11079374_02_SAJR-28-2766-g003.jpg
case_images: F0003
case_images: The CECT thorax revealed a hypoplastic left lung with a rudimentary blind ending left upper lobe bronchus and absence of left upper lobe parenchyma, suggesting left upper lobe aplasia (Figure 3a). The left pulmonary artery was also hypoplastic and showed an aberrant course anterolateral to the left main bronchus (Figure 3b). An isthmus of lung parenchyma was seen from the posterobasal segment of the right lower lobe, crossing the midline, and separated from the left lower lobe parenchyma by only a thin fissure, representing pseudo-HL morphology (Figure 3c). The superior and inferior pulmonary veins on the right side also combined to form an anomalous common right pulmonary vein, which in turn drained into the supra-hepatic IVC (Figure 3d).
case_images: (a) Coronal oblique maximum intensity projection (MIP) image of the contrast enhanced computed tomography (CECT) chest demonstrates aberrant systemic arterial supply from the abdominal aorta to both lower lobes. (b) Sagittal oblique MIP image on mediastinal window shows a hypoplastic aortic arch (white arrows) with distinct narrowing of the aortic isthmus (blue arrow), just distal to the origin of the left subclavian artery (blue star), representing pre-ductal coarctation of the aorta. (c) Axial CECT image demonstrates a large ventricular septal defect (star). (d) Axial CT through the upper abdomen shows the midline position of the stomach (solid star), an absent spleen and a relatively large, transversely placed liver, suggesting situs ambiguous with right isomerism.
case_images: SAJR-28-2766-g004.jpg
case_images: PMC11079374_02_SAJR-28-2766-g004.jpg
case_images: F0004
case_images: Aberrant systemic arteries arising from the abdominal aorta were present bilaterally, supplying the lower lobes (Figure 4a). The aortic arch was relatively narrow in calibre and a distinct narrowing of the aortic isthmus was present just distal to the origin of the left subclavian artery, representing pre-ductal coarctation of the aorta with aortic arch hypoplasia (Figure 4b). A large inlet ventricular septal defect was also seen (Figure 4c). Sections of the upper abdomen revealed a midline position of the stomach, absent spleen and a relatively large transversely placed liver, suggesting situs ambiguous with right isomerism (Figure 4d).
case_images: PMC11079374_03
case_images: Pseudo-horseshoe lung in a 3-month-old male associated with right lung hypoplasia, anomalous unilateral single pulmonary vein and superimposed pulmonary infection. (a) Axial maximum intensity projection image of contrast enhanced CT chest (mediastinal window) shows the origin of the hypoplastic right pulmonary artery (arrow) from the main pulmonary artery. (b) Axial CT lung window image reveals fusion of the basal segments of the lower lobes with an intervening isthmic fissure (arrows). The isthmus of lung parenchyma is present posterior to the heart and anterior to the aorta and the oesophagus (as indicated by the nasogastric tube). An area of consolidation is present in the left lower lobe. (c and d) 3D volume rendered images demonstrate the fusion of the basal segments of both lungs via a parenchymal isthmus (red star) arising from the hypoplastic right lung.
case_images: SAJR-28-2766-g005.jpg
case_images: PMC11079374_03_SAJR-28-2766-g005.jpg
case_images: F0005
case_images: The CECT revealed hypoplasia of the right lung and right pulmonary artery (Figure 5a). The isthmus of lung parenchyma originating from the right lower lobe formed a curvilinear fissure at the junction with the left lower lobe, representing a pseudo-HL morphology (Figure 5b-d).
case_images: (a) Axial maximum intensity projection (MIP) image and (b) Coronal MIP image of the contrast enhanced computed tomography (CECT) chest reveal an anomalous unilateral single right pulmonary vein (arrows) that is tortuous and draining into the left atrium (white star). (c) Axial CT image and (d) oblique coronal MIP image of the CECT chest show an aberrant systemic artery (arrows) arising from the abdominal aorta and supplying the right basal lung parenchyma.
case_images: SAJR-28-2766-g006.jpg
case_images: PMC11079374_03_SAJR-28-2766-g006.jpg
case_images: F0006
case_images: An anomalous unilateral single pulmonary vein was present on the right side, which was tortuous in course, but drained into the left atrium (Figure 6a, 6b). A systemic artery arising from the abdominal aorta was also seen supplying part of the right lower lobe (Figure 6c, 6d).
case_images: PMC11079374_04
case_images: Bilateral intralobar pulmonary sequestration associated with true horseshoe lung in a 5-year-old girl with recurrent chest infections. (a) Frontal chest radiograph reveals consolidation with cavitation (white arrow) in the left mid and lower zones and patchy consolidation in the right lower zone, near the cardiophrenic angle (green arrow). (b) High frequency ultrasound image of the chest depicts the left lung consolidation. (c) Ultrasound image, transverse view through the epigastrium, shows abnormal soft tissue just above the diaphragm at the bases of both lower lobes (white arrows). This soft tissue is seen in continuity across the midline anterior to the aorta and posterior to the oesophagus (green arrows). (d) Transverse ultrasound image with colour doppler demonstrates an aberrant arterial branch (blue arrows) arising from the abdominal aorta and supplying the soft tissue, suggesting pulmonary sequestration.
case_images: SAJR-28-2766-g007.jpg
case_images: PMC11079374_04_SAJR-28-2766-g007.jpg
case_images: F0007
case_images: The chest radiograph showed consolidation with cavitation in the left mid and lower zones, along with a small patchy opacity near the right cardiophrenic angle (Figure 7a). Ultrasound of the chest showed areas of consolidation in the left infra-scapular and infra-axillary regions with a few small fluid-filled cavities within the consolidated lung (Figure 7b). This soft tissue was seen in continuity across the midline anterior to the aorta and posterior to the oesophagus (Figure 7c). A branch of abdominal aorta was seen supplying the soft tissue, which was suggestive of pulmonary sequestration (Figure 7d).
case_images: (a and b) Axial CT images (a, lung window and b, mediastinal window) confirm the presence of lung sequestration within the basal segments of both lower lobes, which are fused together in the midline anterior to the aorta (arrows). A partial accessory fissure is seen in the right lower lobe and consolidation with cavitation in the left lower lobe. (c) Axial maximum intensity projection (MIP) image shows an aberrant systemic arterial branch traversing through the bridging isthmus from left to right (arrows) and supplying the sequestered lung segments bilaterally. (d) Coronal MIP image demonstrates the origin of the systemic arterial branch (white arrows) from the abdominal aorta, as well as the area of consolidation in the left lower lobe. Bilateral inferior pulmonary veins (blue arrows) are draining the respective sequestered areas in each lung.
case_images: SAJR-28-2766-g008.jpg
case_images: PMC11079374_04_SAJR-28-2766-g008.jpg
case_images: F0008
case_images: T11 level (Figure 8 a-c). The branches of this systemic artery were seen to traverse through the midline isthmus from the left to the right (Figure 8c). Venous drainage of the pulmonary sequestration was into the inferior pulmonary veins on either side (Figure 8d).